Bioremediation of distillery sludge into soil-enriching material through vermicomposting with the help of Eisenia fetida.

The aim of the present study was bioremediation of distillery sludge into a soil-enriching material. It was mixed with a complementary waste, cattle dung, and subjected to vermicomposting with (V) and without (T, control) Eisenia fetida in the ratio of 0:100 % (V1, T1), 10:90 (V2, T2), 25:75 (V3, T3), 50:50 (V4, T4), 75:25 (V5, T5) and 100:0 % (V6, T6), respectively. Survival rate, growth rate, onset of maturity, cocoon production and population build-up increased with increasing ratio of cattle dung. Maximum mortality of earthworm was observed in V6 mixture. On the basis of response surface design, the concentration of sludge giving highest number of worms, cocoons and hatchlings came out to be 21.11, 24.51 and 17.19 %, respectively. Nitrogen, phosphorus, sodium and pH increased during vermicomposting but decreased in the products without earthworm and there was increase in the contents of transition metals in the products of both the techniques. However, organic carbon, electrical conductivity and potassium showed an opposite trend.