| Organic and inorganic flocculants have been used widely due to their low prices and good effect. However, their disadvantages have drawn people's attention. Aluminium remaining in drinking water easily leads to senile dementia. The monomer of polyacrylamide (PAA) can't be degraded and it's both neurotoxic and oncogenic for human body. Thus, safe biodegradable flocculants that are both environment-friendly and effective are urgently needed. A lot of researches have revealed that microbioflocculant (MBF) is the right thing we are searing for. Therefore, researchers are showing a growing concern on the development of MBF. Eighty strains of bacteria were isolated from active sludge and soil, which was described in this paper. Then twelve strains of bacteria that can produce MBF were screened from these separate bacteria through flocculating experiment. After rescreening, a bacterium named P-7 with higher flocculating performance is obtained. The bioflocculant produced by the bacterium was named MBFP-7. The bacterium was identified as Bacillus megetarium. Substituting beer ferment wastewater for culture medium, the fermented liquid of P-7 presented some flocculating performances. Further investigations can be carried out so that the cost for nutrition can be reduced for large-scale industrial manufacture. Kaolin suspension was treated with MBF, which showed that the temperature, pH, as well as the amount of MBF and Ca2+ influence the flocculating activity. And then this paper makes a study on) the flocculating mechanism of MBF. The application of flocculant produced by MBFP-7 shows that it is good for bauxite, bentonite and feldspar as well as kaolin, the settleability of active sludge in SBR reactor treated wastewater bioflocculated is greatly enhanced and MBF can directly provide nutrition for microorganism in biologic reactor.
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