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  • 1.
    Abaid, Mohammed
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Evaluation of Jatropha Curcas as future en-ergy crop in some African countries.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Biofuels now days consider as one of the successful alternative to meet the challenges associated with climate change and peak oil, as well as a way for poorer countries to develop an industry in order to enhance social and economic development. In many developing countries and particularly in Africa, this has led to large-scale investments in lands by foreign companies, and as a consequence there has been a debate on whether these actions are environmentally sustainable and whether this kind of activity actually brings economic development. The investments of biofuels in Africa, espe-cially the Jatropha plantations are debatable. Several arguments have been concentrat-ed on development goals, economic issues and environmental concerns. This report evaluates the status of some Jatropha projects in Sudan, Ethiopia, Kenya and Tanza-nia, the outcomes of the report show that biofuels from Jatropha lead to a significant socio -economic benefits by creating many jobs opportunities and improve the stand-ard of living in Africa. However, inadequate funding’s, high investment costs, no clear policies for biodiesel are the most challenging for Jatropha in Africa which need fur-ther mechanisms and ideology by African scientists, leaders, NGOs, farmers and deci-sion makers. In the studied countries, it was reported that the Jatropha produce low yields of oil seeds especially in the marginal lands with no enough water supplies. In Kenya the productivity of Jatropha is very low for large scale- project. Moreover some social and environmental impacts are also seen for Jatropha cultivations in Ethiopia, Kenya and Tanzania. Some Jatropha projects have impacted the food security nega-tively; nevertheless some biofuels experts believe that Jatropha has no any adverse im-pacts on food security since it is inedible and grown on marginal lands. In Ethiopia, the main environmental impacts of Jatropha are related to biodiversity, water quality and quantity. In Kenya, the environmental impacts are related to biodiversity, carbon emissions, water withdrawal, pollution of agro- chemicals usage, deforestation and soil erosion, whereas in Tanzania, the main environmental issues are connected to the change of land use system, impacts on biodiversity and impacts on water resources.

  • 2.
    Acheampong, Isaac
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Urban biodiversity; a global perspective.2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A majority of the world’s cities are situated in or near areas of high biodiversity. Rise in global urban population resulting in rapid urban expansions (larger cities) is a threat to urban biodiversity, which has implications for the ecological health and general well being of humans. The study exploits consistent global land use data to compare 102 cities across the globe on a measure of urban biodiversity, within 15 km and 30 km from the approximate centres of the cities. Cities with high population and higher percentage of land use dedicated to artificial infrastructure recorded lower percentage size reserved for natural habitat, and vice versa. Further testing in regression analysis with birds and plants species as response variables shows a relation with urban extent and size of natural habitat which seeks to promote sustaining ecosystems services. Since urban biodiversity has implications for human ecological health, its indicators must be constantly measured and monitored, while adhering to best practices that conserve nature.

  • 3.
    Agarwal, Tushar
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    The Ganges drainage basin: Hydrological transitions due to anthropogenic water use.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Hydrological changes in catchments world over have affected regional climate and pose serious challenge to future water resource management. The Ganges drainage basin (GDB) is one such region which has undergone rapid transformation in land and water use, more specifically in the latter half of 20th century. GDB has a population of more than half a billion people and is spread across India, China (Tibet), Nepal and Bangladesh. Further, hydrological investigations accounting land and water use changes in GDB are rare. This study is an attempt to resolve hydrological changes in the Ganges basin using the fundamental water balance, focusing particularly on water use changes through irrigation. Between the period 1951-1959 and 1991- 2000, precipitation (P) in the Ganges basin has reduced by 11.25 % while evapotranspiration (ET) has only reduced by 3.61 %. In addition, the ET/P has increased from 0.483 to 0.525 during the same period suggesting a larger partitioning of P towards ET. This suggests greater utilization of P to release water vapor in the atmosphere and thus causing a reduced water flow downstream. With water availability at the fulcrum of future concern for regional and national water security, these findings should encourage policy makers to account for hydrological changes in the GDB in planning sustainable water use.

  • 4.
    Agnarsson, Madelene
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Larsson, Marie
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Hjälpmedel vid beräkning av grundvattensänkning för att underlätta prissättning i anbudsfas.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Grundvattensänkningar är något som ofta behöver utföras innan konstruktion av anläggningar i jord. Att sätta pris på en grundvattensänkning är inte särskilt lätt när information eller kompetenser saknas som krävs för att göra en rimlig bedömning. Veidekke Entreprenad Anläggning Öst är ett anläggningsföretag som oftast jobbar i generalentreprenadsform. Vid en generalentreprenad så är projekteringen redan gjord och pris ska sättas på de olika posterna som behöver utföras.

    Denna rapport presenterar en förenklad process för kalkylberäkningar i anbudsfas. Därför har en mall har tagits fram åt Veidekke. Denna mall består av fyra representativa typjordar och ekvationer som gör den användarvänlig. För att kontrollera mallens duglighet så testades den sedan på tre projekt som Veidekke utfört grundvattensänkningar på. Mallens beräknade resultat kunde då jämföras med observerade resultat. Det visade sig att mallen ger en god approximation på hur grundvattensänkningen kan se ut och en fingervisning på hur lång tid det kan ta innan stationär grundvattensänkning uppkommer.

  • 5.
    Ahmad, Arslan
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Evaluation of organic residues and their mixtures with Peepoos to produce fertilizer.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Peepoo, self-sanitising, biodegradable toilet is characterized by low carbon to nitrogen (C-N) ratio and low dry matter (DM) content. Principal nutrients (nitrogen (N), phosphorous (P) and potassium (K)) are also not in a balance as required by most crops. It was expected that the mixing of used Peepoos with other organic materials might balance its chemical characteristics. In this thesis, availability and suitability of common organic materials produced in Kenya has been investigated for mixing with used Peepoo bags to obtain a balanced fertilizer product from the crop nutrition aspect. Seven organic residues were selected from the list of 13 on the basis of their availability near the processing site in Nairobi. The selected residues were then chemically analyzed for their individual plant nutrient content. The analysis results were used subsequently to simulate the chemical composition of a wide range of Peepoo-Residue mixtures. The evaluation of the theoretical mixtures based on DM content, C-N ratio and NPK ratio showed that the majority of investigated mixtures had DM content below 60 %. Majority of the mixtures showed C-N ratio between 10-1:1. All the mixtures deviated from the common nutrient uptake ratio of crops (1:0.5:1.4). Composite mixtures with more than 2 ingredients resulted in a balanced fertilizer product. The study concludes and recommends that the composite mixtures with more than two ingredients should be considered for practical processing of Peepoos into a commercial fertilizer product.

  • 6.
    Akram, Muhammad
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    A Freundlich-based model for prediction of pH-dependent sulfate adsorption in forest soil.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The period of industrialization after the second World War in Europe released SO2 and NOx by combustion of fossil fuels and contributed the formation of S and N compounds in the forest ecosystem. The Swedish forest soil systems were influenced by emissions of SO2 followed by H2SO4 deposition, consequently the pool of SO42- had increased in the forest ecosystem. This thesis studied SO42- adsorption in a podzolic Bs horizon soils taken from a Swedish forest soil system. The soil samples from five different sampling sites were collected and the results revealed different amounts of adsorbed SO42- in response to changes in equilibrium concentration and pH. This study found that the amount of adsorbed SO42- (mmol/kg) increased with an added equilibrium concentration of SO42- (mmol/l) and with a decreasing pH. This was determined by equilibration experiments. Based on the results a Freundlich-based model was developed to predict the pool of adsorbed SO42- in the soil samples. The model predicted the pool of adsorbed SO42- (mmol/kg) as a function of pH and the equilibrium concentration of SO42- (mmol/l) in the soil solution system. The extended Freundlich model was optimized in three different ways: by use of unconstrained, constrained and simplified two-point calibration. The results showed that the adsorption of sulfate in the Kloten Bs1 and Risbergshöjden B soils was higher as compared to the Tärnsjo B, Österström B, and Risfallet B soils. The coefficient of determination (R2) determined from an unconstrained fit of the extended Freundlich model (with three adjustable parameters) for Risbergshöjden B and Kloten Bs1 were R2 =0.998 and R2=0.993. Nearly as good fits were found in a constrained fit with two adjustable parameters when it was assumed that nearly 2 protons (2 H+) are co-adsorbed with one SO42- ion (Risbergshöjden B; R2=0.997 and Kloten Bs; R2=0.992). The simplified two-point calibration with two adjustable parameters showed similar parameter values for all most soils and was considered the best optimization method of extended Freundlich model, especially as it requires only limited input data.

  • 7.
    Alam, Mohammad Faiz
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Evaluating the benefit-cost  ratio of groundwater abstraction for additional irrigation water on global scale.2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Projections show that to feed a growing population which is expected to reach 9.1 billion in 2050 would require raising overall food production by some 70 percent by 2050. One of the possible ways to increase agricultural production is through increasing yields by expanding irrigation. This study assesses the potential costs and benefits associated with sustainable groundwater abstraction to provide for irrigation.The feasibility of groundwater abstraction is determined using a combination of three indicators:groundwater recharge, groundwater quality (salinity) and sustainability (no depletion). Global groundwater recharge estimates used, are simulated with the Lund-Potsdam-Jena dynamic global vegetation model with managed lands (LPJmL). The cost of groundwater abstraction is determinedon a spatially explicit scale on global level at a grid resolution of 0.5°. Groundwater abstraction cost is divided into two parts: capital costs and operational costs. The potential benefit of increased water supply for irrigation is given by the water shadow price which is determined by using a Model of Agricultural Production and its Impact on the Environment (MAgPIE). The water shadow price for water is calculated in areas where irrigation water is scarce based on the potential increase in agricultural production through additional water and it reflects the production value of an additional unit of water. The water shadow price is given on a 0.5° grid resolution in US $/m3. Combining the cost of abstraction and the water shadow price, the benefit cost ratio is calculated globally on a spatially explicit scale to determine where investment in groundwater irrigation wouldbe beneficial. Finally, the results are analysed in global, regional and country perspectives. The results show that groundwater abstraction is beneficial for an area of 135 million hectares which is around 8.8% of the total crop area in the year 2005. Europe show the highest potential with an area of ~ 50 million hectares with a majority of the area located in France, Italy, Germany and Poland. Second is North America with an area of ~ 43.5 million hectares located in the Eastern states where the irrigation infrastructure is less developed as compared to the Western states. Sub-Saharan Africa shows a potential of ~ 15.4 million hectares in the Southern and Eastern countries of Zimbabwe, Kenya, Malawi, Tanzania, Ethiopia and some parts of South Africa. South Asia despite extensive groundwater extraction shows only a moderate potential of ~ 9 million hectares, mostly located in India whereas China shows almost no potential. This is due to extensive groundwater depleted areas which were removed from the analysis and low water shadow prices which made abstraction not beneficial. Well installation costs play an important role in developing countries in regions of Sub-Saharan Africa and South Asia, where a reduction in costs would lead to an increase in area by more than 30%. Subsidy analyses shows that substantial increase in crop land areas where a benefit cost ratio >1 takes place in India with subsidised energy prices but this effect is found to be negligible in Mexico. This study is, to the author’s knowledge, the first to assess the benefit cost ratio of groundwater abstraction on a global scale by determining spatially explicit abstraction costs. The results show that a great potential for groundwater abstraction exists in all regions despite problems of groundwater depletion due to disparity in distribution and development of groundwater resources. Energy subsidies and cheap well installation techniques are the two factors that could bring down the abstraction costs which are quite important in developing regions where farm incomes are low. Also, groundwater irrigation potential not only exists in arid areas of Africa and South Asia where irrigation is needed but also in humid areas of Europe and North America where groundwater irrigation can play an important role in building resilience to events of drought. However, it is essential to not to follow the path that has led to groundwater depletion in many parts of the world and develop this potential in a sustainable way through groundwater use regulations, policies and efficient technologies.

  • 8.
    Al-Azawi, Sundus
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Hydrophobic sand to combat water scarcity – Properties and possible chemical risk.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The city of Dubai, which lies in the Middle East is, as many other cities in the area, suffering from shortage of fresh water resources. This issue is handled by desalination of sea water, which is a rather expensive procedure. Recently, the city tends to promote using hydrophobic sand in order to reduce irrigation water quantity and watering durations. Economically, this procedure has fewer costs than water desalination but concerns were raised regarding whether the chemical compounds, used in the treatment process of normal sand, impose any contamination risks for soil and groundwater.

    Due to the fact that normal sand has high permeability comparing to other types of soil, such as silt and clay, the rates of water seepage in normal sand is considerably high which results high water consumption in agriculture. One of the objectives of this thesis is to identify the most effective design for utilizing hydrophobic sand and normal sand layers to obtain the most suitable permeability rates for plantation purposes. Another objective is to discuss the probability of organic chemicals and heavy metals seepage when using the hydrophobic sand in soil; leaching tests were carried out to provide input to this discussion. The study showed that the hydrophobic sand has higher permeability than normal sand when it is saturated with water. However, it needs a considerably longer time in order to reach the saturation stage so recommendations were provided to use a separate layer of hydrophobic sand beneath the normal sand layer where vegetation is planted and avoid using sand mixtures.

    Based on the leaching tests’ results, it was also concluded that negligible concentrations of the organic silica compounds will be released into soil and ground water and the rates of heavy metals in leaching water were within the allowable limits. However, the possibility of the transformation of the organic compounds, used for normal sand treatment, into silica-free organic compounds was not discussed in this thesis. In other words, the usage of hydrophobic sand for agriculture purposes does not threaten the safety of neither soil nor groundwater concerning the leaching of the chemical compounds and metals that were tested in this study.

  • 9.
    Alcalá Borao, Raquel
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Oxidation of pharmaceuticals by chlorine dioxide in wastewater effluent.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The presence of pharmaceuticals in the environment has raised an emerging interest due to the fact that they pose negative environmental impact and health hazards related to long-term toxicity effects. As conventional treatments are not able to totally remove these substances it is necessary to seek for alternative advanced technologies such as oxidation with chlorine dioxide (ClO2). The objective of this master thesis is thus to find the most optimal dose – reaction time of ClO2 for the oxidation and maximum removal of selected environmentally relevant pharmaceuticals. Factorial design and subsequent optimization with MODDE was selected as the best approach to find the optimal dose – time. Batch oxidation tests were conducted on 100mL aliquots treated with ClO2 using wastewater effluent from Henriksdal WWTP. Thereafter solid phase extraction and final determination of pharmaceuticals was carried out on a high performance liquid chromatography- triple quadrupole mass spectrometry (HPLC-MS/MS). Results showed that applying a dose of 5 mg ClO2/L and a reaction time of 10 minutes, it is possible to remove more than a half of the 17 analyzed substances. Besides most of the pharmaceuticals with high and moderate environmental risk, would pose a low risk for the environment after treatment with the optimal ClO2 dose – reaction time. Despite the fact that ClO2 could successfully degrade most environmentally relevant pharmaceuticals, deeper research concerning the formation of toxic by-products after oxidative treatment needs to be done before upscaling this technology to pilot or full scale as a suitable end of pipe technology for pharmaceuticals removal.

  • 10. Al-Yaarubi, A. H.
    et al.
    Pain, C. C.
    Grattoni, C. A.
    Zimmerman, Robert W.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Navier-Stokes Simulations of Fluid Flow Through a Rock Fracture2013In: Dynamic Fluids and Transport Through in Fractured Rock, American Geophysical Union (AGU), 2013, p. 55-64Chapter in book (Other academic)
    Abstract [en]

    A surface profilometer was used to measure fracture profiles every 10 microns over the surfaces of a replica of a fracture in a red Permian sandstone, to within an accuracy of a few microns. These surface data were used as input to two finite element codes that solve the Navier-Stokes equations and the Reynolds equation, respectively. Numerical simulations of flow through these measured aperture fields were carried out at different values of the mean aperture, corresponding to different values of the relative roughness. Flow experiments were also conducted in casts of two regions of the fracture. At low Reynolds numbers, the Navier-Stokes simulations yielded transmissivities for the two fracture regions that were closer to the experimental values than were the values predicted by the lubrication model. In general, the lubrication model overestimated the transmissivity by an amount that varied as a function of the relative roughness, defined as the standard deviation of the aperture divided by the mean aperture. The initial deviations from linearity, for Reynolds numbers in the range 1-10, were consistent with the "weak inertia" model developed by Mei and Auriault for porous media, and with the results obtained computationally by Skjetne et al in 1999 on a two-dimensional self-affine fracture. In the regime 10 < Re < 40, both the computed and measured transmissivities could be fit very well to a Forchheimer-type equation, in which the additional pressure drop varies quadratically with the Reynolds number.

  • 11.
    Amatya, Anjali
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Study on Process Performance and Evaluation of Dala Vatten’s Two Municipal Wastewater Treatment Plants.2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Dala Vatten AB has been operating two municipal wastewater treatment plant namely Gagnef wastewater treatment plant and Tällberg wastewater treatment plant since 1970’s and 1950’s respectively in Dalarna, middle of Sweden. These both traditional treatment plants have been updated with continuous and intermittent aerated biological treatment facilities: Moving bed biofilm reactor (MBBR) in 2012 and 2007 respectively. Recently, more detailed process performance and evaluation of both plants is required focusing on energy consumption. The objective of this master thesis is thus to investigate the opportunities in reducing energy consumption from both plants to save operation cost, identify the opportunities for chemical saving, if possible reduce the excess sludge so produced from the plant and potential optimization of the process for its plant’s sustainability. The laboratory study was made in May and August, 2015 with grab sampling and flow proportional sampling method. The analysation was carried out with several wastewater parameters: BOD7, COD, TOC, TP, NH4-N and TN with Hach Lange analysing method.

    Results showed that both continue and intermittent aerated plants have higher process performance with lower effluent organic (BOD7, COD) and TP loading to the recipient. Gagnef WWTP with continuous aeration has demonstrated an excessive use of chemical, sludge production and high-energy consumption by the blower serving MBBR during the studied period. By contrast, Tällberg WWTP with intermittent aeration has proved to be successful in terms of lower energy consumption by the blower serving the MBBR but failed to show improved specific energy efficiency for each pollutant load during the studied period. The recommendation in improvising energy saving and saving operation cost at both treatment plants was put forward.

  • 12.
    Andersson, Sara
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mapping Uncertainties – A case study on a hydraulic model of the river Voxnan.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis gives an account for the numerous uncertainties that prevail one-dimensional hydraulic models and flood inundation maps, as well as suitable assessment methods for different types of uncertainties. A conducted uncertainty assessment on the river Voxnan in Sweden has been performed. The case study included the calibra-tion uncertainty in the spatially varying roughness coefficient and the boundary condi-tion uncertainty in the magnitude of a 100-year flood, in present and future climate conditions.

    By combining a scenario analysis, GLUE calibration method and Monte Carlo analysis, the included uncertainties with different natures could be assessed. Significant uncer-tainties regarding the magnitude of a 100-year flood from frequency analysis was found. The largest contribution to the overall uncertainty was given by the variance between the nine global climate models, emphasizing the importance of including projections from an ensemble of models in climate change studies.

    Furthermore, the study gives a methodological example on how to present uncertainty estimates visually in probabilistic flood inundation maps. The conducted method of how the climate change uncertainties, scenarios and models, were handled in frequency analysis is also suggested to be a relevant result of the study.

  • 13.
    Annaduzzaman, Md
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Chitosan biopolymer as an adsorbent for drinking water treatment: Investigation on Arsenic and Uranium2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In many countries over the world (including Sweden), metal toxicity in freshwater resources causes a severe drinking water quality problem and poses a threat to the environment and human health. Among the different toxic metals in the water resources of Sweden, arsenic and uranium are the biggest threats to health. These elements, over long time consumption, may even lead to cancer and/or neurological disorder. Most of the wells are installed in crystalline and sedimentary bedrock and the received water comes from water bearing fractures in the bedrock. The handling of such water is an issue and there is a need to reduce the arsenic and uranium exposure by improving processes and technologies. It is a very serious problem demanding a safe, sustainable and eco-friendly arsenic and uranium removal technology prior to drinking water supply. Different treatment systems are available, but many of them are not suitable due to their high cost, operation complexity and waste management issues. Through this study, chitosan biopolymer the second largest abundant polysaccharide on earth after cellulose, was verified as a potential adsorbent for arsenic(V) and uranium(VI) removal from water solution. Adsorbent characterizations were also conducted by XRD, FTIR, SEM, UV-visible spectrum and TGA/DTA investigations. Bench-scale batch experiments were conducted using chitosan biopolymer (DDA-85%) as an adsorbent to determine the arsenic(V) and uranium(VI) removal efficiency, by allowing four important effective parameters e.g. chitosan dosages, pH, contact time and contaminant concentration. The adsorption data at optimum conditions were fitted with Langmuir, Freundlich and Dubinin-Radushkhevic (D-R) isotherm and Lagergren pseudo-first-order and pseudo-second-order kinetic model to investigate the adsorption process. The characterization of materials assured the presence of effective amino, hydroxyl, and carboxyl groups of chitosan. Another advanntage is that the materials are bio-degradable. The results show that the arsenic(V) and uranium(VI) removal efficiency was 100% and 97.45% after 300 minutes with optimum pH of 6.0 and 7.0 respectively. The optimum adsorbent dosages and initial concentration were 60 and 80g/L and 100 and 250 µg/L respectively. The adsorption process was suitably described by Freundlich isotherm (R2 = 0.9933) and Langmuir isotherm (R2 = 0.9858) correspondingly for arsenic(V) uranium(VI) compared to other isotherms. This is an important indicator of homogeneous monolayer adsorption of metals. For both of arsenic(V) and uranium(VI), pseudo-second-order explained the adsorption kinetics better than pseudo-first-order and the second-order kinetic regression coefficient (R2) were 0.9959 and 0.9672 correspondingly. Connecting to the above mentioned results, it can be summed up that the chitosan biopolymer (DDA 85%) can be used as an inexpensive, sustainable and environment-friendly treatment option for arsenic(V) and uranium(VI) contaminated drinking water.

  • 14.
    Annaduzzaman, Md.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Deshpande, Paritosh Chakor
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Ersoz, M.
    Lazarova, Z.
    Chitosan biopolymer: a treatment option for uranium(VI) removal from drinking waterManuscript (preprint) (Other academic)
  • 15.
    Annaduzzaman, Md.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Ersoz, M.
    Lazarova, Z.
    Characterization of a chitosan biopolymer and arsenate removal for drinking water treatment2014In: One Century of the Discovery of Arsenicosis in Latin America (1914-2014): As 2014 - Proceedings of the 5th International Congress on Arsenic in the Environment, CRC Press, 2014, p. 745-747Conference paper (Refereed)
    Abstract [en]

    Chitosan biopolymer with a deacetylation degree of 85%, was assessed for its capability to adsorb As(V) from drinking water by batch experiments. To characterize the chitosan biopolymer, chitosan was analyzed by FTIR and SEM. The results showed that chitosan is an effective and promising sorbent for As(V) from drinking water. From the batch tests, results showed a maximum adsorption of 355 μg/L of As(V) with 1.18 μg g-1 adsorption capacity at pH 6. The kinetic data, obtained at pH 6 could be fitted with pseudo-second order equation (adsorption capacity: 0.923 μg g-1) and the process was suitably described by a Freundlich (R2 = 0.9933) model than by a Langmuir model (R2 = 0.9741). The results above indicated that chitosan is a very favorable sorbent for As(V) removal from aqueous solution.

  • 16.
    Annaduzzaman, Md.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Ersoz, M.
    Lazarova, Z.
    Evaluation and optimization of chitosan biopolymer as an adsorbent for arsenic(V) in drinking watert treatmentManuscript (preprint) (Other academic)
  • 17. Aronson, M.F.J.
    et al.
    La Sorte, F.A.
    Nilon, C.H.
    Katti, M.
    Goddard, M.A.
    Lepczyk, C.A.
    Warren, P.S.
    Williams, W.P.S.
    Cilliers, S.
    Clarkson, B.
    Dobbs, Cynnamon
    Dolan, R.
    Hedblom, M.
    Klotz, S.
    Louwe Kooijmans, Jip
    Kühn, I.
    MacGregor-Fors, I.
    McDonnell, Mark
    Mörtberg, Ulla
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Pyšek, P.
    Siebert, S.
    Sushinsky, J.
    Werner, Peter
    Winter, M.
    A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers2014In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 281, no 1780, p. 20133330-Article in journal (Refereed)
    Abstract [en]

    Urbanization contributes to the loss of the world's biodiversity and the homogenization of its biota. However, comparative studies of urban biodiversity leading to robust generalities of the status and drivers of biodiversity in cities at the global scale are lacking. Here, we compiled the largest global dataset to date of two diverse taxa in cities: birds (54 cities) and plants (110 cities). We found that the majority of urban bird and plant species are native in the world's cities. Few plants and birds are cosmopolitan, the most common being Columba livia and Poa annua. The density of bird and plant species (the number of species per km2) has declined substantially: only 8% of native bird and 25% of native plant species are currently present compared with estimates of non-urban density of species. The current density of species in cities and the loss in density of species was best explained by anthropogenic features (landcover, city age) rather than by non-anthropogenic factors (geography, climate, topography). As urbanization continues to expand, efforts directed towards the conservation of intact vegetation within urban landscapes could support higher concentrations of both bird and plant species. Despite declines in the density of species, cities still retain endemic native species, thus providing opportunities for regional and global biodiversity conservation, restoration and education.

  • 18.
    Arregul, Ane
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Innovative solutions for odours reduction from wastewater treatment.2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 19. Arts, Jos
    et al.
    Faith-Ell, Charlotta
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    New governance approaches for sustainable project delivery2012In: Transport Research Arena 2012, Elsevier, 2012, Vol. 48, p. 3239-3250Conference paper (Refereed)
    Abstract [en]

    Studies show that many infrastructure projects have problems to deliver sustainability commitments made earlier in the planning process. One problem is that many decisions influencing project design and environmental performance are made after the (formal) planning process and consent decision. Also, many parties are involved in project delivery and there is lack of information transfer (follow-up) from planning stages to construction and implementation. In addition, the effectiveness of project studies has been questioned (i.e. do project studies delivering their outcomes?). In international practice various approaches are adopted to overcome these problems. One approach is to move towards more collaborative relationships between various parties (governmental, private and public). Also, authorities and companies increasingly use procurement and contracting as an environmental policy instrument to further the environmental performance of projects (green procurement). Furthermore, new tools for securing sustainability commitments are increasingly used in infrastructure design and construction (e.g. rating tools such as CEEQUAL, BREEAM, LEED). The various approaches have developed independently but nevertheless seem to head in the same direction i.e. achieving more environmental sustainable outcomes of (infrastructure) projects. An important challenge is how these approaches can be combined to reinforce each other for more sustainable project delivery. Various relationships can be developed between the different 'tracks' of impact assessment, green procurement and partnering contracts in order to come to a more integrated approach. This paper aims at discussing and comparing different approaches for delivering sustainability in infrastructure projects. By integrating green procurement, partnering and sustainability declaration, an integrated approach could be developed in order to safeguard sustainable performance beyond the formal decision-making phase of infrastructure projects. This integrated approach would enable transfer of information, communication, learning from experience and adaptive environmental management.

  • 20.
    Asimakopoulos, George
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Start–up of a Thermophilic Digestion of Sewage Sludge from Mesophilic Conditions.2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this Master thesis is to study two different ways of start-up in anaerobic digesters under thermophilic conditions. As awareness for energy supply is growing, municipal waste water treatment uses a common treatment to stabilize sewage sludge which is called, anaerobic digestion (AD). Anaerobic digestion can transform the organic matter to combustible biogas which contains 60-70% methane. Biogas is usually referred to as a mixture of carbon dioxide (C02) and methane gas (CH4). The most common way to anaerobically treat sewage sludge at wastewater treatment plants in Sweden is on mesophilic conditions (30-40℃). Only 12 plants in the country treat sewage sludge in thermophilic conditions 50-60℃. Mesophilic digestion is considered as a more stable process but requires a longer hydraulic retention time to reach digestibility compared to thermophilic digestion. The higher temperature also enables a pathogenic destruction capacity which means that thermophilic digestion can be used as a sanitation method for sewage sludge.

  • 21.
    Azcarate, Juan
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Beyond impacts: Contextualizing strategic environmental assessment to foster the inclusion of multiple values in strategic planning2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Strategic environmental assessment (SEA) has the potential to improve strategic planning. However, meeting this expectation is a major challenge since SEA practice still constraints itself to assess the impacts of strategic planning initiatives. To advance the role of SEA beyond impact assessment, it has been argued that SEA needs to adapt to strategic planning contexts. Yet, there is a lack of consensus on how SEA should adapt to strategic planning contexts as these are complex, vary considerably and carry high levels of uncertainty. Against this background, the aim of this thesis is to contribute to the development of SEA by creating knowledge on ways in which it can be contextualized to different strategic planning situations. Three case studies addressing different values and strategic planning contexts were designed from which experiences on SEA conceptualization were drawn. The results show that developing strategic focused SEA frameworks that enhance dialogue, collaboration and knowledge generation on multiple values can address issues such as: the lack of data and objectives in developing planning contexts; gaps in knowledge and uncertainty associated to environmental monitoring in transboundary contexts; and the recognition of the importance of ecosystem services and their needed green qualities in urbanizing contexts. Based on the gained case study experiences, it is argued that SEA contextualization can mean addressing strategic planning intentions, identifying and engaging actors, deriving and prioritizing key values, collaborating to generate knowledge on key issues, and using this knowledge to shape strategic planning. Due to the complexity of the issues involved, contextualizing SEA is considered to be challenging to achieve and requires time and resources. However, based on the SEA case studies, it can be argued that the value added to strategic planning outweighs these requirements. Continuing to study the practice of context adaptable, strategic focused and participatory based SEA processes may contribute to advance SEA’s role beyond impact assessment and enable reaching its expected potentials.

  • 22.
    Azcarate, Juan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Bring, Arvid
    Stockholm University.
    Destouni, Georgia
    Stockholm University.
    Strategic environmental assessment and monitoring: Arctic key gaps and bridging pathways2013In: Environmental Research Letters, ISSN 1748-9326, E-ISSN 1748-9326, Vol. 8, no 4, p. 044033-Article in journal (Refereed)
    Abstract [en]

    The Arctic region undergoes rapid and unprecedented environmental change. Environmental assessment and monitoring is needed to understand and decide how to mitigate and/or adapt tothe changes and their impacts on society and ecosystems. This letter analyzes the application of strategic environmental assessment (SEA) and the monitoring, based on environmental observations, that should be part of SEA, elucidates main gaps in both, and proposes an overarching SEA framework to systematically link and improve both with focus on the rapidly changing Arctic region. Shortcomings in the monitoring of environmental change are concretized by examples of main gaps in the observations of Arctic hydroclimatic changes. For relevant identification and efficient reduction of such gaps and remaining uncertainties under typical conditions of limited monitoring resources, the proposed overarching framework for SEA application includes components for explicit gap/uncertainty handling and monitoring, systematically integrated within all steps of the SEA process. The framework further links to adaptive governance, which should explicitly consider key knowledge and information gaps that are identified through and must be handled in the SEA process, and accordingly (re)formulate and promote necessary new or modified monitoring objectives for bridging these gaps.

  • 23.
    Azcarate, Juan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Destouni, Georgia
    Stockholm University.
    Bring, Arvid
    Stockholm University.
    Scenario-based Transboundary Approach to Shape Arctic Futures2013Conference paper (Refereed)
    Abstract [en]

    Technological advances, climate change and increased strategic interest in the Arctic are causing rapid and long lasting transformations that challenge established governance and collaboration practices, and increase information demands to support regional decision making. In the rapidly transforming Arctic, however, scenarios of environmental change risk being insufficiently accounted for in adaptation planning, as monitoring of key environmental parameters has declined or is poorly optimized. Furthermore, application of support instruments for environmental planning, such as strategic environmental assessment, has been limited. This poster presents recent advancements in efforts to combine quantitative analysis of environmental monitoring in the Arctic with strategic governance research to develop instruments, such as scenarios, projections and assessment processes, which can facilitate relevant planning and decision making for change adaptation. The research explores and aims to improve the preconditions for and links between environmental management, policy-relevant monitoring, and climate change adaptation strategies in the Arctic. Results include environmental monitoring assessment for the Arctic, and design of a transboundary strategic environmental assessment approach that includes scenarios as a main component for enabling strategic dialogues, information exchange and decision support. In this proposed approach, focus is placed on identifying conflicts of interest, gaps of knowledge and uncertainties, and on developing inclusive scenarios and future projections that could be used by different actors to facilitate improved understanding of climate change impacts on sensitive and unique Arctic ecosystems. The approach can be used to discuss and arrive at shared projections, visions and objectives for the Arctic, and its application and testing in research may aid in enabling Arctic actors to establish networks, interact, share information and develop their capacities to improve decisions on Arctic futures.  

  • 24.
    Azcarate, Juan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Destouni, Georgia
    Stockholm University.
    Bring, Arvid
    Stockholm University.
    Transboundary approach proposal for sustainable and climate change adaptation strategies in the Arctic2012Conference paper (Other academic)
    Abstract [en]

    Introduction

    Decisions on the development of the Arctic should be given increased attention as its environmental, socio-economic and political circumstances are being significantly influenced by major trends that reinforce and support each other and together are causing long lasting transformations in the region.

    Increased strategic interest in the Arctic combined with rapid technological advances and climate change are leading to growing economic activities and natural resource extraction that challenge regional sustainable management and governance practices and international collaboration.

    Furthermore, environmental transformations risk being insufficiently accounted for in adaptation planning as environmental assessment application in the Arctic has been limited and monitoring of key environmental parameters has declined or is poorly optimized just when better information is a strong need. 

    In an effort to better understand the forces behind rapid Arctic transformations and to support key development decisions, a collaborative research project between the Royal Institute of Technology and Stockholm University has been established.1

    The aim of the project is to combine recent frontline research on strategic governance with quantitative analysis of environmental monitoring to develop decision making tools and assessment processes and explore and improve the preconditions for and links between environmental management, policy-relevant monitoring and climate change adaptation strategies in the Arctic.

    Methods

    A context analysis of Arctic institutional and governance frameworks is being carried out, where policies, sustainability objectives, environmental assessment practice, actors, and the effects of climate change are compiled, systematized and synthesized.

    Furthermore, a transboundary and participative strategic environmental assessment for information and skill exchange is being developed. Focus is placed on identifying conflicts of interest, gaps of knowledge and uncertainties, and on developing inclusive scenarios of future development possibilities that could be used by different stakeholders to discuss and arrive at shared development visions and objectives for the Arctic.

    Results and Discussion

    The collaborative research will enable Arctic actors to interact, increase and share information, skills and knowledge, build networks and, by this, develop their capacities. Moreover, experience will be gained in developing transboundary and participative assessment approaches that can be used to arrive at accepted and inclusive scenarios, visions and objectives for the Arctic, facilitating an improved understanding of climate change impacts on sensitive and unique Arctic ecosystems. Most importantly, it is thought that the research project will support decision makers to consider sustainability issues when deciding upon the measures and choices that will shape the future development of the Arctic.2

    Conclusion

    The proposed collaborative research project serves to develop transboundary and participative assessment approaches and tools to identify strategies towards sustainable development in the Arctic. This is done by creating platforms for stakeholder participation and dialogue where inclusive and accepted development objectives are formulated to address the rapid and profound changes that confront the Arctic. Depending on the results of the Arctic case study, similar transboundary approaches can be applied in other regions where there is a need to involve a plurality of stakeholders to take fair, legitimate and sustainable decisions.    

    1(http://www.kth.se/abe/inst/lwr/grupper/ema/research/shaping-a-sustainability-strategy-for-the-arctic-1.82268).

    2(http://iaia.org/conferences/iaia11/uploadedpapers/final%20drafts/Shaping%20a%20Sustainability%20Strategy%20for%20the%20Arctic.pdf).

  • 25.
    Azcarate, Juan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mörtberg, Ulla
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Green qualities in transport efficient cities2013Conference paper (Refereed)
    Abstract [en]

    A main stream postulation in urban planning is that denser cities enhance energy efficiency and city attractiveness by offering shorter travel distances and a variety of functions that reduce car traffic and facilitate walking, biking and public transit. However, the complex links that exist between city density and its implications for energy efficiency and city attractiveness call for a better understanding of the factors that influence an integrated planning of regional cities. In this context, one factor that could be of interest to study is that of green urban open spaces such as green wedges, parks, wetland areas, shore lines, gardens, cemeteries, golf courses and treed boulevards that provide protection for biodiversity as well as many other valuable ecosystem services. However, discussions on developing compact, energy efficient and attractive regional cities are raising conflicts with policies that aim at conserving green urban open spaces. The aim of this paper is to increase knowledge on and contribute to the development of strategies and measures to best manage the conflicts that are emerging between developing dense, low traffic cities and planning for good quality, valuable and accessible green urban open spaces. To achieve this aim, a conflict mapping exercise is being carried out by identifying, reviewing and assessing literature on the subject. In parallel, relevant examples are being analyzed and seminars, workshops and interviews are taking place with actors of the Stockholm city region. Obtained results are conflicting perceptions on the role that green urban open spaces should play in city development, conflicts of governance and collaboration, conflicts between different objectives at varying decision making scales, and significant limitations to integrated and systemic socio-ecological understandings of the city region and its changing values. The conflict mapping exercise is a valuable starting point to identify the proposal of alternative land use practices, discuss how these can be assessed, and define measures that can enhance compactness, energy efficiency and green qualities in city region planning and development.

  • 26.
    Azcarate, Juan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Khoshkar, Sara
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Practitioner perspectives on conflicts and measures for green qualities in the Stockholm regionManuscript (preprint) (Other academic)
  • 27.
    Azcarate, Juan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mörtberg, Ulla
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Gordon, Sara
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    CES provision and pressure in compacting Stockholm2015Conference paper (Refereed)
  • 28.
    Azcarate, Juan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mörtberg, Ulla
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Haas, Jan
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Reaching compact green cities: A study of the provision of and pressure on cultural ecosystem services in StockholmManuscript (preprint) (Other academic)
  • 29.
    Babelon, Ian
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mapping place values for the green, compact and healthy city: Interlinking softGIS, sociotope mapping and communities of practice.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Urban planning research and practice provides forceful evidence that urban place-making processes should not be driven by experts and planning professionals alone: they should also build on the experiential knowledge and values of lay citizens. Experience shows that the construction of the green, compact, and healthy city fostered by sustainable development policies requires considering how places are used and valued by all relevant stakeholders. SoftGIS is a form of web-based Public Participation Geographic Information Systems (PPGIS) that provides both a method and tools for mapping the values that people attach to places and for integrating these in professional urban planning practice. This report focuses on three softGIS tools: Mapita’s Maptionnaire, Spacescape’s Bästa Platsen, and SKL’s Geopanelen. Five case studies from Finland and Sweden are analysed so as to discuss some of the main substantive issues surrounding the uptake of softGIS applications urban planning practice and decision-making, particularly in the context of urban densification measures. In so doing, the extent to which softGIS can support dialogue between lay citizens and planning professionals is assessed, with a focus on urban ecosystem services in green areas. It is demonstrated that the potential of softGIS to help broaden communities of practice in urban planning hinges on a conducive institutional context for public participation and dialogue. Furthermore, it is argued that the use of softGIS tools is optimised when it is integrated in a comprehensive multifunctional toolbox that combines both physical and digital forms of public participation.

  • 30. Babelon, Ian
    et al.
    Ståhle, Alexander
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Toward Cyborg PPGIS: exploring socio-technical requirements for the use of web-based PPGIS in two municipal planning cases, Stockholm region, Sweden2017In: Journal of Environmental Planning and Management, ISSN 0964-0568, E-ISSN 1360-0559, Vol. 60, no 8, p. 1366-1390Article in journal (Refereed)
    Abstract [en]

    Web-based Public Participation Geographic Information Systems (PPGIS) are increasingly used for surveying place values and informing municipal planning in contexts of urban densification. However, research is lagging behind the rapid deployment of PPGIS applications. Some of the main opportunities and challenges for the uptake and implementation of web-based PPGIS are derived from a literature review and two case studies dealing with municipal planning for urban densification in the Stockholm region, Sweden. A simple clustering analysis identified three interconnected themes that together determine the performance of PPGIS: (i) tool design and affordances; (ii) organisational capacity; and (iii) governance. The results of the case studies augment existing literature regarding the connections between the different socio-technical dimensions for the design, implementation and evaluation of PPGIS applications in municipal planning. A cyborg approach to PPGIS is then proposed to improve the theoretical basis for addressing these dimensions together.

  • 31. Baken, Stijn
    et al.
    Sjöstedt, Carin
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Seuntjens, Piet
    Desmet, Nele
    De Schutter, Jan
    Smolders, Erik
    Characterisation of hydrous ferric oxides derived from iron-rich groundwaters and their contribution to the suspended sediment of streams2013In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 39, p. 59-68Article in journal (Refereed)
    Abstract [en]

    When Fe(II) bearing groundwaters surface in streams, particulate authigenic Fe-rich material is produced by oxidation. Such freshly precipitated Fe minerals may be transported as suspended sediment and have a profound impact on the fate of trace metals and nutrients in rivers. The objective of this study was to monitor changes in mineralogy and composition of authigenic material from its source to streams of increasing order. Groundwaters, surface waters, and suspended sediment in streams of different order were sampled in the Kleine Nete catchment (Belgium), a lowland with Fe-rich groundwaters (3.5-53.8 mg Fe/L; pH 6.3-6.9). Fresh authigenic material (>0.45 mu m) was produced by oxidising filtered (<0.45 mu m) groundwater and surface water. This material contained, on average, 44% Fe, and smaller concentrations of C, P, and Ca. Iron EXAFS (Extended X-ray Absorption Fine Structure) spectroscopy showed that the Fe was present as poorly crystalline hydrous ferric oxides with a structure similar to that of ferrihydrite. The Fe concentration in the suspended sediment samples decreased to 36-40% (stream order 2), and further to 18-26% (stream order 4 and 5). Conversely, the concentrations of organic C, Ca, Si, and trace metals increased with increasing stream order, suggesting mixing of authigenic material with suspended sediment from a different source. The Fe speciation in the suspended sediment was similar to that in fresh authigenic material, but more Fe-Fe interactions were observed, i.e. it was increasingly hydrolysed, suggesting ageing reactions. The suspended sediment in the streams of order 4 and 5 is estimated to contain between 31% and 59% of authigenic material, but more data are needed to refine this estimate. The authigenic material is an important sink for P in these streams which may alleviate the eutrophication risk in this catchment.

  • 32.
    Bakyayita Kizito, Grace
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Norrström, Ann-Catrine
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Nalubega, Mai
    Water and Sanitation Department, African Development Bank, Tunis.
    Robinah, Kulabako
    Department of Civil and Environmental Engineering, Makerere University, Uganda .
    Kinetic studies of Cd (II) and Pb (II) ions biosorption from aqueous media using untreated and chemically treated biosorbents2014In: Water Science and Technology: Water Supply, ISSN 1606-9749, E-ISSN 1607-0798, Vol. 69, no 11, p. 2230-2236Article in journal (Refereed)
    Abstract [en]

    Untreated and chemically treated Albizia coriaria, Erythrina abyssinica and Musa spp were studied in batch for uptake of Cd2+ and Pb2+ ions at pH 2.0–9.0 and agitation time; 30–390 min. Optimum biosorption conditions were; pH 4 for Pb2+ ions and pH 5 for Cd2+ ions, contact time was 3.5 hours at 24 ± 1 °C for 10 mg/L biosorbent dosage and initial metal ions concentration of 20 mg/L. Chemical treatment had a 10–17% biosorption efficiency enhancement for Cd2+ ions and a 1.6–2.3% reduction effect for Pb2+ ions. The sorption capacities for Cd2+ and Pb2+ ions for treated biosorbents were between 1.760–1.738 mg g−1 compared to 1.415–1.539 mg g−1 for untreated materials. The pseudo second order model suitably fitted the Cd2+ and Pb2+ ions biosorption data with regression coefficients (R2) between 0.9784–0.9999. Fitting of the Ho model to the experimental data showed that the biosorption mechanism for both metal ions studied was mainly a chemisorption process. Therefore, treated A. coriaria, E. abyssinica and Musa spp were potential biosorbents for remediation of Cd2+ ions and the untreated materials suitable for removing Pb2+ ions from contaminated aqueous media.

  • 33.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Successful water, waste and energy management2013Conference paper (Other academic)
  • 34.
    Balfors, Berit
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Azcarate, Juan
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mörtberg, Ulla
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Karlson, Mårten
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Odelius Gordon, Sara
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Impacts of urban development on biodiversity and ecosystem services2016In: Handbook on Biodiversity and Ecosystem Services in Impact Assessment / [ed] Davide Geneletti, Edward Elgar Publishing, 2016, p. 167-194Chapter in book (Refereed)
    Abstract [en]

    Global urbanization has increased rapidly and it is expected to continue. Due to the continuing urbanization process, green areas are transformed into areas for housing, industry and infrastructure. As a consequence, ecosystems in urbanizing areas are affected, which results in degradation of habitats, due to fragmentation and disturbances, with significant impacts on biodiversity and ecosystem services. In cities, green areas are of primary interest to support biodiversity as well as in their role as producers of ecosystem services; that is, services that ecosystems produce to the benefit of humans often without any costs. In addition, publicly accessible urban green areas enhance life quality for urban citizens. To strengthen biodiversity and ecosystem services considerations in the planning process and contribute to the preservation of biodiversity in the long term, a consistent assessment of potential impacts is required. In particular, a landscape approach in urban planning and assessment is needed to address the scales of ecological processes, to strengthen important landscape structures and functions in urban, regional and infrastructure planning. A landscape approach calls for methods for assessing the impacts of human actions on biodiversity at a landscape level, across administrative borders. Such methods should allow an analysis of cumulative impacts of many single planning decisions. Several of the processes involved have a temporal and spatial dimension and are possible to quantify, analyse, and visualize with geographical information systems (GIS) combined with spatial ecological models. This allows for localization and quantification of predicted effects of urbanization on biodiversity components over landscape and regional scales. This chapter addresses impacts of urbanization on biodiversity and urban green areas’ capacity in providing ecosystem services. A brief description of the role of biodiversity and ecosystem services provides a framework for a landscape approach in biodiversity assessments and for the practical examples from the Stockholm region. Related to the assessment, tools for predicting and assessing biodiversity impacts at a landscape level will be discussed as well as planning and management of urban green areas. The chapter concludes with lessons learned and key recommendations for best practice.

  • 35.
    Balfors, Berit
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Hammer, Monica
    Mörtberg, Ulla
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Khoshkar, Sara
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Ecosystem services and impact assessment: Examples from Swedish municipal planning2016Conference paper (Refereed)
  • 36.
    Balian, Daniel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Garis, Sargon
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Granskning av länsstyrelsens arbete för en minskad naturgrusutvinning.2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Naturgrus används i stora delar av byggindustrin i allt från betong till vägkonstruktioner. Det fungerar även som ett skyddande filter i miljön för att bland annat förhindra föroreningar från att nå grundvattnet. Därför är det viktigt att försöka vara sparsam med dessa täkter, vilket Sveriges riksdag klarlagt genom införandet av miljökvalitetsmålen. Det är sedan länens uppgift att stimulera kommuner och andra samhällsaktörer för att gemensamt arbeta mot dessa mål.

    Denna rapport granskar länsstyrelsernas arbete för en minskad utvinning av naturgrus med hänsyn till de uppsatta miljökvalitetsmålen. Arbetet grundas framförallt på intervjuer med representanter från fyra olika län av skild karaktär för att få ett bredare perspektiv. Svaren från intervjuerna jämförs för att tydliggöra skillnader och likheter i de olika länsstyrelsernas miljöarbete. En djupare analys görs för respektive län med hjälp av data från bland annat kartor hämtade från Sveriges geologiska undersökning.

    Resultatet visar bland annat att minskningen av naturgrusutvinningen har stagnerat under senare år, vilket med stor säkerhet beror på att miljökvalitetsmålet kopplat till naturgrus inte har reviderats. Vidare visar studien att det finns skillnader i länens arbetssätt för att nå målen. Detta påvisar behov av ett större utbyte av erfarenheter och idéer mellan länen.

  • 37. Baresel, Christian
    et al.
    Lüdtke, Maximilian
    Levlin, Erik
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Fortkamp, Uwe
    Ekengren, Östen
    Slamavvattning i kommunala reningsverk: Nuläget, begränsningar och perspektiv2014Report (Other academic)
  • 38. Begum, Shamim A.
    et al.
    Hyder, A. H. M. Golam
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Vahdat, Nader
    Adsorption isotherm and kinetic studies of As(V) removal from aqueous solution using cattle bone char2016In: Journal of Water Supply: Research and Technology - Aqua, ISSN 0003-7214, E-ISSN 1365-2087, Vol. 65, no 3, p. 244-252Article in journal (Refereed)
    Abstract [en]

    The As(V) adsorption onto bone char was investigated as a function of bone char dosage, pH and contact time in batch tests. The initial As(V) concentrations were varied from 0.1 to 1 mg/L to evaluate the adsorption kinetics and isotherm. The As(V) concentrations were analyzed using a graphite furnace atomic absorption spectrophotometer. The highest As(V) removal was found to be 62% after 3 d using 3 g bone char at a pH level of 4.0 for 0.5 mg/L As(V) concentration. The maximum adsorption capacity was 0.13 for 1 mg/L As(V) concentration. A Langmuir isotherm and second order adsorption kinetics were observed for As(V) adsorption.

  • 39. Berger, T.
    et al.
    Mathurin, F. A.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering. Swedish University of Agricultural Sciences, Sweden.
    Peltola, P.
    Åström, M.E.
    The impact of fluoride on Al abundance and speciation in boreal streams2015In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 409, p. 118-124Article in journal (Refereed)
    Abstract [en]

    The impact of fluoride on the abundance and speciation of aluminium (Al) was investigated in three boreal streams characterised by overall high concentrations of fluoride and dissolved organic matter. Stream-water sampling was carried out several times a year for at least 4 years, and a chemical equilibrium model (Visual MINTEQ) was applied in order to model the proportion of colloidal and organically/inorganically complexed Al in the waters. The Al concentrations in filtered (0.45 μm) water samples were inversely correlated with pH, and reached values up to approximately 1. mg/L during low pH conditions (pH < 6.0). In a stream with high fluoride concentrations, as compared to a similar stream with only moderately elevated fluoride concentrations, the Al concentrations were consistently elevated. For the stream with high concentrations of fluoride and Al, the model predicted both high concentrations and proportions of Al-fluoride complexation. This prediction indicates that high fluoride levels contribute to raise both the Al abundance and the ratio of inorganic to organic Al complexation in stream water. In contrast, for another stream with high fluoride concentrations and consistently high (near neutral) pH, there was no evidence of fluoride affecting Al concentration or complexation. These results show that it is important to focus future studies on the role of high levels of dissolved fluoride on both the speciation and the toxicity of Al in stream water.

  • 40. Bhowmick, S.
    et al.
    Nath, B.
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Biswas, Ashis
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Majumder, S.
    Mondal, P.
    Chakraborty, S.
    Nriagu, J.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Iglesias, M.
    Roman-Ross, G.
    Guha Mazumder, D.
    Bundschuh, J.
    Chatterjee, D.
    Arsenic mobilization in the aquifers of three physiographic settings of West Bengal, India: Understanding geogenic and anthropogenic influences2013In: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 262, p. 915-923Article in journal (Refereed)
    Abstract [en]

    A comparative hydrogeochemical study was carried out in West Bengal, India covering three physiographic regions, Debagram and Chakdaha located in the Bhagirathi-Hooghly alluvial plain and Baruipur in the delta front, to demonstrate the control of geogenic and anthropogenic influences on groundwater arsenic (As) mobilization. Groundwater samples (n=90) from tube wells were analyzed for different physico-chemical parameters. The low redox potential (Eh=-185 to -86mV) and dominant As(III) and Fe(II) concentrations are indicative of anoxic nature of the aquifer. The shallow (&lt;100m) and deeper (&gt;100m) aquifers of Bhagirathi-Hooghly alluvial plains as well as shallow aquifers of delta front are characterized by Ca2+HCO3 - type water, whereas Na+ and Cl- enrichment is found in the deeper aquifer of delta front. The equilibrium of groundwater with respect to carbonate minerals and their precipitation/dissolution seems to be controlling the overall groundwater chemistry. The low SO4 2- and high DOC, PO4 3- and HCO3 - concentrations in groundwater signify ongoing microbial mediated redox processes favoring As mobilization in the aquifer. The As release is influenced by both geogenic (i.e. geomorphology) and anthropogenic (i.e. unsewered sanitation) processes. Multiple geochemical processes, e.g., Fe-oxyhydroxides reduction and carbonate dissolution, are responsible for high As occurrence in groundwaters.

  • 41. Bhowmick, Subhamoy
    et al.
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Nriagu, Jerome
    Mazumder, Debendra Nath Guha
    Roman-Ross, Gabriela
    Chatterjee, Debashis
    Iglesias, Monica
    Speciation of Arsenic in Saliva Samples from a Population of West Bengal, India2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 12, p. 6973-6980Article in journal (Refereed)
    Abstract [en]

    Saliva, an easily accessible biofluid, is validated as biomarker of arsenic (As) exposure in several villages of West Bengal, India. Pentavalent arsenic [As(V)] was found to be the predominant species in saliva, with the amount of inorganic As [As(V) and trivalent form, As(III)] being more than half of the total As in the samples. Significant association was found between total daily ingestion of As and As(V) (r = 0.59; p = 0.000), As(III) (r = 0.60; p = 0.000), dimethylarsinous acid (DMA(V)) (r = 0.40; p = 0.000), and monomethylarsonous acid (MMA(V)) (r = 0.44; p = 0.000), implying that these species have mainly been derived from the methylation of the inorganic As in the water that study participants drank and the food they ate. Analysis of confounding effects of age, sex, smoking, body mass index and the prevalence of skin lesion suggests that women and controls with no skin lesion had a higher capacity to methylate the ingested As compared to the rest of the population. Thus, our study demonstrates that As species in saliva can be an useful tool to predict the individual susceptibility where higher As exposure and a lower methylation capacity are implicated in the development of As-induced health effects.

  • 42.
    Biswas, Ashis
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Arsenic Geochemistry in the Alluvial Aquifers of West Bengal, India: Implications for targeting safe aquifers for sustainable drinking water supply2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The natural occurrences of high (>10 μg/L) dissolved arsenic (As) in groundwater of Bengal Basin has put millions of people under the threat of chronic As exposure through drinking water. Present study has examined the processes that regulate As mobilization and its distribution in shallow aquifers and the potentiality of finding safe aquifers within shallow depth (<50 m) for drinking water supply. The results indicate that in terms of aquifer sediment colors and water quality two types of aquifer namely brown sand aquifer (BSA) and grey sand aquifer (GSA) can be distinguished within the depth, accessible by low-cost drilling. The redox condition in the BSA is delineated to be Mn oxyhydroxides reducing, not sufficiently lowered for As mobilization resulting in high Mn and low Fe and As in groundwater. While in GSA, currently the reductive dissolution of Fe oxyhydroxides is the prevailing redox process causing As mobilization into groundwater of this aquifer type. It is revealed that the vertical distribution of As and other aqueous redox parameters is related to the redox zonation within aquifer. The decoupling of As and Fe release into groundwater is evident in the shallowest part of aquifer because of Fe enrichment by weathering of silicate minerals especially of biotite, the precipitation of secondary mineral phases like siderite and vivianite and incomplete reduction of Fe oxyhydroxides. It is characterized that the seasonal variations of As and other aqueous solutes are limited within the upper portion of aquifer only (<30 m bgl) and can be related to seasonal cycling of redox status, aggregation and dispersion of As scavenging colloids, local groundwater abstraction and monsoonal recharge. The results of surface complexation modeling indicate that PO43- is the major competitor of As(III) and As(V) adsorption onto Fe oxyhydroxides. This study concludes that the reductive dissolution of Fe oxyhydroxides followed by competitive sorption reactions with the aquifer sediment is the process conducive for As enrichment in groundwater of Bengal Basin. Present study advocates that despite low concentration of As in groundwater, a rigorous assessment of attendant health risk for Mn is necessary prior to considering mass scale exploitation of the BSA for sustainable drinking water supply. This study also validates that TW platform colors can be used as a rapid screening tool for As and Mn in drinking water wells to prioritize As mitigation management.

  • 43.
    Biswas, Ashis
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mukherjee, Abhijit
    Nath, Bibhash
    Alexanderson, Helena
    Kundu, Amit K.
    Chatterjee, Debashis
    Jacks, Gunnar
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Delineation of shallow hydrostratigraphy in arsenic affected region of Bengal Basin: implication for targeting safe aquifers for drinking water supplyManuscript (preprint) (Other academic)
  • 44.
    Biswas, Ashis
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Mukherjee, Abhijit
    Nath, Bibhash
    Alexanderson, Helena
    Kundu, Amit K.
    Chatterjee, Debashis
    Jacks, Gunnar
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Shallow hydrostratigraphy in an arsenic affected region of Bengal Basin: Implication for targeting safe aquifers for drinking water supply2014In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 485, p. 12-22Article in journal (Refereed)
    Abstract [en]

    To delineate arsenic (As) safe aquifer(s) within shallow depth, the present study has investigated the shallow hydrostratigraphic framework over an area of 100 km(2) at Chakdaha Block of Nadia District, West Bengal. Drilling of 29 boreholes and subsequent hydrostratigraphic modeling has identified three types of aquifer within 50 m below ground level (bgl). Aquifer-1 represents a thick paleochannel sequence, deposited parallel to the River Hooghly and Ichamati. Aquifer-2 is formed locally within the overbank deposits in the central floodplain area and its vertical extension is strictly limited to 25 m bgl. Aquifer-3 is distributed underneath the overbank deposits and represents an interfluvial aquifer of the area. Aquifer-3 is of Pleistocene age (similar to 70 ka), while aquifer-1 and 2 represent the Holocene deposits (age <951 ka), indicating that there was a major hiatus in the sediment deposition after depositing the aquifer-3. Over the area, aquifer-3 is markedly separated from the overlying Holocene deposits by successive upward sequences of brown and olive to pale blue impervious clay layers. The groundwater quality is very much similar in aquifer-1 and 2, where the concentration of As and Fe very commonly exceeds 10 mu g/L and 5 mg/L, respectively. Based on similar sediment color, these two aquifers have jointly been designated as the gray sand aquifer (GSA), which constitutes 40% (1.84 x 10(9) m(3)) of the total drilled volume (4.65 x 10(9) m(3)). In aquifer-3, the concentration of As and Fe is very low, mostly <2 mu g/L and 1 mg/L, respectively. This aquifer has been designated as the brown sand aquifer (BSA) according to color of the aquifer materials and represents 10% (4.8 x 10(8) m(3)) of the total drilled volume. This study further documents that though the concentration of As is very low at BSA, the concentration of Mn often exceeds the drinking water guidelines.

  • 45.
    Biswas, Ashis
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Neidhardt, H.
    Karlsruhe Institute of Technology, Germany.
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Kundu, A.K.
    University of Kalyani, India.
    Chatterjee, Debashis
    University of Kalyani, India.
    Berner, Z.
    Karlsruhe Institute of Technology, Germany.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Surface complexation modeling of temporal variability of arsenic in groundwater: Estimating the role of competing ions in the mobilization processes2013Conference paper (Refereed)
    Abstract [en]

    This study investigates the relative roles of different competing ions on the mobilization of arsenic (As) by surface complexation modeling of As rich groundwater in the aquifer of Bengal Basin. Two sets of piezometers, installed at different depths of the shallow aquifer (<50 m), have been monitored for As and other relevant hydrogeochemical parameters over a period of 20 months. The potentiality of two different surface complexation models (SCM), developed for ferrihydrite and goethite has been explored to account for the observed temporal variation in As(III) and As(V) concentration in groundwater. The SCM for ferrihydrite appears as the better predictor for the observed variation in both As(III) and As(V) concentration. It is estimated that among the competing ions PO43- is the major competitor of As(III) and As(V) adsorption into Fe oxyhydroxide and competing ability of the ions decreases as PO43- >> Fe(II) > H4SiO4 = HCO3-. The result of sensitivity test indicates that the competition of PO43- with As for the adsorption sites might already reach nearly to the stage of maxima. It is also shown that a slight increase or decrease in pH can have overwhelming effect on the mobility of As(III) and As(V) by changing their concentration oppositely. It appears that only the reductive dissolution of Fe oxyhydroxide cannot explain the observed high As concentration in the groundwater of Bengal Basin. In absence of potential competition for the adsorption sites, As released due to reductive dissolution of Fe oxyhydroxide would have been re-adsorbed into the residual Fe phases. This study suggests that the reductive dissolution of Fe oxyhydroxide followed by competitive ion exchange with the aquifer sediment is the processes conducive for As enrichment in groundwater of the sedimentary aquifers.

  • 46.
    Biswas, Ashis
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Neidhardt, Harald
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Kundu, Amit K.
    Chatterjee, Debashis
    Berner, Zsolt
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Role of competing ions in the mobilization of arsenic in groundwater of Bengal Basin: Insight from surface complexation modeling2014In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 55, p. 30-39Article in journal (Refereed)
    Abstract [en]

    This study assesses the role of competing ions in the mobilization of arsenic (As) by surface complexation modeling of the temporal variability of As in groundwater. The potential use of two different surface complexation models (SCMs), developed for ferrihydrite and goethite, has been explored to account for the temporal variation of As(III) and As(V) concentration, monitored in shallow groundwater of Bengal Basin over a period of 20 months. The SCM for ferrihydrite appears as the better predictor of the observed variation in both As(III) and As(V) concentrations in the study sites. It is estimated that among the competing ions, PO43- is the major competitor of As(III) and As(V) adsorption onto Fe oxyhydroxide, and the competition ability decreases in the order PO43- >> Fe(II) > H4SiO4 = HCO- (3.) It is further revealed that a small change in pH can also have a significant effect on the mobility of As(III) and As(V) in the aquifers. A decrease in pH increases the concentration of As(III), whereas it decreases the As(V) concentration and vice versa. The present study suggests that the reductive dissolution of Fe oxyhydroxide alone cannot explain the observed high As concentration in groundwater of the Bengal Basin. This study supports the view that the reductive dissolution of Fe oxyhydroxide followed by competitive sorption reactions with the aquifer sediment is the processes responsible for As enrichment in groundwater.

  • 47.
    Biswas, Ashis
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Neidhardt, Harald
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Kundu, Amit K.
    Chatterjee, Debashis
    Berner, Zsolt
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Role of competing ions on the mobilization of arsenic in groundwater of sedimentary aquifers: insight from surface complexation modelingManuscript (preprint) (Other academic)
  • 48.
    Biswas, Ashis
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering. University of Kalyani.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering. Swedish University of Agricultural Sciences.
    Neidhardt, Harald
    Karlsruhe Institute of Technology, Germany.
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering. University of Kalyani.
    Kundu, Amit Kumar
    University of Kalyani, India.
    Chatterjee, Debashis
    University of Kalyani, India.
    Berner, Zsolt
    Karlsruhe Institute of Technology, Germany.
    Bhattacharya, Prosun
    University of Kalyani.
    Estimating the role of competing ions on the arsenic mobilization processes in the aquifers of Bengal Basin by surface complexation modeling2013Conference paper (Refereed)
    Abstract [en]

    This study investigates the relative roles of the different competing ions on the arsenic (As) mobilization in the sedimentary aquifers of Bengal basin by surface complexation modeling of the temporal varaibility of As in shallow (<50 m) groundwater. Two sets of piezometers (2×5 = 10), installed at the two sites with relatively contrasting dissolved As concentration in groundwater, were monitored bi-weekly for As and other hydrogeochemical parameters over a period of 20 months. The estimation of the standard deviation (SD) for As(III) reflects strong temporal variation (SD ≥10 μg/L) in all the piezometers of two sites over the monitoring period. Particularly, the variation is more prominent in the shallowest part of the aquifer, where the site specific cyclic trends are evident. While, As(V) shows significant temporal variation in the piezometers of high As site only and no specific trend is reflected in the variation.

    Two different surface complexation models (SCMs), developed for ferrihydrite and goethite have been explored to account for the observed temporal variation in As(III) and As(V) concentrations. The SCM for ferrihydrite has provided the better estimation for both As(III) and As(V) variations.

    Among the different competing ions, PO43- appears as the major competitor of As(III) and As(V) adsorption onto ferrihydrite and the competition ability decreases in the order PO43- >> Fe(II) > H4SiO4 = HCO3-. It is further revealed that a small decrease in pH significantly increases the concentration of As(III) and decreases the As(V) concentration and vice versa. The present study suggests that the reductive dissolution of Fe oxyhydroxides alone cannot explain the observed high As concentration in groundwater of the sedimentary aquifers. Perhaps, the reductive dissolution of Fe oxyhydroxides followed by competitive sorption reactions with the aquifer sediment is the processes conducive for As enrichment in the groundwater of Bengal basin.

  • 49.
    Biswas, Ashis
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Neidhardt, Harald
    Kundu, Amit K.
    Halder, Dipti
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Chatterjee, Debashis
    Berner, Zsolt
    Jacks, Gunnar
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Spatial, vertical and temporal variation of arsenic in the shallo aquifers of Bengal Basin: Controlling geochemical processesManuscript (preprint) (Other academic)
  • 50.
    Bitow Meles, Desbele
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Review of Methods of Wastewater Reuse to Diminish Non-Biodegradable Organic Compounds.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Wastewater reuse is very important in water resource management for both environmental and economic reasons. Unfortunately, wastewater from textile industries is difficult to treat by convectional wastewater treatment technologies. Now days, polluted water due to color from textile dyeing and finishing industries is burning issue for researchers. Textile or industrial wastewaters contain non-biodegradable organic compounds, which cannot be easily biodegraded because of their complex chemical structure. Dye wastewater discharged from textile wastewaters is one example of non-biodegradable organic compounds and it is difficult to remove dye effluent by convectional wastewater treatment methods. Therefore, this thesis deals about a review of advanced treatment technologies, which can de-colorize and remove non-biodegradable organic compounds from textile wastewater effluents. In addition to this, the potential and limitation of these advanced treatment methods are reviewed. Advanced treatment technologies reviewed in this paper are; Adsorption process, Membrane bioreactor (MBR) and advanced oxidation process (AOPs).

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