The Gx <sub> 4 </ Sub> -1 Bacteria Use Fishmeal Wastewater Flocculants Applied Research

Several kinds of wastewater as the culturing medium of the strain GX4-1,which was screened by us from activated sludge as the bioflocculant producing bacterium, was tested .We found that it can produce bioflocculant with high flocculating rate if we only used fish meal wastewater as the culturing medium.Under the optimum culture conditions: the COD(the concentration) of diluted fish meal wastewater about 10000~20000mg/L,pH 7~9,30癈, 150~200rpm,with the inoculation amount of 10 percent,cultivated for 3 days in flask,the flocculating rate of the bioflocculant to kaolin clay suspension can reach 99 percent.The main flocculating material was found in the culture broth,but not in the microbial cells.If the medium was not sterilized, the flocculating activity of the bioflocculant the strain produced was no less than that with medium sterilized.However,the yield on the former condition was a little less than that on the latter condition.Maybe the reason is that the bacterium could grow rapidly and occupy a dominant position in the system soon because it was inoculated with high activity after it had been activated.In experiments,we also found that the process of semi-continuous culture of the bacterium using fish meal wastewater as medium was steady.And on both the conditions of medium sterilized and not sterilized, the flocculating activity of the bioflocculant the strain produced was similar.The bioflocculant produced by strain 6X4-1 using fish meal wastewater show high flocculating rate to kaolin clay suspension, soil suspension,fine activate carbon powder suspension,carbon ink water and wastewater from electroceramics plant.And it also has a high ability to remove the turbidity of domestic sewage,catalyzed dead oil wastewater,dyeing wastewater in knitting plant and wastewater generated in the coking process in chemical plant and to degrade their values of COD. At same time,we found that the flocculating activity of the bioflocculant is higher when the coagulating system is in a little basic condition.As the adding volume of CaCl2 solution which mass concentration is 10% is 15ml and the doses of the bioflocculant is 30ml with pH about 8,the fish meal wastewater's COD value decreased to 21,600mg/L with the initial COD value about 80,000mg/L for floculating by the bioflocculant.The degrading rate of COD reaches about 73%, and the OD550 of the wastewater could be decreased to 0.22 with the initial value of far beyond 2. At same time, about 48.5% crude protain was found in the sediment,and it may be used as feed additive.