Biological Treatment Of Acidic Zinc-containing Sulfate Wastewater

Pollution of Acid Sulphate wastewater is widespread and serious. The was- tewater with low pH value, great acidity, and containing a lot of copper, lead, zinc, cadmium and other heavy metals, etc., generally can not be recycled directly. Espe- cially with the development of science,technology,metallurgy and chemical indu- stry, and the growing development of zinc-containing products, zinc-containing wastewater pollution are becoming more serious.From the protection of human environment or from the resource conservation, to resolve the problem of wastewater with zinc-pollution is imminent. However, some problem exist in traditional methods with wastewater treatment.Anaerobic micro-organisms method as a most promising methods, not only is efficient,with no secondary pollution, but also is low cost and has a broad prospect.With the upflow anaerobic moving bed biofilm reactor whose effective Volume is 7.5L.The activated sludge from sewage plant was modified anaerobically to tre- at a high concentration sulfate-containing wastewater.The various factors affecting the removal of sulfate were investigated, including different temperature and initialρ(COD) /ρ(SO42- ).In the paper, innovative experiments on the Tolerated acidity and activity Inhi- bition of SRB was made. As a result,when the pH value was above or equal to 4.0, SRB grew well and a good SO42- removal was abtained.when the pH value was below 4.0, activity of SRB was inhibited,and with the pH value increased, SRB resto- red the activity.From the experiment on treatment sulfate wastewater with zinc ion,the below result was abtained: when the concentration of zinc ion was below 400mg/L,the removal rate of zinc ion was above 95% and the removal rate of SO42- was reached 92%.In this paper, the growth factor C was added innovatively.the experiment with growth factor C and without growth factor C to deal with sulfate wastewater with zinc ion concentration of 400mg/L and the experiment on SO42- load was carried on.As a result,the effect with growth factor C on treatment the wastewater was better than without growth factor C. When the Influent SO42-load from 2.4 kg/(m3 ? d) increased to 7.5 kg/(m3 ? d), corresponding the SO42- concentrations from 1.0 g/L increased to 3.12 g/L. at this time of the removal rate of SO42- stabilized at 90% with a short running time and effluent SO42-concentrations below 250 mg/L below the national emission standards.When the concentration of SO42- from 3.12 g/L Lincreased to 3.598 g/L, the removal rate also can reach 90% but with a longer running time.