Challenging wastewaters: From carwash to oily wastewaters

Recycling industrial wastewater is a significant challenge due to its complexity. However, achieving the global sustainable development goal 6—clean water and sanitation—requires suitable treatment technologies to upgrade and recycle water, thereby reducing drinking water consumption and water stress. This presentation focuses on two challenging wastewater streams:carwash and oily wastewater, demonstrating how membrane technology with appropriate pretreatment can facilitate water recycling.The carwash industry produces substantial wastewater annually. While larger car wash facilities have partial internal water recycling systems while smaller facilities often lack them. A compact and portable system, suitable for smaller carwash operations, was tested using paper filtration, ozonation, and nanofiltration, enabling the recycling of over 80% of the water. Efficient oil-water separation is also crucial due to stricter discharge limits for produced water in the oil and gas industry, process water in the petrochemical industry, and bilge water in the marine industry. Ultrafiltration can reduce oil concentrations in water to less than 1 ppm. Combined with proper pretreatment, it offers an energy-efficient and compact solution. This presentation will demonstrate how membrane processes can recycle challenging industrial wastewaters, thereby reducing the demand for fresh water.