Biochar and nitrate reduce risk of methylmercury in soils under straw amendment

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境化学与生态毒理学国家重点实验室

	Biochar and nitrate reduce risk of methylmercury in soils under straw amendment
	Zhang, Yue; Liu, Yu-Rong; Lei, Pei; Wang, Yong-Jie; Zhong, Huan
刊名	SCIENCE OF THE TOTAL ENVIRONMENT
	2018-04-01
卷号	619 页码:384-390
关键词	Paddy soil Methylmercury Straw return Bioaccumulation Rice
ISSN号	0048-9697
文献子类	Article
英文摘要	There is growing evidence that incorporating crop straw into soils, which is being widely encouraged in many parts of the world, could increase net methylmercury (MeHg) production in soils and MeHg accumulation in crops. We explored the possibility of mitigating the risk of increased MeHg levels under straw amendment by transforming straw into biochar (BC). Greenhouse and batch experiments were conducted, in which soil MeHg concentrations, MeHg phytoavailability and accumulation in rice, dynamics of sulfate, nitrate and abundances of sulfate reducing bacteria (SRB) were compared in 'Control' (Hg contaminated soil), 'Straw' (soil with 1% rice straw), 'Straw + BC' (soil with 1% straw and 1% biochar), and 'Straw + BC + N' (soil with 1% straw, 1% biochar and 0.12% nitrate). Our results indicate that straw amendment increased MeHg concentrations in soils (28-136% higher) and rice plants (26% higher in grains, 'Straw' versus 'Control'), while co-application of biochar with straw reduced grain MeHg levels (60% lower, 'Straw + BC' versus 'Straw'). This could be mainly attributed to the reduced MeHg availability to rice plants (phytoavailability, extraction rates of MeHg by ammonium thiosulfate) under biochar amendment (64-99% lower, 'Straw+BC' versus 'Straw'). However, biochar amendment enhanced soil MeHg levels (5-75% higher, 'Straw + BC' versus 'Control'). Interestingly, nitrate addition helped reduce soil MeHg concentrations (11-41% lower, 'Straw + BC + N' versus 'Straw + BC') by facilitating nitrate reduction while inhibiting SRB activities. Subsequently, addition of nitrate with biochar, compared with biochar alone, further reduced grain MeHg levels by 34%. Therefore, straw biochar together with nitrate could possibly be effective in mitigating the risk of MeHg under straw amendment. Furthermore, the results evidence the impacts of straw management on the risk posed by MeHg in soils and emphasize the necessity to carefully consider the straw management policy in Hg-contaminated areas. (C) 2017 Elsevier B.V. All rights reserved.
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/40887]
专题	生态环境研究中心_环境化学与生态毒理学国家重点实验室
推荐引用方式 GB/T 7714	Zhang, Yue,Liu, Yu-Rong,Lei, Pei,et al. Biochar and nitrate reduce risk of methylmercury in soils under straw amendment[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2018,619:384-390.
APA	Zhang, Yue,Liu, Yu-Rong,Lei, Pei,Wang, Yong-Jie,&Zhong, Huan.(2018).Biochar and nitrate reduce risk of methylmercury in soils under straw amendment.SCIENCE OF THE TOTAL ENVIRONMENT,619,384-390.
MLA	Zhang, Yue,et al."Biochar and nitrate reduce risk of methylmercury in soils under straw amendment".SCIENCE OF THE TOTAL ENVIRONMENT 619(2018):384-390.