【作者】 乔玮；

【导师】 曾光明； 黄国和；

【作者基本信息】 湖南大学 ， 环境工程， 2004， 硕士

【摘要】 随着人民生活水平的提高，城市垃圾的产生量日益增大，成为影响人类生存环境和社会发展的重大问题之一，许多城市已经陷入垃圾的包围之中。城市垃圾中含有大量可利用物质，城市垃圾的处理越来越注重资源化，在能源最大化利用的同时力求尽量降低垃圾处理所带来的社会和环境负荷。 城市生活垃圾的厌氧消化处理是主要针对垃圾中的有机组分，经过生物厌氧发酵作用将其转化为甲烷。本文针对我国城市垃圾的特性，分别就一阶段湿式厌氧消化工艺、城市垃圾与污泥混合厌氧消化工艺和城市垃圾与污泥两相厌氧消化工艺三种工艺进行研究。在一阶段湿式完全混合厌氧消化工艺中，消化温度分别为中温消化（35℃）、高温消化（55℃），固体含量（TS）为10％、20％和30％三种，C：N比分别控制在15：1和25：1，研究发现中温消化和高温消化系统消化液pH值变化趋势相同，高温消化系统消化液VFA（挥发性脂肪酸）浓度低于中温消化VFA浓度。垃圾粒径越小，消化系统pH值越高，粒径5mm效果最好。在城市垃圾与污泥混合厌氧消化工艺中，当TS增大到40％时，消化系统pH值维持在4.0以下，出现酸化现象，进料中纤维素的厌氧降解率较小。在城市垃圾与污泥两相厌氧消化工艺中，分别用UASB（升流式厌氧污泥床）和AF（厌氧生物滤池）作为产甲烷相。实验发现，产酸相pH值与一阶段湿式完全混合工艺相近，UASB和AF出水pH值可以维持在6.0以上。产酸相COD_Cr浓度大于15000.0mg／L，产甲烷相UASB出水COD_Cr浓度为3000.0mg／L左右。AF出水COD_Cr浓度较高，采用二次循环出水后COD_Cr浓度在6000.0mg／L左右。厌氧消化产物进行简单的好氧堆肥，在10d内，堆料含水率、C：N比和纤维素含量呈明显下降。更多还原

【Abstract】 With the improvement of peoples’ life, the quantities of municipal solid waste (MSW) increasingly build up. Disposal of MSW had become a crucial problem which affected the living environment and hindered development of society. Many cities had been encircled by refuse. MSW contained many reusable materials, so recently the aim of refuse treatment had turn to resource utilization in order to reduce social and environmental burden.Anaerobic digestion processes mainly treat organic components of MSW. Organic materials were converted to CH4 finally in anaerobic process which was regarded as a good choice to the purpose of MSW’s resource utilization. According to characteristics of domestic refuse, this paper focused on one stage wet anaerobic digestion, co-digestion of MSW and sewage sludge; two stage anaerobic digestion of MSW and sewage sludge. In the experiments, MSW contained mainly food solid waste, market refuse. The temperature of anaerobic digestion were determined at 35癈 and 55癈. TS (total solid concentration) were 10%, 20% and 30% respective. C: N ratios were 15:1 and 25:1. In one stage wet anaerobic digestion, the pH tendency were nearly the same in 35 C and 55 C. The concentration of VFA(volatile fatty acid) was lower in mesophilic anaerobic digestion than in thermophilic anaerobic digestion. The particle size of MSW was controlled. Results showed that the smaller particle size lead to higher pH value in liquid phase. The optimal particle size was 5mm. In co-digestion of MSW and sewage sludge experiment, when TS increased to 40 percent, the digestion system turned up acidification. The pH value maintained lower than 4.0. Cellulose substrates degradation was little.In two stage anaerobic digestion of MSW and sewage sludge process, UASB (up flow anaerobic sludge bed) and AF(anaerobic filter) were selected to treat acid effluent from acid phase. According to one stage anaerobic digestion system, in two stage process pH in methane phase maintained at above 6.0. CODCr concentration in acid phase was higher than 15000.0mg/L, CODcr concentration in UASB was3000.0mg/L. Effluent from AF reactor contain high CODcr, so the effluent flow back to AF reactor, results showed CODcr concentration in the second effluent was 6000.0mg/L approximately. After anaerobic fermentation, the feedstock were treated in aerobic composting within 10 days, results showed that H2O percent, C:N ratio and cellulose percent dropped notability.更多还原