Efficiency evaluation of rainwater quality modification by utilizing mixing method with surface water and groundwater

Due to industrial development, lack of water resources on a global scale and increasing water demands in both rural and urban societies, quests for reviving water resources and finding reproducible ones have soared in recent years. Meanwhile, rainwater is one of the most accessible water resources in societies with high rainfall seasons which could be utilized as a sustainable and reproducible resource of water supply. Average amount of TDS (Total Dissolved Solids) in surface water is about 300 MgL-1, while for ground water is usually more than 1000 MgL-1. Rain water contains very low amount of TDS (0-10) MgL-1. Besides the biological effects of low TDS water on the body, problems of taste and odour are always being reported by consumers. Mixing rainwater with water from other resources with higher TDS is one of the proposed solutions to solve this problem. In this research, we at first try to gather information about acceptability of rainwater quality (taste, hardness etc.) by questionnaire from the inhabitant of villages in the study area. Results indicated that more than 85 percent of inhabitants were displeased with the water quality. Then samples were analyzed to obtain primitive amount of physicochemical parameters and mixed with water from surface and underground resources in 3 ratio (1/10, 2/10and 3/10) to obtain the best ratio of mixing for providing water with optimum TDS and TH. After statistical analysis of data, 2/10 mixing ratio was picked as the optimum rate in this experiment. By utilizing 2/10 mixing ratio with surface water (S/R), final TDS of rainwater was increased up to (80-94) MgL-1 and TH up to (73-89) MgL-1caco3, While this value is about (121-159) MgL-1 for TDS,