Applying real-time control for realization and stabilization of shortcut nitrification-denitrification in domestic water treatment

摘要

A sequencing batch reactor (SBR) was used to treat real domestic wastewater focusing on thenachievement, maintenance and the feasibility of nitrite accumulation under real-time control.nKeeping temperature, MLSS and dissolved oxygen (DO) in reactor at 28 ^ 18C, 2,400mg/L andnhigher than 2.0mg/L respectively, shortcut nitrification-denitrification was successfully achievednafter about two months. But the sudden raise of ammonia loading rate (ALR) caused deteriorationnof nitrite accumulation and occurrence of filamentous sludge bulking. These undesirablensituations could be solved by pre-anaerobic operation mode. If applying long-term real-timencontrol strategy to supervise the nitrification course, the sludge population optimization and highnnitrite accumulation rate at different DO levels could be achieved. The strategy taking pH andnaeration quantity as control parameters for nitrification in SBR was put forward under invariablenDO conditions in this paper. By maintaining low DO level (below 1.0mg/L), the shortcutnnitrification-denitrification could be achieved in the same reactor with simultaneous nitrificationnand denitrification (SND), through which the removed nitrogen accounted for 49.12% to 66.81%nof total nitrogen (TN) in influent at the end of shortcut nitrification.