Application of a Dead-End Hollow-Fiber Ultrafiltration Membrane Module Characterized by a Center-Distributor Structure to Highly Turbid Water Sources

Abstract

Dead-end filtration is commonly used for water filtration owing to its low energy requirement, high water recovery rate, and small equipment size. However, it is unsustainable when applied to high-turbidity water sources because of high water loss and energy consumption. In this study, the effects of physical cleaning of GL-0101-S4 (GL, Kuraray Co., Tokyo, Japan), a unique dead-end hollow-fiber ultrafiltration membrane module with “center-distributor” structure, were investigated to evaluate the feasibility of its application to dead-end filtration of high-turbidity water. Pilot-scale experiments were conducted using artificial feedwater, and the GL’s cleanability was evaluated under various physical cleaning conditions. The results indicated that increasing the air flow rate per membrane area, along with the air diffuser and center distributor cleaning time, enhanced the cleaning performance. Computer-aided engineering fluid and fouling index analyses revealed that the inhibiting effects of foulant accumulation on the membrane surface were similar to those observed during cross-flow filtration, because the feedwater was supplied vertically in the fiber direction of the hollow-fiber membrane from the center distributor supply ports in the GL. This study demonstrated that uniquely structured modules such as the GL, which are characterized by a center distributor, can effectively handle high physical solid loads in simple artificial feedwater to achieve cleaning. This highlights their potential for the dead-end filtration of highly turbid water sources with minimal biological activity. Our findings may contribute to reducing energy and water losses by expanding the application of dead-end filtration systems to high-turbidity water sources.