Progressive Changes in Physico-chemical Constituent of Rainwater; a Case of Oyoko, Sekyere-East District of Ashanti Region, Ghana

Abstract

This study involves an experimental design where rainwater samples were collected progressively from a single point-source and analyzed with various scientific methods in accordance with standard procedures for analyzing physicochemical properties of water for drinking and for domestic use. The chemical and physical characteristics of rainwater harvested from a typical rooftop were progressively studied. The samples of rainwater collected were analyzed for pH, major ion concentrations, total dissolve solids (TDS), turbidity, and conductivity. As rainfall progresses, all these physico-chemical constituents fell within the world health organization (WHO 1998) guideline limits for drinking water at some point. Almost all the components of rainwater quality measured showed higher concentrations during the early stages of rainfall and reduce as time progresses. There was a downward trend in terms of pH as rain progressed, with 18% of the samples recording pH below the WHO lower limit of 6.5 from the 30 minutes sampling time. It was observed that iron concentration was above the WHO threshold value of 0.3 mg/l on occasions of heavy rains. However the mean monthly and progressive values were all below the WHO standards for drinking water. The results revealed that most of physicochemical characteristics of rainwater samples were generally below the WHO threshold, as such, the rainwater characteristics showed satisfactory conditions in terms of physicochemical constituents.