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| Effects of Microcystis aeruginosa decay on migration of antimony and arsenic in surface sediments |
| HUANG Tianyin*,ZHU Tian |
| School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China |
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Abstract To explore the effects of Microcystis aeruginosa(M. aeruginosa)on the water environment and the migration of arsenic(As)and antimony(Sb)in sediment,the column of sediment and over-lying water was employed as the research object to monitor the change of environmental factors and substance concentrations during the decay of algae with different concentrations, and analyze the effects of algae on the migration of As and Sb in sediments. The results show that the dissolved oxygen and electric potential in overlying water are both obviously decreased which benefited the dissolution of sediment. The algae cells penetrating into sediment promotes the migration of As and Sb from sediment to pore water, and the release rate reaches the maximum on the second day after adding Microcystis aeru-ginosa. The maximum release rate of As occurs at -4 cm in the sediment in both low algae dosage co-lumn(LAD)and high algae dosage column(HAD)with value of 2.20 and 3.67 respectively, while the maximum release rates of Sb occurring at -2 cm in the sediment with rate of 1.01 and 1.21 in LAD and HAD. It is inferred that the release of As and Sb is mainly caused by the dissolution during intaking nutrients from sediment by algae cells. The decay of algae turns the water environment into reductive condition which promotes As release with the rate of 0.82 and 1.58 in LAD and HAD respectively, but inhibites Sb release due to the solidifying form of reductive Sb, with release rate of 0.13 and 0.12 in LAD and HAD respectively. Algal activity in HAD exhibites a stronger effect on the migration of As and Sb. The research indicates that algal activity has an effect on the migration of As and Sb in sediment, which provides the basis of control of heavy metals in eutrophication water.
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Received: 18 June 2021
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