title: Effect of vermicomposting on concentration and speciation of heavy metals in sewage sludge with additive materials.
abstract: The aim of this work was to evaluate the total content and speciation of heavy metals (As, Cr, Cd, Cu, Fe, Mn, Ni, Pb and Zn) during vermicomposting of sewage sludge by Eisenia fetida earthworm with different additive materials (soil, straw, fly ash and sawdust). Results showed that the pH, total organic carbon were reduced, while the electric conductivity and germination index increased after a combined composting - vermicomposting process. The addition of bulking agents accelerated the stabilization of sludge and eliminated its toxicity. The total heavy metals after vermicomposting in 10 scenarios were lowered as compared with the initial values and the control without amendment. BCR sequential extraction indicated that vermicomposting significantly decreased the mobility of all heavy metals by increasing the residual fractions. The activity of earthworms and appropriate addition of amendment materials played a positive role in sequestering heavy metals during the treatment of sewage sludge.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: He
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China. Electronic address: zhang_yx@hnu.edu.cn.
authors.forename: Yaxin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Maocai
authors.initials: M
authors.lastname: Shen
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zeng
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Mucen
authors.initials: M
authors.lastname: Zhou
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Meirong
authors.initials: M
authors.lastname: Li
mesh_terms: D000818:Animals; D060729:Coal Ash / Q000494:pharmacology; D019216:Metals, Heavy / Q000032:analysis*; D009835:Oligochaeta; D012722:Sewage / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000819:agonists* / Q000032:analysis; D018508:Water Purification / Q000379:methods
chemical_list: D060729:Coal Ash; D019216:Metals, Heavy; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants
keywords: Additive materials; Heavy metals; Sewage sludge; Speciation; Vermicomposting