title: Enhancement of sludge reduction and methane production by removing extracellular polymeric substances from waste activated sludge.
abstract: The management of waste activated sludge (WAS) recycling is a concern that affects the development of the future low-carbon society, particularly sludge reduction and biomass utilization. In this study, we investigated the effect of removing extracellular polymeric substances (EPS), which play important roles in the adhesion and flocculation of WAS, on increased sludge disintegration, thereby enhancing sludge reduction and methane production by anaerobic digestion. EPS removal from WAS by ethylenediaminetetraacetic acid (EDTA) significantly enhanced sludge reduction, i.e., 49 ± 5% compared with 27 ± 1% of the control at the end the digestion process. Methane production was also improved in WAS without EPS by 8881 ± 109 CH4 μmol g(-1) dry-weight of sludge. Microbial activity was determined by denaturing gradient gel electrophoresis and real-time polymerase chain reaction, which showed that the hydrolysis and acetogenesis stages were enhanced by pretreatment with 2% EDTA, with a larger methanogenic community and better methane production.
authors.affiliation: Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196, Japan.
authors.forename: Minh Tuan
authors.initials: MT
authors.lastname: Nguyen
authors.affiliation: Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196, Japan.
authors.forename: Nazlina Haiza
authors.initials: NH
authors.lastname: Mohd Yasin
authors.affiliation: Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Miyazaki
authors.affiliation: Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196, Japan; Research Center for Advanced Eco-fitting Technology, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196, Japan. Electronic address: toshi.maeda@life.kyutech.ac.jp.
authors.forename: Toshinari
authors.initials: T
authors.lastname: Maeda
mesh_terms: D000693:Anaerobiosis; D001704:Biopolymers / Q000737:chemistry*; D005427:Flocculation; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001704:Biopolymers; D012722:Sewage; D014874:Water Pollutants, Chemical
keywords: Extracellular polymeric substances; Methane production; Sludge disintegration; Waste activated sludge