Valuable and Sustainable Option for Reusing Carwash Wastewater in Nyarugenge District, Rwanda

Carwash wastewater has a considerable influence on environmental pollution due to rapid development and urbanization. Herein, to consummate that issue in an environmentally friendly manner, coagulation and sand filtration technologies were coupled in this study to investigate whether this combination could be a sustainable solution. Various metrics, such as potential hydrogen (pH), turbidity, chemical oxygen demand (COD), total suspended solids (TSS), oil, and grease amount, have been tested to assure the quality of the water that is treated. The findings reveal that the type of washed vehicle, carwash location, washing method, detergent type, and dose are contributing to environmental pollution. This study evinced considerable removal efficiency of pollutants, where turbidity, chemical oxygen demand, total suspended solids, oil, and grease concentration removal rates were 97.25%, 98.68%, 99.76%, and 94.42%, respectively. This study suggests that implementing this type of wastewater treatment plant in carwashes could effectively contribute economically and environmentally, as the effluent can be reused to save water usage.