RBC SYSTEM FOR INTEGRATED ORGANIC AND NITROGEN REMOVAL.

Laboratory experiments were conducted using a three stage RBC unit followed by lime precipitation and sedimentation with effluent recycle to the first stage. The purpose was to evaluate the effects of hydraulic loadings (0. 03057 - 0. 07643 m**3/m**2d and recycle rates 100 - 300%) on the removal of organic and nutrients from domestic waste water. Results showed that optimal nitrification and nitrogen removal occurred at the lowest hydraulic loading of 0. 03057m**3/m**2d at a recirculation rate of 300%, while high BOD and COD removal was at 0. 05350 m**3/m**2d. However at lower and higher loadings, 300% recycle gave best removals. Operating the flocculator at pH 10. 4 - 11 removed more than 90% phosphorus. Effluent suspended solids was over 40 mg/1.