Assessment of heavy metal pollution in groundwater with respect to distance from ash pond by using heavy metal evaluation index

Chanchal Verma,Sangeeta Madan,Athar Hussain,Vinit Kumar

doi:10.1007/s13201-021-01390-9

Chanchal Verma, Sangeeta Madan + Show 2 more

Open Access

https://doi.org/10.1007/s13201-021-01390-9

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Abstract

In order to assess the quality of groundwater near ash pond of Parichha Thermal Power Plant (Jhansi), heavy metal evaluation index (HEI)was calculated. An unlined ash pond is being used for a long time to dispose fly ash generated by thermal power plant. To assess the level of groundwater contamination due to ash slurry disposal, both groundwater and ash slurry samples were collected and analysed in terms of their chemical concentration. In the present study, it was observed that significant amount of trace elements can leach out from ash slurry and may contaminate groundwater due to downward percolation through soil strata in an unlined ash pond. Obtained results revealed the range of heavy metals concentration in groundwater as [Ni (0.02–0.07 mg/l), Pb (0.14–0.41 mg/l), Fe (0.20–7.21 mg/l), Mn (0.01–0.14 mg/l), Cr (0.03–0.05 mg/l) and Al (0.05–0.26 mg /l)]. HEI showed a heavy load of metal pollution within the range of 5 km from the ash pond while moderate pollution within the range of 7 km and very low at a distance of 15 km.

Highlights

Fly ash disposal in an unlined ash pond may contaminate groundwater with heavy metals due to downward movement of leachate generated in ash pond (Theis and Gardner 1990; Carlson and Adriano 1993; Chanchal and Hussain 2014)
Ash slurry which was being disposed into ash pond was collected and analysed for its chemical characteristics, significant amount of major elements (K, Ca, Mg) and trace elements
Elements like K, Ca, Mg, Fe, Ni, Al, Co, Pb, Si, Mn and Ba were found to be present in decant water but their concentrations were much less when compared with the chemical concentration in ash slurry, while in the filtrate of fresh ash slurry, the concentration of Ca, Mg, K and Fe was found to be negligible as compared to the ash slurry

Summary

Introduction

Fly ash disposal in an unlined ash pond may contaminate groundwater with heavy metals due to downward movement of leachate generated in ash pond (Theis and Gardner 1990; Carlson and Adriano 1993; Chanchal and Hussain 2014). When fly ash in slurry form is continuously disposed and accumulates for a long time in disposal site, it leads to percolation of leached heavy metals through soil profile and joins to groundwater (Mandal and Sengupta 2005; Chanchal and Hussain 2014). The ash slurry water or leachate from ash pond gets percolated downward through the soil and joins groundwater table

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Conclusion