A Study On Treating The Odor Of Sewage Treatment Plants With Biological Method

The main sources of odor pollution, the composition and hazards of odor, and thecommonly used deodorization technologies were introduced with a preliminaryinvestigation of odor pollutants; Hydrogen sulfide and ammonia which are the majorpollutants of odor pollution were selected to be the research objects and treated with thebiotrickling filter process for biological control research. The research contents includedthe cultivation and domestication of deodorization microorganism, the mechanism ofbiological deodorization and the influencing factors of running the biological tricklingfilter process. This research would provide a basis for removing the multi-componentcomplex gas which has hydrogen sulfide and ammonia as the representative componentsand it will have a good application prospect in the market.The main results of this research paper were as follows:1. The cultivation and acclimation of biological membrane used this method: firstlybiofilm colonization and then inlet domestication, the membraneforming time was20days.The results showed that the method was suitable for the laboratory test, and alsorecommended for being used in the pilot plant projects and the practical projects.2. The operating conditions of removing hydrogen sulfide with biotrickling filter were:when the temperature was25℃and the spray quantity of circulation water was15L/h, theremoval rate was above95%with0.5m³/h of inlet airflow and less than600mg/m³ofinlet concentration; the removal rate was above94%with0.4m³/h of inlet airflow and lessthan900mg/m³of inlet concentration; the removal rate was above95%with0.3m³/h ofinlet airflow and less than1400mg/m³of inlet concentration. The conditions were ideal forremoving hydrogen sulfide.3. The operating conditions of removing hydrogen sulfide with biotrickling filter were:when the temperature was25℃and the spray quantity of circulation water was15L/h, theremoval rate was above99%with0.5m³/h of inlet airflow and less than600mg/m³ofinlet concentration.4. The removal efficiency of hydrogen sulfide were higher in both acidic and neutralpH conditions, however the pH should be around7when removing ammonia. So whenremoving the mixed gas, the pH value of the circulation water should be around7.5. The influence of the spray quantity of the circulation water were different betweentreating hydrogen sulfide and treating ammonia. Removing ammonia required much lesscirculation water than removing hydrogen sulfide under the same conditions. 6. When the inlet concentration of hydrogen sulfide ranged from900to1400mg/m³,bio packing whose particle size are30mm were more suitable for the running of the reactor,well the bio packing with15mm of particle size had better effects when treating lowerconcentration gases. It is mainly because large amounts of sulfur produced by high loadblocked the packing.7. The following results could be got from the results and the phenomenon: thedegradation process of hydrogen sulfide was H₂S（g）—H₂S（1）—elementary sulfur—SO42-; the degradation process of ammonia was NH₃（g）—NH₄⁺—NO₂^-—NO₃^-—N₂. Thenitrogen element would be lost in the whole process.8. The composition of the circulation water wasn’t be online tracking monitored in theexperiment, the material content changes such element nitrogen and element carbon couldbe measured in future research, the mechanism of the degradation process of hydrogensulfide and ammonia could be further researched.9. Pilot biotrickling filter used to removing hydrogen sulfide and ammonia for2000m³/d biogas were designed according to the design and operation parameters of thelaboratory experiment.