Mass reduction and recovery of nutrients through vermicomposting of fly ash

Abstract

In view of the environmental problems generated by large-scale production of fly ash, increasing attention is now being paid to the recycling of fly ash as a good source of nutrients. Because availability of many nutrients is very low in fly ash, available ranges of such nutrients must be improved to increase the effectiveness of fly ash as a soil amendment. In our experiment, we assessed the possibility of increasing total nitrogen, total phosphorus, total potassium and micronutrients in fly ash through vermicomposting. Fly ash was mixed with cow dung at 1:3, 1:1, and 3:1 ratios and incubated with Eudrilus eugeniae for 60 days. The concentration of above said macro and micronutrient was found to increase in the earthworm-treated series of fly ash and cow dung combinations compared with the fly ash alone. This helped to transform considerable amounts of total nitrogen, total phosphorus, total potassium and micronutrients from fly ash into more soluble forms and thus resulted in increased bioavailability of the nutrients in the vermicomposted series. Among different combinations of fly ash and cow dung, nutrient availability was significantly higher in the 1:3 fly ash to cow dung treatment compared with the other treatments. © 2008, Penkala Bt.