Studies On Screening And Degradation Properties Of High-efficiency Bacteria Capable Of Degrading Hydrogen Sulfide

There is a lot of odor gas in wastewater treatement plants,industry and agriculture, and it is mostly hydrogen sulfide.Hydrogen sulfide is a kind of colourless toxic gases, and the olfactory coefficient is 0.000755 mg/m³.When it gets into human's blood, combines with hemoglobin,and generates unreducible sulfide hemoglobin,which causes poisoning symptom.It also erodes experiments and pipes,and causes catalyst damage.The conventional physical and chemical desulfurization methods have high running cost and serious secondary pollution.By contrast,biological desulfurization technology will be given more attention increasingly because of high removal rate and never adding in chemical agent.In this paper,it is a comprehensive summary of source,feature,the present processing technical aspect and progress,etc.In addition,it also shows a thorough research systematically about the degradation properties of the dominant bacteria isolated from activated sludge,capable of degrading hydrogen sulfide,which offers new idea for the feasibility studies of desulfurization.The bacteria was chosen from the naturalized activated sludge,and it was isolated, screened out,and identified in conventional way.Then the bacteria's optimal growing condition was found out and the chosen bacteria was used to do degrading properties experiment,so as to choose the high-efficiency desulfurated bacteria and study its degradation properties.Six heterotrophic bacterial strains and one chemolithotrophy bacterial strain were isolated,which were designated Y1,Y2,Y3,Y4,Y5,Y6,and W1. They were identified as follows:Y1,Y4 are Bacillaceae sp,Y2,Y5 are Xanthomonas, Y3 are AgroBacterium,Y6 is Pseudomonaceae sp,W1 is Thiobacillus denitrificans.A bacterial strain of Xanthomonas was isolated from actived sludge,which was inoculated in the bio-trickling filter to purify hydrogen sulfide.Keep the following conditions:the inlet concentration of H₂S is 350～1100 mg/m³,the nutrient fluid spray is 1.25L/hr,and the air input is 1L/min.When the inlet concentration increases 1012 mg/m³, the removal efficiency of H₂S can reach above 92%.It shows that the strain bacterium can edure the high pollution load and has a good capability of removing efficiency of H₂S.Keep the nutrient fluid spray 1.25L/hr,and HRT 156s,78s,39s,26s,19.5s,it can make sure that the optimal HRT is no less than 78s from the removing efficiency of H₂S. A strain of Thiobacillus denitrificans was isolated from soil,which was inoculated in the bio-trickling filter to purify hydrogen sulfide,the removal efficiency can reach above 92%under following conditions:the concentration of inlet 1000mg/m³,and GRT 78s. The strain bacterium can endure the high pollution load and possess the larger buffer capacity and removing efficiency of hydrogen sulfide,which offers basis for the industrial application.