title: Characterization of bioflocculants from biologically aerated filter backwashed sludge and its application in dying wastewater treatment.
abstract: In this study, the feasibility of bioflocculant extraction from backwashing sludge to reduce its production costs was investigated. Results showed that ultrasound and base treatment could significantly enhance bioflocculant extraction efficiency, however, flocculating activity was affected. It was observed that bioflocculants extracted from sludge of pH 11.0 had no flocculating activity. In contrast, bioflocculants extracted from sludge of pH 5.0, named as M-1, had good flocculating activity. To further study the flocculating activity of M-1, factors such as bioflocculant dosage, temperature and pH of the reaction solution were tested. The optimal conditions were 6.0mg/l bioflocculant dosage and pH 5.0, at a temperature of 10 degrees C. Under these conditions, the flocculating rate of kaolin clay was 92.67%. The effectiveness of such bioflocculants in the decolorization of synthetically dyed wastewater was then examined. In flocculating methylene blue and fast blue in aqueous solutions, decolorization efficiency levels were 82.9% and 77.8%, respectively.
authors.affiliation: State Key Lab for Agrobiotechnology, Center of Biomass Engineering, Key Laboratory of Agro-Microbial Resource and Application, Ministry of Agriculture, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: WeiJie
authors.initials: W
authors.lastname: Liu
authors.forename: HongLi
authors.initials: H
authors.lastname: Yuan
authors.forename: JinShui
authors.initials: J
authors.lastname: Yang
authors.forename: BaoZhen
authors.initials: B
authors.lastname: Li
mesh_terms: D004396:Coloring Agents; D005374:Filtration; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D014865:Waste Disposal, Fluid; D018508:Water Purification / Q000379:methods*
chemical_list: D004396:Coloring Agents; D007220:Industrial Waste; D012722:Sewage