title: Extended filaments of bulking sludge sink in the floc layer with particulate substrate.
abstract: Recent studies have showed that particulate substrate has a positive effect on sludge settleability. This study was driven by the question of how the extended filaments disappeared when soluble substrate was switched to particulate substrate. A lab-scale aerobic completely stirred tank reactor was performed and evaluated for a period of two months. The results showed that extended filaments were quickly induced with soluble substrate. Total extended filament length of activated sludge decreased and sludge settleability was significantly improved after the soluble substrate was switch to particulate substrate. Due to the lack of hydrolysis products in the bulk liquid when particulate substrate was fed, extended filaments were forced to grow towards the inside of the flocs and finally sink in the floc layer. A physical model was proposed to explain the evolution of extended filaments caused by soluble substrate and cured by particulate substrate.
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an 710055, China. Electronic address: 176059974@qq.com.
authors.forename: Binbin
authors.initials: B
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Dangcong
authors.initials: D
authors.lastname: Peng
authors.forename: Yinping
authors.initials: Y
authors.lastname: Hou
authors.forename: Liying
authors.initials: L
authors.lastname: Pei
authors.forename: Lifang
authors.initials: L
authors.lastname: Yu
mesh_terms: D005427:Flocculation; D007381:Intermediate Filament Proteins / Q000737:chemistry; D008956:Models, Chemical; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D013213:Starch / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014873:Water Pollutants / Q000737:chemistry*
chemical_list: D007381:Intermediate Filament Proteins; D012722:Sewage; D014873:Water Pollutants; D013213:Starch
keywords: Extended filaments; Hydrolysis; Particulate substrate; Sludge settleability; Total extended filament length