Abstract

Prakash E. Gandhi, Rahu Kiran Chandra and Shashi Montek Sen

Geo-environmental evaluation of heavy metals in/and around hazardous waste disposal sites located in the north-western part of Hyderabad (India) was carried out to define the degree of contamination of soil environment. Approximately 50,000 tonnes per annum of hazardous/industrial waste is deserted as landfill over 200 acres of area in the city outskirts, contaminating soil resource. In the present study, heavy metals (As, Cr, Cu, Ni, Pb, Zn) in soil samples were analysed by X-ray fluorescence spectrometer to quantify their concentrations. Natural background values were used to delineate their derivation as geogenic or anthropogenic. The average concentrations of As, Cr, Pb was found to exceed the threshold and natural background values, whereas the upmost concentrations of Cu, Ni and Zn exceeded the prescribed threshold limit. Soil pH varies from 5.7 to 8.9 and is acidic to near neutral and alkaline in nature. Soil pH significantly affects the solubility and mobility of these metals, as most of the metals are soluble in acid soils than in neutral or slightly basic soils. The methodology used has proved to be a useful tool to separate geological and anthropogenic causes of variation in soil heavy metal content and to identify common pollution sources