FNA enhanced short-cut nitrification device and method for deep denitrification and dephosphorization of sub-influent UCT

Abstract

The invention relates to a device and method for deep denitrification and dephosphorization of segmented influent UCT for enhanced short-range nitrification by FNA, belonging to the field of sewage treatment. The device includes: a raw water tank, a bioreactor, a secondary settling tank, and a sludge treatment reactor. The method is as follows: the domestic sewage enters the anaerobic zone and the anoxic zone of the bioreactor in sections, anaerobic phosphorus release is performed in the anaerobic zone to store the internal carbon source, and the denitrifying bacteria in the first anoxic zone use the internal carbon source to convert the backflow sub Nitrate nitrogen is reduced to nitrogen gas, while anoxic denitrification removes phosphorus. Then enter the aerobic zone, ammonia oxidizing bacteria oxidize ammonia nitrogen to nitrite nitrogen, enter the second anoxic zone and use the carbon source in the second stream of water for denitrification. The sludge age is controlled by regularly discharging excess sludge, and part of the return sludge is treated with free nitrous acid (FNA) and then returned to the bioreactor; this method uses FNA to inhibit nitrite-oxidizing bacteria much more than ammonia-oxidizing bacteria. Realize short-range nitrification, alternate anoxic and aerobic intermittent aeration to maintain a stable short-range, and realize deep denitrification and phosphorus removal of urban sewage continuous flow.

Description

technical field [0001] The invention relates to a device and method for deep denitrification and dephosphorization of segmented water inflow UCT with FNA enhanced short-range nitrification, and belongs to the technical field of sewage biological treatment. In the staged water inflow UCT process, part of the return sludge is treated with FNA side, and the inhibition of nitrite oxidizing bacteria by FNA is much greater than that of ammonia oxidizing bacteria, so as to elutriate nitrite oxidizing bacteria and realize continuous flow aerobic zone Short-range nitrification, and alternating anoxic and aerobic intermittent aeration can maintain the stability of short-range nitrification, so as to make full use of raw water carbon sources, save aeration, and achieve deep nitrogen and phosphorus removal of continuous flow domestic sewage. Background technique [0002] With the development of society and economy, the content of nitrogen and phosphorus in industrial and domestic wastew...

AI Technical Summary

Problems solved by technology

It can be seen that the multi-stage A / O series process of segmental inflow is equivalent to alternating anoxic and aerobic intermittent aeration, which can also inhibit NOB and promote the stable maintenance of short-term nitrification. However, the continuous flow segmental inflow process is limited to denitrification and often requires external investment Dosing chemicals for chemical phosphorus removal

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