Analysis of Physicochemical Parameters, Anions and Major Heavy Metals of Rainwater from Rajshahi City Corporation, Rajshahi, Bangladesh

This study was carried out to determine the physicochemical properties and heavy metal concentration of rain water from twenty different sites in Rajshahi City Corporation area of Bangladesh. Rain water samples were collected during the rainy season and analyzed for various parameters such as temperature, odor, color, transparency, electrical conductivity, turbidity, total dissolved solid, pH, total hardness, chloride, nitrate, sulphate, lead, cadmium, manganese, chromium and arsenic. The ranges of parameters such as temperature, electrical conductivity, turbidity, total dissolved solid, pH, total hardness, chloride, nitrate and sulphate were: 28.8-29.1oC, 8-20.33 ?Scm-1, 2.33-4.88 NTU, 5.6-14.29 ppm, 6.03-6.99, 4.8-15.2 ppm, 0-7.81 ppm, 0-5.9 ppm and 0-13 ppm, respectively. The rainwater samples were odorless, colorless and transparent. The pH values of the samples show that rain water over the Rajshahi City Corporation area is slightly acidic. All the parameters studied have been discussed in detail using international standards applicable to potable water. The ranges of heavy metal concentrations such as lead, cadmium, manganese, chromium and arsenic were: 1.0024-11.9124 ppb, 0.0501-0.494 ppb, 0.2035-1.75 ppb, 0.05002-1.974 ppb and 1.531-2.7465 ppb. The heavy metal concentrations of rainwater samples are within the permissible limit for drinking purpose in almost all places during the investigation period. Rain water quality of this investigation area, is found suitable for most uses including drinking.