title: Extracellular polymeric substances for Zn (II) binding during its sorption process onto aerobic granular sludge.
abstract: The aim of this study was to evaluate the interaction between extracellular polymeric substances (EPS) and Zn (II) during the sorption process of Zn (II) onto aerobic granular sludge. Batch results showed that the adsorption rate of Zn (II) onto aerobic granular sludge was better fitted with pseudo-second order kinetics model, and the adsorption isotherm data agreed well with Freundlich equation. Extracellular polymeric substances (EPS) for Zn (II) binding during sorption process was investigated by using a combination of three-dimensional excitation-emission matrix (3D-EEM), synchronous fluorescence spectra, two-dimensional correlation spectroscopy (2D-COS) and Fourier transform infrared spectroscopy (FTIR). Results implied that the main composes of EPS, including polysaccharide (PS) and protein (PN), decreased from 5.92±0.13 and 23.55±0.76 mg/g SS to 4.11±0.09 and 9.55±0.68 mg/g SS after the addition of different doses of Zn (II). 3D-EEM showed that the intensities of PN-like substances and humic-like substances were obviously decreased during the sorption process. According to synchronous fluorescence spectra, the quenching mechanism between PN-like substances and Zn (II) was mainly caused by a static quenching process. Additionally, 2D-COS indicated that PN-like substances were more susceptible to Zn (II) binding than humic-like substances. It was also found that the main functional groups for complexation of Zn (II) and EPS were OH groups, N-H groups and C=O stretching vibration. The findings of this study are significant to reveal the fate of heavy metal during its sorption process onto aerobic granular sludge through EPS binding, and provide useful information on the interaction between EPS and heavy metal.
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China; Shan Dong Lan Xi Environmental Protection Technology Co., Ltd, Jinan 250022, PR China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wei
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China.
authors.forename: Mengting
authors.initials: M
authors.lastname: Li
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China; Shan Dong Lan Xi Environmental Protection Technology Co., Ltd, Jinan 250022, PR China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Han
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China.
authors.forename: Lusheng
authors.initials: L
authors.lastname: Li
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Guo
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China.
authors.forename: Lijie
authors.initials: L
authors.lastname: Ai
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Fang
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China.
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China. Electronic address: dubin61@gmail.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Du
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D000327:Adsorption; D000332:Aerobiosis; D001704:Biopolymers / Q000737:chemistry*; D019149:Bioreactors; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D001704:Biopolymers; D012722:Sewage; D014874:Water Pollutants, Chemical; D015032:Zinc
keywords: Aerobic granular sludge; Biosorption; Excitation-emission matrix (EEM); Extracellular polymeric substances (EPS); Metal wastewater