Conceptual design of UF and RO for advanced treatment of wastewater

UF/RO treatment of wastewater is becoming an essential element for water conservation around the world. The treatment scheme is applied to municipal as well as various industrial sectors. This study focuses on conceptual design of UF/RO treatment system to generate high quality water that can be used safely for irrigation or industrial applications. The design is applied to an existing wastewater treatment facility in Kuwait with a capacity of 80,000 m3/d. Design of the proposed systems is made by simple models as well as the more detailed solution diffusion model. Simple models provide quick estimates for the system layout, which includes the required membrane area, total number of membrane elements, and total number of pressure vessels. Two single pass configurations are adopted for the design of the proposed UF/RO systems. The UF resistance model is used to determine the transmembrane pressure profile that provides constant permeate flux. Also, the solution-diffusion model is used to determine the membrane area, the permeate/reject flow rates and concentrations, and the number of membrane elements. Analysis of the proposed system economics shows a unit product cost of $0.22/m3, which is consistent with current field practice