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Zuo, Minyu
Publications (7 of 7) Show all publications
Zuo, M., Renman, G., Gustafsson, J. P. & Klysubun, W. (2018). Dual slag filters for enhanced phosphorus removal from domestic waste water: performance and mechanisms. Environmental science and pollution research international, 25(8), 7391-7400
Open this publication in new window or tab >>Dual slag filters for enhanced phosphorus removal from domestic waste water: performance and mechanisms
2018 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 25, no 8, p. 7391-7400Article in journal (Refereed) Published
Abstract [en]

The phosphorus (P) removal of five combinations of dual filters consisting of blast furnace slag (BFS), argon oxygen decarburisation slag (AOD) and electric arc furnace slag (EAF) was evaluated in column experiments with domestic waste water. The columns were fed with waste water for 24 days. The column with only EAF had the best P removal performance (above 93% throughout the experiment). The speciation of the bound P was evaluated by P K-edge X-ray absorption near-edge structure (XANES) spectroscopy. In all five columns, the main P species of the slag packed in the outlet chamber was amorphous calcium phosphate (ACP). In samples from the inlet chambers, the contributions from crystalline Ca phosphates, P adsorbed on gibbsite and P adsorbed on ferrihydrite were usually much greater, suggesting a shift of P removal mechanism as the waste water travelled from the inlet to the outlet. The results provide strong evidence that P was predominantly removed by the slags through the formation of ACP. However, as the pH decreased with time due to the progressively lower dissolution of alkaline silicate minerals from the slag, the ACP was rendered unstable and hence redissolved, changing the P speciation. It is suggested that this process strongly affected the lifespan of the slag filters. Of the slags examined, EAF slag had the best P removal characteristics and BFS the worst, which probably reflected different dissolution rates of alkaline silicates in the slags.

Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2018
Keywords
Metallurgical slags, Calcium phosphate, Phosphate speciation, Precipitation, Adsorption, Metal release
National Category
Environmental Sciences
Identifiers
urn:nbn:se:kth:diva-225206 (URN)10.1007/s11356-017-0925-y (DOI)000427398200029 ()29280098 (PubMedID)2-s2.0-85039055686 (Scopus ID)
Note

QC 20180403

Available from: 2018-04-03 Created: 2018-04-03 Last updated: 2018-05-23Bibliographically approved
Renman, G., Zuo, M., Gustafsson, J. P. & Klysybun, W. (2018). Phosphorus removal by slag depends on its mineralogical composition: A comparative study of AOD and EAF slags. Journal of Water Process Engineering, 25, 105-112
Open this publication in new window or tab >>Phosphorus removal by slag depends on its mineralogical composition: A comparative study of AOD and EAF slags
2018 (English)In: Journal of Water Process Engineering, ISSN 2214-7144, Vol. 25, p. 105-112Article in journal (Refereed) Published
Abstract [en]

Electric arc furnace slag (EAF) and argon oxygen decarburization slag (AOD) were investigated in column experiments to determine the effect of mineralogical composition on their P removal performance and lifespan. Polyethylene glycol (PEG) and NaOH solutions were used for pretreatment of the slags to adjust their dissolution properties. The modified slags exhibited better P removal performance at the beginning of the experiment, but had shorter lifespan than the unmodified slags. AOD and EAF modified with PEG and NaOH achieved 100% P removal during the first 84 and 60 pore volumes, respectively, which were ≥20 pore volumes longer than virgin AOD and EAF. However, virgin EAF and AOD both had a P removal efficiency above 90% during the first 280 pore volumes. Possibly, soluble minerals such as free lime are lost during the modification step, causing a decreased long-term P removal capacity. The XRD results showed that the high P removal ability of AOD and EAF was attributed to the dissolution of beta dicalcium silicate (β-C2) and gamma dicalcium silicate (γ-C2S), which were dominant mineral phases in the slags. Results from SEM-EDS analysis revealed significant P accumulation on the slag surface. Cracks on the EAF slag surface contributed to its longer lifespan. Analysis with P K-edge XANES spectroscopy showed that the P retained on the slag surface was dominated by amorphous calcium phosphate, with a substantial amount of carbonate apatite (around 30%). Amorphous calcium phosphate was transformed to crystalline apatite as the slag aged with column operating time.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Engineering and Technology
Research subject
Land and Water Resources Engineering
Identifiers
urn:nbn:se:kth:diva-233321 (URN)10.1016/j.jwpe.2018.07.003 (DOI)000444525600014 ()2-s2.0-85050236846 (Scopus ID)
Funder
VINNOVA
Note

QC 20180817

Available from: 2018-08-15 Created: 2018-08-15 Last updated: 2018-10-22Bibliographically approved
Zuo, M. (2017). Enhanced phosphorus removal from wastewater using virgin and modified slags: performance, speciation and mechanisms. (Doctoral dissertation). KTH Royal Institute of Technology
Open this publication in new window or tab >>Enhanced phosphorus removal from wastewater using virgin and modified slags: performance, speciation and mechanisms
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Argon oxygen decarburization slag (AOD) was tested in batch and column experiments to investigate its phosphorus (P) removal performance. The effects of factors such as AOD dose, initial P concentration of the feeding solution, and aging on the P removal ability of the slags were analyzed. In a column experiment, electric arc furnace slag (EAF), blast furnace slag (BFS) and AOD were combined in five different ways to determine optimal conditions for P removal. In another column experiment, the three types of slag were modified with polyethylene glycol (PEG) and NaOH to adjust their dissolution properties and the effect on P removal performance was examined. In the batch experiments, AOD exhibited very promising P removal ability. It removed 94.8% of P from 6.5 mg P L-1 synthetic solution in 4 hours with a dose of 5 g L-1. Maximum P removal capacity of 27.5 mg P g-1 was achieved. In the dual-filter column experiment, the column packed with only EAF had the best P removal performance (consistently above 93%). Amorphous calcium phosphate (ACP) was identified as the main P species in the five slag samples collected from the outlet chambers. The contributions from crystalline calcium phosphate (Ca-P) and P adsorbed on iron/aluminum (hydr)oxides were greater in samples from the inlet chambers. The P speciation results revealed that P was predominantly removed by the slags through formation of ACP. The second column experiment showed that modification with PEG and NaOH solution only enhanced short-term P removal by the slags. However, exhaustion of the modified slags occurred much earlier, indicating that the modification process had shortened the lifespan of the slags. Untreated AOD showed better P removal than untreated EAF until pore volume 244, probably due to faster dissolution rate of gamma dicalcium silicate (dominating in AOD according to the XRD results) than of beta dicalcium silicate (dominating in EAF).

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2017. p. 54
Series
TRITA-SEED-PHD ; 2017:01
Keywords
AOD, EAF, BFS, Calcium phosphate, XANES, slag mineralogy
National Category
Water Engineering
Research subject
Land and Water Resources Engineering
Identifiers
urn:nbn:se:kth:diva-213415 (URN)978-91-7729-516-7 (ISBN)
Public defence
2017-09-29, Sal V1, Teknikringen 76, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20170830

Available from: 2017-08-31 Created: 2017-08-30 Last updated: 2017-08-31Bibliographically approved
Zuo, M., Renman, G. & Gustafsson, J. P. (2016). Effect of aging on phosphorus removal of metallurgical slag and heat reactivation of aged slag. In: : . Paper presented at 2016 IWA water congress & exhibition.
Open this publication in new window or tab >>Effect of aging on phosphorus removal of metallurgical slag and heat reactivation of aged slag
2016 (English)Conference paper, Oral presentation only (Other academic)
Keywords
ageing, heating, AOD, EAF, BFS
National Category
Civil Engineering
Research subject
Land and Water Resources Engineering
Identifiers
urn:nbn:se:kth:diva-213412 (URN)
Conference
2016 IWA water congress & exhibition
Note

QC 20170830

Available from: 2017-08-30 Created: 2017-08-30 Last updated: 2017-08-30Bibliographically approved
Zuo, M., Renman, G., Gustafsson, J. P. & Klysubun, W. Dual slag filters for enhanced phosphorus removal from domestic wastewater: performance and mechanisms. Environmental science and pollution research international
Open this publication in new window or tab >>Dual slag filters for enhanced phosphorus removal from domestic wastewater: performance and mechanisms
(English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499Article in journal (Refereed) Submitted
Place, publisher, year, edition, pages
Springer
Keywords
metallurgical slags, calcium phosphate, phosphates speciation, precipitation, adsorption, metal release
National Category
Water Engineering
Research subject
Land and Water Resources Engineering
Identifiers
urn:nbn:se:kth:diva-213407 (URN)
Note

QC 20170830

Available from: 2017-08-30 Created: 2017-08-30 Last updated: 2017-08-30Bibliographically approved
Zuo, M., Renman, G., Gustafsson, J. P. & Klysubun, W.Phosphorus removal performance and lifespan prediction through mineralogical composition: A comparative study of AOD and EAF slags.
Open this publication in new window or tab >>Phosphorus removal performance and lifespan prediction through mineralogical composition: A comparative study of AOD and EAF slags
(English)Manuscript (preprint) (Other academic)
Keywords
amorphous calcium phosphate, carbonate apatite, fluoroapatite, larbite, gamma dicalcium silicate
National Category
Engineering and Technology
Research subject
Land and Water Resources Engineering
Identifiers
urn:nbn:se:kth:diva-213411 (URN)
Note

QC 20170830

Available from: 2017-08-30 Created: 2017-08-30 Last updated: 2017-08-30Bibliographically approved
Zuo, M., Renman, G., Gustafsson, J. P. & Klysubun, W.Phosphorus removal performance and lifespan prediction through minerology analysis: A comparative study of AOD and EAF slags.
Open this publication in new window or tab >>Phosphorus removal performance and lifespan prediction through minerology analysis: A comparative study of AOD and EAF slags
(English)Manuscript (preprint) (Other academic)
Keywords
amorphous calcium phosphate, carbonate apatite, fluoroapatite, larnite, gamma dicalcium silicate
National Category
Engineering and Technology
Research subject
Land and Water Resources Engineering
Identifiers
urn:nbn:se:kth:diva-213414 (URN)
Note

QC 20171107

Available from: 2017-08-30 Created: 2017-08-30 Last updated: 2017-11-07Bibliographically approved
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