Nitrification–Denitrification of Opto-electronic Industrial Wastewater by Anoxic/Aerobic Process

Abstract This research focused on the biological treatment of high-strength organic nitrogen wastewater, and presented the results from the nitrification and denitrification of an actual industrial wastewater using anoxic/aerobic process. The opto-electronic industrial wastewater often contains a significant quantity of organic nitrogen compounds and has a ratio over 95% in organic nitrogen (Org-N) to total nitrogen (T-N). In this study, a 2-stage anoxic/aerobic process was established and evaluated the efficiency of wastewater treatment. Raw wastewater from an actual TFT-LCD manufacturing plant was obtained as the sample for looking into the feasibility of opto-electronic industrial wastewater treatment. After toxicity identification evaluation (TIE) test of raw wastewater, the inhibition was related to organic nitrogen (TMAH, MEA) and unionized ammonia (free ammonia, NH3) with high pH. Therefore, pH control is important for biological treatment of high-strength organic nitrogen industrial wastewater. Be...