| Diseased animals and deteriorated meat are the objective products of animal breeding,slaughtering business activities and animal quarantine supervision process, its harmfulness toenvironment and social development has become a major public safety issue for the currentsociety need to face. As a exhaustive harmless disposal method, the high temperture andpressure process can completely solve the problem of disease spread. While the kind ofapproach will produce large amounts of malodorous gases, seriously affecting the ecologicalenvironment quality of the harmless disposal workshop and surrounding areas, and it impedethe application of the harmless diposal technology which needs to be solved.Biotrickling Filter （Biotrickling Filter, BTF） has become one of the most widely priorityused method for biological deodorization at home and abroad. It has a lot of advantages, suchas easy to operate and control, hard to jam and higher removal efficiency of malodorous gases.In this study, the BTF reactor is used to treat mixed malodourou gases which are produced inthe harmless process of diseased animals disposal. The domestication characteristics andoptimum operating conditions were studied, also the dynamic operation characteristics andshock load performance, meanwhile according to pollutant degradation products to analysisthe microbial degradation characteristics. The research could provide some design basis forthe animal carcasses and meat deterioration harmless air pollution control practicalengineering projects.The inoculation sludge was from Liede Sewage Treatment Plant in Guangzhou. Afterdomesticated for9days, it was vaccinated to the three different kinds of packing in theBiotrickling Filter. The inflow flow was0.1m3/h; circulating fluid spray volume was3.9L/h;the temperature was2530℃; pH was7.07.5in circulating fluid; the concentration of NH3was32.7mg/m3300.5mg/m3; the concentration of H2S was159.5mg/m3696.9mg/m3.Operate the reactor through gradually increasing the inlet concentration. In the end,14days,16days and19days were needed for the little ceramsite, big ceramsite, plastic ring respectively.The results were: the removal efficiency of malodorous gases was more than85%; theremoval efficiency of NH3and H2S were about80%. In the Biotrickling Filter packed withlittle ceramsite, the removal efficiency of NH3and H2S were the biggest, reached to81.2% and81.2%respectively, the removal efficiency of malodorous gases was89.1%.Through various factors influenced on removing H2S and NH3were studied by Singlefactor transformation method. The optimum operation condition was: gas flow was0.3m3/h（The gas residence time is48.9s）; inlet concentration of NH3was400mg/m3, inletconcentration of H2S was730mg/m3; circulating fluid spray quantity was4.2L/h（The spraydensity is0.49m3/m2·h）; pH of circulating fluid was7.07.5.Comparing the removal efficiency of NH3and H2S in three reactors, It showed that thelittle ceramsite was the most suitable packing, the removal loading of H2S and NH3werereached52.68gNH3/（m3·h） and91.16gH2S/（m3·h）, so it was choosen to fill the reactor to dothe following experiments. By investigating the operating characteristics of reactor underoptimal working conditions, when NH3and H2S gas inlet load were lower than42.7g/（m3·h）and69.94g/（m3·h）, the reactor of NH3and H2S removal rate can reach more than91.5%and91.4%, respectively.By investigating the reactor shock load performance, reactor get a strong resistanceability while inlet of NH3and H2S load greater fluctuation occurs. In the condition ofoverload operation in a short period of time will not collapse, after25h buffer the reactorcan be restored to normal processing level. Under the premise of fluctuations in the volume,the reactor is still ensures that the removal rate of85%above, the stability is very good. Inaddition, through the analysis of degradation products, known microorganisms on thedegradation of NH3and H2S has experienced the following main process respectively: NH3（g）â†'NH3（l）â†'NH4+â†'NO2-â†'NO3-; H2S （g）â†'H2S （l）â†'S2-â†'S0â†'SO32-â†'SO42-.In summary, under the experimental conditions of this study, the use of biotrickling filterreactor treating H2S and NH3containing malodorous gases by animal diseases harmlessprocess get a good purification effect, and the reactor under the condition of large loadfluctuation will not collapse, impact resistance performance is very good. The research resultsof this paper provide basic data for animal carcasses and meat deterioration harmless airpollution control practical engineering projects. |
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