Factors affecting phosphorus removal in two biofilter system treating wastewater from car-washing facility

Abstract

A two-biofilter system operated under alternating anaerobic/aerobic conditions was tested to remove nutrient as well as organics from wastewater generated from car-washing facility. The wastewater was characterized by relatively low organic and high phosphorus content. The factors affecting phosphorus removal in the two-biofilter system were investigated. Operational parameters examined in this study were hydraulic retention time, organic, suspended solid and nitrogen loading rate. The factors affecting phosphorus removal in biological filter appeared to be influent GOD, COD/T-P, BOD/COD, nitrogen, and SS/T-P. Nitrite and nitrate produced in the biofilter in aerobic condition affected phosphorus removal by the two-biofilter system. The biomass wasted during backwash procedure also affected total phosphorus removal by the system.