Swine wastewater treatment in a two stage sequencing batch reactor using real-time control

A laboratory scale two-stage sequencing batch reactor (TSSBR) was used to s tudy the effectiveness of pH as a real-time control parameter in swine wast ewater treatment. A Ringlace media was inserted into the A/O (Anoxic/Oxic) reactor for bacteria immobilization. The TSSBR was subjected to three level s of organic loading. The pH and ORP (Oxidation Reduction Potential) patter ns obtained were consistent with distinct features, enabling the real-time control strategy to effectively set a flexible aeration time pending on inf luent concentration, hence resulting in flexible cycle time and HRT (Hydrau lic Retention Time) for the system. The real-time process ensured a removal efficiency of over 99% and 95%, respectively, for ammonia and TOC (Total O rganic Carbon). For NO3--N and PO4-3, the run with influent TOC = 4,000 mg/ L yielded the most efficient removal of 61% and 95%, respectively. Test res ults suggest that pH can be a viable tool for on-line real-time control of a biological treatment process.