城市污泥及落叶蚯蚓处理最优条件因子实验研究

Experimental Factors to Optimal Conditionfor Earthworm Treatment by Using Municipal Sewage Sludge and Foliar Litters

蚯蚓的环境生态作用具有促进微生物和其他土壤动物活动、消化分解土壤中重金属的功能,并且能够破碎与分解枯落物。通过城市污泥和城市落叶发酵后建立起蚯蚓养殖基床,以赤子爱胜蚓为主体,通过蚯蚓对污泥中重金属的富集作用实现城市污泥无害化,达到城市污泥与落叶资源化的目的。通过设计四因子四水平正交试验探索赤子爱胜蚓处理城市污泥及落叶的最优条件组合。实验结果表明:在落叶添加比例为35%,蚓床湿度为75%,培养温度为14℃,饲养密度为32mg/g时,赤子爱胜蚓对城市污泥和落叶的处理指标达到峰值,蚯蚓床对于污泥中重金属Cu和Zn的富集量分别为274.32μg/箱和420.98μg/箱,处理效果最佳。

A large quantity of municipal sludge is produced during the process of urban wastewater treatment,and the city landscape plants also generate large numbers of foliar litters.The environmental ecological function of earthworm may enhance the activities of microbes and other soil animals,and also can digest the heavy metals and break the fallen leaves.A vermiculture bed was built by using fermented municipal sludge and urban fallen leaves,in which the Eisenia foetida was mainly cultured.The Eisenia foetida has positive effects on the enrichment of heavy metal inside municipal sludge.An Orthogonal test L16(45)of tetrad factors and tetrad horizontals was also designed to identify the optima combination of environmental conditions for the earthworm treatment by using municipal sludge and urban foliar litters.Results show that the best deciduous ratio,humidity of the vermiculture bed,ambient culturing temperature and culturing density for Eisenia foetidaare 35%,75%,14℃,32mg/g,respectively.The enrichments of heavy metals such as Cu and Zn in municipal sludge are 74.32μg and 420.98μg per container under the action of vermiculture bed,respectively.