Multi-membrane combined double-circulation bioreactor, multi-membrane combined double-circulation biological treatment system and low-carbon-nitrogen-ratio organic wastewater treatment method

Abstract

The invention provides a multi-membrane combined double-circulation bioreactor, a multi-membrane combined double-circulation biological treatment system and a low-carbon-nitrogen-ratio organic wastewater treatment method, and belongs to the technical field of wastewater treatment. The multi-membrane combined double-circulation bioreactor is reasonable in structural arrangement and can realize double internal circulation, and when the multi-membrane combined double-circulation biological treatment system based on the multi-membrane combined double-circulation bioreactor is used for treating low-carbon-nitrogen-ratio organic wastewater, a carbon source and a phosphorus removal agent are not added, and an advanced treatment unit is not additionally arranged; meanwhile, under the conditions of low energy consumption and low residual sludge yield, stable and efficient nitrogen and phosphorus removal effects can be realized; in addition, the suspended sludge amount and transmembrane pressure difference in the treatment process can be reduced, the reduction of membrane flux is delayed, the service life and the working period of the membrane are prolonged, and the investment and operation maintenance cost of a treatment system is saved.

Description

technical field [0001] The invention relates to the technical field of waste water treatment, in particular to a multi-membrane combined double-cycle bioreactor, a multi-membrane combined double-cycle biological treatment system and a method for treating organic waste water with a low carbon-to-nitrogen ratio. Background technique [0002] Township domestic sewage treatment is one of the key points of water pollution control at present, and its treatment projects are characterized by geographical dispersion, small scale, and lack of funds and operation management talents. The membrane-bioreactor (MBR) treatment technology combined with biological treatment technology and membrane separation technology has the advantages of small footprint, high treatment efficiency, and good effluent quality, avoiding the occupation caused by the traditional urban sewage treatment plant treatment process. Large land area, inconvenient operation and management, and high energy consumption per...

AI Technical Summary

Problems solved by technology

However, when the traditional activated sludge MBR process treats organic wastewater with a low carbon-to-nitrogen ratio (C / N) with a certain amount of ammonia nitrogen and total phosphorus, due to the low C / N (usually 2 to 16), biological nitrogen removal is prone to occur. Poor phosphorus effect, effluent total nitrogen and total phosphorus are not up to standard, usually need to add carbon source and phosphorus removal agent (such as polyaluminum chloride, abbreviated as PAC), etc., and even need to increase advanced treatment to meet GB18918-2002 Level A standard

[0003] Compared with conventional biological treatment, the total aeration demand of the MBR process increases by about 50% during actual operation, because in addition to the oxygenation and aeration required for the growth and reproduction of microorganisms, it is also necessary to use the aeration airflow to perform a certain intensity on the membrane. Continuous flushing, high energy consumption; In addition, the sludge concentration in the membrane pool is relatively high, the transmembrane pressure difference increases and the membrane flux decreases rapidly, and the service life and working cycle of the membrane are affected. Increased investment and maintenance costs; at the same time, the process produces a large amount of residual sludge, which increases the difficulty of sludge treatment

These shortcomings have seriously hindered the popularization and application of MBR technology in the field of domestic sewage treatment in towns and villages.

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