Study On Screening Of Flocculant Producing Bacteria Of B-4 And Its Application

Ten strains of flocculant-producing microorganisms were isolated from activated sludge. A strain with high flocculating activity was obtained after rescreening from those strains and identified as Achromobacter sp., named b-4. According to the single factor experiment, the optimum component proportion of medium was sucrose 20 g/L, peptone 1.2 g/L,KH2PO40.5 g/L, initial pH 8.0. The optimum culture condition was agitation at 100r/min with 30℃ for 48 hours in flask. The result showed that the optimum flocculating condition was 2mL fermentation liquid dosage at pH7.5 with addition of Ca2+, which could obviously enhance flocculating activity. Furthermore, flocculating conditions were studied with Kaoling clay suspension. At the optimum conditions, the rate of flocculation of fermentation liquid of the strain b-4 was beyond 97% against 1% Kaoling clay suspension.Under the same conditions, the fermentation broth of b-4 on sewage treatment capacity is stronger than polyacrylamide on sewage treatment capacity nearly 20%.It is good for industrial sewage, simulated sewage processing capacity, processing capacity of the ink of up to 89.4%. And the capability of processing the industrial sewage is up to 81%. Moreover, it excels at treating soil suspension and expired milk.Microbial flocculant has good application prospects, which is expected to be new generation flocculant with the features of efficient, no toxic and no secondary pollution.It may replace or partially replace the traditional synthesis of inorganic polymer and organic polymer flocculant in the future. Microbial flocculant with its characteristics and advantages will widely applied to water treatment technology, which shows a broad prospect.