生活垃圾堆肥渗滤液污染物组成与演化规律研究

为阐明堆肥渗滤液的组成和演化规律,寻找合适的处理技术,研究了某堆肥厂不同堆肥时期渗滤液中无机阴离子、氨氮、重金属及有机物等的组成和演化特性.结果显示,随着堆肥的进行,EC及F-、Cl-、SO24-、NH4+-N的浓度呈下降趋势,而NO2--N、NO3--N及Org-N的含量与渗滤液的氧化还原氛围有关;渗滤液中重金属Pb、Cd、Cu、Zn及类金属As随堆肥进行浓度呈下降趋势,而重金属Cr、Ni、Fe、Mn随堆肥进行浓度上升;堆肥渗滤液有机物主要为类蛋白物质,但也含有类腐殖质物质,适合先生化后物化处理依次去除;堆肥过程中类蛋白物质相对含量先增加后减少,而类腐殖质相对含量先减少后增加.堆肥渗滤液盐分和重金属含量较高,不宜堆肥回流利用,应先生化后物化处理达标后排放.

Composition and Transformation of Leachates During Municipal Solid Waste Composting

The composition and evolution characteristics of inorganic anions, ammonia, heavy metals and organic compounds in leachates with different composing times were studied in a composting plant in order to clarify its composition and evolution and search for a suitable processing technology. The results showed that concentrations of EC, F^-, Cl^-, SO₄^2- and NH₄⁺-N decreased during the composting process, while the contents of NO₂^--N, NO₃^--N and Org-N were related to the oxidation reduction atmosphere of leachates. The Pb, Cd, Cu, Zn and As concentrations in leachates exhibited a decrease trend during the composting process, while contents of heavy metals Cr, Ni, Fe, Mn showed an increase trend with increasing composting time. The composting leachate organics comprised mainly of protein-like substance, but also consisted of humic-like substances. The leachate organics were suitable to be treated by biochemical process firstly, and then by physico-chemical technique. The relative content of protein-like substances firstly increased and then decreased, while that of humic-like matter exhibited an opposite trend. The contents of salinity and heavy metal in compost leachates were high, which caused the improper reflux utilization of leachates. The compost leachates should be treated by the combined biochemical and physico-chemical process before emission.