Abstract
Reuse system for car wash water by flocculation, cellulose acetate (CA) ultrafiltration membrane and activated carbon treatments was developed. Multi-blended flocculating agent containing bentonite, Al2 (SO4) 3, sodium alginic acid and cationic polyacrylamide showed higher removals of COD and turbidity for waste car wash water compared with inorganic flocculating agent such as Al2 (SO4) 3 or polymeric flocculating agent individually. Practical scale experiment with membrane area of 48 m2 were conducted under the membrane pressure of 20 kPa. When waste car wash water was treated by this multi-blended flocculating agent of 50 mg/l, permeation flux through the CA membrane showed 1.0 m3/ (m2· day) for more than 6 months. The BOD, COD and extract by n-hexane values of reuse water were 2.5 to 14.0 mg/l, 3.7 to 15.7 mg/l and below 0.5 mg/l, respectively.
