Occurrence of acid rain over delhi

摘要

Precipitation samples were collected as wet-fall only and primarily on event basis in Delhi during the monsoon period of 1995. Concentrations of major anions (SO~2-, _4, NO~- _3 and Cl~-) And cations (Ca~2+, Mg~2+, Na~+ and K~+) were determined. The pH of the rain water was found to Be more than 5.6, showing alkalinity during the early phase of monsoon, but during the late phase Of monsoon pH tendency was towards acidity due to lack of proper neutralization of acidic ions. Neutralization is not only due to he local process but also due tot he pre-monsoon 'Andhi' which Brings Suspended Particulate Matter (SPM) containing Ca~2+, Mg~2+, Na~+ and K~+ as well as the Local emission of NH_3.