Investigation of Alkaline Nature of Rain Water in India

Precipitation chemistry of Lhasa and other remote towns, Tibet

“…In the western part of the USA, the calculated mean pH values of rainfall were alkaline during the 50s and 60s [Liljestrand and Morgan, 1979], when there was a lack of direct measurement of pH subsequently it has become more acidic. In India, the natural rain should be alkaline, although the rainfall pH of many areas is below 7 (Kulshrestha et al, 2001). Our measurements at a permanent monitoring station, Lhasa, also show a dangerous trend in rainfall acidification for Tibet.…”

Study of Physicochemical Parameters of Rainwater: A Case Study of Karachi, Pakistan

“…Composition of rainwater varies from site to site and it is difficult to control as it is influenced by both natural and anthropogenic sources. If the source is influenced by man made activities more, it will contribute to acidic gases like NO x and SO x due to which rainwater becomes acidic and basic gases like NH 3 [8] [9]. Environmental adverse effects of acid rain include changes in the leaching rates of nutrients from plant foliage and soil nutrients, acidification of lakes and rivers, effects on metabolism of organisms and corrosion of structures [10] [11].…”

Buffer Capacity of Open Atmospheric Gas–Liquid Systems

“…The ratios of the sum of anions-to-cations (TA/TC) (e.g., (SO 4 2− + NO 3 − )/(Ca 2+ + Mg 2+ + NH 4 + )) have also been considered as indicator for acidity. If TA/TC is less than one it indicates alkaline nature of rainwater and the ratio TA/TC greater than unity indicates the presence of free anions which is responsible for precipitation acidity (Kulshrestha et al, 2001;Kumar, Rani, Singh, Kumari, & Srivastava, 2002).…”

“…A large number of studies have been carried out on the chemical composition and pH of atmospheric water (rain-, cloud-and fogwater) (Hegg & Hobbs, 1981;Munger, Jacob, Waldman, & Hoffman, 1983;Zeng & Hopke, 1989;Li & Aneja, 1992;Kulshrestha, Sarkar, Srivastava, & Parashar, 1995;Kaya & Tuncel, 1997;Kulshrestha et al, 2001;Tang, Zhuang, Wang, Yuan, & Sun, 2005). The pH scale is used to measure the acidity which is determined by hydrogen ion content (H + ).…”

“…For example, the roles of NH 4 + , Ca 2+ and Mg 2+ in neutralization of atmospheric water acidity may be validated by calculating NFs as below (Kulshrestha et al, 1995;Kulshrestha et al, 2001;Tang et al, 2005):…”