Operation Practice And Improvement Of Biofilter Treatment For Malodorous Gas In Municipal Sewage Plant

With the rapid development of economy and society,urban sewage treatment plants which were originally located in suburbs are gradually surrounded by residential areas.The sewage treatment plant aims to clean the sewage,but in the process,the stench of sewage and sludge is generated.Bio-filter has attracted worldwide attention due to its low operating cost,high treatment efficiency,large gas volume and no secondary pollution.However,there is little research on deodorant microorganisms.Therefore,in this paper,the actual operation process of a sewage treatment plant in Baotou was improved.Typical odorous gases NH₃ and H₂S were used as indicators of contamination,Organic and inorganic mixed filler and activated sludge inoculation were adopted.The removal effect of hydrogen sulfide and ammonia in bio-filtration reactor was studied.Based on the analysis of microbial community of filler,the dominant bacteria of deodorization in bio-filter were also been discussed.Summarized as the following aspects:?1?According to the practical operation effect of sewage plant deodorization project,it could be known that although the factory boundary indexes of H₂S and NH₃ after the biological filter have reached the secondary standard of the pollutant discharge standard of urban sewage treatment plant?GB18918-2002?.However,the deodorization effect of the odor source was not ideal,and the average NH₃ removal rate of the fine grid reached74.6%,which was very low and needed to be improved.?2?Before the start of the model,hydrogen sulfide and ammonia were used as research indicators to monitor for 24 hours continuously,so as to master the discharge law of odor substances in sewage plants.In order to observe the growth of biofilms,the concentration values of COD,TN and TP,in the sprayed nutrients of in-out water,the cumulative values of sulfate and nitrate ion concentrations in circulating water,and the removal rates of hydrogen sulfide and ammonia gases were monitored during the process of membrane hanging culture.To show that after 15 days,the microorganisms had little use of nutrients;The cumulative concentration of sulfate and nitrate ions increased rapidly,and the removal rate of hydrogen sulfide and ammonia reached up to 99.2%and 97.5%respectively,all of which exceed 75%.Besides,the deodorization effect was better than the actual operation process,which proved that the film was in a good condition.?3?The results of microbial community analysis of fillers shown that Alphaproteobacteria,Betaproteobacteria,Gammaproteobacteria and Acidobacteria were all dominant deodorant bacteria.In addition,except for Gammaproteobacteria,the richness of other bacteria in group S1 was greater than that in groups S2 and S3.Therefore,combining with the previous monitoring data,we concluded that the deodorization effect of biological filter in the experimental group was better than that of the actual process because of the increase in the number of dominant bacteria.