Change search
ReferencesLink to record
Permanent link

Direct link
Geological controls on groundwater chemistry and arsenic mobilization: Hydrogeochemical study along an E-W transect in the Meghna basin, Bangladesh
KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering. (KTH-International Groundwater Arsenic Research Group)
KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering. (KTH-International Groundwater Arsenic Research Group)ORCID iD: 0000-0003-4350-9950
Show others and affiliations
2009 (English)In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 378, no 1-2, 105-118 p.Article in journal (Refereed) Published
Abstract [en]

Hydrogeochemical investigations along an E-W transect in the middle Meghna basin show groundwater chemistry and redox condition vary considerably with the change in geology. Groundwater in the Holocene shallow (< 150 m bgl) alluvial aquifer in western part of the transect is affected by high arsenic concentration (As > 10 mu g/l) and salinity. On the other hand, groundwater from the Pliocene Dupi Tila sandy aquifer in the eastern part is fresh and low in As (< 10 mu g/l). The Holocene shallow aquifers are high in dissolved As. HCO3-, Fe and dissolved organic carbon (DOC), but generally low in SO2- and NO3-. High HCO3- concentrations (250-716 mg/l) together with high DOC concentrations (1.4-21.7 mg/l) in these aquifers reflect active sources of degradable natural organic matter that drives the biogeochemical process. There is generally de-coupling of As from other redox-sensitive elements. In contrast, the Pliocene aquifers are low in As, HCO3- and DOC. Molar ratio of HCO3-/H4SiO4 suggests that silicate weathering is dominant in the deeper Holocene aquifers and in the Pliocene aquifers. Molar ratios of Cl-/HCO3- and Na+/Cl- suggest mixing of relict seawater with the fresh water as the origin of groundwater salinity. Speciation calculations show that saturation indices for siderite and rhodochrosite vary significantly between the Holocene and Pliocene aquifers. Stable isotopes (delta H-2 and delta O-18) in groundwater indicate rapid infiltration without significant effects of evaporation. The isotopic data also indicates groundwater recharge from monsoonal precipitation with some impact of altitude effect at the base of the Tripura Hills in the east. The results of the study clearly indicate geological control (i.e. change in lithofacies) on groundwater chemistry and distribution of redox-sensitive elements such as As along the transect.

Place, publisher, year, edition, pages
2009. Vol. 378, no 1-2, 105-118 p.
Keyword [en]
Groundwater chemistry, Holocene and Pliocene aquifers, Redox, conditions, Transect, Meghna basin, Bangladesh, western bengal basin, quaternary stratigraphy, southeastern bangladesh, reducing conditions, alluvial aquifers, deep groundwater, matlab, upazila, ganges delta, india, shallow
National Category
Environmental Sciences
URN: urn:nbn:se:kth:diva-18954DOI: 10.1016/j.jhydrol.2009.09.016ISI: 000271679700009ScopusID: 2-s2.0-70349972973OAI: diva2:337001
QC 20100525Available from: 2010-08-05 Created: 2010-08-05 Last updated: 2011-11-29Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Hasan, M. AzizBhattacharya, Prosunvon Brömssen, MattiasJacks, Gunnar
By organisation
Land and Water Resources Engineering
In the same journal
Journal of Hydrology
Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 68 hits
ReferencesLink to record
Permanent link

Direct link