Sewage treatment optimizing operation system under high discharge standard

Abstract

The invention relates to a sewage treatment optimizing operation system and method under a high discharge standard, and belongs to the technical field of sewage treatment. The sewage treatment optimizing operation system comprises a pre-hypoxia tank, an anaerobic tank, a hypoxia tank, an aerobic tank, a selection tank, an oxygen elimination enhancing tank, an endogenous denitrification tank, a post-hypoxia tank, a post-aerobic tank, a secondary sedimentation tank and a deep treatment unit; a sludge backflow system is arranged between the secondary sedimentation tank and the pre-hypoxia tank, the tail end of the aerobic tank is provided with an online ammonia nitrogen instrument, the post-hypoxia tank is provided with a post-hypoxia tank carbon source putting system, and the deep treatmentunit is provided with a chemical phosphorus removal agentia putting system. According to the sewage treatment optimizing operation system, the oxygen elimination enhancing tank is arranged to controlthe carbon source loss of the hypoxia tank and the post-hypoxia tank; by optimizing setting of carbon source putting points, the tank volume utilization rate of the hypoxia tank is increased, and internal carbon sources are sufficiently utilized accordingly; through the arrangement of the endogenous denitrification tank, denitrification enhancing measures of endogenous denitrification are enhanced; meanwhile, by optimizing setting of chemical phosphorus removal agentia putting points, the biological phosphorus removal efficiency is recovered.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, and in particular relates to an optimized operation system for sewage treatment under high discharge standards. Background technique [0002] In recent years, Beijing, Tianjin and other places have promulgated and implemented local discharge standards that are more stringent than the current national standard "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002), such as the local standard promulgated by Tianjin in 2015 ( DB12 / 599-2015), the standards are divided into three grades A, B, and C, among which the discharge limit of TN in the effluent of A standard is increased from 15mg / L to 10mg / L, and it is required to be administratively effective from January 1, 2018 Sewage treatment plants with a design scale of more than 10,000 tons per day in the region shall implement the Landmark A standard. [0003] The Bardenpho process has the advantages of high denitr...

AI Technical Summary

Problems solved by technology

[0003] The Bardenpho process has the advantages of high denitrification efficiency, relatively low internal reflux ratio, and power saving. It is the mainstream process used in upgrading and renovation projects of urban sewage treatment plants or new projects under the current high discharge standards. However, the survey found that the current Bardenpho process In the system operation practice, there are still high DO concentrations in the backflow nitrification liquid and the inflow of the post-anoxic tank, serious ineffective loss of carbon sources, unreasonable setting of carbon source dosing points, underutilization of internal carbon sources, high cost of carbon source dosing, and chemical synergistic removal. Excessive dosing of phosphorus chemicals inhibits biological phosphorus removal, low pool capacity utilization, and unreasonable fan configuration. It is urgent to propose an optimal operation method for the current Bardenpho process system to guide the engineering design of urban sewage treatment plants under high discharge standards. and operation management

[0004] Taking a sewage treatment plant upgrade project using the Bardenpho process in the north as an example, the current main operational problems are as follows: ① The influent carbon source is seriously insufficient. According to statistics, the cumulative frequency of influent BOD5 / TN less than 4 in 2016 reached 64 %; ②Unreasonable fan configuration leads to excessive aeration in the aerobic tank, which leads to the end DO of the aerobic tank usually as high as 6mg / L; ③Returning nitrifying liquid and inflowing DO (6mg / L) in the post-anoxic tank leads to ineffective carbon sources The loss is serious, among which the backflow of nitrifying liquid DO leads to a carbon source loss of up to 13.2mg / LCOD at an internal reflux ratio of 220%, and the inflow of DO in the post-anoxic pool results in a loss of an external carbon source of up to 12mg / LCOD at a 100% external reflux ratio; ④ anoxic pool The unreasonable setting of carbon source dosing points (set in the first anoxic tank) leads to the pool capacity utilization rate of the anoxic tank not exceeding 50% (nitrate nitrogen has been basically denitrified and removed in the first anoxic tank), which in turn leads to The carbon source and even the influent carbon source have not been fully utilized; ⑤The design pool capacity of the aerobic pool is too large, so the utilization rate of the aerobic pool capacity usually does not exceed 70%; ⑥Excessive dosage of chemical synergistic phosphorus removal chemicals (PAC dosage 133mg / L) resulting in no biological phosphorus removal efficiency in the system

Images