Effect Of Heterotrophic Denitrification Desulfurization Bacteria On Simultaneous Removal Of Carbon, Nitrogen And Sulfur Process

With electric power, light industry, pharmaceutical and other industries developedrapidly, it leads to resulting in a large number of water containing reduced sulfurcompounds, sulfate wastewater from factory production process. If this kind ofwastewater does not to undergo a rigorous treatment, it will cause serious environmentpollution. Therefore, the research on sulfide in water removal has become a keyproblem of water pollution treatment.The integrated simultaneous removal of carbonnitrogen and sulfur, can not only remove the three major pollutants of carbon, nitrogenand sulfur in wastewater, and has the advantages of simple process, low operation cost,no twice pollution, especially can also recover sulfur to achieve water reuse.The laboratory has purified a new heterotrophic denitrifying bacteria, with highdesulfurization performance, which was named Pseudomonas sp.C27. The research ofthe paper is studying on metabolic rule in different nutritional environment. Studieshave found that C27cannot survive not only in the autotrophic condition,but also nonitrogen and sulfur heterotrophic condition.But in heterotrophic conditions withoutsulfur and nitrogen,it still has the ability of denitrification.Acetic acid salt can bedegraded by more than80%, nitrate are all degraded, but the degradation time requiredfor a relatively longer. In the condition of C:N=1.26, sulfur and nitrogen ratio dividesfour different gradients ranging from t2.5,1,0.625to0.5, the horizontal comparison ofC27has proved to have obvious effect of sulfur and nitrogen ratio on the metabolism ofC27. In high sulfur and nitrogen ratio condition, the capacity of C27on carbon nitrogensulfur metabolic will increase. The capacity of C27to degrade sulfides has no obviousrelationship with the acetate concentration,but relates to the nitrate concentration. Theexperimental results show that the best sulfur and nitrogen ratio of pollutant degradationis5:8.In the condition of the ratio of carbon to nitrogen1:1and HRT=10h, adjusting theinfluent sulfide concentrations from200mg·L-1to800mg·L-1, we investigate the impactof C27in a integrated simultaneous removal of carbon nitrogen and sulfur processsystem in EGSB reactor. When the concentration of sulfide is200mg·L-1and400mg·L-1,the result shows that sulfide, nitrate and acetate removal rate can reach100%. As theconcentration of sulfide increases to800mg·L-1, the sulfide removal rate was above90%, while the removal rate of acetic acid salt100%, nitrate removal rate fluctuatedaround85%. C27has certain positive effects for the sulfur recovery and increasing thenitrate degradation rate.We want to study the effect of different carbon and sulfur ratio to the integratedsimultaneous removal of carbon nitrogen and sulfur process system. The result showsthat carbon and sulfur ratio of3:4is benefit to elemental sulfur recovery, but the sulfate and nitrate content in the effluent increased; while the carbon and sulfur ratio increases,the sulfide removal rate reduces. On the contrary, the concentration of sulfate and nitratein water decreased.Compared the test of C27, it can be seen better tolerance on thesulfide load and the nitrate load.