Effect of sewage-water irrigation on physico-chemical parameters with special reference to heavy metals in agricultural soil of Haridwar city

Abstract

The present study revealed that use of sewage for irrigation of agricultural soil of Haridwar city improved the water holding capacity (+27.98%), electrical conductivity (+196.15%), sulphate (+2.34%), organic carbon (+30.48%), total Kjeldhal nitrogen (+87.5%), available potassium (+25.77%) and available phosphorous (+59.97%) and fertility status of the soil in comparison to natural water irrigated soil. Further sewage irrigation also resulted in a significant build-up of total Pb (+98.95%), Ni (+128.29%), Cu (+253.17%), Fe (+39.74%), Cd (+30.92%), Zn (+696.03%) and Cr (+13.15%) than the natural water irrigated soil. The mean concentrations of these metals were below the permissible limits of Indian standards. The enrichment factor (Ef) for Cu (9.62) was maximum and minimum for Cr (1.13).The Ef for different metals was in the order of Cu> Zn > Ni > Pb > Cd > Cr > Fe. Pollution index (Pi) value of the sewage water irrigated soil ranged from 0.505 to 0.901 which indicated that the soil was not yet polluted.