System and method for enhanced nitrogen removal of sewage through denitrification

Abstract

The invention relates to a system and method for enhanced nitrogen removal of sewage through denitrification. The system for enhanced nitrogen removal of sewage through denitrification comprises an anaerobic pool, an anoxic pool, an aerobic pool and a secondary sedimentation pool which are in successive connection. The system further comprises a control system, wherein the control system is connected with an aeration system and a carbon source feeding system; the control system controls the aeration of an aerator so as to allow the DO concentration of the aerobic pool to be 0.5 to 2.9 mg / L andthe ammonia nitrogen concentration of an effluent to be 0.5 to 1.5 mg / L; the carbon source feeding system comprises a nitrate nitrogen on-line monitor and a carbon source feeding device; the nitratenitrogen on-line monitor feeds a nitrate nitrogen concentration back to the control system; and when the nitrate nitrogen concentration of the effluent of the aerobic pool is higher than the set valueof 10 mg / L, the control system controls the carbon source feeding device to feed 5 to 7 units of a carbon source per unit of nitrate into the anoxic pool. According to the invention, intermittent aeration of a sewage treatment plant is realized, so the effluent stably reaches the standard, and energy consumption in aeration is saved; meanwhile, highly-efficient nitrogen removal is realized through accurate chemical feeding in an anoxic area by using the carbon source feeding system according to the nitrate nitrogen concentration of the effluent, so energy consumption in aeration can be saved,and the DO concentration of a reflux liquid is reduced; and the carbon source is accurately added according to the nitrate nitrogen concentration, so highly-efficient denitrification is realized, andthe cost of the carbon source is saved.

Description

technical field [0001] The invention relates to a denitrification system, in particular to a sewage enhanced denitrification denitrification system and a method, belonging to the field of sewage treatment. Background technique [0002] With the continuous development of the economy and the continuous improvement of environmental protection requirements, my country's water quality requirements for sewage treatment plants are becoming more and more stringent, especially for sewage treatment plants in key river basins ("three lakes and three rivers"). For water-deficient cities, the tail water of sewage treatment plants can be used as reclaimed water for urban greening, river replenishment and road irrigation, etc. Therefore, the water quality of sewage treatment plant tail water has attracted more and more attention. [0003] Urban sewage treatment plants mainly remove pollutants such as COD, TP and TN in sewage. COD in sewage can be easily removed by microorganisms. At prese...

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Problems solved by technology

[0005] In traditional sewage treatment plants, it is difficult to control the amount of aeration in the aerobic zone, resulting in excessively high dissolved oxygen, sludge aging and waste of energy consumption; excessively high dissolved oxygen in the internal reflux causes the limited carbon source in the anoxic zone to be ineffectively utilized by oxygen consumption; influent carbon source Insufficient denitrification is inhibited, and the concentration of TN in the effluent is too high, etc.

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