title: Sorption and detoxification of chromium(VI) by aerobic granules functionalized with polyethylenimine.
abstract: This study describes the modification of aerobic granules by grafting polyethylenimine (PEI) for simultaneous sorption and detoxification of Cr(VI). After modification, the uptake capacity of modified aerobic granules (MAG) showed about 401.5 mg/g at pH 5.5 and increased by 274% compared to the control. Adsorption experiments were carried out as a function of contact time, pH and concentration of Cr(VI). It was found that the equilibrium sorption can be attained within 3 h and the process obeys the Redlich-Peterson isotherm model. The adsorption process is a function of pH of the solution, with the greater adsorption at pH 5.2. The interaction characteristics between the Cr and MAG were elucidated by applying FTIR and XPS analyses. FTIR results showed that the -NH2 groups in the sorbent are involved in the adsorption process. XPS results verified the presence of Cr(III) on the MAG surface in the pH range 1.5-8.5, suggesting that some Cr(VI) anions were reduced to Cr(III) during the sorption.
authors.affiliation: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China. xfsun06@gmail.com
authors.forename: Xue-Fei
authors.initials: XF
authors.lastname: Sun
authors.forename: Yue
authors.initials: Y
authors.lastname: Ma
authors.forename: Xian-Wei
authors.initials: XW
authors.lastname: Liu
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Wang
authors.forename: Bao-Yu
authors.initials: BY
authors.lastname: Gao
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Li
mesh_terms: D000327:Adsorption; D002857:Chromium / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D011094:Polyethyleneimine