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Sulfur cycling in freshwater sediments: A cryptic driving force of iron deposition and phosphorus mobilization.
Sci Total Environ. 2019 Mar 20; 657:1294-1303.ST

Abstract

Sulfur cycling in freshwater ecosystems has been previously considered minor, and the direct evidence of its impacts on iron and phosphorus cycles in freshwater sediments remains unclear. In this study, mesocosms with amended acetate and various sulfate concentrations (1.5-3.0 mmol L-1) were set up to investigate sulfur cycling and its influences on iron-rich freshwater sediments. Acetate addition induced hypoxia and provided substrates, which stimulated the sulfur cycling with evidence of SO42- decline, ΣS2-, S0 increase and corresponding variations of sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria. Meanwhile, the growth of iron-reducing bacteria (IRB) was suppressed, and lower Fe(II) release was correspondingly related to larger SRB abundance at higher sulfate level, indicating that microbial iron reduction might be blocked by SRB activities. However, continuous dissolution of Fe(III) oxides and generation of iron sulfides were observed, suggesting that sulfide-mediated chemical iron reduction (SCIR) became the dominant iron-reducing pathway, and Fe(II) was buried as iron sulfides instead of released to water column, which resulted in a transition of iron cycling into unidirectional SCIR. Consequently, continuous dissolution of Fe(III) oxides led to significant increase of PO43- concentration in the water column and sediment pore-water, revealing the phosphorus mobility in sediments derived from the SCIR process. To note, sustained accumulation of iron sulfides was observed even without ΣS2- presence, suggesting that ΣS2- precipitation occurred prior to diffusion. Thus, ΣS2--missing sulfur cycling seemed "cryptic" in this study. To highlight, the transition of the iron-reducing pathway and resulting PO43- release can be induced even under current sulfate level of Lake Taihu, and elevated sulfate levels could significantly intensify SCIR and phosphorus mineralization. Thus, the stimulated iron deposition and the resulting phosphorus release derived from the sulfur cycling should be paid more attention to in the treatment of eutrophic freshwater ecosystems.

Authors+Show Affiliations

Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, School of Environment, Nanjing Normal University, Nanjing 210023, China.Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, School of Environment, Nanjing Normal University, Nanjing 210023, China.Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, School of Environment, Nanjing Normal University, Nanjing 210023, China.Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, School of Environment, Nanjing Normal University, Nanjing 210023, China.Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, School of Environment, Nanjing Normal University, Nanjing 210023, China.Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, School of Environment, Nanjing Normal University, Nanjing 210023, China. Electronic address: wangguoxiang@njnu.edu.cn.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

30677896

Citation

Wu, Songjun, et al. "Sulfur Cycling in Freshwater Sediments: a Cryptic Driving Force of Iron Deposition and Phosphorus Mobilization." The Science of the Total Environment, vol. 657, 2019, pp. 1294-1303.
Wu S, Zhao Y, Chen Y, et al. Sulfur cycling in freshwater sediments: A cryptic driving force of iron deposition and phosphorus mobilization. Sci Total Environ. 2019;657:1294-1303.
Wu, S., Zhao, Y., Chen, Y., Dong, X., Wang, M., & Wang, G. (2019). Sulfur cycling in freshwater sediments: A cryptic driving force of iron deposition and phosphorus mobilization. The Science of the Total Environment, 657, 1294-1303. https://doi.org/10.1016/j.scitotenv.2018.12.161
Wu S, et al. Sulfur Cycling in Freshwater Sediments: a Cryptic Driving Force of Iron Deposition and Phosphorus Mobilization. Sci Total Environ. 2019 Mar 20;657:1294-1303. PubMed PMID: 30677896.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Sulfur cycling in freshwater sediments: A cryptic driving force of iron deposition and phosphorus mobilization. AU - Wu,Songjun, AU - Zhao,Yanping, AU - Chen,Yuanyuan, AU - Dong,Xiumei, AU - Wang,Mingyue, AU - Wang,Guoxiang, Y1 - 2018/12/11/ PY - 2018/10/09/received PY - 2018/12/10/revised PY - 2018/12/10/accepted PY - 2019/1/26/entrez PY - 2019/1/27/pubmed PY - 2019/2/20/medline KW - Freshwater ecosystem KW - Iron reduction KW - Phosphorus mobility KW - Sulfate-reducing bacteria KW - Sulfur cycling SP - 1294 EP - 1303 JF - The Science of the total environment JO - Sci Total Environ VL - 657 N2 - Sulfur cycling in freshwater ecosystems has been previously considered minor, and the direct evidence of its impacts on iron and phosphorus cycles in freshwater sediments remains unclear. In this study, mesocosms with amended acetate and various sulfate concentrations (1.5-3.0 mmol L-1) were set up to investigate sulfur cycling and its influences on iron-rich freshwater sediments. Acetate addition induced hypoxia and provided substrates, which stimulated the sulfur cycling with evidence of SO42- decline, ΣS2-, S0 increase and corresponding variations of sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria. Meanwhile, the growth of iron-reducing bacteria (IRB) was suppressed, and lower Fe(II) release was correspondingly related to larger SRB abundance at higher sulfate level, indicating that microbial iron reduction might be blocked by SRB activities. However, continuous dissolution of Fe(III) oxides and generation of iron sulfides were observed, suggesting that sulfide-mediated chemical iron reduction (SCIR) became the dominant iron-reducing pathway, and Fe(II) was buried as iron sulfides instead of released to water column, which resulted in a transition of iron cycling into unidirectional SCIR. Consequently, continuous dissolution of Fe(III) oxides led to significant increase of PO43- concentration in the water column and sediment pore-water, revealing the phosphorus mobility in sediments derived from the SCIR process. To note, sustained accumulation of iron sulfides was observed even without ΣS2- presence, suggesting that ΣS2- precipitation occurred prior to diffusion. Thus, ΣS2--missing sulfur cycling seemed "cryptic" in this study. To highlight, the transition of the iron-reducing pathway and resulting PO43- release can be induced even under current sulfate level of Lake Taihu, and elevated sulfate levels could significantly intensify SCIR and phosphorus mineralization. Thus, the stimulated iron deposition and the resulting phosphorus release derived from the sulfur cycling should be paid more attention to in the treatment of eutrophic freshwater ecosystems. SN - 1879-1026 UR - https://www.unboundmedicine.com/medline/citation/30677896/Sulfur_cycling_in_freshwater_sediments:_A_cryptic_driving_force_of_iron_deposition_and_phosphorus_mobilization_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0048-9697(18)35006-X DB - PRIME DP - Unbound Medicine ER -