Application of membrane technology on semiconductor wastewater reclamation: A pilot-scale study

Wastewater discharged from semiconductor industry contains high turbidity and conductivity. When membrane systems are used for semiconductor wastewater reclamation without pretreatment, membranes will soon be clogged by the nano-size particles. In this pilot-scale study, a three-stage system has been developed for semiconductor wastewater reclamation. This system (flow = 5 m(3) d(-1)) contained fiber ball (material: polypropylene, diameter = 25 mm) filtration (FF) followed by ultrafiltration (UF) and reverse osmoses (RO) units. The FF was installed as a pretreatment unit (first stage) for particle removal. Spiral wound (SW) UF (material: polyethersulfone) and RO membrane (material: polyamide) were applied in the second and third treatment stages, respectively. Up to 95.8% of suspended solid (SS) could be removed after the pretreatment by FF system with an 88 m hr(-1) filtration velocity. More than 95% of the remaining turbidity can be further removed after the following UF treatment (turbidity dropped from 30 to below 0.6 NTU). After the treatment by RO unit, the effluent conductivity, turbidity, and total dissolved solid dropped to below 69.2 mu S cm(-1), 0.06 NTU, and 53.5 mg L-1, respectively. Knowledge obtained from this study will be useful in designing the three-stage FF and UF/RO system for practical application. (C) 2011 Elsevier B.V. All rights reserved.