title: Production of a value added compound from the H-acid waste water-Bioflocculants by Klebsiella pneumoniae.
abstract: A novel strain (designated as ZCY-7) which could convert H-acid into bioflocculants was isolated from H-acid wastewater sludge. Conditions for bioflocculants production were optimized by response surface methodology (RSM) and determined to be inoculum size 9.65%, initial pH 7.0, and CODCr of the H-acid wastewater 520mg/L. The highest flocculating efficiency achieved for kaolin suspension was 95.1%, after 60h cultivation. The yielded bioflocculant was mainly composed of polysaccharide (82.4%) and protein (14.2%), and maintained its flocculating activity in 0.4% (w/w) kaolin suspensions over pH 2-8 and 20-80°C. Fourier transform infrared (FTIR) spectra showed that amino, amide and hydroxyl groups were present in the bioflocculant molecules. A viable alternative treatment technology of H-acid wastewater using this novel strain is suggested, which could largely reduce bioflocculants costs. In addition, flocculating mechanism investigation reveals that the bioflocculant could cause kaolin suspension instability by means of charge neutralization firstly and then promoted the aggregation of suspension particles by adsorption and bridge. It is evident from the results that H-acid wastewater could be used as a source to manufacture bioflocculants.
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China; School of Chemistry and Life Science, Hubei University of Education, Wuhan 430205, China.
authors.forename: Chunying
authors.initials: C
authors.lastname: Zhong
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Xu
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Buyun
authors.initials: B
authors.lastname: Wang
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Xianghui
authors.initials: X
authors.lastname: Yang
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Wentao
authors.initials: W
authors.lastname: Hong
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Baokun
authors.initials: B
authors.lastname: Yang
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Changhong
authors.initials: C
authors.lastname: Chen
authors.affiliation: School of Materials Science and Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China. Electronic address: wallice24@hotmail.com.
authors.forename: Jiangang
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000143:Acids / Q000737:chemistry*; D001673:Biodegradation, Environmental; D005285:Fermentation; D005427:Flocculation; D007711:Klebsiella pneumoniae / Q000254:growth & development / Q000502:physiology*; D017550:Spectroscopy, Fourier Transform Infrared; D062065:Wastewater / Q000737:chemistry*
chemical_list: D000143:Acids; D062065:Wastewater
keywords: Bioflocculant; Bioflocculant stability; H-acid; Klebsiella pneumoniae; Response surface methodology