Sewage treatment optimization operation system based on changing anaerobic tank into enhanced degassing zone

Abstract

The invention belongs to the technical field of sewage treatment. A sewage treatment optimization operation system comprises an enhanced degassing zone, an anoxic tank, an aerobic tank, a degassing zone, a water outlet zone, a secondary sedimentation tank and a biological tank water inlet system; the anoxic tank is provided with a carbon source adding system, a chemical synergistic dephosphorization dosing system is arranged in the water outlet zone, the enhanced degassing zone is connected with the anoxic tank, the anoxic tank is connected with the aerobic tank, the aerobic tank is connectedwith the degassing zone, the degassing zone is connected with the water outlet zone, a nitrifying liquid backflow system is arranged between the degassing zone and the enhanced degassing zone, a sludge backflow system is arranged between the secondary sedimentation tank and the enhanced degassing zone, and an on-line phosphate meter is arranged at the biological tank water inlet system; and an anaerobic tank is changed into the enhanced degassing zone, and feeds are a backflow nitrifying liquid and backflow sludge. The operation system provided by the invention has the advantages of simple running and operation, a high utilization rate of a carbon source, a good enhanced denitrification effect, significantly-reduced carbon source addition costs, a low addition amount of a phosphorus removal agent, and low operation energy consumption.

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 based on an anaerobic pool instead of a strengthened degassing zone. 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] Sewage treatment p...

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Problems solved by technology

[0003] Sewage treatment plants in industrial parks are important centralized treatment facilities and an important link in water pollution prevention and control. However, under the current high discharge standards, there are generally serious shortages of carbon sources in the influent water and ineffective loss of carbon sources caused by DO in the operation of sewage treatment plants in industrial parks in my country. Large volume, no anaerobic phosphorus release in anaerobic tank, low level of refined management, high energy consumption and material consumption, etc., urgently need to propose optimal operation methods for industrial park sewage treatment plants under high discharge standards, so as to guide their stable compliance and energy saving reduction. consumption

[0004] Taking a sewage treatment plant in an industrial park in the north as an example, the main design process is the UCT process. The current main operational problems are as follows: ① Influential carbon sources are seriously insufficient. According to statistics, the cumulative frequency of influent BOD5 / TN is less than 4 in a year As high as 88%; ②Excessive aeration in the aerobic tank (dosing with suspended filler) results in the DO of the nitrification liquid returning from the degassing zone still as high as about 7mg / L, which in turn leads to a carbon source loss of up to 14mg / L at an internal return ratio of 200% LCOD; ③The return sludge usually contains 2-3 mg / L DO due to the reoxygenation effect of the falling water during the return process, which leads to a carbon source loss of 2-3 mg / L chemical oxygen demand at 100% external return ratio ④ The design hydraulic retention time of the anoxic tank is too small (3h), and the internal reflux from the anoxic tank to the anaerobic tank under the UCT process (the current internal reflux ratio is about 150%) further aggravates the actual hydraulic capacity of the anoxic tank. The problem of insufficient residence time affects its denitrification performance; ⑤The carbon source dosage and dosage are high, the average dosage of sodium acetate is 87.5mg / L, and the dosage cost is about 0.6 yuan / ton of water; ⑥Chemical synergy Excessive dosage of phosphorus removal agent leads to no anaerobic phosphorus release effect in the anaerobic pond. When the influent phosphate is usually lower than 1mg / L, the dosage of chemical synergistic phosphorus removal agent PAC (effective content 8%) is as high as 140mg / L

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