Process and device adopting aerobic nitrification filter in middle and anoxic denitrification filters at two ends

Abstract

The invention discloses a process and a device adopting an aerobic nitrification filter in middle and anoxic denitrification filters at two ends. The device comprises a two-end denitrification system and a program automatic-control system, wherein the two-end denitrification system is formed by serially connecting a front-section anoxic denitrification filter, a middle water tank, a middle-section aerobic nitrification filter, a rear-section anoxic denitrification filter and a clear water tank; the front-section anoxic denitrification filter completes the front-section denitrification process by fully using carbon sources in to-be-treated sewage, the middle-section aerobic nitrification filter completes the nitrification process, the rear-section anoxic denitrification filter completes the denitrification and advanced nitrogen removal process of remaining nitrate of an external carbon source, and the program automatic-control system adjusts the optimal operation condition of the system according to collected and analyzed data. With the adoption of the process and the device, the purpose of advanced nitrogen removal of sewage can be achieved, and the process and the device have the remarkable characteristics of saving investment cost, being low in operation cost and the like.

Description

technical field [0001] The invention belongs to the technical field of water treatment, and specifically relates to a process and a device for a center-mounted aerobic nitrification and anoxic denitrification filter at both ends, which can be applied to Kjeldahl nitrogen concentration and BOD 5 Treatment of municipal sewage and industrial wastewater with high concentration. Background technique [0002] The focus of water pollution control has shifted from simple organic pollution control to the study of eutrophication caused by nutrients such as nitrogen, and the deep denitrification of sewage has become the difficulty and the core. Sewage can be divided into three types of sewage according to different carbon-nitrogen ratio ranges: specifically, the first type of sewage (0≤BOD 5 / TN<1), the second type of sewage (1≤BOD 5 / TN<3), the third type of sewage (3≤BOD 5 / TN). Traditional biological filter denitrification process and devices include pre-denitrification de...

AI Technical Summary

Problems solved by technology

The engineering practice and long-term research of a large number of companies show that this process has many disadvantages in the treatment of municipal sewage or industrial wastewater with high Kjeldahl nitrogen concentration: on the one hand, it is difficult to achieve the purpose of deep denitrification (surface water environmental quality standard , TN≤5mg / L); on the other hand, the process must adopt a high nitrification liquid reflux ratio, which will have many disadvantages, such as in the second and third types of municipal sewage or industrial wastewater, generally in The denitrification section of the first stage needs to supplement the denitrification carbon source. Since the concentration of Kjeldahl nitrogen (organic nitrogen and ammonia nitrogen) is usually higher than 45mg / L, when the total nitrogen in the effluent is less than 15mg / L, the reflux ratio of the nitrification solution is It will be as high as 200%~1300% (the higher the concentration of Kjeldahl nitrogen, the higher the reflux ratio of nitrifying liquid)

High reflux ratio of nitrifying liquid has disadvantages: ①High reflux ratio means that the size of structures with the same residence time, power consumption of backwash fan, and power consumption of aeration fan will increase exponentially, which is very unfavorable for investment and operation cost control; ②High The reflux ratio means that more dissolved oxygen will be carried into the denitrification filter. The increase of dissolved oxygen will not only seriously inhibit denitrification, but also reduce the efficiency of denitrification and carbon removal of sewage. This time, the filter layer will form an aerobic- In the anoxic-anaerobic reaction zone, aerobic microorganisms will consume many biodegradable carbon sources, which will undoubtedly increase the dosage of carbon sources in the denitrification section, thereby significantly increasing the cost of sewage treatment

Images