Modified sequencing batch reactor (MSBR) process for sewage treatment

Abstract

The invention relates to improvement on the traditional modified sequencing batch reactor (MSBR) process. The process is characterized in that: jet aeration working solution of an aerobic tank is from an anoxic tank, the liquid level of the aerobic tank is raised to exceed the liquid level of the anoxic tank through the jet aeration working solution supplied by the anoxic tank, and mixed liquid of the aerobic tank overflows and automatically flows through a liquid level difference and is refluxed to the anoxic tank according to design reflux quantity; aeration devices in two alternate sequencing batch areas perform jet aeration, so that reflux from the aerobic tank to the anoxic tank is unpowered overflow reflux, reflux energy consumption is reduced, aeration oxygen transfer efficiency can be improved by 20 to 30 percent, the energy consumption of the aerobic tank and the anoxic tank in the section can be reduced by 10 to 20 percent, the liquid levels of the aerobic tank and a subsequent treatment unit tank can be raised by 50 to 80cm compared with the original liquid levels, automatic flow treatment is reduced, tank depth engineering construction cost is reduced, the civil engineering investment of a treatment tank can be saved by 10 to 20 percent, and the energy consumption of a lifting pump can be reduced; and jet aerators are arranged in the two alternate sequencing batch areas, and the jet aeration working solution is provided by the other tank, so that an aeration oxygen transfer rate and denitrification efficiency are improved, stirring equipment is eliminated, an aeration system is difficult to damage, and the service life is prolonged.

Description

technical field [0001] The invention is an improvement to the traditional sewage treatment MSBR process, and in particular relates to a sewage treatment MSBR process with high aeration, oxygenation and transfer efficiency, low system operation energy consumption and high denitrification efficiency. Background technique [0002] MSBR (Modified Sequencing Batch Reactor) is an improved sequencing batch reactor, actually composed of A 2 The / O process is connected in series with the SBR system. MSBR does not need to set up primary settling tanks and secondary settling tanks. Drainage, to maximize the pool capacity and equipment utilization, is widely used in municipal sewage and various industrial wastewater treatment. The MSBR reactor usually consists of 7 units to form a rectangular pool, and the typical layout is as follows figure 1 As shown, it includes an aerobic pool 3, sequence batch pools (SBR pools) 4 and 5 opposite to each other at both ends of the aerobic pool 3, an...

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Problems solved by technology

The sequence batch tank is mainly used to replace the secondary settling tank for mud-water separation. Although the process makes aerobic, anoxic and anaerobic changes in time, the denitrification effect is not strong, and it is obviously not as good as the space-separated A / O process. Nitrogen is strong, which is why the denitrification effect of MSBR process is not as good as that of the completely independent anoxic / aerobic pool system

[0003] In the existing MSBR process, the nitrifying liquid in the aerobic tank flows back to the anoxic tank, basically without exception, it is similar to other biological denitrification, and the part of the nitrifying liquid in the aerobic tank is directly transported through pumps, air lifts and other mechanical transportation methods (pump or gas) mention) backflow to the anoxic pool, since the biological denitrification return flow rate is usually 100-300%, objectively resulting in a large power consumption for backflow transportation, resulting in relatively high energy consumption in this section of the operation, for the daily processing capacity of tens of thousands or even Hundreds of thousands of tons of sewage treatment station, the pump (power) to return the liquid is not a small amount of energy consumption

[0004] In addition, in the existing MSBR process, aerobic tank 3 and sequence batch tank 4 / 5 are aerated and supplied with oxygen, and microporous or mesoporous aerators are mostly used. Due to the service life of microporous or mesoporous aerators in sewage treatment Usually only 2-3 years, which objectively results in a short service life of the aeration system; and the aeration system is installed at the bottom of the pool, which makes maintenance complicated. If a small amount of damage is not actually repaired, it will not only increase the consumption of aeration power, but also cause partial aeration. Damage to the device causes a drop in dissolved oxygen efficiency (the microporous aerator is broken, causing most of the air to escape from the crack, and the oxygen transfer efficiency drops sharply), which also increases the operating energy consumption

[0005] In addition, the aeration of mesopores and micropores has little stirring effect on the mixed liquid, while the area of ​​the aerobic tank and the alternate sequence batch tank is usually large. In order to fully mix the mud and water in the treatment tank, it is usually necessary to set up a stirring device separately, which increases the equipment. invest

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