title: Improving abiotic reducing ability of hydrothermal biochar by low temperature oxidation under air.
abstract: Oxidized hydrothermal biochar was prepared by hydrothermal carbonization of Spartina alterniflora biomass (240°C for 4h) and subsequent oxidization (240°C for 10min) under air. Oxidized hydrochar achieved a Fe(III) reducing capacity of 2.15mmol/g at pH 2.0 with 120h, which is 1.2 times higher than un-oxidized hydrochar. Low temperature oxidization increases the contents of carboxyl and carbonyl groups on hydrochar surface. It is supposed that carboxyl groups provide bonding sites for soluble Fe species and carbonyl groups are responsible for Fe(3+) reduction. A Fenton-like process was established with Fe(2+) replaced by oxidized hydrochar and tested for methylene blue (MB) decoloration. Oxidized hydrochar achieved a MB decolorization (200mg/L, pH 7.0) rate of 99.21% within 3h and demonstrates prominent prevail over H2O2 absent control test. This study reveals low temperature oxidization is an effective way to improve and restore abiotic reducing ability of hydrochar.
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Zhenjun
authors.initials: Z
authors.lastname: Lou
authors.affiliation: Shaoxing Drainage Management Co., Ltd, No. 391, ZhongXing Road (Middle), YueCheng District, Shaoxing, Zhejiang 312000, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Yi
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Junyu
authors.initials: J
authors.lastname: Chen
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Xianlong
authors.initials: X
authors.lastname: Ma
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Mi
authors.initials: M
authors.lastname: Li
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Chen
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China. Electronic address: qliu@shu.edu.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Jizhi
authors.initials: J
authors.lastname: Zhou
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, China.
authors.forename: Guangren
authors.initials: G
authors.lastname: Qian
mesh_terms: D018533:Biomass; D002606:Charcoal / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry; D010084:Oxidation-Reduction; D056951:Photoelectron Spectroscopy; D006109:Poaceae; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D002712:Chlorides; D005290:Ferric Compounds; C540010:biochar; D002606:Charcoal; D006861:Hydrogen Peroxide; D008751:Methylene Blue; C024555:ferric chloride
keywords: Fe(III) reduction; Fenton-like process; Hydrochar; Low temperature oxidization; Oxygen contained functional group