title: Preparation of a novel graphene oxide/Fe-Mn composite and its application for aqueous Hg(II) removal.
abstract: A novel graphene oxide/Fe-Mn (GO/Fe-Mn) composite was synthesized (molar ratio of Fe/Mn=3/1 and mass ratio of Fe/GO=1/7.5) and investigated for the sorption characteristics and mechanisms of aqueous mercury (Hg(2+)) as well as the biological effects to wheat and rice. Characterization tests showed that Fe-Mn oxides were impregnated onto GO sheets in an amorphous form through oxygen-containing functional groups (i.e., CO, epoxy COC, carboxyl OCO, and CO) and π-π interactions. GO/Fe-Mn possessed large surface area, surface enhanced Raman scattering with more sp(3) defects, and greater thermal stability than GO. XPS analysis revealed that Fe2O3, FeOOH, MnO2, MnOOH, and MnO were the dominant metal oxides in GO/Fe-Mn. Pseudo-second-order kinetic model and Sips isotherm model fitted well with the sorption kinetic and isotherm data. The maximum sorption capacity for mercury was 32.9mg/g. Ligand exchange and surface complexation were the dominant mechanisms for mercury removal. GO/Fe-Mn greatly reduced the bioavailability of mercury to wheat and rice, even promoted the seedling growth. This work suggests that GO/Fe-Mn can be used as an effective and environmental-friendly adsorbent in heavy metal remediation.
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin 300350, China; Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, Tianjin 300350, China.
authors.forename: Jingchun
authors.initials: J
authors.lastname: Tang
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Huang
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin 300350, China; Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, Tianjin 300350, China. Electronic address: yanyangong@nankai.edu.cn.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Gong
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
authors.forename: Honghong
authors.initials: H
authors.lastname: Lyu
authors.affiliation: Advanced Water Management Centre, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Qilin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Tianjin Academy of Environmental Sciences, Tianjin 300191, China.
authors.forename: Jianli
authors.initials: J
authors.lastname: Ma
keywords: Biological effects; Graphene oxide/Fe-Mn; Mercury removal; Sorption; Water treatment