Abstract: Laundry, industrial or food processing wastewater is purified to the degree that it can be reused. Water quality is ensured through the final process of reverse osmosis (“RO”) which removes dissolved contaminants such as mineral hardness, soils and residual detergents. The process combines a ceramic tubular cross-flow membrane filter to remove the suspended solids, oils and greases ahead of the RO. The RO process employs high temperature, low fouling membranes. This enables the RO process to operate sustainably, i.e. without fouling, plugging or membrane degradation.