污泥蚯蚓堆肥过程中蚯蚓对污泥的适应性及重金属消减的影响

Study on Adaptability of Earthworm and Reduction of Heavy Mental During Earthworm Composting of Sewage Sludge

通过研究污泥理化性质对蚯蚓生长的影响和不同比例的污泥和调理剂（牛粪）对堆肥产品中重金属含量的影响,以及蚯蚓对污泥中重金属的消减作用,为污泥的资源化利用提供参考依据。结果表明,新鲜污泥处理和混合污泥处理的蚯蚓数量显著高于久置污泥;70%含水量处理的蚯蚓数最多,显著高于90%和40%含水量处理,其中40%含水量处理的蚯蚓全部死亡;pH7.82时蚯蚓数最多,与pH5.43和pH9.24处理时的差异达显著水平。污泥与牛粪混合培养蚯蚓的试验中,各处理间蚯蚓数量差异不显著,但纯污泥处理的蚯蚓总重和平均单条重显著高于其他处理,且各重金属含量均高于其他各处理,其中Cd、Pb、B、Cu、Zn含量与其他各处理间差异均达显著水平。试验结束后,纯污泥处理的蚯蚓体内各重金属含量是未处理蚯蚓的2.84~116.80倍,重金属去除率为0.46%~2.64%,吸收系数为0.06~0.38。

To study the fertilizer utilize of sewage sludge, the effect of physical and chemical properties of sewage sludge on the growth of earthworm, the contents and reduction of heavy metals in the decomposition of earthworm composting products, with different ratio of sewage sludge to cow dung, were determined. The results showed that the earthworm number in W1 （fresh sewage sludge） and W3 （mixed sludge） were significant higher than that in W2 （anaerobic sludge）. The earthworm number was the highest when water content was 70%, and the difference with 90% and 30% water content treatments was significant. Moreover the earthworm number was affected by pH value in order of P2 （7.82） 〉P1 （9.24）〉P3 （5.43）, and the difference among them was also significant. The ratio of sewage sludge and cow dung had no effect on the number of earthworm, while when the ration of sewage sludge to cow dung was 1：0 （pure sludge treatment）, the total weight and single weight of earthworm were the largest, and the contents of each heavy metal in earthworm, especially the contents of Cd, Pb, B, Cu and Zn, reached the highest. 2.84-116.80 times than that of normal earthworm, so the removal rates and absorption coefficients of heavy metals achieved 0.46-2.64% and 0.06-0.38 respectively.