| With the rapid development of economy, people have strong demands of livestock products, there are large amounts of large-scale and intensive livestock farms which can cause serious pollution to atmospheric environment. As the main pollutant derived from livestock farms, the odor gas is difficult to be removed due to its complex composition. Based on its high-efficiency and low-cost, the biological deodorization technique has been paid more attention than other techniques, and screening efficient deodorant bacteria is a key step in biological deodorization process.In this paper, the main microbes which can remove H2S and NH3respectively have been got from the biofilters in removal of H2S and NH3. According to the basic microorganism operation, these microbes have been isolated and screened, and their deodorization performance also has been investigated, the following conclusions can be drawn:(1) In this paper, some microbes have been got from the biofilters in removal of odor. After enriching, isolating and screening, these microbes are six heterotrophic sulfide oxidizing bacteria B1～B5, one autotrophic sulfide oxidizing bacterium B7, one heterotrophic ammonia oxidizing bacterium BN1and one autotrophic ammonia oxidizing bacterium BN2. They have stable performance of removing H2S and NH3respectively. The morphological, physiological and biochemical tests are as follows:B1and B5are Micrococcus, B2is Brevibacterium, B3is Paracoccus, B4is Microbacterium, B6is Escherichia, B7is Thiobacillus, BN1is Neisseria, BN2is Nitrosococcus.(2) The preliminary degradation tests for removal of sulfide has been investigated in this paper and the results show that strains B1, B4and B5have good desulfurization ability in the whole process. They can oxidate S2-to SO42-mainly in the biodegradation sulfide process.In this paper, the optimal growth and deodorization conditions have been got through investigating the degradation performance of amaigamate heterotrophic desulfurization bacteria. In the conditions of inoculating the fourth generation bacteria suspension by inoculation amounts10%, pH7.0,28℃, the initial S2-concentration of2mmol/L and160rpm, the optimal desulfurization rate can be up to82.1%for amaigamate heterotrophic bacteria.(3) The results of degradation tests for autotrophic bacterium B7show that its growth speed is very slow. When selecting7d bacteria, the desulfurization rate is up to49.7%and their final product is SO42-, meanwhile there is a few of S element in the biodegradation sulfide process. In this paper, based on optimization step by step, the optimal conditions of desulfurization has been obtained from investigating the influence factors on degradation performance for strain B7. In the conditions of inoculating the fourth generation B7bacteria suspension by inoculation amounts10%, pH6.0,28℃, the initial S2-concentration of10mmol/L, its optimal desulfurization rate can be up to87.8%.(4) The denitrification tests for strain BN1have been investigated and the results show that the optimal ammonia-nitrogen degradation rate of strain BN1can be up to50.1%in conditions of the only carbon source glucose, inoculating the2nd-5th generation bacterium suspension by inoculation amounts10%, pH in7.0-8.0,30℃, the initial NH4+-N concentration of200mg/L and150rpm.(5) The optimal denitrification conditions of strain BN2have been investigated and the results show that the efficient and stable ammonia-nitrogen degradation rate of strain BN2can up to45.7%in conditions of inoculating in the1st～5th generation bacterium suspension, inoculation amounts10%, pH8.0,30℃, the initial NH4+-N concentration of600mg/L and120rpm.In this paper, several strains which can remove respectively of H2S and NH3have been got and the degradation tests for the growth conditions and their biodegradability also have been investigated. Due to the limited experimental conditions, the microbial strains should be identified according to molecular biology. There are many works to do for optimizing strains in the future. |
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