title: Sequential extraction of anaerobic digestate sludge for the determination of partitioning of heavy metals.
abstract: In China, agricultural use of anaerobic digestate sludge is considered a concern due to high heavy metal content of the sludge. In this study, sequential extraction procedure (SEP) was conducted to determine metal speciation which affects release and mobility of metal significantly. The results of SEP showed that each heavy metal possessed different distribution characteristics. Cu mainly reacted with carboxyl functional group to form the fraction bound to organic matter. Zn and Mn were dominated in the fraction bound to Fe-Mn oxides and carbonates, respectively. Pb, Ni, Cr, Cd and As were present as the residual fraction. Examination of mobility factors (MFs) indicated that Zn, Pb, Ni, Mn and Cd were more mobile whereas Cr and As were immobilized in anaerobic digestate. Based on the results, it can be stated that Cu, Zn, Mn, Ni and Cd may be grouped as toxic and active components in sludge and should be regarded as the priority pollutants for elimination. Pb should be monitored in terms of its high mobility factors (MF). Cr and As, nevertheless, were the most stable components in sludge.
authors.affiliation: Biogas Institute of Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China; Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China. Electronic address: zhunengmin2004@163.com.
authors.forename: Neng-min
authors.initials: NM
authors.lastname: Zhu
authors.affiliation: Biogas Institute of Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China; Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China.
authors.lastname: Qiang-Li
authors.affiliation: Biogas Institute of Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China; Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China.
authors.forename: Xu-jing
authors.initials: XJ
authors.lastname: Guo
authors.affiliation: Biogas Institute of Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China; Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China.
authors.lastname: Hui-Zhang
authors.affiliation: Biogas Institute of Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China; Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, 13 4th Section Renmin South Road, Chengdu Sichuan Province 610041, China.
authors.lastname: Yu-Deng
mesh_terms: D002681:China; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis / Q000737:chemistry*; D018570:Risk Assessment; D012722:Sewage / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; D019216:Metals, Heavy; D012722:Sewage
keywords: Anaerobic digestate; Heavy metals; Metal speciation; Sequential extraction; Toxic components