Tags

Type your tag names separated by a space and hit enter

A millimeter-scale observation of the competitive effect of phosphate on promotion of arsenic mobilization in sediments.
Chemosphere. 2017 Aug; 180:285-294.C

Abstract

A millimeter-scale investigation is key to the understanding of the competitive effects of phosphate(P) on arsenic(As) mobility in sediments by taking the great biogeochemical heterogeneity of the sediments into consideration. In this study, a microcosm experiment was performed in this aspect using high-resolution dialysis and diffusive gradients in thin films (DGT) to simultaneously measure dissolved and labile P, As, and iron (Fe) in sediments, respectively. With the increase of P content in water from 0.02 mg L-1 to 0.20 and 2.4 mg L-1, consistent release of As from sediments was observed. The concentrations of DGT-labile As increased significantly especially in the upper sediment layer (up to 12 times of the 0.02 mg P L-1 treatment) due to the competition of phosphate, which corresponded well to the increase in DGT-labile P. There was limited increase in dissolved P and As contents due to the buffering provided by sediment solids, while the concentrations of both dissolved and DGT-labile Fe in sediments decreased. A stoichiometric calculation showed that 47% and 8% of the added P were removed through Fe(II) precipitation for the 0.20 and 2.4 mg P L-1 treatments, respectively, which greatly suppressed the release of As induced by P competition for the 0.20 mg P L-1 treatment. The DGT-induced fluxes in sediments (DIFS) modeling showed an increase in solid resupply to pore water As from elevation of water P through the increases of the desorption rate constant from 5.4 to 31(× 10-7) s-1 and the sorption rate constant from 1.8 to 22(× 10-4) s-1.

Authors+Show Affiliations

Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: smding@niglas.ac.cn.Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.International Network for Environment and Health, National University of Ireland, Galway, Ireland.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

28411545

Citation

Sun, Qin, et al. "A Millimeter-scale Observation of the Competitive Effect of Phosphate On Promotion of Arsenic Mobilization in Sediments." Chemosphere, vol. 180, 2017, pp. 285-294.
Sun Q, Ding S, Zhang L, et al. A millimeter-scale observation of the competitive effect of phosphate on promotion of arsenic mobilization in sediments. Chemosphere. 2017;180:285-294.
Sun, Q., Ding, S., Zhang, L., Chen, M., & Zhang, C. (2017). A millimeter-scale observation of the competitive effect of phosphate on promotion of arsenic mobilization in sediments. Chemosphere, 180, 285-294. https://doi.org/10.1016/j.chemosphere.2017.04.010
Sun Q, et al. A Millimeter-scale Observation of the Competitive Effect of Phosphate On Promotion of Arsenic Mobilization in Sediments. Chemosphere. 2017;180:285-294. PubMed PMID: 28411545.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - A millimeter-scale observation of the competitive effect of phosphate on promotion of arsenic mobilization in sediments. AU - Sun,Qin, AU - Ding,Shiming, AU - Zhang,Liping, AU - Chen,Musong, AU - Zhang,Chaosheng, Y1 - 2017/04/04/ PY - 2017/01/25/received PY - 2017/03/29/revised PY - 2017/04/03/accepted PY - 2017/4/16/pubmed PY - 2017/9/26/medline PY - 2017/4/16/entrez KW - Arsenic KW - High resolution KW - Iron KW - Phosphate KW - Sediment KW - ZrO-Chelex DGT SP - 285 EP - 294 JF - Chemosphere JO - Chemosphere VL - 180 N2 - A millimeter-scale investigation is key to the understanding of the competitive effects of phosphate(P) on arsenic(As) mobility in sediments by taking the great biogeochemical heterogeneity of the sediments into consideration. In this study, a microcosm experiment was performed in this aspect using high-resolution dialysis and diffusive gradients in thin films (DGT) to simultaneously measure dissolved and labile P, As, and iron (Fe) in sediments, respectively. With the increase of P content in water from 0.02 mg L-1 to 0.20 and 2.4 mg L-1, consistent release of As from sediments was observed. The concentrations of DGT-labile As increased significantly especially in the upper sediment layer (up to 12 times of the 0.02 mg P L-1 treatment) due to the competition of phosphate, which corresponded well to the increase in DGT-labile P. There was limited increase in dissolved P and As contents due to the buffering provided by sediment solids, while the concentrations of both dissolved and DGT-labile Fe in sediments decreased. A stoichiometric calculation showed that 47% and 8% of the added P were removed through Fe(II) precipitation for the 0.20 and 2.4 mg P L-1 treatments, respectively, which greatly suppressed the release of As induced by P competition for the 0.20 mg P L-1 treatment. The DGT-induced fluxes in sediments (DIFS) modeling showed an increase in solid resupply to pore water As from elevation of water P through the increases of the desorption rate constant from 5.4 to 31(× 10-7) s-1 and the sorption rate constant from 1.8 to 22(× 10-4) s-1. SN - 1879-1298 UR - https://www.unboundmedicine.com/medline/citation/28411545/A_millimeter_scale_observation_of_the_competitive_effect_of_phosphate_on_promotion_of_arsenic_mobilization_in_sediments_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0045-6535(17)30533-7 DB - PRIME DP - Unbound Medicine ER -