垃圾渗滤液中有机物分子量的分布及在MBR系统中的变化

MOLECULAR WEIGHT DISTRIBUTION OF ORGANIC MATTER IN LANDFILL LEACHATEAND ITS VARIATION THROUGHOUT MBR TREATMENT

利用凝胶层析方法分析了垃圾渗滤液中有机物分子量的分布情况,并考察了利用膜生物反应器(MBR)处理垃圾渗滤液系统中有机污染物分子量的分布以及水溶性腐殖质(AHS)含量的变化研究发现,垃圾渗滤液中的有机物主要由两部分组成,即分子量大于6000的大分子物质和分子量小于1500的小分子物质大分子物质主要是水溶性腐殖质,而小分子物质主要由挥发性有机酸及水溶性腐殖质组成大分子的AHS难以被微生物降解,但能被微滤膜截留大部分小分子的AHS既难以被微生物降解,又不能被膜截留。

The molecular weight distribution of the organic matter in landfill leachate was investigated by means of the gel permeation chromatography (GPC). Its variation and the variation of aquatic humic substances (AHS) in landfill leachate throughout the MBR treatment were studied. The organic matter could be categorized to a high MW fraction (MW>6000) and a low MW fraction (MW<1500). The high MW fraction was mostly composed of AHS, which was recalcitrant to biodegradation but could be cut off by the membrane. The low MW fraction was composed of volatile fatty acids (VFA) and AHS. VFA were easily biodegradable, and most of the AHS in low MW fraction were refractory to biodegradation and could permeate the membrane. This is the reason of high SCOD in the effluent.