Naturally growing Saccharum munja L. on the fly ash lagoons: A potential ecological engineer for the revegetation and stabilization

Abstract

Increasing areas of coal fly ash (FA) deposit pose a serious concern for its safe disposal to maintain the environment quality. Several thousand hectares of land have been occupied for the storage of FA all over the world. FA deposits cause serious environmental pollution through wind erosion and ground water contamination through leaching process. Naturally growing Saccharum munja on the derelict FA lagoons of NTPC Unchahar, India was identified as a native perennial grass in the rehabilitation process. We tested its ecological suitability for the effective restoration of FA lagoons in terms of their abundance and stabilization. The FA contains alkaline pH, and low organic C coupled with toxic metals i.e. Fe, Cd, Cr, Cu, Mn, Ni, Pb and Zn. The concentrations of these metals in different parts of the plant fall in the average range of plants and were found within toxic limits. Natural colonization of S. munja predominate in the areas of FA deposits with fast growth and high biomass which is used by local people for making ropes, baskets, mats, huts, etc. to support their livelihood. These results suggest that S. munja would be potentially useful to rehabilitate the FA dumps more efficiently if it is introduced properly on fresh lagoons to convert barren FA deposits into ecologically and socio-economically productive habitats without any inputs or maintenance.