[Shortcut Nitrification Rapid Start and Stability of Corn Starch Wastewater]

A rapid startup shortcut nitrification method is researched with suppression factors, such as high temperature, high pH, low DO, etc., in a SBR reactor, with anaerobic effluent (C/N 0.93-1.53) from a certain corn starch company wastewater treatment station. Targeting the already started up shortcut nitrification system, the stability and control strategy are studied further after cancelling the high pH and high temperature limiting factors. Results show that shortcut nitrification (NO₂^--N accumulation rate above 80%) can be quick-started after 17 cycles of domestication and culture when the controlling temperature is (30±1)℃, the pH is 7.8-8.2, and the DO of the regular nitrification section is 0.7-1.0 mg·L^-1, combined with on-line control of the pH and DO parameters in the nitrification process. When the limits of high pH and high temperature are cancelled for the already started-up shortcut nitrification system, long-term stable operation can be obtained for a shortcut nitrification of NO₂^--N accumulation rate above 98% under the conditions of sufficient alkalinity, temperature 23-24℃, and DO 0.7-1.0 mg·L^-1 in the regular nitrification section, combined with the on-line control of nitrification process. The control strategies can be summarized as: first, the shortcut nitrification is rapidly started up under high temperature, high pH, and relatively low DO suppression factors, and then the high pH and high temperature limitation factors are eliminated. The control strategies have good practical significance for realizing the long-term stable shortcut nitrification for corn starch wastewater with relatively high ammonia nitrogen concentration and relatively high temperature.