城市生活垃圾蚯蚓处理的因素优化及其重金属富集研究

Factor optimization for municipal domestic wastes treatment by earthworms and its concentration of heavy metals

采用模拟试验、小区试验与生产试验等研究了垃圾成分、软化方式、培养方式、环境温度和蚯蚓杂交等因素对蚯蚓处理城市生活垃圾的影响及其重金属富集效应 .结果表明 ,改变垃圾成分、提高垃圾碳氮比 ,在 2 0℃温度左右时 ,采用蚯蚓粪软化和室内层床培养方式 ,可使蚯蚓增殖率和垃圾腐解率都有所提高 .同时利用驯化的重庆赤子爱胜蚓与背暗异唇蚓进行杂交 ,也可以提高蚯蚓处理垃圾的效果 .蚯蚓处理过程中重金属富集系数与软化方式之间没有显著相关性 ,而与重金属种类、培养方式之间具有较强的依存性 .砷、镉在腐解物中最易富集 ,而汞不易富集 .垄埂式培养比层床式容易富集重金属 。

Simulated experiments,plot tests and applied stuties were conducted to determine the effects of the composition of municipal domestic wastes,their softening and culturing methods,and circumstance temperature on the treatment of municipal domestic wastes (MDW) by earthworms. The results showed that the decomposition rate of MDW and the multiplication rate of earthworms could be elevated by enhancing the C/N ratio of MDW,softening it with earthworms excrements,and culturing with indoor layer at 20℃. Meanwhile,the treatment of MDW was also improved by the hybridization of tamed Chongqing Aisenia foetida and Caliginsoa. The concentration coefficient of heavy metals had no correlation with intenerating method,but were depended upon the types of heavy metals and the culturing method. Arsenic and cadmium were the most easily concentrated ,while mercury oppositely. The concentration element in ridge culture was more easily than that in layer culture,and the concentration element in outdoors culture was more easily than that in indoors culturing.