畜禽养殖废弃物堆肥过程中微生物除臭研究进展

Research Progress of Microbial Deodorization in Livestock and Poultry Wastes Composting

随着世界各国的畜禽养殖业向着集约化、产业化方向发展,养殖废弃物大量产生,严重影响到生态环境并威胁到人畜健康。目前,畜禽养殖废弃物的资源化利用受到人们的广泛关注,其中好氧堆肥技术是当前最有效的处理方法。然而,堆肥过程中产生的异味气体使好氧堆肥技术的推广面临极大挑战。在堆肥过程中,这些异味气体威胁人类健康的同时,还会带来一系列环境问题。因此,充分、有效的去除堆肥过程中异味气体显得十分重要。本文重点阐述了堆肥过程中异味气体排放特征及其源物质转化特征,分析堆肥过程中影响异味气体产生的因素,并从原位除臭技术和异位除臭技术两个方面对异味气体生物处理技术以及微生物控制机理进行讨论。主要结论:异味气体(NH3、H2S和挥发性有机物)主要在堆肥的升温期和高温期产生;控制最佳堆肥温度为55—60℃、水分为50%—60%、pH为7.5—8.5、C/N为25—30、氧气浓度为10%—18%、有机质含量为50%—80%,结合适宜的堆肥方式、翻堆频率以及添加外源微生物,可使异味气体产生量降至最低;一种除臭微生物菌株一般只对一种异味气体具有较高的去除效率,难以同时去除多种成分的异味气体,而复合微生物除臭剂可以同时去除多种异味气体成分,但去除效率相对较低。建议进一步研究有机质转化、微生物群落变化与异味气体产生的规律,从而在堆肥升温期和高温期尽可能地减少异味气体的产生;重点研发复合除臭菌剂,在提高除臭效果的同时探明微生物作用机理。

With the intensive and industrialized development of livestock and poultry breeding industry in the world,a large number of breeding wastes are generated,which seriously affect the ecological environment and threaten the health of human and livestock.Now,the resource utilization of livestock and poultry breeding waste has been widely concerned.Aerobic composting technology is the most favorable treatment method at present.However,the odor produced by composting makes the popularization of aerobic composting technology face huge problems.In the process of composting,the odor gases not only threaten human health,but also bring a series of environmental problems.Therefore,it is very important to remove odor gases adequately and effectively in composting process.The paper summarized the emission characteristics of odor gases and the transformation characteristics of source materials,and analyzed the influencing factors of odor gases during composting in detail.Moreover,the biological treatment technology and the mechanism of microbial control of odor gases were discussed from two aspects:in-situ removal technology and ectopic removal technology.The following conclusions were drawn:odor gases(NH3,H2S and volatile organic compounds)were mainly generated in the heating period and high temperature period of the composting process;the optimum temperature was 55-60℃,with the moisture of 50%-60%,pH of 7.5 to 8.5,C/N for 25-30,oxygen concentration of 10%-18%,and organic matter content of 50%-80%;at the same time,it could choose the right means of compost,optimal frequency of turning heaps and adding exogenous microorganisms to make odor gases minimize;a deodorizing microbial strain usually only had high removal efficiency of one odor gas component,and it was difficult to remove a variety of odor gases at the same time;compound deodorizing microbial agents could remove a variety of odor gas components at the same time,but the removal efficiency was relatively low.It was suggested that the transformation of organic matter,the change of microbial community and the rule of odor gases production should be further studied,so as to reduce the production of odor gases as much as possible during the heating period and high temperature period of compost.Research should focus on development of composite deodorizing microbial agents,and explore the effect and mechanism of microbial deodorization.