Heavy metals pollution in soil-water-vegetation continuum irrigated with ground water and untreated sewage

Ram Bharose; S B Lal; Sudhir K Singh; Prashant K Srivastava

Ram Bharose Department of Environmental Science, School of Forestry and Environment, SHIATS, Allahabad, India
S B Lal Department of Environmental Science, School of Forestry and Environment, SHIATS, Allahabad, India
Sudhir K Singh Centre of Atmospheric and Ocean Studies, Nehru Science Centre, KBCAOS, IIDS, Nehru Science Centre, University of Allahabad, Allahabad-211002, India
Prashant K Srivastava Department of Civil Engineering, University of Bristol, Bristol-BS8 1TR, United Kingdom

Abstract

The field experiments were conducted at the crop-growing farm in southeast part of northern region of India for two years to study the response of different levels of sewage and groundwater irrigation on accumulation of heavy metals in soil and crop (Solanum tuberosum). The source of heavy metals like Cd, Cr, Cu, and Ni is electroplating processing industries and domestic sewage. Physico-chemical properties like total suspended solids (TSS), total solids (TS), Biochemical oxygen demand (BOD), and Chemical oxygen demand (COD) showed higher values in untreated sewage water compared to groundwater. To analyze the effect of heavy metal contamination on crop, five heavy metals (Cd, Cr, Ni, Cu and Pb) were taken into account. Crops were raised in uncontaminated alluvial soil of Allahabad in field condition, irrigated with untreated sewage and groundwater. The nickel, lead, cadmium, chromium, and copper (mg kgâ€“1) of post-harvest soil of potato grown plot were recorded in order of P0, <P1, <P2, <P3 during the entire growth and development. Severity of toxicity was less in plants treated with diluted sewage water (50%) and very low in the groundwater. Heavy metals in P3 treatment tended to be significantly greater than the remaining treatments and decreased with increasing depth, in both groundwater and sewage water irrigated soil.