title: Sorption performance and mechanism of a sludge-derived char as porous carbon-based hybrid adsorbent for benzene derivatives in aqueous solution.
abstract: A porous sludge-derived char was prepared by a new one-step pyrolytic process with citric acid-ZnCl2 mixed fabricating-pore agents. The sludge-derived char was confirmed to be a hierarchically porous hybrid adsorbent containing-elemental carbon, -highly carbonized organic species and -inorganic ash with a great surface area of 792.4m(2)g(-1). It was used as a carbon-based hybrid adsorbent for four benzene derivatives including 4-chlorophenol, phenol, benzoic acid and 4-hydroxylbenzoic acid in aqueous solution. Results showed that their sorption isotherms were nonlinear at low concentrations and linear at high concentrations. The sorption performance could be described by a multiple sorption model (QT=QA+KPCe). The order of these partition sorption coefficients (KP) of these benzene derivatives was consistent with their octanol-water partition coefficients (logKow), but those saturated amounts (QA) were inconsistent with their logKow. The inconstancy was found to be considerably dependent on the preferential interaction of benzoic acid with SiO2 in the sludge-derived char. Quantum theoretical calculation confirmed that the preferential interaction was attributed to the formation of hydrogen bonds (1.61 and 1.69Å) and new Si-O bonds (1.83 and 1.87Å) between the carboxyl of benzoic acid and the SiO2 surface in the sorption process.
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou, 510275, PR China.
authors.forename: Lingjun
authors.initials: L
authors.lastname: Kong
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou, 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, PR China. Electronic address: cesxya@mail.sysu.edu.cn.
authors.forename: Ya
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou, 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, PR China.
authors.forename: Lianpeng
authors.initials: L
authors.lastname: Sun
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou, 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, PR China.
authors.forename: Shuanghong
authors.initials: S
authors.lastname: Tian
authors.affiliation: School of Chemistry and Chemical Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou, 510275, PR China.
authors.forename: Xianyan
authors.initials: X
authors.lastname: Xu
authors.affiliation: School of Chemistry and Chemical Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou, 510275, PR China.
authors.forename: Cunyuan
authors.initials: C
authors.lastname: Zhao
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou, 510275, PR China.
authors.forename: Rongshu
authors.initials: R
authors.lastname: Luo
authors.affiliation: School of Environmental Science and Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou, 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, 510275, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, PR China.
authors.forename: Kaimin
authors.initials: K
authors.lastname: Shih
authors.affiliation: Department of Chemistry, South China University of Technology, Guangzhou, 510641, PR China.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Liu
mesh_terms: D000327:Adsorption; D001555:Benzene Derivatives / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry; D007220:Industrial Waste; D016062:Porosity; D012722:Sewage / Q000737:chemistry; D012996:Solutions; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D001555:Benzene Derivatives; D002712:Chlorides; D007220:Industrial Waste; D012722:Sewage; D012996:Solutions; D014874:Water Pollutants, Chemical; D017967:Zinc Compounds; D019343:Citric Acid; D002244:Carbon; C016837:zinc chloride
keywords: Adsorption; Benzoic acid; Hierarchical pores; Phenol; SiO(2); Sludge char