【作者】 崔玉雪；

【导师】 谢冰；

【作者基本信息】 华东师范大学 ， 环境工程， 2011， 硕士

【摘要】 据统计,我国生活垃圾的年产量已达2亿t,加上历年堆存量高达66亿t,接近发达国家水平,其中填埋处理量达垃圾总量的95%以上。垃圾在转运、平铺、压实、处理及填埋过程中会产生大量强刺激的恶臭气体,对周边环境和人类健康造成直接或间接的影响。因此如何对垃圾产生的恶臭气体进行有效治理与控制,是环境保护领域一个重要的研究课题。目前在国内外恶臭治理的各种技术中,生物法因具有处理效率高、无二次污染、费用低廉和管理维护方便等优点,被广泛地使用。近年来无二次污染的微生物除臭技术在恶臭污染控制中得到迅速发展,但是由于微生物技术存在筛选高效菌种难、见效慢,特别是针对成分复杂的垃圾除臭的微生物制剂较少,已有的微生物菌剂往往不能适应填埋场的恶劣环境等缺点,因此研发出针对垃圾除臭的高效微生物菌剂,研究其除臭机理,为填埋场除臭提供理论依据和技术指导,具有重要意义。本论文从上海市老港垃圾填埋场的污泥和垃圾渗滤液中分离筛选高效除臭菌株,并制成微生物除臭剂。通过实验室模拟小试研究了投加方式、投加比及培养基浓度等对新开发复合菌剂除臭效果的影响,并与国内同类产品的除臭效果进行比较,通过中试试验检验复合菌剂的除臭效果,同时结合传统微生物计数方法和分子生物学PCR-DGGE技术对微生物菌剂中细菌的群落结构进行分析,初步探究了其除臭机理。最后通过毒性实验检测其使用的安全性。本研究得出以下结论：(1)筛选得到7株具有较好除臭能力的菌株。小试结果表明,7株菌株对臭气浓度12 h、24 h、48 h后的去除率分别为10%左右、20%-30%、20%-30%。经过16s rDNA鉴定,这7株菌分别属于芽孢杆菌属、产碱杆菌属、无色菌属、溶藻菌属以及显核菌属,具有较强的环境适应性和抗逆性。(2)开发了两种复合菌剂：将麦麸与EM菌液按照一定的比例搅拌混匀后发酵约一周,得到复合菌剂Ⅰ；将筛选出来的7株除臭菌接种到液态培养基中,恒温培养数天得到复合菌剂Ⅱ。(3)不同投加方式影响复合菌剂Ⅰ的除臭效果。覆盖于污泥表面时,对NH3的去除率前期高于后期。24 h后对NH3的去除效果最好,去除率达57.8%；48 h和72 h后对NH3的去除率分别为44.4%和40.8%。与污泥搅拌时,对NH3的去除率随时间的延长逐渐增大。24 h、48 h、72 h后的去除率分别为22.7%、54.4%和54.7%。另外随着投加量的减少复合菌剂Ⅰ对NH3的去除率逐渐下降。适宜的投加比为10%,此时对NH3去除效果最佳,72 h内对NH3的去除率为40%～60%。(4)当培养基浓度为100‰,投加比为5‰时,复合菌剂Ⅱ对NH3去除效果最好,48 h后对污泥中NH3去除率维持在30%-45%；随着时间的推移,复合菌剂Ⅱ对NH3的去除率呈现先降低后逐渐升高的趋势。(5)复合菌剂Ⅱ对NH3的去除效果好于EM菌液。24 h后对NH3的去除率比EM菌液高10个百分点左右；48 h后比EM高20个百分点,对污泥中NH3的去除率维持在30%～45%,对垃圾中NH3的去除率为25%～35%。中试结果表明,24 h后复合菌剂Ⅱ对NH3的去除率达到37.5%,臭气浓度下降了19.1%。(6)微生物除臭剂主要是靠化学与微生物的联合作用去除NH3。复合菌剂Ⅱ的优势菌种为产碱杆菌、芽孢杆菌和显核菌,都是筛选的除臭菌株；复合菌剂Ⅰ和EM菌液都富含乳酸菌。这些菌株在发酵过程中产酸,使菌液的pH值为3.0～4.0,酸性介质有利于NH3的吸收,同时可以有效抑制恶臭产生菌的代谢活动,从而减少臭气的产生。复合菌剂Ⅱ中异养菌数量较EM菌液多,表现出较好的除臭效果。(7)毒性实验结果表明,复合菌剂Ⅰ和复合菌剂Ⅱ对小白鼠的生长活动无明显影响,不具有致死性、皮肤致敏性。两种复合菌剂都是安全可靠的。更多还原

【Abstract】 According to statistics, the annual output of the solid waste is as much as 200 million tons in China, and will reach up to 660 million tons if the untreated solid waste over the years is calculated, which is close to those of the developed countries. About 95 percent of the solid waste is treated by landfill. A considerable amount of odor is produced in the process of transport, tile, compression, treatment and landfill, which will have direct or indirect influence on both the environment and the health of human being. Therefore, it is of utmost importance to control and treat the odor effectively, and that has been a crucial research project in the environmental protection field.At present, biological technology has been widely and successfully applied due to its high treatment efficiency, no secondary pollution and low operation cost. In recent years, the biological technology has gained more and more popularity in the deodorization of the solid waste. However, there are only a few kinds of microbial deodorizer in allusion to the solid waste, because it is difficult to screen and cultivate the effective strains that can adapt to the harsh environment in the landfill. Consequently, it has great significance to develop a new type of microbial deodorizer and to study on its deodorizing mechanism.In this paper, highly efficient deodorizing strains were isolated from the sludge and leachate collected from the Shanghai Laogang Disposal Plant, and they were made into microbial deodorizer. The odor removal efficiency of the deodorizer was studied in the lab experiment with different dosing method, adding dosage and cultural medium concentration, and was compared with that of the similar domestic deodorizer as well. The removal efficiency was further verified in the pilot test. Fianally, the application security was inspected in the toxicity test. Microbial community structure of various deodorizers was studied, and deodorizing mechanism was primarily explored. The main conclusions of this paper are as follows: (1) Seven highly-efficient deodorizing strains were isolated in our repetitious optimized cultivations process. The results showed that the odor removal efficiency of the strains was about 10% at the first day,20%～30% at both the second and the third day. The strains were proved to be Alcaligenes sp., Achromobacter sp., Bacillus sp., Lysinibacillus sp. and Caryophanon sp.. All of them have good environmental adaptability and stress resistance.(2) Two types of complex microbial deodorizer were developed. Deodorizer I was developed when the mixture of the wheat bran and EM bacteria solution were fermented for about one week. The selected strains were inoculated into certain liquid medium and cultivated for several days to develop Deodorizer II.(3) The ammonia removal efficiency of Deodorizer I was affected by the dosing method. When Deodorizer I was covered on the surface of the sludge, the ammonia removal efficiency was higher in the earlier period than that at the later stage. The maximum removal rate could reach up to 57.8% at the first day, and 44.4% at the second day,40.8% at the third day. When mixed around with the sludge, the removal rate increased gradually with the time going, which was 22.7% in 24 hours, 54.4% in 48 hours and 54.7% in 72 hours. In addition, the ammonia removal rate decreased with the adding dosage reduced. When the dosing proportion was 10%, the highest removal rate was achieved, which was up to 40%-60% in 72 hours.(4) When the concentration of the culture medium was 100%o, and the dosing proportion was 5%o, Deodorizer II had the maximum removal rate, which was 30%-40% in 48 hours. As the time went by, the ammonia removal rate of Deodorizer II decreased at the beginning and then increased gradually.(5) Deodorizer II was more favorable to remove the ammonia than the EM (Efficient Microorganism). Its removal rate was 10 percent points higher than that of the EM in 24hours. The quantity of ammonia released from the sludge decreased by 30%-45%, and 25%-35% from the waste solid in 48 hours, with 20 percent points higher than that of the EM. The ammonia released decreased by 37.5% in the pilot test, while the odor decreased by 19.1%.(6) The microbial deodorizer removed the ammonia by chemical absorption and microbial degradation. The dominant bacteria of Deodorize II were Alcaligenes sp., Bacillus sp. and Caryophanon sp., all of which were the selected strains. Lactobacillus sp. was the dominant bacteria of both Deodorizer I and EM. These strains produced acid during the fermentation. The acid medium was helpful for the ammonia absorption, and inhibited the metabolic activity of the bacteria producing odor. Therefore, the odor was effectively reduced. Heterotrophic bacteria of the Deodorizer I was more than that of the EM, and had better odor removal effect.(7) The results of the toxicity test demonstrated that Deodorizer I and Deodorize II showed no obvious toxic effect or potential of skin sensitization to the animals tested. Therefore, they were safe for the application in the practice.更多还原