In recent years, due to the concentration of population in metropolitan areas, the demand for vehicles has increased, which in turn has boosted the demand for car washing. In addition to mechanical car washes, the recent rise of self-service or manual small and medium-sized car washes has led to a steady increase in the amount of wastewater generated by the car wash industry.
In order to solve the problem of small-scale car wash operators who cannot effectively manage car wash wastewater due to site constraints, this project proposes to use the integrated system module of cyclone filtration technology and electrocoagulation floatation removal technology for wastewater treatment, and to conduct demonstration tests with the main objectives of low pollution, low energy consumption, and small space occupation of equipment.
The project has completed the development of cyclone filtration, electrocoagulation floatation and other two technologies of modular equipment, and has completed three car wash wastewater treatment field demonstration verification. The validation results show that the electrocoagulation floatation equipment can treat various car wash wastewater with appropriate operating parameters, and can reduce the concentration of suspended solids (SS), chemical oxygen demand (COD), anionic surfactants and grease to below the discharge water standard. Cyclone filtration equipment can effectively remove suspended particles from car wash wastewater, and the use of a finer filter can reduce the turbidity of the filtrate to below 1 NTU. If the car wash wastewater is treated with electrocoagulation and floatation first and then cyclone filtration, the cost of the filter can be reduced and the same turbidity removal effect can be achieved.
According to the scale and operation type of the car wash, this project has completed the planning of two types of interception methods: water suction device and water storage tank. The water suction device is mainly used in manual car washes, and the experimental results show that the water collection efficiency can reach more than 90%. Water storage tanks can be used in mechanical and self-service car washes, and water collection facilities have been built in self-service car washes, which can also effectively intercept car wash wastewater.