Effect of industrial emission on atmospheric wet deposition

In order to quantity the role of industries on atmospheric depositions, wet depositions were collected at different sites in Singrauli area of Sonbhad ra district, U.P., India. Rainwater samples were collected on event basis a nd were analyzed for pH and concentration of H+ ion, cations and anions. Th e monthly variations in rainwater pH clearly indicate that early rainfall i s more alkaline and as rainy season proceeds rainwater showed lower pH. The pH of rain from June to September varied from 6.6 to 4.8 at most polluted locality. Among different cations, Ca2+ showed maximum concentration follow ed by NH4+,Na+, Mg2+ and then K+, whereas among anions sulphate concentrati on was maximum followed by nitrate and then chloride. A significant positive correlation observed between sulphate and accumulate d rainfall suggests that the source of sulphate is mainly the industrial ac tivities. While the negative correlations of other cations with accumulated rain suggest their additional sources in the area. The study clearly indic ates that the abundance of alkaline substances reduces the acidity of wet d epositions.