title: Speciation and environmental risk assessment of heavy metal in bio-oil from liquefaction/pyrolysis of sewage sludge.
abstract: Liquefaction bio-oil (LBO) produced with ethanol (or acetone) as the solvent and pyrolysis bio-oil (PBO) produced at 550°C (or 850°C) from sewage sludge (SS) were produced, and were characterized and evaluated in terms of their heavy metal (HM) composition. The total concentration, speciation and leaching characteristic of HMs (Cu, Cr, Pb, Zn, Cd, and Ni) in both LBO and PBO were investigated. The total concentration and exchangeable fraction of Zn and Ni in bio-oils were at surprisingly high levels. Quantitative risk assessment of HM in bio-oils was performed by the method of risk assessment code (RAC), potential ecological risk index (PERI) and geo-accumulation index (GAI). Ni in bio-oil produced by pyrolysis at 850°C (PBO850) and Zn in bio-oil by liquefaction at 360°C with ethanol as solvent (LBO-360E) were evaluated to possess very high risk to the environment according to RAC. Additionally, Cd in PBO850 and LBO-360E were evaluated by PERI to have very high risk and high risk, respectively, while Cd in all bio-oils was assessed moderately contaminated according to GAI.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China. Electronic address: yxz@hnu.edu.cn.
authors.forename: Xingzhong
authors.initials: X
authors.lastname: Yuan
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Lijian
authors.initials: L
authors.lastname: Leng
authors.affiliation: School of Land Resources and Environment, Jiangxi Agricultural University, Nanchang 330045, PR China.
authors.forename: Huajun
authors.initials: H
authors.lastname: Huang
authors.affiliation: School of Business, Central South University, Changsha 410083, PR China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Chen
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Hou
authors.initials: H
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Xiao
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Zhai
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Chen
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zeng
mesh_terms: D056804:Biofuels / Q000032:analysis*; D016000:Cluster Analysis; D054750:Ecotoxicology / Q000379:methods*; D006358:Hot Temperature; D019216:Metals, Heavy / Q000032:analysis*; D018570:Risk Assessment / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D056804:Biofuels; D019216:Metals, Heavy; D012722:Sewage
keywords: Bio-oil; Heavy metal; Liquefaction; Pyrolysis; Risk assessment