title: Study on demetalization of sewage sludge by sequential extraction before liquefaction for the production of cleaner bio-oil and bio-char.
abstract: Demetalization of sewage sludge (SS) by sequential extraction before liquefaction was implemented to produce cleaner bio-char and bio-oil. Demetalization steps 1 and 2 did not cause much organic matter loss on SS, and thus the bio-oil and bio-char yields and the compositions of bio-oils were also not affected significantly. However, the demetalization procedures resulted in the production of cleaner bio-chars and bio-oils. The total concentrations and the acid soluble/exchangeable fraction (F1 fraction, the most toxic heavy metal fraction) of heavy metals (Cu, Cr, Pb, Zn, and Cd) in these products were significantly reduced and the environmental risks of these products were also relived considerably compared with those produced from raw SS, respectively. Additionally, these bio-oils had less heavy fractions. Demetalization processes with removal of F1 and F2 fractions of heavy metals would benefit the production of cleaner bio-char and bio-oil by liquefaction of heavy metal abundant biomass like SS.
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: 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; Collaborative Innovation Center of Resource-Conserving & Environment-friendly Society and Ecological Civilization, Changsha 410083, 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: Jianguang
authors.initials: J
authors.lastname: Shao
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: 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: Institute of Bio-energy, Hunan Academy of Forestry, Changsha 410004, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Collaborative Innovation Center of Resource-Conserving & Environment-friendly Society and Ecological Civilization, 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: Guangming
authors.initials: G
authors.lastname: Zeng
mesh_terms: D000143:Acids / Q000737:chemistry; D018533:Biomass; D002606:Charcoal; D004777:Environment; D004867:Equipment Design; D008401:Gas Chromatography-Mass Spectrometry; D019216:Metals, Heavy / Q000302:isolation & purification*; D009821:Oils; D018570:Risk Assessment; D012722:Sewage; D012995:Solubility; D013696:Temperature; D013818:Thermogravimetry; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D000143:Acids; D019216:Metals, Heavy; D009821:Oils; D012722:Sewage; C540010:biochar; D002606:Charcoal
keywords: Bio-oil/bio-char; Demetalization; Heavy metal; Liquefaction; Sewage sludge