A method for standardizing reverse osmosis operation data

Abstract

The present invention relates to a method for standardizing reverse osmosis operation data. According to the positional relationship between pollution, erosion and the performance change of membrane elements, a method for arranging and combining reverse osmosis systems is proposed, which realizes the reflection of standard data on the performance decline of membrane elements in different parts. At the same time, standard parameters for reverse osmosis operation data standardization (i.e., relative change rate of standard permeate water flow, relative change rate of standard differential pressure, change rate of standard salt rejection rate) are proposed. According to the magnitude of the values, it can be judged whether the system has normal performance attenuation or rapid deterioration, and directly diagnose the reasons for the performance decline of the reverse osmosis system, and take corresponding disposal measures in time to avoid irreversible decline of the reverse osmosis system performance. It has a high diagnostic accuracy and good use effect, is an innovation in the method for standardizing reverse osmosis operation data, and has good social and economic benefits.

Description

Technical Field

[0001] The present invention relates to a reverse osmosis device in a water treatment system, and more particularly to a method for standardizing reverse osmosis operation data. Background Art

[0002] Reverse osmosis water treatment technology is an advanced water treatment desalination technology in modern times, and is widely used in industries such as electric power, chemical industry, petroleum, beverage, steel, pharmaceutical, electronics, municipal administration, and environmental protection.

[0003] Currently, the main performance changes of reverse osmosis devices are mainly measured by the desalination rate of the standard system, the differential pressure of the standard system, and the permeate water flow rate of the standard system. When the surface of the reverse osmosis membrane is fouled by inorganic scale, metal oxides, microorganisms, colloidal particles, and organic matter, the faults of the reverse osmosis system are manifested as changes in the desalination rate of the standard system, the permeate water flow rate of the standard system, and the differential pressure of the standard system. These three indicators may change simultaneously, or a certain indicator may change alone or two indicators may change simultaneously. Because the standard system data cannot reflect the performance degradation of membrane elements in different parts, in actual operation, it is very difficult for these three parameters to directly reflect whether the system has the following problems:

[0004] 1) The parts where the desalination rate of the membrane elements in the system decreases, such as the first membrane element in the system, the last membrane element in the system, a certain membrane element in the system, and the general decrease of the membrane elements in the system.

[0005] 2) The fouled parts of the water flow channels of the membrane elements in the system.

[0006] 3) The parts of mechanical damage (such as mechanical damage or abrasion on the membrane surface, damage or deformation of the O-ring, disconnection or leakage at the membrane bag seal).

[0007] Due to the non-intuitive nature of the existing standardized data for determining the fault location, the operation personnel are inaccurate in judging the cause of reverse osmosis pollution. Taking improper measures not only delays the treatment and is not conducive to restoring the system performance, but also concurrently causes other problems such as compound pollution and unqualified product water. The causes of reverse osmosis pollution can be divided into scale pollution, organic matter pollution, microbial pollution, etc. Different pollution causes should take different measures. For example, for scale pollution, the system recovery rate, the dosage of scale inhibitor, and the scaling tendency of the feed water should be corrected or calculated; for colloid pollution, the SDI of the reverse osmosis feed water should be calculated, and the dosages of coagulant and flocculant in the pretreatment system should be verified. Therefore, its improvement and innovation are imperative. Summary of the Invention

[0008] In view of the above situation, in order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a method for standardizing reverse osmosis operation data, which can effectively solve the problem of reverse osmosis system fault monitoring.

[0009] The technical solution solved by the present invention is:

[0010] A reverse osmosis operation data standardization method, including a reverse osmosis system, and the arrangement combination of the reverse osmosis system is 2-2-1-1;

[0011] The data standardization method includes the following steps:

[0012] Step 1: Taking the reference state as the starting state of a new membrane or stable operation after membrane cleaning, calculate the following performance parameters: SR n1-0 , Δp n1-0 , Q pn1-0 , SR n2-0 , Δp n2-0 , Q pn2-0 , SR n3-0 , Δp n3-0 , Q pn3-0 , SR n4-0 , Δp n4-0 , Q pn4-0 ;

[0013] After an interval of 7 days, calculate the following performance parameters SR n1-7 , Δp n1-7 , Q pn1-7 , SR n2-7 , Δp n2-7 , Q pn2-7 , SR n3-7 , Δp n3-7 , Q pn3-7 , SR n4-7 , Δp n4-7 , Q pn4-7 ;

[0014] The meanings of the above letters are:

[0015] The standard desalination rate SR of the first stage n1 , the standard pressure difference Δp of the first stage n1 , the standard permeate water flow rate Q of the first stage pn1 , the standard desalination rate SR of the second stage n2 , the standard pressure difference Δp of the second stage n2 , the standard permeate water flow rate Q of the second stage pn2 , the standard desalination rate SR of the third stage n3 , the standard pressure difference Δp of the third stage n3 , the standard permeate water flow rate Q of the third stage pn3 , the standard desalination rate SR of the fourth stage n4 , the standard pressure difference Δp of the fourth stage n4 , the standard permeate water flow rate Q of the fourth stage pn4 .

[0016] For example: SR n1-0 is the standard desalination rate of the first stage of the reverse osmosis system in the starting state, SR n1-7The standard desalination rate of the first stage, SR, after the reverse osmosis system starts timing from the initial state and operates for 7 days n1-14 The standard desalination rate of the first stage after the reverse osmosis system starts timing from the initial state and operates for 14 days, and so on

[0017] And so on, calculate the performance parameters of the first, second, third, and fourth stages of the reverse osmosis system every 7 days respectively

[0018] When the standard permeate water flow rate of the membrane element drops by more than 15% compared to the initial state, or the standard desalination rate drops by more than 10% compared to the initial state, or the standard differential pressure rises by more than 15% compared to the initial state, stop the calculation

[0019] Step 2: Calculate the standardized parameters of the reverse osmosis operation data; the standardized parameters are: the relative change rate of the standard permeate water flow rate of the first stage, ΔΦ n1-m,m+7 , the average value of the relative change rate of the standard permeate water flow rate of the first stage The relative change rate of the standard differential pressure of the first stage, ΔΨ n1-m,m+7 , the average value of the relative change rate of the standard differential pressure of the first stage The change rate of the standard desalination rate of the first stage, Δη n1-m,m+7 , the average value of the change rate of the standard desalination rate of the first stage The relative change rate of the standard permeate water flow rate of the second stage, ΔΦ n2-m,m+7 , the average value of the relative change rate of the standard permeate water flow rate of the second stage The relative change rate of the standard differential pressure of the second stage, ΔΨ n2-m,m+7 , the average value of the relative change rate of the standard differential pressure of the second stage The change rate of the standard desalination rate of the second stage, Δη n2-m,m+7 , the average value of the change rate of the standard desalination rate of the second stage The relative change rate of the standard permeate water flow rate of the third stage, ΔΦ n3-m,m+7 , the average value of the relative change rate of the standard permeate water flow rate of the third stage The relative change rate of the standard differential pressure of the third stage, ΔΨ n3-m,m+7 , the average value of the relative change rate of the standard differential pressure of the third stage The change rate of the standard desalination rate of the third stage, Δη n3-m,m+7 , the average value of the change rate of the standard desalination rate of the third stage The relative change rate of the standard permeate water flow rate of the fourth stage, ΔΦ n4-m,m+7 , the average value of the relative change rate of the standard permeate water flow rate of the fourth stage The relative change rate of the standard differential pressure of the fourth stage, ΔΨ n4-m,m+7 , the average value of the relative change rate of the standard differential pressure of the fourth stage The change rate of the standard desalination rate of the fourth stage, Δη n4-m,m+7 , the average value of the change rate of the standard desalination rate of the fourth stage

[0020] Step 3: Analyze the above calculation results and take corresponding measures

[0021] When the change rate of the reverse osmosis operation data normalization parameter is less than 0.5 times the average value or higher than 2.0 times the average value, it indicates that there are fault manifestations in the reverse osmosis water treatment system;

[0022] 1) When ΔΦ n1-m,m+7 <0.5 ΔΨ n1-m,m+7 <0.5 Δη n1-m,m+7 >2.0 0.5 <ΔΦ n2-m,m+7 <2.0 0.5 <ΔΨ n2-m,m+7 <2.0 0.5 <Δη n2-m,m+7 <2.0 it indicates that the addition of acid to the reverse osmosis system is excessive, causing hydrolysis of the membrane. The pH meter of the reverse osmosis feed water should be calibrated, and the acid addition system should be checked;

[0023] 2) When ΔΦ n1-m,m+7 <0.5 ΔΨ n1-m,m+7 <0.5 Δη n1-m,m+7 >2.0 ΔΦ n2-m,m+7 <0.5 ΔΨ n2-m,m+7 <0.5 Δη n2-m,m+7 >2.0 it indicates that there is oxidative erosion in the reverse osmosis system. The oxidation-reduction potential analyzer of the reverse osmosis feed water should be calibrated, and the reducing agent dosing system should be checked;

[0024] 3) When 0.5 <ΔΦ ni-m,m+7 <2.0 0.5 <ΔΨ ni-m,m+7 <2.0 Δη ni-m,m+7 >2.0 at this time, i is 1, 2, 3, 4, indicating that there is a membrane module with leakage from the concentrated water side to the fresh water side in the membrane module of the pressure vessel in the i-th stage. The conductivity of the permeate water of each membrane module in this stage should be checked to determine the membrane module with problems;

[0025] 4) When ΔΦ n1-m,m+7 >2.0 ΔΨ n1-m,m+7 >2.0 Δη n1-m,m+7 > 2.0 0.5 <ΔΦ n2-m,m+7 <2.0 0.5 <ΔΨ n2-m,m+7 <2.0 0.5 <Δη n2-m,m+7 <2.0 When this occurs, it indicates that there is metal corrosion product pollution in the reverse osmosis system, and the selection of materials before the reverse osmosis system should be checked;

[0026] 5) When ΔΦ n1-m,m+7 >2.0 ΔΨ n1-m,m+7 >2.0 Δη n1-m,m+7 >2.0 ΔΦ n2-m,m+7 >2.0 ΔΨ n2-m,m+7 >2.0 Δη n2-m,m+7 >2.0 When this occurs, it indicates that there is colloid pollution in the reverse osmosis system. The intercepted substances of the SDI filter should be analyzed, and whether there is pollution in the water tank and pipeline of the raw water pretreatment system should be checked, and the dosages of coagulant and coagulant aid in the pretreatment system should be calculated;

[0027] 6) When ΔΦ n1-m,m+7 >2.0 ΔΨ n1-m,m+7 >2.0 Δη n1-m,m+7 <0.5 ΔΦ n2-m,m+7 >2.0 ΔΨ n2-m,m+7 >2.0 Δη n2-m,m+7 <0.5 When this occurs, it indicates that there is organic matter pollution in the reverse osmosis system. The intercepted substances of the SDI filter should be analyzed, and the TOC value of the reverse osmosis influent should be monitored;

[0028] 7) When ΔΦ n1-m,m+7 >2.0 0.5 <ΔΨ n1-m,m+7 <2.0 0.5 <Δη n1-m,m+7 <2.0 ΔΦ n2-m,m+7 >2.0 0.5 <ΔΨ n2-m,m+7< 2.0 0.5 < Δη n2-m,m+7 < 2.0 When it is, it indicates that there is microbial contamination in the reverse osmosis system, and the reverse osmosis system should be thoroughly cleaned. At the same time, the pipelines, water tanks, and filters should be disinfected and inspected;

[0029] 8) When 0.5 < ΔΦ n2-m,m+7 < 2.0 0.5 < ΔΨ n2-m,m+7 < 2.0 0.5 < Δη n2-m,m+7 < 2.0 ΔΦ n4-m,m+7 > 2.0 ΔΨ n4-m,m+7 > 2.0 Δη n4-m,m+7 > 2.0 When it is, it indicates that there is scaling contamination in the reverse osmosis system. The recovery rate of the reverse osmosis system should be reduced, the Langelier index of the concentrated water should be calculated, and the scale inhibitor dosing system should be inspected.

[0030] Compared with the prior art, the invention has the following advantages:

[0031] 1. According to the positional relationship between pollution, erosion and the performance change of the membrane element, a reverse osmosis system arrangement and combination method is proposed, realizing the reflection of standard data on the performance decline of membrane elements in different parts.

[0032] 2. The standardized parameters of reverse osmosis operation data (i.e., the relative change rate of standard permeate water flow, the relative change rate of standard differential pressure, and the change rate of standard desalination rate) are proposed. According to the value size, it is judged whether the system is normal performance decay or rapid deterioration, and the reason for the performance decline of the reverse osmosis system is directly diagnosed. Corresponding disposal measures are taken in time to avoid the irreversible decline of the reverse osmosis system performance. The diagnosis accuracy rate is high and the use effect is good. It is an innovation in the standardized method of reverse osmosis operation data and has good social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the instrument measuring points of the reverse osmosis system of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0034] The following further details the specific implementation manners of the present invention in conjunction with the drawings and embodiments.

[0035] A method for standardizing reverse osmosis operation data includes a reverse osmosis system, and the arrangement and combination of the reverse osmosis system is 2-2-1-1;

[0036] The recovery rate of the reverse osmosis system is 75%, the recovery rate of the first stage is 9.5%, the recovery rate of the second stage is 49.0%, the recovery rate of the third stage is 38.9%, and the recovery rate of the fourth stage is 11.5%. The membrane module in the pressure vessel of the first stage contains 1 membrane element, the membrane module in the pressure vessel of the second stage contains 5 membrane elements, the membrane module in the pressure vessel of the third stage contains 5 membrane elements, and the membrane module in the pressure vessel of the fourth stage contains 1 membrane element.

[0037] The arrangement and combination of the reverse osmosis system are to make the output and pressure drop of the membrane elements in each stage equivalent. In the case of no concentrated water recycling, a 2:1 arrangement is usually adopted (that is, the number of membrane modules in the first stage of reverse osmosis is twice that of the second stage) to obtain a system recovery rate of 75%. The 75% system recovery rate is also the standard system recovery rate. Usually, 6m long membrane modules are selected, with 6 membrane elements each 1.016m long installed inside, and the recovery rate of each membrane module is 50%.

[0038] The performance degradation of membrane elements in different parts corresponds to different reasons, and different measures should be taken. To realize the reflection of the standard data on the performance degradation of membrane elements in different parts, and at the same time provide data support for the fault diagnosis of the reverse osmosis system, the present invention adopts a method for arranging and combining the reverse osmosis system, and the arrangement and combination are 2:2:1:1, that is, the ratio of the number of membrane modules in the first, second, third, and fourth stages of reverse osmosis is 2:2:1:1. To ensure that the output and pressure drop of the membrane elements in each stage are equivalent, the first stage membrane module contains 1 membrane element, the second stage membrane module contains 5 membrane elements, the third stage membrane module contains 5 membrane elements, and the fourth stage membrane module contains 1 membrane element. At this time, the recovery rate of the first stage is 9.5%, the recovery rate of the second stage is 49.0%, the recovery rate of the third stage is 38.9%, the recovery rate of the fourth stage is 11.5%, and the system recovery rate is 75%.

[0039] The performance parameters of the reverse osmosis system include: the salt rejection rate SR1 of the first stage, the standard salt rejection rate SR of the first stage n1 , the pressure difference Δp1 of the first stage, the standard pressure difference Δp of the first stage n1 , the permeate water flow rate Q of the first stage p1 , the standard permeate water flow rate Q of the first stage pn1 , the salt rejection rate SR2 of the second stage, the standard salt rejection rate SR of the second stage n2 , the pressure difference Δp2 of the second stage, the standard pressure difference Δp of the second stage n2 , the permeate water flow rate Q of the second stage p2 , the standard permeate water flow rate Q of the second stage pn2 , the salt rejection rate SR3 of the third stage, the standard salt rejection rate SR of the third stage n3 , the pressure difference Δp3 of the third stage, the standard pressure difference Δp of the third stage n3 , the permeate water flow rate Q of the third stage p3 , the standard permeate water flow rate Q of the third stage pn3 , the salt rejection rate SR4 of the fourth stage, the standard salt rejection rate SR of the fourth stagen4 , the pressure difference Δp4 of the fourth stage, the standard pressure difference Δp of the fourth stage n4 , the permeate water flow rate Q of the fourth stage p4 , the standard permeate water flow rate Q of the fourth stage pn4 ;

[0040] The calculation formulas for the performance parameters of the reverse osmosis system are shown in Formulas (1) to (22).

[0041] The salt rejection rate SR1 of the first stage

[0042]

[0043] In the formula: c f1 is the conductivity of the feed water of the first stage, c p1 is the conductivity of the permeate water of the first stage.

[0044] The standard salt rejection rate SR of the first stage n1

[0045]

[0046] In the formula: Q p1 is the permeate water flow rate under the actual operating conditions of the first stage, Q pr1 is the permeate water flow rate under the reference state of the first stage, T J1 is the temperature correction coefficient under the actual operating conditions of the first stage, T Jr1 is the temperature correction coefficient under the reference state of the first stage.

[0047] The pressure difference Δp1 of the first stage

[0048] Δp1 = p f1 - p b1 (3)

[0049] In the formula: p f1 is the feed water pressure of the first stage, p b1 is the concentrated water pressure of the first stage.

[0050] The standard pressure difference Δp of the first stage n1

[0051]

[0052] In the formula: Q br1 is the concentrated water flow rate under the reference state of the first stage, Q pr1 is the permeate water flow rate under the reference state of the first stage, Q b1 is the concentrated water flow rate under the actual operating conditions of the first stage, Q p1 is the permeate water flow rate under the actual operating conditions of the first stage.

[0053] The standard permeate water flow rate Q of the first stage pn1

[0054]

[0055] Where: T J1 is the temperature correction coefficient under the actual operating conditions of the first stage, p f1 is the feed water pressure under the actual operating conditions of the first stage, ΔΠ osm,1 is the osmotic pressure difference under the actual operating conditions of the first stage, p p1 is the permeate water pressure under the actual operating conditions of the first stage, T Jr1 is the temperature correction coefficient under the reference state of the first stage, p fr1 is the feed water pressure under the reference state of the first stage, ΔΠ osm,r1 is the osmotic pressure difference under the reference state of the first stage, p pr1 is the permeate water pressure under the reference state of the first stage.

[0056] The desalination rate of the second stage SR2

[0057]

[0058] Where: is the average feed water conductivity of the second stage, c p2 is the permeate water conductivity of the second stage.

[0059]

[0060] Where: c f2 is the permeate water conductivity of the second stage, and Y2 is the recovery rate of the second stage.

[0061] The standard desalination rate of the second stage SR n2

[0062]

[0063] Where: Q p2 is the permeate water flow rate under the actual operating conditions of the second stage, Q pr2 is the permeate water flow rate under the reference state of the second stage, T J2 is the temperature correction coefficient under the actual operating conditions of the second stage, T Jr2 is the temperature correction coefficient under the reference state of the second stage.

[0064] The pressure difference of the second stage Δp2

[0065] Δp2 = p f2 -p b2 (9)

[0066] Where: p f2 is the feed water pressure of the second stage (also the concentrated water pressure of the first stage), p b2 is the concentrated water pressure of the second stage.

[0067] The standard pressure difference Δp of the second stage n2

[0068]

[0069] In the formula: Q br2 is the concentrated water flow rate under the reference state of the second stage, Q pr2 is the permeate water flow rate under the reference state of the second stage, Q b2 is the concentrated water flow rate under the actual operating conditions of the second stage, Q p2 is the permeate water flow rate under the actual operating conditions of the second stage.

[0070] The standard permeate water flow rate Q of the second stage pn2

[0071]

[0072] In the formula: T J2 is the temperature correction coefficient under the actual operating conditions of the second stage, is the average feed water pressure under the actual operating conditions of the second stage, ΔΠ osm,2 is the osmotic pressure difference under the actual operating conditions of the second stage, p p2 is the osmotic water pressure under the actual operating conditions of the second stage, T Jr2 is the temperature correction coefficient under the reference state of the second stage, is the average feed water pressure under the reference state of the second stage, ΔΠ osm,r2 is the osmotic pressure difference under the reference state of the second stage, p pr2 is the osmotic water pressure under the reference state of the second stage.

[0073] The desalination rate SR3 of the third stage

[0074]

[0075] In the formula: is the average feed water conductivity of the third stage, c p3 is the osmotic water conductivity of the third stage.

[0076]

[0077] In the formula: c f3 is the osmotic water conductivity of the third stage, and Y3 is the recovery rate of the third stage.

[0078] The standard desalination rate SR of the third stage n3

[0079]

[0080] In the formula: Q p3The permeate water flow rate under the actual operating conditions of the third stage, Q pr3 The permeate water flow rate under the reference state of the third stage, T J3 The temperature correction coefficient under the actual operating conditions of the third stage, T Jr3 The temperature correction coefficient under the reference state of the third stage.

[0081] The differential pressure of the third stage Δp3

[0082] Δp3 = p f3 -p b3 (15)

[0083] In the formula: p f3 Is the feed water pressure of the third stage (also the concentrated water pressure of the second stage), p b3 Is the concentrated water pressure of the third stage.

[0084] The standard differential pressure of the third stage Δp n3

[0085]

[0086] In the formula: Q br3 Is the concentrated water flow rate under the reference state of the third stage, Q pr3 Is the permeate water flow rate under the reference state of the third stage, Q b3 Is the concentrated water flow rate under the actual operating conditions of the third stage, Q p3 Is the permeate water flow rate under the actual operating conditions of the third stage.

[0087] The standard permeate water flow rate of the third stage Q pn3

[0088]

[0089] In the formula: T J3 Is the temperature correction coefficient under the actual operating conditions of the third stage, Is the average feed water pressure under the actual operating conditions of the third stage, ΔΠ osm,3 Is the osmotic pressure difference under the actual operating conditions of the third stage, p p3 Is the permeate water pressure under the actual operating conditions of the third stage, T Jr3 Is the temperature correction coefficient under the reference state of the third stage, Is the average feed water pressure under the reference state of the third stage, ΔΠ osm,r3 Is the osmotic pressure difference under the reference state of the third stage, p pr3 Is the permeate water pressure under the reference state of the third stage.

[0090] The salt rejection rate of the fourth stage SR4

[0091]

[0092] In the formula: cf4 is the conductivity of the feed water in the fourth stage, c p4 is the conductivity of the permeate water in the fourth stage.

[0093] The standard desalination rate SR of the fourth stage n4

[0094]

[0095] In the formula: Q p4 is the permeate water flow rate under the actual operating conditions of the fourth stage, Q pr4 is the permeate water flow rate under the reference state of the fourth stage, T J4 is the temperature correction coefficient under the actual operating conditions of the fourth stage, T Jr4 is the temperature correction coefficient under the reference state of the fourth stage.

[0096] The pressure difference Δp4 of the fourth stage

[0097] Δp4 = p f4 -p b4 (20)

[0098] In the formula: p f4 is the feed water pressure of the fourth stage (also the concentrated water pressure of the third stage), p b4 is the concentrated water pressure of the fourth stage.

[0099] The standard pressure difference Δp of the fourth stage n4

[0100]

[0101] In the formula: Q br4 is the concentrated water flow rate under the reference state of the fourth stage, Q pr4 is the permeate water flow rate under the reference state of the fourth stage, Q b4 is the concentrated water flow rate under the actual operating conditions of the fourth stage, Q p4 is the permeate water flow rate under the actual operating conditions of the fourth stage.

[0102] The standard permeate water flow rate Q of the fourth stage pn4

[0103]

[0104] In the formula: In the formula: T J4 is the temperature correction coefficient under the actual operating conditions of the fourth stage, p f4 is the feed water pressure under the actual operating conditions of the fourth stage, ΔΠ osm,4 is the osmotic pressure difference under the actual operating conditions of the fourth stage, p p4 is the permeate water pressure under the actual operating conditions of the fourth stage, T Jr4 is the temperature correction coefficient under the reference state of the fourth stage, p fr4is the feed water pressure under the reference state of the fourth stage, ΔΠ osm,r4 is the osmotic pressure difference under the reference state of the fourth stage, p pr4 is the osmotic water pressure under the reference state of the fourth stage.

[0105] The instrument measuring points of the reverse osmosis system are as Figure 1 shown. In the above formulas, the parameters of pressure, flow rate, temperature, and conductivity can be obtained according to the readings of the measuring points. The temperature correction coefficient is obtained according to the temperature correction coefficient table provided by the reverse osmosis system manufacturer. The osmotic pressure difference is calculated according to the relationship between conductivity and osmotic pressure corresponding to the water quality provided by the manufacturer.

[0106] The data standardization method includes the following steps:

[0107] Step 1: The reference state is the starting state of stable operation after a new membrane or membrane cleaning. Calculate the following performance parameters: SR n1-0 , Δp n1-0 , Q pn1-0 , SR n2-0 , Δp n2-0 , Q pn2-0 , SR n3-0 , Δp n3-0 , Q pn3-0 , SR n4-0 , Δp n4-0 , Q pn4-0 ;

[0108] After an interval of 7 days, calculate the following performance parameters SR n1-7 , Δp n1-7 , Q pn1-7 , SR n2-7 , Δp n2-7 , Q pn2-7 , SR n3-7 , Δp n3-7 , Q pn3-7 , SR n4-7 , Δp n4-7 , Q pn4-7 ;

[0109] The meanings of the above letters are:

[0110] The standard desalination rate of the first stage SR n1 , the standard pressure difference of the first stage Δp n1 , the standard osmotic water flow rate of the first stage Q pn1 , the standard desalination rate of the second stage SR n2 , the standard pressure difference of the second stage Δp n2 , the standard osmotic water flow rate of the second stage Q pn2 , the standard desalination rate of the third stage SR n3 , the standard pressure difference of the third stage Δp n3 , the standard osmotic water flow rate of the third stage Qpn3 , the standard salt rejection rate SR of the fourth stage n4 , the standard differential pressure Δp of the fourth stage n4 , the standard permeate water flow rate Q of the fourth stage pn4 .

[0111] For example: SR n1-0 is the standard salt rejection rate of the first stage of the reverse osmosis system in the starting state, SR n1-7 is the standard salt rejection rate of the first stage of the reverse osmosis system 7 days after starting from the starting state, SR n1-14 is the standard salt rejection rate of the first stage of the reverse osmosis system 14 days after starting from the starting state, and so on.

[0112] And so on, calculate the performance parameters of the first, second, third, and fourth stages of the reverse osmosis system every 7 days respectively;

[0113] When the standard permeate water flow rate of the membrane element drops by more than 15% compared to the starting state, or the standard salt rejection rate drops by more than 10% compared to the starting state, or the standard differential pressure rises by more than 15% compared to the starting state, stop the calculation;

[0114] Conduct chemical cleaning on the reverse osmosis system, and the data will no longer be accumulated. The starting state after stable operation after chemical cleaning is the new starting state. Generally, under normal operation, the reverse osmosis system needs to be chemically cleaned after running for about 180 days.

[0115] Step 2: Calculate the standardized parameters of the reverse osmosis operation data; the standardized parameters are: the relative change rate ΔΦ of the standard permeate water flow rate of the first stage n1-m,m+7 , the average value of the relative change rate of the standard permeate water flow rate of the first stage the relative change rate ΔΨ of the standard differential pressure of the first stage n1-m,m+7 , the average value of the relative change rate of the standard differential pressure of the first stage the change rate Δη of the standard salt rejection rate of the first stage n1-m,m+7 , the average value of the change rate of the standard salt rejection rate of the first stage the relative change rate ΔΦ of the standard permeate water flow rate of the second stage n2-m,m+7 , the average value of the relative change rate of the standard permeate water flow rate of the second stage the relative change rate ΔΨ of the standard differential pressure of the second stage n2-m,m+7 , the average value of the relative change rate of the standard differential pressure of the second stage the change rate Δη of the standard salt rejection rate of the second stage n2-m,m+7 , the average value of the change rate of the standard salt rejection rate of the second stage the relative change rate ΔΦ of the standard permeate water flow rate of the third stage n3-m,m+7 , the average value of the relative change rate of the standard permeate water flow rate of the third stage the relative change rate ΔΨ of the standard differential pressure of the third stage n3-m,m+7, the average relative change rate of the standard pressure difference in the third stage The change rate of the standard desalination rate Δη in the third stage n3-m,m+7 , the average change rate of the standard desalination rate in the third stage The relative change rate of the standard permeate water flow rate ΔΦ in the fourth stage n4-m,m+7 , the average relative change rate of the standard permeate water flow rate in the fourth stage The relative change rate of the standard pressure difference ΔΨ in the fourth stage n4-m,m+7 , the average relative change rate of the standard pressure difference in the fourth stage The change rate of the standard desalination rate Δη in the fourth stage n4-m,m+7 , the average change rate of the standard desalination rate in the fourth stage

[0116] The relative change rate of the standard permeate water flow rate can be used to compare the standard data of different stages of the reverse osmosis system. If the standard permeate water flow rates in the first and second stages both show a significant decrease, but the relative change rate of the standard permeate water flow rate in the first stage is greater than that in the second stage, it indicates that there is a gradual pollution of the front-end membrane elements in the reverse osmosis system.

[0117] Calculate the standardized parameters of the reverse osmosis operation data according to the following formulas (23) to (46):

[0118] The relative change rate of the standard permeate water flow rate ΔΦ in the first stage n1-m,m+7

[0119]

[0120] Where: Q pn1-m is the standard permeate water flow rate on the m-th day in the first stage, and Q pn1-m+7 is the standard permeate water flow rate on the (m + 7)-th day in the first stage.

[0121] The average relative change rate of the standard permeate water flow rate in the first stage

[0122]

[0123] The relative change rate of the standard pressure difference ΔΨ in the first stage n1-m,m+7

[0124]

[0125] Where: Δp n1-m is the standard pressure difference on the m-th day in the first stage, and Δp n1-m+7 is the standard pressure difference on the (m + 7)-th day in the first stage.

[0126] The average relative change rate of the standard pressure difference in the first stage

[0127]

[0128] The change rate Δη of the standard desalination rate in the first stage n1-m,m+7

[0129]

[0130] The average value of the change rate of the standard desalination rate in the first stage

[0131]

[0132] The relative change rate ΔΦ of the standard permeate water flow rate in the second stage n2-m,m+7

[0133]

[0134] Where: Q pn2-m is the standard permeate water flow rate on the m-th day in the second stage, and Q pn2-m+7 is the standard permeate water flow rate on the (m + 7)-th day in the second stage.

[0135] The average value of the relative change rate of the standard permeate water flow rate in the second stage

[0136]

[0137] The relative change rate ΔΨ of the standard differential pressure in the second stage n2-m,m+7

[0138]

[0139] Where: Δp n2-m is the standard differential pressure on the m-th day in the second stage, and Δp n2-m+7 is the standard differential pressure on the (m + 7)-th day in the second stage.

[0140] The average value of the relative change rate of the standard differential pressure in the second stage

[0141]

[0142] The change rate Δη of the standard desalination rate in the second stage n2-m,m+7

[0143]

[0144] The average value of the change rate of the standard desalination rate in the first stage

[0145]

[0146] The relative change rate ΔΦ of the standard permeate water flow rate in the third stage n3-m,m+7

[0147]

[0148] In the formula: Q pn3-m is the standard permeate water flow rate on the m-th day of the third stage, and Q pn3-m+7 is the standard permeate water flow rate on the (m + 7)-th day of the third stage.

[0149] Average value of the relative change rate of the standard permeate water flow rate in the third stage

[0150]

[0151] Relative change rate of the standard differential pressure in the third stage ΔΨ n3-m,m+7

[0152]

[0153] In the formula: Δp n3-m is the standard differential pressure on the m-th day of the third stage, and Δp n3-m+7 is the standard differential pressure on the (m + 7)-th day of the third stage.

[0154] Average value of the relative change rate of the standard differential pressure in the third stage

[0155]

[0156] Change rate of the standard desalination rate in the third stage Δη n3-m,m+7

[0157]

[0158] Average value of the change rate of the standard desalination rate in the third stage

[0159]

[0160] Relative change rate of the standard permeate water flow rate in the fourth stage ΔΦ n4-m,m+7

[0161]

[0162] In the formula: Q pn4-m is the standard permeate water flow rate on the m-th day of the fourth stage, and Q pn4-m+7 is the standard permeate water flow rate on the (m + 7)-th day of the fourth stage.

[0163] Average value of the relative change rate of the standard permeate water flow rate in the fourth stage

[0164]

[0165] Relative change rate of the standard differential pressure in the fourth stage ΔΨ n4-m,m+7

[0166]

[0167] Where: Δp n4-m is the standard differential pressure on the m-th day of the fourth stage, and Δp n4-m+7 is the standard differential pressure on the (m + 7)-th day of the fourth stage.

[0168] Average relative change rate of the standard differential pressure in the fourth stage

[0169]

[0170] Change rate of the standard desalination rate in the fourth stage Δη n4-m,m+7

[0171]

[0172] Average change rate of the standard desalination rate in the fourth stage

[0173]

[0174] The parameters in the above formula can be obtained according to the data in the previous steps.

[0175] Step 3: Analyze the above calculation results and make corresponding dispositions

[0176] When the change rate of the standardized parameters of the reverse osmosis operation data is lower than 0.5 times the average value or higher than 2.0 times the average value, it indicates that there are fault manifestations in the reverse osmosis water treatment system;

[0177] 1) When ΔΦ n1-m,m+7 <0.5 ΔΨ n1-m,m+7 <0.5 Δη n1-m,m+7 >2.0 0.5 <ΔΦ n2-m,m+7 <2.0 0.5 <ΔΨ n2-m,m+7 <2.0 0.5 <Δη n2-m,m+7 <2.0 it indicates that the addition of acid to the reverse osmosis system is excessive, causing hydrolysis of the membrane. The pH meter of the reverse osmosis feed water should be calibrated and the acid addition system should be checked;

[0178] Excessive acid addition causes degradation of the membrane, which mostly occurs in the first membrane element of the reverse osmosis system; the degradation of the membrane is manifested as a significant increase in the change rate of the standard desalination rate, and a decrease in the relative change rates of the standard permeate water volume and the standard differential pressure.

[0179] 2) When ΔΦ n1-m,m+7 <0.5 ΔΨ n1-m,m+7 <0.5 Δη n1-m,m+7 >2.0 ΔΦ n2-m,m+7 <0.5 ΔΨ n2-m,m+7 <0.5 Δη n2-m,m+7 >2.0 When it is the case, it indicates that there is oxidative erosion in the reverse osmosis system. The redox potential analyzer of the reverse osmosis feed water should be calibrated, and the reductant dosing system should be checked;

[0180] Oxidative erosion of the feed water will cause degradation of multiple membrane elements from front to back. The degradation of the membrane is manifested as a significant increase in the change rate of the standard salt rejection rate, and a decrease in the relative change rates of the standard permeate water volume and the standard differential pressure.

[0181] 3) When 0.5 <ΔΦ ni-m,m+7 <2.0 0.5 <ΔΨ ni-m,m+7 <2.0 Δη ni-m,m+7 >2.0 When it is the case, where i = 1, 2, 3, 4, it indicates that there is a membrane module with leakage from the concentrated water side to the fresh water side in the membrane module of the pressure vessel in the i-th stage. The conductivity of the permeate water of each membrane module in this stage should be checked to determine the membrane module with problems;

[0182] The existence of leakage from the concentrated water side to the fresh water side in the membrane element will cause a small amount of feed water to directly enter the permeate water. Since the conductivity of the feed water is usually 100 times that of the permeate water, it will cause a significant increase in the change rate of the standard salt rejection rate, but the relative change rates of the standard permeate water volume and the standard differential pressure change little.

[0183] 4) When ΔΦ n1-m,m+7 >2.0 ΔΨ n1-m,m+7 >2.0 Δη n1-m,m+7 >2.0 0.5 <ΔΦ n2-m,m+7 <2.0 0.5 <ΔΨ n2-m,m+7 <2.0 0.5 <Δη n2-m,m+7 <2.0 When it is the case, it indicates that there is metal corrosion product pollution in the reverse osmosis system. The material selection before the reverse osmosis system should be checked;

[0184] The fouling of the membrane caused by metal corrosion products mostly occurs in the first membrane element of the reverse osmosis system. The relative change rates of the standard permeate flow rate and the standard differential pressure increase significantly. At the same time, the feed water concentration polarization is increased, resulting in a significant increase in the change rate of the salt rejection rate of this membrane element.

[0185] 5) When ΔΦ n1-m,m+7 >2.0 ΔΨ n1-m,m+7 >2.0 Δη n1-m,m+7 >2.0 ΔΦ n2-m,m+7 >2.0 ΔΨ n2-m,m+7 >2.0 Δη n2-m,m+7 >2.0 It indicates that there is colloid pollution in the reverse osmosis system. The intercept of the SDI filter should be analyzed, and whether there is pollution in the water tank and pipeline of the raw water pretreatment system should be checked. The dosages of coagulant and coagulant aid in the pretreatment system should be calculated.

[0186] Colloidal particles will cause fouling of multiple membrane elements from front to back. The relative change rates of the standard permeate flow rate and the standard differential pressure increase significantly. At the same time, the feed water concentration polarization is increased, resulting in a significant increase in the change rate of the salt rejection rate of the polluted membrane elements.

[0187] 6) When ΔΦ n1-m,m+7 >2.0 ΔΨ n1-m,m+7 >2.0 Δη n1-m,m+7 <0.5 ΔΦ n2-m,m+7 >2.0 ΔΨ n2-m,m+7 >2.0 Δη n2-m,m+7 <0.5 It indicates that there is organic matter pollution in the reverse osmosis system. The intercept of the SDI filter should be analyzed, and the TOC value of the reverse osmosis influent should be monitored.

[0188] Insoluble organic matter will cause fouling of multiple membrane elements from front to back. The relative change rates of the standard permeate flow rate and the standard differential pressure increase significantly. At the same time, it deposits on the membrane surface to produce the effect of an additional barrier, resulting in a decrease in the change rate of the salt rejection rate of the polluted membrane elements.

[0189] 7) When ΔΦ n1-m,m+7 >2.0 0.5 <ΔΨ n1-m,m+7 <2.0 0.5 <Δη n1-m,m+7 <2.0 ΔΦn2-m,m+7 > 2.0 0.5 < ΔΨ n2-m,m+7 < 2.0 0.5 < Δη n2-m,m+7 < 2.0 When it is the case, it indicates that there is microbial contamination in the reverse osmosis system, and the reverse osmosis system should be thoroughly cleaned. At the same time, the pipelines, water tanks, and filters should be disinfected and inspected;

[0190] Most microbial contaminations occur in the membrane elements at the front end of the reverse osmosis system. In the initial stage of contamination, the impact on the standard pressure difference and standard salt rejection rate is relatively small, while the impact on the standard permeate water volume is relatively large.

[0191] 8) When 0.5 < ΔΦ n2-m,m+7 < 2.0 0.5 < ΔΨ n2-m,m+7 < 2.0 0.5 < Δη n2-m,m+7 < 2.0 ΔΦ n4-m,m+7 > 2.0 ΔΨ n4-m,m+7 > 2.0 Δη n4-m,m+7 > 2.0 When it is the case, it indicates that there is scaling contamination in the reverse osmosis system. The recovery rate of the reverse osmosis system should be reduced, the Langelier index of the concentrated water should be calculated, and the scale inhibitor dosing system should be inspected.

[0192] Most inorganic salt scaling contaminations occur in the last membrane element and generally do not occur in the front-end membrane elements. Scaling contamination will cause significant increases in the rate of change of the standard salt rejection rate, the relative rate of change of the standard permeate water volume, and the relative rate of change of the standard pressure difference.

[0193] The following further illustrates the present invention with a specific application example

[0194] The arrangement combination of a certain reverse osmosis system is 2-2-1-1. The recovery rate of the reverse osmosis system is 75%, the recovery rate of the first stage is 9.5%, the recovery rate of the second stage is 49.0%, the recovery rate of the third stage is 38.9%, and the recovery rate of the fourth stage is 11.5%. The membrane module in the pressure vessel of the first stage contains 1 membrane element, the membrane module in the pressure vessel of the second stage contains 5 membrane elements, the membrane module in the pressure vessel of the third stage contains 5 membrane elements, and the membrane module in the pressure vessel of the fourth stage contains 1 membrane element.

[0195] The first step, the reference state is the starting state of the stable operation of the new membrane, and SR n1-0 , Δp n1-0 , Q pn1-0 , SRn2-0 , Δp n2-0 , Q pn2-0 , SR n3-0 , Δp n3-0 , Q pn3-0 , SR n4-0 , Δp n4-0 , Q pn4-0 .

[0196] Calculate SR at an interval of 7 days n1-7 , Δp n1-7 , Q pn1-7 , SR n2-7 , Δp n2-7 , Q pn2-7 , SR n3-7 , Δp n3-7 , Q pn3-7 , SR n4-7 , Δp n4-7 , Q pn4-7 .

[0197] Calculate SR again at an interval of 7 days n1-14 , Δp n1-14 , Q pn1-14 , SR n2-14 , Δp n2-14 , Q pn2-14 , SR n3-14 , Δp n3-14 , Q pn3-14 , SR n4-14 , Δp n4-14 , Q pn4-14 .

[0198] And so on, calculate the performance parameters of the first, second, third, and fourth stages of the reverse osmosis system respectively, as shown in Table 1

[0199] Table 1 Performance parameters of the first, second, third, and fourth stages of the reverse osmosis system

[0200]

[0201] In the second step, calculate the standardized parameters of the reverse osmosis operation data, as shown in Table 2

[0202] Table 2 Standardized parameters of the reverse osmosis operation data

[0203]

[0204] As can be seen from formulas (23) to (28), the relative change rate of the standard permeate water flow rate in the first stage, ΔΦ n1-63,70 is 2.47%, and the average value of the relative change rate of the standard permeate water flow rate in the first stage is 0.33%, and the relative change rate of the standard pressure difference in the first stage, ΔΨ n1-63,70is 2.28%, and the average relative change rate of the standard pressure difference in the first stage is 0.33%, and the change rate Δη of the standard desalination rate in the first stage n1-63,70 is 0.61%, and the average change rate of the standard desalination rate in the first stage is 0.21%.

[0205] From formulas (29) to (34), the relative change rate ΔΦ of the standard permeate water flow rate in the second stage n2-63,70 is 1.22%, and the average relative change rate of the standard permeate water flow rate in the second stage is 0.37%, and the relative change rate ΔΨ of the standard pressure difference in the second stage n2-63,70 is 1.44%, and the average relative change rate of the standard pressure difference in the second stage is 0.35%, and the change rate Δη of the standard desalination rate in the second stage n2-63,70 is 0.48%, and the average change rate of the standard desalination rate in the second stage is 0.21%.

[0206] In the third step, according to the analysis and disposal method, if the change rate of the standardized parameters of the reverse osmosis operation data is less than 0.5 times the average value or higher than 2.0 times the average value, it indicates that there are fault manifestations in the reverse osmosis water treatment system.

[0207] Because ΔΦ n1-63,70 >2.0 ΔΨ n1-63,70 >2.0 Δη n1-63,70 >2.0 ΔΦ n2-63,70 >2.0 ΔΨ n2-63,70 >2.0 Δη n2-63,70 >2.0 It indicates that there is colloid pollution in the reverse osmosis system. The intercept of the SDI filter should be analyzed, and whether there is pollution in the water tank and pipeline of the raw water pretreatment system should be checked, and the dosage of coagulant and coagulant aid in the pretreatment system should be calculated.

[0208] Subsequently, the intercept of the SDI filter of the reverse osmosis influent was analyzed, and it was found that the intercept was a light yellow jelly-like substance. Then, the intercept of the SDI filter of the effluent of the pretreatment system was detected, and no light yellow jelly-like substance was found, indicating that there was pollution in the clear water tank. Opening the manhole, it was found that there was a large amount of khaki mud deposit at the bottom of the tank, and the polyurea anti-corrosion layer on the inner wall of the tank bulged. After thoroughly cleaning the tank and related pipelines and repairing the internal anti-corrosion of the tank, the reverse osmosis system returned to normal operation.

[0209] The applicant has achieved good technical effects through actual application, as shown in the following table:

[0210]

[0211]

Claims

1. A method for standardizing reverse osmosis operation data, including a reverse osmosis system, characterized in that, The arrangement of the reverse osmosis system is 2-2-1-1; The data standardization method includes the following steps: Step 1: With the reference state being the starting state of a new membrane or stable operation after membrane cleaning, calculate the following performance parameters: SR n1-0 , Δp n1-0 , Q pn1-0 , SR n2-0 , Δp n2-0 , Q pn2-0 , SR n3-0 , Δp n3-0 , Q pn3-0 , SR n4-0 , Δp n4-0 , Q pn4-0 ; Calculate the following performance parameter SR at an interval of 7 days n1-7 , Δp n1-7 , Q pn1-7 , SR n2-7 , Δp n2-7 , Q pn2-7 , SR n3-7 , Δp n3-7 , Q pn3-7 , SR n4-7 , Δp n4-7 , Q pn4-7 ; The meanings of the above letters are: The standard salt rejection rate SR of the first stage n1 , the standard pressure difference Δp of the first stage n1 , the standard permeate water flow rate Q of the first stage pn1 , the standard salt rejection rate SR of the second stage n2 , the standard pressure difference Δp of the second stage n2 , the standard permeate water flow rate Q of the second stage pn2 , the standard salt rejection rate SR of the third stage n3 , the standard pressure difference Δp of the third stage n3 , the standard permeate water flow rate Q of the third stage pn3 , the standard salt rejection rate SR of the fourth stage n4 , the standard pressure difference Δp of the fourth stage n4 , the standard permeate water flow rate Q of the fourth stage pn4 ; SR n1-0 is the standard desalination rate of the first stage of the reverse osmosis system in the starting state, SR n1-7 is the standard desalination rate of the first stage of the reverse osmosis system 7 days after starting operation since the starting state, SR n1-14 is the standard desalination rate of the first stage of the reverse osmosis system 14 days after starting operation since the starting state, and so on; And so on, calculate the performance parameters of the first, second, third, and fourth stages of the reverse osmosis system every 7 days respectively; When the standard permeate water flow rate of the membrane element drops by more than 15% compared to the starting state, or the standard salt rejection rate drops by more than 10% compared to the starting state, or the standard pressure difference rises by more than 15% compared to the starting state, stop the calculation; Step 2: Calculate the normalization parameters of the reverse osmosis operation data; the normalization parameters are: the relative change rate of the standard permeate flow rate in the first stage ΔΦ n1-m,m+7 , the average value of the relative change rate of the standard permeate flow rate in the first stage The relative change rate of the standard differential pressure in the first stage ΔΨ n1-m,m+7 , the average value of the relative change rate of the standard differential pressure in the first stage The change rate of the standard salt rejection rate in the first stage Δη n1-m,m+7 , the average value of the change rate of the standard salt rejection rate in the first stage The relative change rate of the standard permeate flow rate in the second stage ΔΦ n2-m,m+7 , the average value of the relative change rate of the standard permeate flow rate in the second stage The relative change rate of the standard differential pressure in the second stage ΔΨ n2-m,m+7 , the average value of the relative change rate of the standard differential pressure in the second stage The change rate of the standard salt rejection rate in the second stage Δη n2-m,m+7 , the average value of the change rate of the standard salt rejection rate in the second stage The relative change rate of the standard permeate flow rate in the third stage ΔΦ n3-m,m+7 , the average value of the relative change rate of the standard permeate flow rate in the third stage The relative change rate of the standard differential pressure in the third stage ΔΨ n3-m,m+7 , the average value of the relative change rate of the standard differential pressure in the third stage The change rate of the standard salt rejection rate in the third stage Δη n3-m,m+7 , the average value of the change rate of the standard salt rejection rate in the third stage The relative change rate of the standard permeate flow rate in the fourth stage ΔΦ n4-m,m+7 , the average value of the relative change rate of the standard permeate flow rate in the fourth stage The relative change rate of the standard differential pressure in the fourth stage ΔΨ n4-m,m+7 , the average value of the relative change rate of the standard differential pressure in the fourth stage The change rate of the standard salt rejection rate in the fourth stage Δη n4-m,m+7 , the average value of the change rate of the standard salt rejection rate in the fourth stage Step 3: Analyze the above calculation results and make corresponding dispositions When the change rate of the standardized parameters of the reverse osmosis operation data is less than 0.5 times the average value or higher than 2.0 times the average value, it indicates that there are fault manifestations in the reverse osmosis water treatment system; 1) When this occurs, it indicates that the addition of acid to the reverse osmosis system is excessive, causing hydrolysis of the membrane. The pH meter of the reverse osmosis feed water should be calibrated and the acid addition system should be inspected; 2) When occurs, it indicates that there is oxidative erosion in the reverse osmosis system. The redox potential analyzer of the reverse osmosis feed water should be calibrated and the reducing agent dosing system should be inspected. 3) When is true, i is 1, 2, 3, or 4, indicating that there is a membrane module with leakage from the concentrated water side to the fresh water side in the i-th section of the pressure vessel membrane module. The conductivity of the permeate water of each membrane module in this section should be checked to determine the membrane module with problems; 4) When it indicates that there is pollution of metal corrosion products in the reverse osmosis system, and the selection of materials before the reverse osmosis system should be checked; 5) When it indicates that there is colloid pollution in the reverse osmosis system. The intercepted substances of the SDI filter should be analyzed, whether there is pollution in the water tank and pipeline of the raw water pretreatment system should be checked, and the dosages of coagulant and coagulant aid in the pretreatment system should be calculated; 6) When occurs, it indicates that there is organic pollution in the reverse osmosis system. The intercept of the SDI filter should be analyzed and the TOC value of the reverse osmosis influent should be monitored; 7) When it indicates that there is microbial contamination in the reverse osmosis system. The reverse osmosis system should be thoroughly cleaned, and at the same time, the pipelines, water tanks, and filters should be disinfected and inspected; 8) When occurs, it indicates that there is scaling and fouling in the reverse osmosis system. The recovery rate of the reverse osmosis system should be reduced, the Langelier index of the concentrated water should be calculated, and the scale inhibitor dosing system should be inspected; The standardized parameters of the reverse osmosis operation data in Step 2 are calculated according to the following formulas (23) to (46): The relative change rate ΔΦ of the standard permeate water flow in the first stage n1-m,m+7 Where: Q pn1-m is the standard osmotic water flow on the m-th day of the first stage, and Q pn1-m+7 is the standard osmotic water flow on the (m + 7)-th day of the first stage; Average relative change rate of the first-stage standard seepage water flow rate The relative change rate ΔΨ of the first-stage standard pressure difference n1-m,m+7 Where: Δp n1-m is the standard differential pressure on the m-th day of the first stage, and Δp n1-m+7 is the standard differential pressure on the (m + 7)-th day of the first stage; Average value of the relative change rate of the first-stage standard pressure difference The change rate Δη of the first-stage standard desalination rate n1-m,m+7 Average value of the change rate of the first-stage standard desalination rate Relative change rate ΔΦ of the second-stage standard seepage water flow n2-m,m+7 where: Q pn2-m is the standard permeate flow rate on the m-th day of the second stage, and Q pn2-m+7 is the standard permeate flow rate on the (m + 7)-th day of the second stage; Average relative change rate of the standard permeate water flow rate in the second stage The relative change rate of the standard pressure difference in the second stage, ΔΨ n2-m,m+7 where: Δp n2-m is the standard differential pressure on the m-th day of the second stage, and Δp n2-m+7 is the standard differential pressure on the (m + 7)-th day of the second stage; Average value of the relative change rate of the second-stage standard pressure difference The change rate Δη of the second-stage standard desalination rate n2-m,m+7 Average value of the change rate of the second-stage standard desalination rate Relative change rate ΔΦ of the standard permeated water flow in the third stage n3-m,m+7 Where: Q pn3-m is the standard osmotic water flow rate on the m-th day of the third stage, and Q pn3-m+7 is the standard osmotic water flow rate on the (m + 7)-th day of the third stage; Average relative change rate of standard seepage water flow in the third section The relative change rate of the standard pressure difference in the third stage ΔΨ n3-m,m+7 Where: Δp n3-m is the standard differential pressure on the m-th day of the third stage, and Δp n3-m+7 is the standard differential pressure on the (m + 7)-th day of the third stage; Average relative change rate of the standard pressure difference in the third section The change rate Δη of the standard desalination rate in the third stage n3-m,m+7 Average value of the change rate of the third-stage standard desalination rate Relative change rate ΔΦ of the standard permeated water flow in the fourth stage n4-m,m+7 Where: Q pn4-m is the standard permeate water flow rate on the m-th day of the fourth stage, and Q pn4-m+7 is the standard permeate water flow rate on the (m + 7)-th day of the fourth stage; Average relative change rate of standard seepage water flow in the fourth section The relative change rate ΔΨ of the standard pressure difference in the fourth stage n4-m,m+7 Where: Δp n4-m is the standard differential pressure on the m-th day of the fourth stage, and Δp n4-m+7 is the standard differential pressure on the (m + 7)-th day of the fourth stage; Average value of relative change rate of standard pressure difference in the fourth segment Fourth paragraph: Change rate Δη of standard desalination rate n4-m,m+7 Average value of the change rate of the standard desalination rate in the fourth stage 2. The reverse osmosis operation data standardization method according to claim 1, wherein The recovery rate of the reverse osmosis system is 75%, the recovery rate of the first stage is 9.5%, the recovery rate of the second stage is 49.0%, the recovery rate of the third stage is 38.9%, and the recovery rate of the fourth stage is 11.5%; the membrane module in the first-stage pressure vessel contains 1 membrane element, the membrane module in the second-stage pressure vessel contains 5 membrane elements, the membrane module in the third-stage pressure vessel contains 5 membrane elements, and the membrane module in the fourth-stage pressure vessel contains 1 membrane element.

3. The reverse osmosis operation data standardization method according to claim 1, wherein, The performance parameters of the reverse osmosis system include: the salt rejection rate SR1 of the first stage, the standard salt rejection rate SR of the first stage n1 , the pressure difference Δp1 of the first stage, the standard pressure difference Δp of the first stage n1 , the permeate water flow rate Q of the first stage p1 , the standard permeate water flow rate Q of the first stage pn1 , the salt rejection rate SR2 of the second stage, the standard salt rejection rate SR of the second stage n2 , the pressure difference Δp2 of the second stage, the standard pressure difference Δp of the second stage n2 , the permeate water flow rate Q of the second stage p2 , the standard permeate water flow rate Q of the second stage pn2 , the salt rejection rate SR3 of the third stage, the standard salt rejection rate SR of the third stage n3 , the pressure difference Δp3 of the third stage, the standard pressure difference Δp of the third stage n3 , the permeate water flow rate Q of the third stage p3 , the standard permeate water flow rate Q of the third stage pn3 , the salt rejection rate SR4 of the fourth stage, the standard salt rejection rate SR of the fourth stage n4 , the pressure difference Δp4 of the fourth stage, the standard pressure difference Δp of the fourth stage n4 , the permeate water flow rate Q of the fourth stage p4 , the standard permeate water flow rate Q of the fourth stage pn4 ; The calculation formulas for the performance parameters of the reverse osmosis system are shown in Formulas (1) to (22): The salt rejection rate of the first stage SR1 where: c f1 is the conductivity of the feed water in the first stage, and c p1 is the conductivity of the permeate water in the first stage; The first-stage standard salt rejection rate SR n1 Where: Q p1 is the permeate water flow rate under the actual operating conditions of the first stage, Q pr1 is the permeate water flow rate under the reference state of the first stage, T J1 is the temperature correction coefficient under the actual operating conditions of the first stage, T Jr1 is the temperature correction coefficient under the reference state of the first stage; The pressure difference of the first stage Δp1 Δp1 = p f1 -p b1 (3) Where: p f1 is the feed water pressure of the first stage, and p b1 is the concentrate water pressure of the first stage; The first standard pressure difference Δp n1 Where: Q br1 is the concentrated water flow rate under the reference state of the first stage, Q pr1 is the permeate water flow rate under the reference state of the first stage, Q b1 is the concentrated water flow rate under the actual operating conditions of the first stage, Q p1 is the permeate water flow rate under the actual operating conditions of the first stage; The first-stage standard permeate water flow rate Q pn1 Where: T J1 is the temperature correction coefficient under the actual operating conditions of the first stage, p f1 is the feed water pressure under the actual operating conditions of the first stage, ΔΠ osm,1 is the osmotic pressure difference under the actual operating conditions of the first stage, p p1 is the osmotic water pressure under the actual operating conditions of the first stage, T Jr1 is the temperature correction coefficient under the reference state of the first stage, p fr1 is the feed water pressure under the reference state of the first stage, ΔΠ osm,r1 is the osmotic pressure difference under the reference state of the first stage, p pr1 is the osmotic water pressure under the reference state of the first stage; The salt rejection rate of the second stage SR2 In the formula: is the average feed water conductivity of the second stage, c p2 is the permeate water conductivity of the second stage; where: c f2 is the conductivity of the permeate water in the second stage, and Y2 is the recovery rate of the second stage; Second-stage standard desalination rate SR n2 Where: Q p2 is the permeate water flow rate under the actual operating conditions of the second stage, Q pr2 is the permeate water flow rate under the reference state of the second stage, T J2 is the temperature correction coefficient under the actual operating conditions of the second stage, T Jr2 is the temperature correction coefficient under the reference state of the second stage; The pressure difference of the second stage Δp2 Δp2 = p f2 -p b2 (9) where: p f2 is the feed water pressure of the second stage (also the concentrated water pressure of the first stage), and p b2 is the concentrated water pressure of the second stage; Second standard pressure difference Δp n2 Where: Q br2 is the concentrated water flow rate under the reference state of the second stage, Q pr2 is the permeate water flow rate under the reference state of the second stage, Q b2 is the concentrated water flow rate under the actual operating conditions of the second stage, Q p2 is the permeate water flow rate under the actual operating conditions of the second stage; Second-stage standard permeate water flow rate Q pn2 Where: T J2 is the temperature correction coefficient under the actual operating conditions of the second stage, is the average feed water pressure under the actual operating conditions of the second stage, ΔΠ osm,2 is the osmotic pressure difference under the actual operating conditions of the second stage, p p2 is the osmotic water pressure under the actual operating conditions of the second stage, T Jr2 is the temperature correction coefficient under the reference state of the second stage, is the average feed water pressure under the reference state of the second stage, ΔΠ osm,r2 is the osmotic pressure difference under the reference state of the second stage, p pr2 is the osmotic water pressure under the reference state of the second stage; The salt rejection rate of the third stage SR3 Wherein: is the average feed water conductivity of the third stage, c p3 is the permeate water conductivity of the third stage; where: c f3 is the conductivity of the permeate water in the third stage, and Y3 is the recovery rate of the third stage; Third-stage standard salt rejection SR n3 Where: Q p3 is the permeate water flow rate under the actual operating conditions of the third stage, Q pr3 is the permeate water flow rate under the reference state of the third stage, T J3 is the temperature correction coefficient under the actual operating conditions of the third stage, T Jr3 is the temperature correction coefficient under the reference state of the third stage; The pressure difference of the third stage Δp3 Δp3 = p f3 -p b3 (15) Where: p f3 is the feed water pressure of the third stage (also the concentrated water pressure of the second stage), and p b3 is the concentrated water pressure of the third stage; The third-stage standard pressure difference Δp n3 Where: Q br3 is the concentrated water flow rate under the reference state of the third stage, Q pr3 is the permeate water flow rate under the reference state of the third stage, Q b3 is the concentrated water flow rate under the actual operating conditions of the third stage, Q p3 is the permeate water flow rate under the actual operating conditions of the third stage; The third - stage standard permeate water flow rate Q pn3 Where: T J3 is the temperature correction coefficient under the actual operating conditions of the third stage, is the average feed water pressure under the actual operating conditions of the third stage, ΔΠ osm,3 is the osmotic pressure difference under the actual operating conditions of the third stage, p p3 is the osmotic water pressure under the actual operating conditions of the third stage, T Jr3 is the temperature correction coefficient under the reference state of the third stage, p fr3 is the average feed water pressure under the reference state of the third stage, ΔΠ osm,r3 is the osmotic pressure difference under the reference state of the third stage, p pr3 is the osmotic water pressure under the reference state of the third stage; The salt rejection rate of the fourth stage SR4 where: c f4 is the conductivity of the feed water in the fourth stage, and c p4 is the conductivity of the permeate water in the fourth stage; Fourth paragraph, standard salt rejection rate SR n4 Where: Q p4 is the permeate water flow rate under the actual operating conditions of the fourth stage, and Q pr4 is the permeate water flow rate under the reference state of the fourth stage, T J4 is the temperature correction coefficient under the actual operating conditions of the fourth stage, and T Jr4 is the temperature correction coefficient under the reference state of the fourth stage; The pressure difference of the fourth stage Δp4 Δp4 = p f4 -p b4 (20) Where: p f4 is the feed water pressure of the fourth stage (also the concentrated water pressure of the third stage), and p b4 is the concentrated water pressure of the fourth stage; Fourth-stage standard pressure difference Δp n4 Where: Q br4 is the concentrated water flow rate under the reference state of the fourth stage, Q pr4 is the permeate water flow rate under the reference state of the fourth stage, Q b4 is the concentrated water flow rate under the actual operating conditions of the fourth stage, Q p4 is the permeate water flow rate under the actual operating conditions of the fourth stage; Fourth paragraph: Standard seepage water flow rate Q pn4 Where: Where: T J4 is the temperature correction coefficient under the actual operating conditions of the fourth stage, p f4 is the feed water pressure under the actual operating conditions of the fourth stage, ΔΠ osm,4 is the osmotic pressure difference under the actual operating conditions of the fourth stage, p p4 is the osmotic water pressure under the actual operating conditions of the fourth stage, T Jr4 is the temperature correction coefficient under the reference state of the fourth stage, p fr4 is the feed water pressure under the reference state of the fourth stage, ΔΠ osm,r4 is the osmotic pressure difference under the reference state of the fourth stage, p pr4 is the osmotic water pressure under the reference state of the fourth stage.

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