Interfacial oxygen nanobubbles reduce methylmercury production ability of sediments in eutrophic waters

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	Interfacial oxygen nanobubbles reduce methylmercury production ability of sediments in eutrophic waters
	Ji, Xiaonan; Liu, Chengbin; Pan, Gang
刊名	ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
	2020-01-30
卷号	188 页码:1-8
关键词	Mercury pollution Mercury methylation Anoxia remediation Organic matter Mercury microbial methylator
ISSN号	0147-6513
英文摘要	Eutrophication can induce hypoxia/anoxia and rich organic matter at the sediment-water interface in surface waters. When eutrophic waters are impacted with mercury (Hg) pollution, methylmercury (MeHg) production ability (MPA) of surface sediment would increase and more MeHg might be produced. To tackle this risk, this study firstly collected samples of surface sediment and overlying water from a typical eutrophic lake-Taihu Lake. Then from a sediment-water simulation system, we demonstrated that eutrophic waters were able to methylate Hg spontaneously, and that sediment is the major Hg sink in the system. After the addition of HgCl2 solution (approximately 1 mg L-1 in the slurry), MeHg concentrations in the sediment increased by 11.7 times after 48 h. The subsequent column experiments proved that O-2 nanobubbles could significantly decrease the MPA of surface sediment, by up to 48%. Furthermore, we found that O-2 nanobubbles could remediate anoxia mainly by increasing dissolved oxygen (from 0 to 2.1 mg L-1), oxidation-reduction potentials (by 37% on average), and sulfate (by 31% on average) in the overlying water. In addition, O-2 nanobubbles could also help decrease organic matter concentration, as was revealed by the decline of dissolved organic carbon in the overlying water (by up to 57%) and total organic carbon in surface sediment (by up to 37%). The remediation of anoxia and reduction of organic matter could contribute to the decrease of hgcA gene abundance (by up to 86%), and thus result in the reduction of MPA after the addition of O-2 nanobubbles. This study revealed the risk of MeHg production in case Hg pollution occurs in eutrophic waters and proposed a feasible solution for MeHg remediation.
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/44952]
专题	生态环境研究中心_环境水质学国家重点实验室
推荐引用方式 GB/T 7714	Ji, Xiaonan,Liu, Chengbin,Pan, Gang. Interfacial oxygen nanobubbles reduce methylmercury production ability of sediments in eutrophic waters[J]. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY,2020,188:1-8.
APA	Ji, Xiaonan,Liu, Chengbin,&Pan, Gang.(2020).Interfacial oxygen nanobubbles reduce methylmercury production ability of sediments in eutrophic waters.ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY,188,1-8.
MLA	Ji, Xiaonan,et al."Interfacial oxygen nanobubbles reduce methylmercury production ability of sediments in eutrophic waters".ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 188(2020):1-8.