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Flocculation method is a simple and effective removal of suspended solids in the water treatment process. Although the organic and inorganic chemical flocculants the efficient flocculation effects and excellent low-cost characteristics, however, due to their strong neurotoxic and carcinogenic shortcomings, it is limited on the application. In recent years, in order to solve environmental problems, bio-degradable, non-toxic and harmless, no secondary pollution of microbial flocculant by the extensive attention. Microbial flocculant (Microbial Flocculant, MBF) is generated from the process of the growth of the microorganism, can Waters suspended particles, bacterial cells, and the colloidal particles flocculation and precipitation of a class of secondary metabolites. Flocculants can produce a wide range of micro-organisms, widely distributed in the soil, activated sludge and sewage. The purpose of this project for screening efficient flocculant-producing bacteria, their optimized culture conditions, and characteristics of flocculant, flocculation mechanism, its development and application in the real wastewater systems research. A flocculation of strong and stable performance producing flocculant microorganisms isolated from river sediment, tentatively named BS-5. By changing the culture medium composition, culture time, temperature, pH and other conditions, determine the optimal culture conditions: a BS-5 flocculant soluble starch 10g, Nano 3 3G K 2 < / sub> the HPO 4 1.2g MgSO 4 · 7H 2 O 0.5g of KCl 0.5g, distilled water 1000ml, pH = 6.0; the bacteria at 30 ℃, shaking speed 150r/min conditions cultured 32h kaolin suspension flocculation rate can be as high as 97.5%. Different microbial flocculants have different performance, experimental results show that MBFBS-5 has the general microbial flocculant unparalleled fine features. Kaolin suspension to as flocculation object, MBFBS-5 is a good flocculation effect, and without having to add any metal ions as coagulant aid, the amount is only 0.1ml / L, about General Microbiology flocculant dosage of 1/10 to 1/100. In addition, the flocculant has a short incubation time, the wide pH range of applications, heat resistance characteristics, significantly better than other general microbial flocculant. Beer wastewater, printing and dyeing wastewater containing algae lake, to examine the effect of the practical application of MBFBS-5. Experimental results show that CaCl 2 Coagulation Aid, MBFBS-5 have good beer wastewater, printing and dyeing wastewater treatment effect, the technical indicators better than conventional chemical flocculants such as PAC, PAM; synergy with PAC treatment containing algae lake, not only to handle to good effect, but also reduce the amount of PAC, to some extent, reduce secondary pollution.
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