To investigate the application of compound bioflocculant （CBF） in drinking water treatment at pilot plant, CBF and polymerized aluminium ferrum chloride （PAFC） coagulant were used to treat raw water taken from Lon...To investigate the application of compound bioflocculant （CBF） in drinking water treatment at pilot plant, CBF and polymerized aluminium ferrum chloride （PAFC） coagulant were used to treat raw water taken from Longhupao Reservoir in Heilongjiang Province for the removal of turbidity, COl）, UV254 and residual Al. Coagulation test shows that the coagulation enhanced by CBF and PAFC exhibits more effective performance than that enhanced by the individual of them, and the total combination dosage is lower than that of the individual. The residual Al from PAFC can be removed efficiently by CBF. The removal efficiency of turbidity reaches 76.6% by combining CBF of 2 mg/L and PAFC of 15 mg/L, COl） is decreased from 3.80 mg/L to 1.62 mg/ L, and the concentration of residual Al is only 0. 033 mg/L in the product water. It can be speculated that adsorption-bridging and sweep-coagulation processes are predominant in the flocculation process by the combination of CBF and PAFC.展开更多
The flucculation efficiency of compound bioflocculant produced by flocculant-producing bacteria was investigated in this study. Cheap cellulose was selected as the substrate for the production of a lower cost bioflocc...The flucculation efficiency of compound bioflocculant produced by flocculant-producing bacteria was investigated in this study. Cheap cellulose was selected as the substrate for the production of a lower cost bioflocculant. The end product of cellulose decomposing bacteria was utilized as substrate for flocculant-producing bacteria. The optimum fermentation conditions were determined as follows： the initial fermentation and fermentation time was 5 d and 1 d respectively, the temperature was 30 ℃, the rotation speed was 120 r/min, the amount of CaCl2 solution （ 10% ） was 1.5 ml/L. The flocculation test indicated that the bioflocculant had high efficiency in the removal of the turbldity raw water from Songhua River.展开更多
A compound bioflocculant CBF,produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its production and flocculating properties. The optimization of the culture...A compound bioflocculant CBF,produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its production and flocculating properties. The optimization of the culture medium constituents including carbon source,nitrogen source and C / N ratio,metal ions and ionic strength on CBF production were studied. Flocculating properties of CBF were examined by a series of experiments and CBF had good flocculating activities in kaolin suspension with divalent cations and stable over wide range of p H. Studies of the flocculating properties revealed that the flocculation could be stimulated by cations Ca2+,Mg2+,Fe2+,Al3+and Fe3+. In addition,it was stable at 4-30 ℃ in the presence of Ca Cl2. It was found to be effective for flocculation of a kaolin suspension under neutral and weak alkaline conditions( p H 7. 0- 9. 0),and flocculating activities of higher than 95% were obtained when the CBF concentrations among 6- 14 mg / L at p H 8. 0. The results of this study indicate that CBF is a potential replacement of conventional synthetic flocculants and is widely applied in water treatment and downstream processing of food and fermentation industries.展开更多
Compared with single bioflocculant,compound bioflocculant(CBF)normally has more stable and higher flocculation efficiencies.In order to produce a new compound bioflocculant,four bacterial strains with relative high ra...Compared with single bioflocculant,compound bioflocculant(CBF)normally has more stable and higher flocculation efficiencies.In order to produce a new compound bioflocculant,four bacterial strains with relative high rate of flocculation were selected from the coastal zone sediment,all of which were determined as Pseudomonas sp.by 16S rRNA sequencing.Through compounding,the ideal proportion of compound bioflocculant consisting of two bacterial strains(F5∶M5)was determined as 1∶2,resulting in 6%increase in terms of flocculation rate.The significant fermentation factors in culture media and their limitations were investigated via single factor experiments and Plackett⁃Burman design,obtaining four key variables,MgSO_(4),(NH_(4))_(2)SO_(4),sucrose and peptone,which were further optimized by response surface methodology(RSM)for their optimal concentrations.Finally,the ideal culture medium was determined,containing(NH_(4))_(2) SO_(4)0.523 g,MgSO_(4)3.7 g,sucrose 12.82 g,K_(2)HPO_(4)4 g,KH_(2)PO_(4)3 g,NaCl 33 g,and deionized water 1 L.The flocculation rate of experimental data(88.92)agreed well with the model prediction,which was 16.60 higher than original rate.展开更多
文摘To investigate the application of compound bioflocculant （CBF） in drinking water treatment at pilot plant, CBF and polymerized aluminium ferrum chloride （PAFC） coagulant were used to treat raw water taken from Longhupao Reservoir in Heilongjiang Province for the removal of turbidity, COl）, UV254 and residual Al. Coagulation test shows that the coagulation enhanced by CBF and PAFC exhibits more effective performance than that enhanced by the individual of them, and the total combination dosage is lower than that of the individual. The residual Al from PAFC can be removed efficiently by CBF. The removal efficiency of turbidity reaches 76.6% by combining CBF of 2 mg/L and PAFC of 15 mg/L, COl） is decreased from 3.80 mg/L to 1.62 mg/ L, and the concentration of residual Al is only 0. 033 mg/L in the product water. It can be speculated that adsorption-bridging and sweep-coagulation processes are predominant in the flocculation process by the combination of CBF and PAFC.
基金Sponsored by the Science Foundation of Heilongjiang Province(Grant No.GB02C202 -02).
文摘The flucculation efficiency of compound bioflocculant produced by flocculant-producing bacteria was investigated in this study. Cheap cellulose was selected as the substrate for the production of a lower cost bioflocculant. The end product of cellulose decomposing bacteria was utilized as substrate for flocculant-producing bacteria. The optimum fermentation conditions were determined as follows： the initial fermentation and fermentation time was 5 d and 1 d respectively, the temperature was 30 ℃, the rotation speed was 120 r/min, the amount of CaCl2 solution （ 10% ） was 1.5 ml/L. The flocculation test indicated that the bioflocculant had high efficiency in the removal of the turbldity raw water from Songhua River.
基金Sponsored by the National High Technology Research and Development Program of China(Grant No.2009AA062906)the"Twelfth Five-Year Plan"National Key Technology R&D Program of China(Grant No.2012BAD14B06-04)+2 种基金the National Natural Science Foundation of China(Grant No.51478140&51408200)State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(Grant No.2015DX06)Promising Youngsters Training Program of Heilongjiang University of Science and Technology(Grant No.Q20120201)
文摘A compound bioflocculant CBF,produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its production and flocculating properties. The optimization of the culture medium constituents including carbon source,nitrogen source and C / N ratio,metal ions and ionic strength on CBF production were studied. Flocculating properties of CBF were examined by a series of experiments and CBF had good flocculating activities in kaolin suspension with divalent cations and stable over wide range of p H. Studies of the flocculating properties revealed that the flocculation could be stimulated by cations Ca2+,Mg2+,Fe2+,Al3+and Fe3+. In addition,it was stable at 4-30 ℃ in the presence of Ca Cl2. It was found to be effective for flocculation of a kaolin suspension under neutral and weak alkaline conditions( p H 7. 0- 9. 0),and flocculating activities of higher than 95% were obtained when the CBF concentrations among 6- 14 mg / L at p H 8. 0. The results of this study indicate that CBF is a potential replacement of conventional synthetic flocculants and is widely applied in water treatment and downstream processing of food and fermentation industries.
基金Sponsored by the China Postdoctoral Science Foundation(Grant No.2015M581456)the Weihai Major Science and Technology Projects(Grant No.2017QYCX09)。
文摘Compared with single bioflocculant,compound bioflocculant(CBF)normally has more stable and higher flocculation efficiencies.In order to produce a new compound bioflocculant,four bacterial strains with relative high rate of flocculation were selected from the coastal zone sediment,all of which were determined as Pseudomonas sp.by 16S rRNA sequencing.Through compounding,the ideal proportion of compound bioflocculant consisting of two bacterial strains(F5∶M5)was determined as 1∶2,resulting in 6%increase in terms of flocculation rate.The significant fermentation factors in culture media and their limitations were investigated via single factor experiments and Plackett⁃Burman design,obtaining four key variables,MgSO_(4),(NH_(4))_(2)SO_(4),sucrose and peptone,which were further optimized by response surface methodology(RSM)for their optimal concentrations.Finally,the ideal culture medium was determined,containing(NH_(4))_(2) SO_(4)0.523 g,MgSO_(4)3.7 g,sucrose 12.82 g,K_(2)HPO_(4)4 g,KH_(2)PO_(4)3 g,NaCl 33 g,and deionized water 1 L.The flocculation rate of experimental data(88.92)agreed well with the model prediction,which was 16.60 higher than original rate.
