A low-cost wastewater treatment unit for reducing the usage of fresh water at car wash stations in Pakistan

Abstract

In this study, a careful survey was conducted at twenty-nine different car-wash stations in Peshawar city to collect wastewater samples and evaluate the usage of fresh water in those stations. Experiments were carried out on a prototype treatment unit comprising sedimentation and filtration. After treatment, the TSS reduced from 1000 to 200 mg/L, hardness 321.60 to 120 mg/L and turbidity 253 to 3.70 NTU, TDS 591 to 400 mg/L and oil contents 27 to 14 mg/L. The quality of treated water was found suitable for car washing again. Furthermore, a design and cost estimation of a commercial scale low-cost wastewater treatment unit has been provided. It was found that the installation of low-cost wastewater treatment units can save 12 m3/day of fresh water in a carwash station.