Rotating biological contactors for wastewater treatment in an equatorial climate

The purpose of the study was to investigate the use of the Rotating Biological Contactor (RBC) to treat high strength wastewater in an equatorial climate. Total Organic Carbon, BOD and COD were used as analytical parameters to determine the efficiency of treatment of the wastewater, using high influent concentrations and high loading rates with a laboratory scale rotating disk system operating under ambient temperatures in Singapore. The effect of recirculation of the effluent was also studied. The results indicated that the RBC system could produce high treatment efficiencies at high ambient temperatures, however there were problems with first stage due to the high reaction rate. The Stover-Kincannon relationship appeared to adequately model the process when TOC was used as the major analytical parameter for loading rates up to 20 gm(-3) d(-1). Higher loading rates produced first-stage problems and lower removal efficiencies. Recirculation had little effect on the treatment efficiency at low loading rates. (C) 1997 IAWQ. Published by Elsevier Science Ltd.