title: Production and flocculating performance of sludge bioflocculant from biological sludge.
abstract: Excess biological sludge was utilized to prepared bioflocculant with hydrochloric acid. The prepared crude bioflocculant was purified and fractionally precipitated to attain four purified sludge bioflocculant defined as PSB1-4. The PSB-2 has higher flocculating rate for kaolin suspension than others. When the pH of the flocculation system ranged from 4.0 to 11.0 the flocculating rates of PSB-2 were over 96.0%. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectra showed that amino and hydroxyl groups were present in the bioflocculant molecules. More amine group existed in the bioflocculant PSB-2 relatively. The amino group was believed to play an important role in flocculation. The experiment of zeta potential measuring indicated that the charge neutralization contributed to flocculation process. Flocculating mechanism investigation reveals that the sludge bioflocculant caused kaolin suspension instability by means of charge neutralization firstly and then promoted the aggregation of suspension particles by adsorption and bridge.
authors.affiliation: Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China. Electronic address: tgazxh@163.com.
authors.forename: Xiuhong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
authors.affiliation: Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Xiuxiu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Jiti
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000327:Adsorption; D005427:Flocculation; D006851:Hydrochloric Acid / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007616:Kaolin / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D012722:Sewage; D007616:Kaolin; D006851:Hydrochloric Acid
keywords: Acid disintegrating; Bioflocculant; Excess biological sludge; Recycling