title: Effect of NaX zeolite-modified graphite felts on hexavalent chromium removal in biocathode microbial fuel cells.
abstract: Two kinds of NaX zeolite-modified graphite felts were used as biocathode electrodes in hexavalent chromium (Cr(VI))-reducing microbial fuel cells (MFCs). The one was fabricated through direct modification, and the other one processed by HNO3 pretreatment of graphite felt before modification. The results showed that two NaX zeolite-modified graphite felts are excellent bio-electrode materials for MFCs, and that a large NaX loading mass, obtained by HNO3 pretreatment (the HNO3-NaX electrode), leads to a superior performance. The HNO3-NaX electrode significantly improved the electricity generation and Cr(VI) removal of the MFC. The maximum Cr(VI) removal rate increased to 10.39±0.28 mg/L h, which was 8.2 times higher than that of the unmodified control. The improvement was ascribed to the strong affinity that NaX zeolite particles, present in large number on the graphite felt, have for microorganisms and Cr(VI) ions.
authors: College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China.
authors: Xiayuan
authors: X
authors: Wu
authors: Key Laboratory of Precious Metal Chemistry and Technology of Jiangsu Province, Jiangsu University of Technology, Changzhou 213001, Jiangsu, PR China.
authors: Fei
authors: F
authors: Tong
authors: College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China.
authors: Xiaoyu
authors: X
authors: Yong
authors: College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China.
authors: Jun
authors: J
authors: Zhou
authors: College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China.
authors: Lixiong
authors: L
authors: Zhang
authors: College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China. Electronic address: hhjia@njtech.edu.cn.
authors: Honghua
authors: H
authors: Jia
authors: College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China.
authors: Ping
authors: P
authors: Wei
mesh_terms: D001674:Bioelectric Energy Sources; D002857:Chromium / Q000737:chemistry*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D017942:Nitric Acid / Q000737:chemistry; D017641:Zeolites / Q000737:chemistry*
chemical_list: D002857:Chromium; D017641:Zeolites; C074702:chromium hexavalent ion; D017942:Nitric Acid; D006108:Graphite
keywords: Biocathode; Cr(VI) removal; Microbial fuel cell; NaX; Zeolite-modifed electrode