Environmental impact assessment of ash disposal system of a thermal power plant

•The slurry suspension of fly ash shows the non-Newtonian flow characteristics at high solid concentration.•Sodium bi-carbonate as an additive leads to improve the rheology of fly ash slurry suspension.•The elements Mg, Zn, Cu and Co are within prescribed limits and elements Cr, Pb, Ni and Fe have crossed the limits.•The additive sodium bi-carbonate reduced the tracing element concentration of fly ash.

The disposal of fly ash in the thermal power plant is a challenging task. Presently coal ash with water is transporting through pipeline in ash disposal system with very low solid concentration, result not only consumes huge amount of water and pumping energy but also causes serious environmental problem at the disposal site. The objective of the present study was to investigate the rheological and tracing element characteristics of the fly ash at high solid concentration with an additive of sodium bi-carbonate. The solid concentration of fly ash slurry varied from 40 to 60% (by weight). The slurry suspension of fly ash shows the non-Newtonian flow characteristics. Result data shows that, the addition of small proportion of additive, leads to improve the rheological characteristics and reduced the tracing element characteristics of fly ash. This aspect of the study will also suggest the improvement in ash disposal system of thermal power plant to minimize the environment impact.

Graphical abstractTracing elements concentration of fly ash with & without additive.Figure optionsDownload full-size imageDownload as PowerPoint slide