Studies on bioefficacy of coal ash to promote plant growth


Coal ash, the residue formed after burning of coal, is of two types namely fly ash and bottom ash. Fly ash is the fine particles which are collected from flue gas and bottom ash is the residual solid. The fly ash and bottom ash consists of heavy metals and hence their disposal poses a great challenge. Fly ash and bottom ash are used as soil amendments to improve plant growth due to the presence of nutrients such as N, P, K, Ca, Mg, etc. They are great alternatives to dispose coal ash. Disposal of coal ash in landfills pose the risk of leachate formation and contamination of ground water. The present study explores a way to overcome the accumulation of heavy metals by the use of fungus Trichoderma viride. The bioremediation of fly ash and bottom ash result in the reduction of heavy metal levels and increase the concentration of nutrients such as N, P, K, and Mg. The untreated and treated coal ash was studied for their potential to promote plant growth in Vigna radiata and Vignamungo. The results of the study proved that 25% blending of treated ash with soil was beneficial. In conclusion, we have developed a process not only to use coal ash as an ecofriendly amendment for bio-fertilizers but also safe disposal of coal ash.