Optimized chemical dosing method of membrane subassembly backwashing of membrane bioreactor

Abstract

The invention discloses an optimized chemical dosing method of membrane subassembly backwashing of a membrane bioreactor. Operation of the membrane bioreactor is carried out at a constant water yield. The optimized chemical dosing method comprises following steps: a current membrane flux change rate dJ / dt of a membrane subassembly of the membrane bioreactor in a continuous water production period is calculated; a membrane flux change rate reference value mu is set, and the specific ratio (R) of the current membrane flux change rate dJ / dt of the membrane subassembly of the membrane bioreactor in the continuous water production period to the membrane flux change rate reference value mu is calculated, R=(dJ / dt) / mu; the value of R is compared with a threshold value, if the value of R is in a threshold value range, chemical dosing amount of membrane subassembly backwashing of the membrane bioreactor is adjusted, otherwise, the chemical dosing amount of membrane subassembly backwashing of the membrane bioreactor is not adjusted. According to the optimized chemical dosing method, the chemical dosing amount is adjusted based on practical situations of membrane contamination so as to eliminate MBR membrane pollution at a forming stage, avoiding collaborative deterioration effect caused because of delayed membrane pollution control, saving time, and prolonging service life of the membrane subassembly.

Description

technical field [0001] The invention relates to the technical field of sewage treatment. More specifically, the present invention relates to an optimized dosing method for membrane module backwashing of a membrane bioreactor. Background technique [0002] MBR membrane bioreactor is a new method of sewage treatment that combines activated sludge method and membrane separation technology, and replaces the secondary sedimentation tank in traditional conventional activated sludge method with membrane separation technology. Compared with the traditional activated sludge method, it has many advantages such as good and stable effluent quality, less residual sludge output, small footprint, easy installation, and convenient operation. At the same time, in the actual application process, the membrane fouling of the MBR membrane module during operation will cause the membrane flux to decay rapidly, and the required membrane area will increase, resulting in an increase in investment. ...

AI Technical Summary

Problems solved by technology

There are some problems in this cleaning method, such as 1) when the chemical cleaning is started, the membrane fouling has accumulated to a certain extent, which increases the difficulty of chemical cleaning; The minimum critical membrane flux does not guarantee complete cleaning of the membrane components; 3) The dosing amount is added according to experience, and the quantification requirements are low; or the maximum dosing amount is set for cleaning, which will cause a certain degree of waste of chemicals when the membrane fouling is relatively light

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