Screen Of Bio-flocculants-producing Strain And Study On Flocculating Activity

Bioflocculant is a kind of natural high polymer material produced by microoganism intheir growth process, which has the flocculation Capability. Its principal components arecellulose, polysaccharide, glycoprotein, peptide and protein substances. Compared withpresent widely used traditional flocculants, the bioflocculant has the advantages of safe,non-toxic, high efficiency, wide application, readily biodegradable and no secondary pollution.Nowadays, the environmental problems are becoming more serious and there is a growingemphasis on the environmental protection. The development of new environment-friendlybioflocculants, has very important practical significance to the human health and theenvironmental protection. However, the high cost of production and use of microorganismflocculants, led to large-scale industrial application has not been achieved. The paper took thisas a starting point, launch the experimental studies on the screen of bio-flocculants-producingstrain, optimize the culture conditions and studies on the application and mechanism of thebioflocculants.A strain with high flocculating activity was screened from the sanitary sewage of NorthUniversity of China. The strain can produce a strong-activating flocculant, with flocculatingrate of above 95.2 % for Kaolin suspension. According to the results on the morphology,physiological and biochemical analysis of the strain, the strain was identified as VeillonellaPrevot, named Veillonellaceae Rogosa-T18. Its optimum temperature was about 37℃andoptimum pH was 7.0~8.5. Veillonellaceae Rogosa-T18 can use various saccharides as goodsources of carbon, and the verify check of microbial flocculants produced by VeillonellaceaeRogosa-T18 proved that the microbial flocculants contain reducing sugars. Concluded that themechanism of the bioflocculants were adsorption bridging mechanism and mechanism of sediment caught in mist nets. Comparative test of Flocculation showed that this microbialflocculants was better than the PAM and PAC. The flocculants produced by the strain has asignificant flocculation effect on loess suspension and nano-scale copper-carbon-graphitesuspension, and showed fine research and application importance.