【作者】 周效志；

【导师】 桑树勋；

【作者基本信息】 中国矿业大学 ， 地球化学， 2009， 博士

【摘要】 垃圾填埋场稳定化过程中不断释放出渗滤液与填埋气体(LFG),能够产生一系列的资源与环境问题。从生活垃圾填埋流体无害化处置与资源化开发并重的高度去研究垃圾填埋场流体的产生与地球化学迁移转化行为,进而探索新型的生物反应器填埋技术与工艺,可为生活垃圾的无害化与资源化处理提供科学的理论依据与实践方法。论文以理论分析为基础,自主设计的不同规模、不同相似性尺度的模拟填埋装置为实验平台,室内模拟填埋实验为主要研究方法,结合填埋场现场调研及数学建模等辅助手段,从生活垃圾填埋处理无害化与资源化相统一的新视角研究了填埋垃圾降解流体产生与地球化学迁移转化过程。构建了填埋场碳元素生物地球化学迁移转化模式,揭示了填埋体系固、液、气三相演化特征及三相间演化的定量关系,探明了各因素影响下的填埋垃圾降解流体产生规律、建立了垃圾生物气人工诱导理论,探讨了填埋场水分运移对生物化学作用的影响及其机理,提出了一种新的精控型间歇式厌氧生物反应器填埋工艺,并构建了精控型间歇式厌氧生物反应器填埋场的结构及运行模式。论文研究表明:①垃圾生物质的不断损失是造成填埋场二次污染及LFG资源化水平不高的根本原因,减少垃圾生物质损失量的同时提高其气相转化率,是进行人工干预、实现城市生活垃圾填埋无害化与资源化处理的理论关键。②较高的反应温度及产甲烷菌代谢能力能够促进固相生物质的快速水解;水解发酵菌长期的水解酸化主导作用导致垃圾生物质累计损失量不断增加,而产甲烷菌的代谢活动则可减小垃圾生物质的累计损失量。使填埋体系快速进入稳定的产气阶段,并促进不产甲烷菌与产甲烷菌的协同代谢,成为减少垃圾生物质损失、提高垃圾生物质气相转化率的重要措施。③渗滤液定期排放情况下,填埋垃圾厌氧降解渗滤液及LFG产生速率变化分别符合指数型函数Y=A0*e-kt及Y’=V0*e-k’t。渗滤液产生潜力(A0/k)主要受反应温度的影响,LFG产生潜力(V0/k′)受垃圾含水率、反应温度、微生物接种、垃圾粒径多种因素的共同影响;渗滤液产生速率衰减常数k、渗滤液最大日产率转化系数η及η/k对填埋场渗滤液产生速率预测结果影响显著。④在垃圾填埋降解过程中,提高固相生物质的水解速率、减少液相生物质的损失、促进产甲烷菌对液相生物质的快速消耗,并形成不产甲烷菌与产甲烷菌之间稳定的协同代谢是进行人工诱导产气的机理;多方式综合人工干预诱导是实现垃圾生物气资源化的有效途径。⑤渗滤液定期排放情况下,难以形成产甲烷菌适宜的生物地球化学环境条件,不利于产甲烷菌对水解发酵产物的快速消耗,严重抑制了填埋垃圾的降解。模拟降雨入渗情况下,入渗水持续的冲刷作用促进了固相有机质的快速水解,但CODCr累计净溶出量明显增加,不利于填埋场渗滤液污染控制。渗滤液全量回灌情况下,产甲烷菌适宜的生物地球化学环境形成相对较快,有利于不产甲烷菌与产甲烷菌的协同代谢,加快了填埋垃圾固相有机质的溶出与去除。⑥精控型间歇式厌氧生物反应器填埋可快速形成产甲烷菌适宜的生物地球化学环境条件,促进了填埋垃圾固相有机质快速水解与分解消耗,不仅显著缩短了填埋场稳定化周期、提高了渗滤液水质,而且填埋体系LFG/CH4累计产生量、LFG/CH4产生速率稳定性、LFG中CH4浓度也都有了大幅度提高。此外,精控型间歇式厌氧生物反应器填埋处理方式下,填埋垃圾生物质气相转化率明显提高、损失率显著下降,这对提高垃圾填埋场LFG资源化潜力、减少填埋场对周围环境的二次污染都具有重要的意义。更多还原

【Abstract】 Leachate and landfill gas (LFG) are released continually in the process of landfill stabilization, which causes a series of resources and environment problems. It can provide theoretical basis and practical methods for municipal solid waste (MSW) harmlessness and resource that fluid production and geochemistry migration and transformation are researched by paying equal attention to MSW harmless disposal and resource development, that new bioreactor landfill technology and process are further explored.This dissertation was based on theoretical analysis, took simulation landfill device of different type and different similar scale as the experiment platform, took indoor simulated landfill experiments as main research methods, combined with on-site survey and mathematical modeling, researched fluid production and geochemistry migration and transformation in the process of landfill MSW degradation from the new viewpoint of unified harmless disposal and resource. In the dissertation, biogeochemistry migration and transformation mode of carbon element was constructed, quantitative relationship and characteristics among solid, liquid and gas evolution in the landfill were revealed, fluid production rule of landfill MSW degradation influenced by various factors was found out, artifcial induction theory of biomass was established, the effects of water migration on biogeochemistry activities and its mechanism were studied, eventually new technology of precision controlled anaerobic batch bioreactor landfill was put forward, and structure and operation mode of precision controlled anaerobic batch bioreactor landfill was constructed. By the research of this dissertation, main conclusions were drawn as follows:①Biomass loss is the basic reason of landfill secondary pollution and low LFG resource level. The key theory of manual intervention and MSW harmlessness and resource are the decrease of biomass loss and the increase of biomass gas transformation rate.②High reaction temperation and methanogens metabolism ability can promote rapid hydrolysis of solid biomass. The long-term leading role of hydrolysis acidification leads to increase of cumulative biomass loss; however, metabolic activity of methanogens can decrease it. Landfill system entering stable gas production stage rapidly, promoting cooperative metabolism between methanogens and non- methanogens are important measures of biomass loss decrease and biomass gas transformation rate increase.③In the case of regular leachate emission, the production rate of leachate and LFG are in line with the exponential function Y=A0*e-kt and Y’=V0*e-k’t respectively. The potential of leachate production (A0/k) is mainly influenced by reaction temperature, the potential of LFG production (V0/k′) is influenced by water content, reaction temperature, microbial inoculation and MSW particle size. The attenuation constant of leachate production rate (k), the maximum day production rate coefficient of leachate (ηandη/k) have a significant effect on prediction results of leachate production rate.④In the process of MSW degradation, the mechanism of artificial induction gas production includes improving hydrolysis rate of solid biomass, decreasing loss of liquid biomass, promoting rapid consumption of methanogens on liquid biomass, and forming stable cooperative metabolism between non-methanogens and methanogens. Integrated multi-mode artificial induction is the effective way for implementing resource utilization of biomass.⑤It is difficult to form suitable biogeochemistry environment for methanogens in the case of regular leachate emission, which makes against rapid consumption of methanogens on hydrolysis acidification products, inhibits MSW degradation seriously. In the case of rainfall infiltration simulation, continuous washing of infiltrating water makes solid organic matter hydrolyze rapidly, meanwhile cumulative net leaching amount of CODCr increases significantly, which makes against the pollution control of leachate in landfill. In the case of leachate total recirculation, it is easy to form suitable biogeochemistry environment for methanogens, which is benefical to cooperative metabolism between non-methanogens and methanogens, accelerates leaching and removal of solid organic matter.⑥Precision controlled anaerobic batch bioreactor landfill can form suitable biogeochemistry environment for methanogens rapidly, promote hydrolysis and decomposition of solid organic matter, shorten landfill stabilization period, improve leachate quality, increase cumulative production and production rate stability of LFG and CH4, and CH4 concentration in LFG greatly. Besides, in this mode, biomass gas transformation rate increases obviously, loss rate decreases significantly, which are very important to improve potential of LFG resource and reduce landfill secondary pollution.更多还原