Role of extracellular polymeric substances in biosorption of dye wastewater using aerobic granular sludge

• DOI: 10.1016/j.biortech.2015.02.084
• Publication Date: 2015-02-27T00:49:40Z
• Authors: Dong Wei; Bingfeng Wang; Huu Hao Ngo; Wenshan Guo; Fei Han; Xiaodong Wang; Bin Du; Qin Wei
• Keywords: Sewage; Wastewater; Models, Biological; 01 natural sciences; 6. Clean water; Absorption, Physiological; Water Purification; Bacteria, Aerobic; Biodegradation, Environmental; Biopolymers; Computer Simulation; Coloring Agents; Water Pollutants, Chemical; 0105 earth and related environmental sciences

In this study, the role of extracellular polymeric substances (EPS) in biosorption of dye wastewater was evaluated using aerobic granular sludge as biosorbent. Based on the experimental data, the removal efficiencies of methylene blue (MB) by EPS and Sludge were 9.38 and 80.72%, respectively, implying that EPS made a certain contribution for MB removal. The adsorption rates of EPS, Sludge, and total Sludge+EPS for MB were better fitted with pseudo-second order kinetic model, and the equilibrium adsorption isotherm data agreed well with Langmuir model. The interaction between EPS and MB was explored by a combined three-dimensional excitation-emission matrix (3D-EEM) and synchronous fluorescence spectra. 3D-EEM indicated that protein- and humic acid-like substances were the main peaks of EPS, and gradually quenched with increased MB concentrations. According to synchronous fluorescence spectra, the main fluorescence quenching was caused by tryptophan residues, and the type belonged to a combined dynamic and static quenching.