北方干旱地区非正规垃圾填埋场堆体特征及环境影响分析

Waste pile property and environmental impact analysis of the informal landfill in northern arid areas

填埋是我国垃圾处理的主要途径。处于不同气候条件的垃圾堆体对周边环境影响程度不同,在治理过程中要充分考虑填埋场特征选择适宜的污染防治及修复措施。以北方干旱地区典型非正规垃圾填埋场为研究对象,通过垃圾堆体理化性质、填埋气组成以及微生物群落结构的检测分析,研究干旱条件下垃圾堆体的特性。结果表明:场内垃圾呈弱碱性,有机质浓度为5.9%~17.4%,含水率为5.4%~7.8%;填埋气组成与准好氧填埋场相近,垃圾堆体中有机质浓度对CH4、CO2和CO生成量起到决定性作用;堆体内优势降解菌为Firmicutes(厚壁菌门)、Proteobacteria(变形菌门)、Actinobacteria(放线菌门)以及Bacteroidetes(拟杆菌门),物种丰度与垃圾降解进程及有机质浓度密切相关;在北方干旱地区垃圾填埋场渗滤液产生量小,堆体对周边环境影响较小;对于有机质浓度低于20%,pH呈弱碱性的垃圾堆体,在制定封场方案时可因地制宜地采用简易覆盖方式进行差异化治理修复。

Landfill has been the most common approach of waste disposal.The waste piles in different climates had different environmental impacts on the surroundings.The characteristics of landfill site should be fully considered and appropriate pollution prevention and remediation measures should be chosen during the treatment process.Taking the typical informal landfill in northern arid areas of China as the research object,through the detection and analysis of the physico-chemical properties,landfill gas composition and microbial community,the characteristics of the waste pile in the arid climates were studied.The results showed that the pile presented the slightly alkaline,with the content of organic matter fluctuating between 5.9%-17.4%,and the moisture between 5.4%-7.8%.The composition of landfill gas was similar to that of quasi aerobic landfill.The organic matter of the waste pile played a decisive role in the production of CH4,CO2 and CO.Firmicutes,Proteobacteria,Actinobacteria and Bacteroidetes were the dominant bacteria in the landfill.The species abundance was significantly affected by the process of waste degradation and the concentration of organic matter.In the northern arid areas,the amount of landfill leachate was small,and the landfill had minor effect on the surrounding environment.For the waste pile with the organic matter content less than 20%and pH weakly alkaline,the simple covering method could be adopted for differentiated treatment and remediation according to the local conditions when formulating the site closure scheme.