CN-122006491-A - Nanofiltration membrane service life evaluation method and system for water treatment and electronic equipment

CN122006491ACN 122006491 ACN122006491 ACN 122006491ACN-122006491-A

Abstract

The invention belongs to the technical field of water treatment, and particularly relates to a nanofiltration membrane service life evaluation method, a nanofiltration membrane service life evaluation system and electronic equipment for water treatment. The method comprises the steps of constructing a multidimensional evaluation index system covering membrane performance of the nanofiltration membrane, running cost of the nanofiltration membrane and effluent quality of the nanofiltration membrane, determining index weight by combining a subjective and objective comprehensive weighting method, establishing a quantitative evaluation model, and judging whether the nanofiltration membrane needs to be replaced or not by calculating a comprehensive evaluation index and comparing a preset threshold value. The invention solves the problems that the existing nanofiltration membrane replacement condition depends on manual experience, lacks objective judgment basis and has insufficient rationality, maximizes the use value of the nanofiltration membrane on the premise of ensuring that the effluent quality reaches the standard, reduces the comprehensive operation cost of a drinking water treatment system, and is suitable for various drinking water treatment nanofiltration systems.

Inventors

QIAN HAO
XIA PING
XU LIKE
JIANG SHUHONG
ZHENG YOUWEN
ZHANG HUA
WU WENCHAO
HONG XUEQIAN

Assignees

上海城市水资源开发利用国家工程中心有限公司
上海城投水务（集团）有限公司制水分公司

Dates

Publication Date: 20260512
Application Date: 20260122

Claims (10)

1. A method for evaluating the service life of a nanofiltration membrane for water treatment is characterized by comprising the following steps: Acquiring attribute data of the nanofiltration membrane, wherein the attribute data comprise membrane performance of the nanofiltration membrane, running cost of the nanofiltration membrane and effluent quality of the nanofiltration membrane; preprocessing the attribute data of the nanofiltration membrane to obtain standardized data of the nanofiltration membrane; inputting the standardized data of the nanofiltration membrane into a nanofiltration membrane evaluation system model to obtain a comprehensive evaluation index of the nanofiltration membrane; And judging whether to replace the nanofiltration membrane according to the comprehensive evaluation index of the nanofiltration membrane.
2. The method of claim 1, further comprising constructing a nanofiltration membrane evaluation system model based on a weighting method: , w i =Aw si +Bw oi , Wherein E is a comprehensive evaluation index, the value range of E is [0,1], n is the total number of evaluation indexes, x i ' is standardized data of the ith index, w i is the comprehensive weight of the ith index, w si is the subjective weight of the ith index, w oi is the objective weight of the ith index, A is the proportion of the subjective weight, B is the proportion of the objective weight, A+B=1, and 1> B > A >0.
3. The method of claim 1, wherein preprocessing the attribute data of the nanofiltration membrane to obtain standardized data of the nanofiltration membrane comprises: calculating index data of the membrane performance according to the current data of the membrane performance and the historical acquisition data of the membrane performance, calculating index data of the operation cost according to the current data of the operation cost and the historical acquisition data of the operation cost, and calculating index data of the water quality according to the current data of the water quality and the historical acquisition data of the water quality, wherein the index data of the membrane performance, the index data of the operation cost and the index data of the water quality are the index data of the nanofiltration membrane; carrying out forward treatment on index data of the nanofiltration membrane and historical index data of the corresponding nanofiltration membrane to obtain forward treatment data of the nanofiltration membrane; Normalizing the forward data of the nanofiltration membrane to obtain normalized data of the nanofiltration membrane.
4. A method according to claim 3, wherein calculating the index data of the membrane performance from the current data of the membrane performance and the historical acquisition data of the membrane performance comprises: membrane flux decay rate = (J 0 J t )/J 0 ×100%, Rate of decrease in retention for sulfate group= (R 0 R t )/R 0 ×100%, Transmembrane pressure differential increase rate= (TMP) t TMP 0 )/TMP 0 ×100%, Wherein J 0 is the initial flux of the new membrane, J t is the current operating membrane flux, R 0 is the initial rejection rate, rt is the current rejection rate, TMP 0 is the initial transmembrane pressure difference of the new membrane, TMP t is the current transmembrane pressure difference, the initial flux of the new membrane, the initial rejection rate, and the initial transmembrane pressure difference of the new membrane are historical collected data of membrane performance, and the current operating membrane flux, the current rejection rate, and the current transmembrane pressure difference are current data of membrane performance.
5. The method of claim 3, wherein the step of, The forward processing of the index data of the nanofiltration membrane and the history index data of the corresponding nanofiltration membrane to obtain forward data of the nanofiltration membrane comprises the following steps: The index data of the membrane performance and the corresponding historical index data are obtained by a reciprocal method to obtain forward data of the membrane performance, the index data of the running cost and the corresponding historical index data are obtained by a reciprocal method to obtain forward data of the running cost, the index data of the effluent quality and the corresponding historical index data are the forward data of the effluent quality, and if the index data of the nanofiltration membrane is 0, the minimum epsilon=10 is adopted 6 Instead of 0, forward data of membrane performance, forward data of running cost and forward data of effluent quality are forward data of nanofiltration membrane; the normalizing the forward data of the nanofiltration membrane to obtain the normalized data of the nanofiltration membrane comprises the following steps: And mapping all the forward data to a [0,1] interval based on x' = (x + -x + min )/(x + max -x + min ), wherein x + is forward data of index data, x + max is a maximum value of forward historical index data corresponding to the index, and x + min is a minimum value of forward historical index data corresponding to the index.
6. The method of claim 1, wherein said determining whether to replace the nanofiltration membrane based on the integrated evaluation index comprises: when the comprehensive evaluation index is greater than the forced replacement threshold, judging that replacement is not needed; When the comprehensive evaluation index is less than or equal to the forced replacement threshold value, the replacement is judged to be necessary, wherein, The forced replacement threshold is preset according to the minimum requirements of the drinking water quality standard and the membrane performance limit.
7. The method of claim 6, wherein determining that replacement is not needed when the integrated rating index > forced replacement threshold further comprises: Setting an early warning threshold based on the upper limit of unit water production cost and the water quality standard allowance, setting a reminding threshold according to the rated service life and the average decay rate of the membrane, wherein the reminding threshold is greater than the early warning threshold and greater than the forced replacement threshold; When the comprehensive evaluation index is greater than the reminding threshold value, the operation state of the nanofiltration membrane is prompted to be good, and no significant attenuation exists; When the reminding threshold value is more than or equal to the comprehensive evaluation index > early warning threshold value, prompting the performance of the film to start to decay, and suggesting continuous monitoring of index change; When the early warning threshold value is more than or equal to the comprehensive evaluation index > forced replacement threshold value, the film performance is prompted to be seriously attenuated, and a replacement plan is recommended to be made and replaced within 1-3 months.
8. An evaluation system for lifetime of nanofiltration membrane for water treatment, comprising: The construction module is used for constructing a nanofiltration membrane evaluation system model based on a weight method; The acquisition and preprocessing module is used for acquiring attribute data of the nanofiltration membrane, and preprocessing the attribute data of the nanofiltration membrane to obtain standardized data of the nanofiltration membrane; the model processing module is used for substituting the standardized data into a nanofiltration membrane evaluation system model to obtain a comprehensive evaluation index of the nanofiltration membrane; And the evaluation module is used for judging whether the nanofiltration membrane is replaced or not according to the comprehensive evaluation index.
9. An electronic device, wherein the electronic device comprises: Processor, and A memory storing computer executable instructions that, when executed, cause the processor to perform the method of any of claims 1-7.
10. A computer readable storage medium, wherein the computer readable storage medium stores one or more programs which, when executed by a processor, implement the method of any of claims 1-7.

Description

Nanofiltration membrane service life evaluation method and system for water treatment and electronic equipment Technical Field The invention belongs to the technical field of water treatment, and particularly relates to a nanofiltration membrane service life evaluation method, a nanofiltration membrane service life evaluation system and electronic equipment for water treatment. Background Nanofiltration membrane (Nanofiltration Membranes) is used as an important branch of membrane separation technology, the separation performance of the nanofiltration membrane is between ultrafiltration and reverse osmosis, and the molecular weight of the nanofiltration membrane can be accurately intercepted to be 200Organic matters (such as dye and humic acid) of 2000Da and salt ions (such as divalent anions) have important application value in the scenes of advanced treatment of industrial wastewater, purification of drinking water and the like. Nanofiltration membrane is a core component of the drinking water advanced treatment system, and the running state of the nanofiltration membrane directly influences the quality of effluent water and the treatment cost. In the long-term operation process, the nanofiltration membrane can be attenuated due to pollution, abrasion and other problems, and needs to be replaced in time to ensure the water supply safety. Currently, the judgment of nanofiltration membrane replacement nodes in the water treatment industry is mainly based on a single index (such as membrane flux reduction and membrane-spanning pressure difference doubling) or the operation experience of staff. The method has the obvious defects that only the membrane performance parameters are concerned, the cooperative influence of the operation cost and the water quality standard boundary is ignored, and the replacement decision is either too conservative (membrane resource waste is caused by too early replacement) or too dangerous (water quality exceeding standard or energy consumption surge is caused by too late replacement). In the prior art, a set of multidimensional and quantitative evaluation system is lacking, the relationship among water quality guarantee, membrane service life and operation cost cannot be balanced, and scientific and reasonable node replacement suggestions are difficult to be given. Therefore, it is highly desirable to construct a life evaluation method and system for a comprehensive multi-factor nanofiltration membrane. Disclosure of Invention The invention aims to provide a multi-dimensional and quantitative evaluation system which balances the relationship among water quality guarantee, membrane service life and operation cost and provides scientific and reasonable node replacement suggestions. The aim of the invention is realized by the following technical scheme: In a first aspect of the present invention, the present invention provides a method for evaluating the lifetime of a nanofiltration membrane for water treatment, comprising: Acquiring attribute data of the nanofiltration membrane, wherein the attribute data comprise membrane performance, running cost and effluent quality of the nanofiltration membrane; And inputting the standardized data of the nanofiltration membrane into a nanofiltration membrane evaluation system model to obtain a comprehensive evaluation index of the nanofiltration membrane, and judging whether to replace the nanofiltration membrane according to the comprehensive evaluation index of the nanofiltration membrane. In some embodiments of the invention, the method further comprises constructing a nanofiltration membrane evaluation system model based on a weighting method: , wi=Awsi+Bwoi, The method comprises the steps of determining a comprehensive evaluation index, wherein the value range [0,1] of E is the total number of evaluation indexes, x i' is standardized data of an ith index, w i is the comprehensive weight of the ith index, w si is the subjective weight of the ith index, the subjective weight is determined through an AHP expert survey, w oi is the objective weight of the ith index, the objective weight is determined through an entropy weight method based on historical standardized data of a nanofiltration membrane, the historical standardized data of the nanofiltration membrane corresponds to standardized data attributes of the nanofiltration membrane, A is the ratio of the subjective weight, B is the ratio of the objective weight, A+B=1, and 1> B > A >0. In some embodiments of the present invention, the preprocessing the attribute data of the nanofiltration membrane to obtain standardized data of the nanofiltration membrane includes: calculating index data of the membrane performance according to the current data of the membrane performance and the historical acquisition data of the membrane performance, calculating index data of the operation cost according to the current data of the operation cost and the historical acquisition data of the operation cost,