MEASUREMENT OF pH AND CHEMICAL ANALYSIS OF RAIN WATER IN RURAL AREA OF INDIA

Large number of rain water samples, at 7 rural locations in the semi-arid region of the Deccan Plateau were collected during 4 consecutive monsoon seasons (1979-1982).pH, conductivity and the major ionic components (Cl-, SO4=, NO3-, NH4+, Na+, K+, Ca++, Mg++ of the above samples were determined. The pH of rain water was found to be highly alkaline and the values varied from 6.4 to 7.8. Soil-oriented elements showed good correltioan (r~0.6) with pH values of rain water. The high concentration of soil-oriented elements, specially Ca++, is found to play an important role in neutralizing the acidity of rain water and maintaining high alkaline pH. The study suggested that the contribution of atmospheric aerosol of natural sources (sea and soil) to the chemical composition of rain water is more than that of anthropogenic origin.