Screening Of Efficient Deodorant Microbial Strains And Deodorizing Mechanism Of Swine Feces

With the rapid development of intensive, scale livestock industry in China, the massive livestock manure without the ineffectively reclamation treatment, have become the main pollution that harmful for the environment. Therefore, it has the positive significance to livestock industry that reducing environmental pollution and effectively utilizing reclamation of livestock manure. In this study, microbial strains were isolated and purified from the different samples(flesh swine feces、composted swine feces 、activated sludge、rotten corn straw and garbage) by the streak plate separation method; the deodorant microorganisms strains were screened by combining a first qualitative screening of the NH3 and H2 S selective media, with a second quantitative screening of the boric acid absorption and zinc amine complex salt absorption colorimetric methods; an L8(27)orthogonal optimum design was employed to identify the combinations of different strains with high deodorizing efficiency; the optimal combination for deodorizing microbial strains was studied under differing fermentation conditions; several previously isolated efficient deodorizing and cellulose-decomposing microbes strains were grouped optimally as compound microbial deodorizer, to study its effects on deodorization and compost characteristics during the livestock manure composting, the dynamic changes and loss pathways of nitrogen and sulfur were analyzed quantitatively during manure composting and explored the deodorizing mechanism of the compound microbe. The results were following:(1) A total of 130 strains were isolated from 5 samples, and 5 strains and 3 strains were identified which could efficiently reduce NH3 and H2 S release, respectively, of which, a strain designated BX3 achieved emission reduction rates of NH3 and H2 S with 80.07% and 76.92%, respectively, compared with control treatments.(2) The optimal deodorant strain combination “AF2+DZ1+BX3+DZ3+BZ1+EZ3+AX4” to have the significantly lower emission reductions rates of NH3 and H2 S than those of other combinations. Compared with the blank control, the emission reductions rates of NH3 and H2 S on 5 d were 82.14% and 80.84%, respectively.(3)The emissions of NH3 and H2 S were the smallest under the condition of 10%inoculation, 30% moisture and 10% bran, and 15% inoculation, 40% moisture and10% bran, respectively.(4) The compound microbial deodorizer have made the emission reduction rates for NH3, H2 S to achieve 70% and 60% in the first 20 day, and simultaneously, the p H,moisture content and carbon-nitrogen ratio were decreased, stack temperature raised rapidly and high temperature period extended. Stack temperature of swine feces and chicken feces achieved to the highest values in 25 and 20 day, and the scorching temperatures above 50 ℃ continued to 15 and 20 day, respectively.(5)Comparing with natural composts, the N-loss of the swine feces and chicken feces composts were as low as 25.84% and 28.65%, respectively, by applying microbial deodorizer in the end of compost. The contents of total nitrogen(TN) and nitrate nitrogen(NO3--N) were significantly higher than those of the natural composts(P<0.05). The microbial deodorizer could also promote sulfur into inorganic sulfur(SO42-), causing the content of SO42- significantly higher than that of the natural composts(P<0.05).The microbial deodorant strain screened and compound in this study have the efficient and stable functions on deodorizing. The compound microbial deodorizers could reduce the losses of fertilizer efficiency and accelerate the process of compost maturity, which have the better application potential in the fields such as the reclamation and harmless treatment of livestock waste and the amelioration of environment pollution.