Reverse osmosis scale inhibitor for recycling coking wastewater and preparation method of reverse osmosis scale inhibitor

Abstract

The invention relates to a reverse osmosis scale inhibitor for recycling coking wastewater, which is prepared from the following raw materials in parts by mass: 20 to 40 parts of bio-based polyether carboxylic acid multipolymer, 10 to 20 parts of modified polyepoxysuccinic acid, 5 to 10 parts of polyepoxysuccinic acid, 0.1 to 1 part of zinc citrate and a proper amount of water. The invention also relates to a preparation method of the reverse osmosis scale inhibitor for recycling coking wastewater. The preparation method comprises the following steps: adding the bio-based polyether carboxylic acid multipolymer, the modified polyepoxysuccinic acid, the polyepoxysuccinic acid and the zinc citrate into water, mixing, heating and uniformly stirring. The reverse osmosis scale inhibitor has the following beneficial effects: when the reverse osmosis scale inhibitor is used for treating water, the reverse osmosis scale inhibitor can effectively prevent membrane organic sewage blockage, has a sterilization effect and a good silicon scale inhibition effect, so that reverse osmosis operation is stable and orderly, and the membrane cleaning period is prolonged; in addition, the reverse osmosis scale inhibitor for recycling the coking wastewater is free of phosphorus and pollution, small in dosage and biodegradable.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water treatment, in particular to a reverse osmosis scale inhibitor for coking wastewater reuse and a preparation method thereof. BACKGROUND

[0002] With the continuous development of the national economy, the discharge of industrial wastewater is increasing. Coking wastewater, as a kind of refractory organic wastewater, is complex in composition and contains sulfocyanide, sulfide, cyanide, phenol, aniline, aromatic compounds, heterocyclic compounds and other substances, which have certain toxicity. In response to the national energy-saving and emission-reducing policy and local environmental protection measures, many coking enterprises in China are facing the problems of coking wastewater deep treatment and reuse and upgrading of existing deep treatment and reuse process.

[0003] At present, membrane method is mainly used in the process of coking wastewater deep treatment and reuse, but the complex components in wastewater have a great impact on the operation performance of the membrane. The core difficulties in reverse osmosis treatment stage are:

[0004] (1) RO membrane surface is easy to accumulate organic-inorganic-microbial composite pollution layer, the main pollutants include salt deposition formed by calcium, magnesium, iron and other ions (especially when the concentration of iron ions is > 4.5 mg / L, it combines with organic matter to aggravate pollution); residual phenols, polycyclic aromatic hydrocarbons and heterocyclic compounds form colloidal or macromolecular adhesion layer and other organic pollutants; residual microorganisms in biochemical section reproduce on the membrane surface to form biological pollution block. The pollution layer structure is dense, which significantly reduces the membrane flux and desalination rate, and frequent cleaning is required with great difficulty.

[0005] (2) Water quality fluctuation shocks the system, coking wastewater still has fluctuations in COD, ammonia nitrogen and iron ion concentration after pretreatment, which leads to unstable RO inlet water quality; high TDS increases osmotic pressure, which requires to increase operating pressure and the water temperature is relatively high.

[0006] Coking wastewater adopts double membrane treatment process, and all membrane manufacturers in the world have also launched anti-pollution membranes. However, the reverse osmosis membrane system in coking wastewater reuse needs to be cleaned once in 20 to 60 days. Reverse osmosis scale inhibitor is an effective guarantee for the normal and stable operation of reverse osmosis. The existing reverse osmosis scale inhibitor has remarkable effect on conventional water quality, but there are some problems in water reuse or high TDS and high COD water quality. Most scale inhibitors are designed only for inorganic scale, lack of synergistic function of bacteriostasis / anti-organic pollution, which leads to the need for additional bactericides, increasing the complexity of the system.

[0007] Organic phosphonates such as HEDP, ATMP have high CaCO3 scale inhibition rate and high temperature resistance, but phosphorus content is easy to cause water eutrophication, and have poor inhibition effect on silica scale (SiO2); polycarboxylic acids (such as PAA, PMA) are phosphorus-free and environmentally friendly, and have excellent dispersing performance, but are easy to fail under high salinity (charge shielding effect); sulfonic acid copolymer (such as AA-AMPS copolymer) is resistant to high pH and high chlorine, but has no inhibition effect on organic pollution; petroleum-based polyether (such as APEG) depends on non-renewable resources and does not meet the carbon neutralization trend. SUMMARY

[0008] In view of the above deficiencies in the prior art, the technical problem to be solved by the present application is to provide a coking wastewater recycling reverse osmosis scale inhibitor and a preparation method thereof, which solves the problems of poor organic pollution resistance, easy biological pollution and poor biodegradability of existing reverse osmosis scale inhibitors.

[0009] To solve one of the above technical problems, the technical solution adopted by the present application is: a coking wastewater recycling reverse osmosis scale inhibitor, comprising the following raw materials: 20-40 parts of bio-based polyether carboxylic acid multi-copolymer, 10-20 parts of modified polyepoxysuccinic acid, 5-10 parts of polyepoxysuccinic acid (PESA), 0.1-1 parts of zinc citrate, and an appropriate amount of water.

[0010] Preferably, the bio-based polyether carboxylic acid multi-copolymer is BA-AMPS-(PLA-PEG-PLA)-NVP copolymer.

[0011] Preferably, the modified polyepoxysuccinic acid is quaternary ammonium polyepoxysuccinic acid.

[0012] Preferably, the bio-based polyether carboxylic acid multi-copolymer is 27 parts, the modified polyepoxysuccinic acid is 13 parts, the polyepoxysuccinic acid is 7 parts, the zinc citrate is 0.2 parts, and the water is an appropriate amount.

[0013] Preferably, the bio-based polyether carboxylic acid multi-copolymer is 36 parts, the modified polyepoxysuccinic acid is 14 parts, the PESA is 8 parts, the zinc citrate is 0.8 parts, and the water is 41.2 parts.

[0014] The technical solution of the present application also includes a preparation method of the coking wastewater recycling reverse osmosis scale inhibitor, comprising the following steps:

[0015] (1) Weigh the required raw materials according to the proportion;

[0016] (2) Mix and heat stir the bio-based polyether carboxylic acid multi-copolymer, the modified polyepoxysuccinic acid, the polyepoxysuccinic acid, and the zinc citrate in water until they are uniformly mixed, the stirring temperature is 10-35℃, and the stirring time is 30-60min;

[0017] Preferably, the preparation method of the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer comprises:

[0018] S1: pretreatment, butenoic acid (BA) is neutralized to pH 6.0 with potassium hydroxide solution (KOH), and polyethylene glycol dimer lactic acid (PLA-PEG-PLA) (Mn=1500) is pre-dissolved in ultrapure water at 40℃;

[0019] S2: under nitrogen protection, polyethylene glycol dimer lactic acid (PLA-PEG-PLA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), and vinyl pyrrolidone (NVP) are added to the mixture of butenoic acid and initiator, and the reaction is carried out at 65℃ for 6 hours;

[0020] S3: the mixture obtained in S2 is purified by ultrafiltration (5kDa MWCO) and freeze-dried to obtain a white powder, i.e. the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer.

[0021] Preferably, in the preparation method of the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer, the feeding ratio is BA:AMPS:(PLA-PEG-PLA):NVP=3:1:0.6:0.4 in molar ratio.

[0022] Preferably, in the preparation method of the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer, the initiation system is an oxidation-reduction initiation system composed of potassium persulfate (KPS) and L-ascorbic acid (Vc), the molar ratio of potassium persulfate (KPS) to L-ascorbic acid (Vc) is 1:1, the initiation is carried out at low temperature of 60℃ to reduce branching, and the amount of initiator is 1.5%.

[0023] Preferably, the molecular weight control target Mw=4000±500Da, RAFT polymerization is used, the chain transfer agent is S-dodecyl-S'-(α,α'-dimethyl-α''-acetic acid) trithiocarbonate (CTA), and the amount is 0.5%.

[0024] The bio-based polyether carboxylic acid multi-copolymer has the following structural formula:

[0025]

[0026] R is:

[0027]

[0028] Preferably, the preparation method of the modified polyepoxysuccinic acid comprises: dissolving polyepoxysuccinic acid (PESA) in deionized water (concentration 10% w / v), stirring until completely dissolved; slowly adding 1M KOH solution, maintaining pH at 10.3-10.7; adding 60% glycidyltrimethylammonium chloride (GTMAC) aqueous solution dropwise, the molar ratio of polyepoxysuccinic acid to glycidyltrimethylammonium chloride is 1:(0.5-0.8), controlling the temperature at 50±2℃, maintaining pH at 10-11, and reacting for 6-8 hours to obtain the modified polyepoxysuccinic acid.

[0029] The modified polyepoxysuccinic acid has the following structure:

[0030]

[0031] Butenolic acid provides carboxyl groups (-COOH) and has smaller steric hindrance than acrylic acid, so it is easier to embed into the gap of scale crystals and improve the inhibition capacity of Ca3(PO4)2.

[0032] AMPS provides strong polar sulfonic acid groups, which are not easy to precipitate in high-calcium and high-alkaline environments, ensuring high-temperature resistance and high-salt tolerance.

[0033] Modified polyepoxysuccinic acid: After quaternary ammonium modification, PESA can interact with the negative microbial membrane, destroy its structure, and has both scale inhibition (carboxyl group) and bactericidal (quaternary ammonium group) functions.

[0034] Polyethylene glycol dimer lactic acid (PLA-PEG-PLA) is a kind of three-block copolymer with unique structure, which is formed by the alternating connection of polyethylene glycol (PEG) and poly lactic acid (PLA). Amphiphilic: the PEG part is hydrophilic, and the PLA part is lipophilic. This amphiphilic property enables PLA-PEG-PLA to self-assemble into structures such as nanoparticles and micelles. In addition, the PLA segment (hydrophobic) enhances the adsorption on the membrane surface, reducing drug loss, and the PEG segment (hydrophilic) inhibits colloids / organic scale (such as silicon scale, humic acid) through steric hindrance; the biodegradability of the PLA part enables PLA-PEG-PLA to gradually decompose in water, and ultimately metabolize into carbon dioxide, with a biodegradability of >70%

[0035] The introduction of vinyl pyrrolidone (NVP) reduces the surface energy of the membrane, reduces the adsorption of organic matter on the membrane surface, and reduces the flux decay rate by 35%.

[0036] Zinc citrate is added as a synergist to inhibit biofilm formation by destroying microbial extracellular polymeric substances.

[0037] Compared with the prior art, the technical scheme has the following beneficial effects:

[0038] (1) The reverse osmosis scale inhibitor of the present application has good synergistic effect of each component, good scale inhibition and dispersion effect, good stability, good high temperature resistance and high salt tolerance.

[0039] (2) The reverse osmosis scale inhibitor of the present application has good bactericidal and bacteriostatic performance, can inhibit biological pollution, can prolong the reverse osmosis membrane cleaning cycle, and can improve the water production efficiency and the stable and durable membrane flux.

[0040] (3) The reverse osmosis scale inhibitor of the present application does not contain phosphorus, has little impact on the environment, and the bio-based polyether is easy to degrade, so there is no problem of excessive phosphorus discharge in concentrated water, and it is an environmentally friendly reverse osmosis scale inhibitor.

[0041] (4) The scale inhibitor provided by the present application only needs to maintain a concentration of 3-10 ppm during continuous use, so that the surface of the reverse osmosis membrane can be kept clean and the water production of the reverse osmosis membrane can be stabilized, and it is especially suitable for the treatment of coking wastewater with high organic matter content, so as to ensure the normal operation of the reverse osmosis membrane device. DETAILED DESCRIPTION

[0042] The present application is further described below by specific examples, which are helpful to interpret and define the inventive content of the present application but are not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application, and other embodiments obtained by other researchers without making a comparatively outstanding creative effort shall be within the protection scope of the present application.

[0043] Example 1: A reverse osmosis scale inhibitor for coking wastewater reuse, comprising the following raw materials: bio-based polyether carboxylic acid multi-copolymer 20 parts, modified polyepoxysuccinic acid 10 parts, PESA 5 parts, zinc citrate 0.1 part, and water 64.9 parts.

[0044] In this embodiment, the bio-based polyether carboxylic acid multi-copolymer is BA-AMPS-

[0045] (PLA-PEG-PLA)-NVP copolymer, and the modified polyepoxysuccinic acid is quaternized polyepoxysuccinic acid.

[0046] In this embodiment, a preparation method of a reverse osmosis scale inhibitor for coking wastewater reuse comprises the following steps: (1) weighing the required raw materials according to the proportion;

[0047] (2) adding the bio-based polyether carboxylic acid multi-copolymer, the modified polyepoxysuccinic acid, the polyepoxysuccinic acid, and the zinc citrate into water, mixing and heating to stir uniformly, the stirring temperature is 10-35℃, and the stirring time is 30-60 min;

[0048] The preparation method of the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer comprises the following steps:

[0049] S1: pretreatment, neutralizing BA to pH 6.0 with KOH, and pre-dissolving PLA-PEG-PLA (Mn=1500) in ultrapure water at 40℃;

[0050] S2: under nitrogen protection, adding PLA-PEG-PLA, AMPS, and NVP into the mixture of BA and initiator, and reacting at 65℃ for 6 hours;

[0051] S3: after the mixture obtained in S2 is purified by ultrafiltration (5kDa MWCO) and freeze-dried, a white powder is obtained, i.e. the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer.

[0052] The feeding ratio is in terms of molar ratio, BA:AMPS:(PLA-PEG-PLA):NVP=3:1:0.6:0.4.

[0053] The initiation system is an oxidation-reduction initiation system composed of potassium persulfate (KPS) and L-ascorbic acid (Vc), the molar ratio of the potassium persulfate (KPS) to L-ascorbic acid (Vc) is 1:1, the initiation is carried out at a low temperature of 60℃, the branching is reduced, and the amount of initiator is 1.5%.

[0054] The molecular weight control target Mw=4000±500Da, RAFT polymerization is adopted, the chain transfer agent is S-dodecyl-S'-(α,α'-dimethyl-α''-acetic acid) trithiocarbonate (CTA), and the amount is 0.5%.

[0055] The preparation method of the modified polyepoxysuccinic acid comprises the following steps: dissolving PESA in deionized water (concentration 10% w / v) and stirring until completely dissolved; slowly adding 1M KOH to reduce the liquid, and maintaining pH at 10.3-10.7; adding 60% glycidyltrimethylammonium chloride (GTMAC) aqueous solution dropwise, adding GTMAC dropwise according to the molar ratio (PESA repeating unit: GTMAC=1:0.5 to 1:0.8), controlling the temperature at 50±2℃, maintaining the pH at 10-11 (by automatic titration or manual addition of alkali), and reacting for 6-8 hours to obtain the modified polyepoxysuccinic acid.

[0056] Example 2: a reverse osmosis scale inhibitor for coking wastewater reuse, comprising the following raw materials: 40 parts of bio-based polyether carboxylic acid multi-copolymer, 20 parts of modified polyepoxysuccinic acid, 10 parts of PESA, 1 part of zinc citrate, and 29 parts of water in terms of mass fraction. The other operation steps are consistent with those of Example 1.

[0057] Example 3: A coking wastewater reuse reverse osmosis antifouling agent, comprising the following raw materials: bio-based polyether carboxylic acid multi-copolymer 30 parts by mass, modified polyepoxysuccinic acid 15 parts, PESA 7.5 parts, zinc citrate 0.5 parts, and water 47 parts. Other operation steps are consistent with example 1.

[0058] Example 4: A coking wastewater reuse reverse osmosis antifouling agent, comprising the following raw materials: bio-based polyether carboxylic acid multi-copolymer 25 parts by mass, modified polyepoxysuccinic acid 12 parts, PESA 5 parts, zinc citrate 0.3 parts, and water 57.7 parts. Other operation steps are consistent with example 1.

[0059] Example 5: A coking wastewater reuse reverse osmosis antifouling agent, comprising the following raw materials: bio-based polyether carboxylic acid multi-copolymer 36 parts by mass, modified polyepoxysuccinic acid 14 parts, PESA 8 parts, zinc citrate 0.8 parts, and water 41.2 parts. Other operation steps are consistent with example 1.

[0060] Comparative Example 1:

[0061] Other operation steps are consistent with example 5, except that no bio-based polyether carboxylic acid multi-copolymer is added.

[0062] Comparative Example 2:

[0063] Other operation steps are consistent with example 5, except that the amount of bio-based polyether carboxylic acid multi-copolymer added is 10 parts.

[0064] Comparative Example 3:

[0065] Other operation steps are consistent with example 5, except that the amount of bio-based polyether carboxylic acid multi-copolymer added is 50 parts.

[0066] Comparative Example 4:

[0067] Other operation steps are consistent with example 5, except that no modified polyepoxysuccinic acid is added.

[0068] Performance test:

[0069] I. Antifouling rate and sterilization rate test

[0070] The calcium carbonate antifouling performance is determined according to the national standard GB / T 16632-2008 "Determination of water treatment agent antifouling performance - calcium carbonate deposition method". This method prepares a test solution containing water containing insoluble salt ions and water treatment agent, raises the temperature, maintains for a period of time, makes the test solution quickly reach its natural balance, and then measures the stable concentration of calcium ions in the test solution, and calculates the antifouling rate. Similarly, the calcium sulfate antifouling performance is determined according to Q / SY 17126-2019.

[0071] Silicon scale inhibition test method: In a polyethylene bottle, 500 ml of Na2SiO3 solution with a mass concentration of 500 mg / L (concentration calculated as SiO2) was prepared, and a certain amount of the above prepared scale inhibitor was added; the pH value of the solution was adjusted to 7.0±0.1, and a blank test was carried out at the same time. The water sample was placed in a 40°C constant temperature water tank, and the supernatant was taken every 4 hours within 48 hours, filtered with a 0.45 μm filter membrane, diluted to a certain multiple, and then the SiO2 content in the water sample was determined by the molybdenum blue colorimetric method, and the scale inhibition rate was calculated. The bactericidal performance test was carried out according to DL / T1116-2009, and the bactericidal rate was tested. The above reagent tests all used an addition amount of 3 ppm, and the results are shown in Table 1.

[0072] Table 1 Scale inhibition rate and bactericidal rate test data of examples and comparative examples

[0073]

[0074] As can be seen from the data in Table 1, when the reverse osmosis membrane scale inhibitor sample of the present application is added at 3 ppm, the scale inhibition effect on CaCO3, CaSO4 and SiO2 is excellent, and the bactericidal effect is good. The addition of the multi-polymer and the modified polyepoxysuccinic acid can significantly improve the silicon scale inhibition performance and the bactericidal performance. It is found that when the addition amount is 6 ppm and 10 ppm, the scale inhibition rate reaches 100% and the bactericidal rate is close to 100% when the addition amount is 10 ppm, and the scale inhibition rate and the bactericidal rate do not increase significantly when the addition amount continues to increase.

[0075] II. Performance test of the coking wastewater recycling reverse osmosis scale inhibitor prepared in Example 1-5 in a certain energy enterprise in Henan:

[0076] The coking wastewater generated by a certain energy enterprise in Henan contains refractory high-concentration organic matter, calcium and magnesium ions, chloride ions, etc., and the COD and ammonia nitrogen are relatively high. After pretreatment and hardness removal, the water quality data are as follows: conductivity 10580 μs / cm, turbidity 1.2 NTU, total alkalinity 120 mg / L, calcium 20.44 mg / L, magnesium 4.16 mg / L, silicon dioxide 56 mg / L, chloride ion 3448.6 mg / L, sulfate 1350 mg / L, COD 268 mg / L, and ammonia nitrogen 2.5 mg / L.

[0077] The coking wastewater recycling reverse osmosis scale inhibitor was added to the reverse osmosis feed water through a dosing device, and then entered the reverse osmosis membrane device 1# unit, and was compared with the control group without adding the scale inhibitor and only adding the organic phosphorus scale inhibitor. The addition amount of the coking wastewater recycling reverse osmosis scale inhibitor was 3 ppm, the membrane feed water amount was 100 m 3 / h, and the initial membrane water production was 75 m 3 / h, when the membrane system first stage pressure difference is greater than 0.2 MPa, then cleaning (first stage pressure difference reflects the degree of membrane pollution). In order to facilitate and blank control, the membrane water production is the data of the tenth day of operation, and the experimental comparison results are shown in Table 2:

[0078] Table 2

[0079] Blank Organophosphorus agent Example 1 Example 2 Example 3 Example 4 Example 5 Addition amount (ppm) 0 3 3 3 3 3 3 Membrane water production m 3 / h]] 35 60 74 75 74 74 75 First-stage pressure difference MPa 0.21 0.10 0.04 0.03 0.035 0.032 0.03 Cleaning cycle, days 10 30 90 102 99 95 100

[0080] From Table 2, compared with the previous addition of scale inhibitor, the addition of coking wastewater reuse reverse osmosis scale inhibitor can prolong the cleaning period by at least 8 times. Compared with conventional organic phosphorus scale inhibitor, the addition of coking wastewater reuse reverse osmosis scale inhibitor can reduce the membrane cleaning frequency, and the inhibition effect of membrane organic pollution is very significant, the anti-pollution effect is good, and the membrane flux is effectively improved, and the treatment capacity of the recycled water is increased.

[0081] Three, the coking wastewater reuse reverse osmosis scale inhibitor is added to the reverse osmosis feed water through the dosing device, and then enters the reverse osmosis membrane device 2# unit, and is compared with the blank control group without adding scale inhibitor and only adding organic phosphorus scale inhibitor. The addition amount of coking wastewater reuse reverse osmosis scale inhibitor is 6 ppm, the membrane water inlet is 100 mm 3 / h, the initial membrane water production is 75 m 3 / h, when the membrane system first stage pressure difference is greater than 0.2 MPa, then cleaning (first stage pressure difference reflects the degree of membrane pollution). In order to facilitate and blank control, the membrane water production is the data of the tenth day of operation, and the experimental comparison results are shown in Table 3:

[0082] Table 3

[0083] Blank Organophosphorus agent Example 1 Example 2 Example 3 Example 4 Example 5 Addition amount (ppm) 0 6 6 6 6 6 6 Membrane water production m 3 / h]] 35 66 75 75 75 75 75 First-stage pressure difference MPa 0.21 0.09 0.03 0.02 0.03 0.025 0.027 Cleaning cycle, days 10 35 120 122 123 121 124

[0084] Four, the coking wastewater reuse reverse osmosis scale inhibitor is added to the reverse osmosis feed water through the dosing device, and then enters the reverse osmosis membrane device 3# unit, and is compared with the blank control group without adding scale inhibitor and only adding organic phosphorus scale inhibitor. The addition amount of coking wastewater reuse reverse osmosis scale inhibitor is 10 ppm, the membrane water inlet is 100 m 3 / h, the initial membrane water production is 75 m 3 / h, when the membrane system first stage pressure difference is greater than 0.2 MPa, then cleaning (first stage pressure difference reflects the degree of membrane pollution). In order to facilitate and blank control, the membrane water production is the data of the tenth day of operation, and the experimental comparison results are shown in Table 4:

[0085] Table 4

[0086] Blank Organophosphorus agent Example 1 Example 2 Example 3 Example 4 Example 5 Addition amount (ppm) 0 10 10 10 10 10 10 Membrane water production m 3 / h]] 35 55 75 75 75 75 75 First-stage pressure difference MPa 0.21 0.15 0.02 0.02 0.02 0.021 0.022 Cleaning cycle, days 10 28 129 130 133 134 134

[0087] From the above table 2, 3, 4, it can be seen that the organic phosphorus scale inhibitor is added in the concentration of 3ppm-10ppm, the water production increases slightly, the cleaning cycle is prolonged by 5 days, the concentration is continuously increased to 10ppm, the water production decreases instead, and the cleaning cycle is shortened, because the organic phosphorus promotes the pollution of microorganisms; after the scale inhibitor of the application is added, the water production increases slightly with the increase of the concentration, and the improvement is not great with the continuous increase, which shows that 6ppm can achieve good effect for the water quality, and the economy is better.

[0088] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

[0089] The parts not described in detail in the present application are well-known to those skilled in the art.

Claims

1. A reverse osmosis antiscalant for coking wastewater reuse, characterized in that, The raw materials include the following: by mass, 20-40 parts of bio-based polyether carboxylic acid copolymer, 10-20 parts of modified polyepoxysuccinic acid, 5-10 parts of polyepoxysuccinic acid, 0.1-1 parts of zinc citrate, and appropriate amount of water.

2. The reverse osmosis antiscalant for coking wastewater reuse according to claim 1, characterized in that, The bio-based polyether carboxylic acid copolymer is a BA-AMPS-(PLA-PEG-PLA)-NVP copolymer.

3. The reverse osmosis antiscalant for coking wastewater reuse according to claim 1, characterized in that, The modified polyepoxysuccinic acid is quaternized polyepoxysuccinic acid.

4. The reverse osmosis antiscalant for coking wastewater reuse according to claim 1, characterized in that, The raw materials include the following: by mass parts, 36 parts of bio-based polyether carboxylic acid copolymer, 14 parts of modified polyoxysuccinic acid, 8 parts of PESA, 0.8 parts of zinc citrate, and 41.2 parts of water.

5. A method for preparing a reverse osmosis antiscalant for coking wastewater reuse according to any one of claims 1-4, characterized in that, Includes the following steps, (1) Weigh out the required raw materials according to the proportions; (2) Add bio-based polyether carboxylic acid copolymer, modified polyepoxysuccinic acid, polyepoxysuccinic acid and zinc citrate to water, mix and heat and stir evenly. The stirring temperature is 10-35℃ and the stirring time is 30-60min.

6. The method for preparing a reverse osmosis antiscalant for coking wastewater reuse according to claim 2, characterized in that, The preparation method of the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer includes: S1: Pretreatment, neutralize butenoic acid with potassium hydroxide solution to pH 6.0, and predissolve polyethylene glycol dimerlactic acid (Mn = 1500) in ultrapure water at 40℃; S2: Under nitrogen protection, polyethylene glycol dimer lactic acid, 2-acrylamido-2-methylpropanesulfonic acid, and vinylpyrrolidone are added to a mixture of butenoic acid and initiator, and reacted at 65°C for 6 hours. S3: After ultrafiltration purification and freeze-drying of the mixture obtained in S2, a white powder is obtained, which is the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer.

7. The method for preparing a reverse osmosis antiscalant for coking wastewater reuse according to claim 6, characterized in that, In the preparation method of the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer, the feed ratio, expressed as a molar ratio, is BA:AMPS:(PLA-PEG-PLA):NVP = 3:1:0.6:0.

4.

8. The method for preparing a reverse osmosis antiscalant for coking wastewater reuse according to claim 7, characterized in that, In the preparation method of the BA-AMPS-(PLA-PEG-PLA)-NVP copolymer, the initiation system is a redox initiation system composed of potassium persulfate and L-ascorbic acid, the molar ratio of potassium persulfate to L-ascorbic acid is 1:1, the initiation is carried out at a low temperature of 60°C to reduce branching, and the amount of initiator is 1.5%.

9. The method for preparing a reverse osmosis antiscalant for coking wastewater reuse according to claim 8, characterized in that, The target molecular weight was Mw = 4000 ± 500 Da. RAFT polymerization was used, and the chain transfer agent was S-dodecyl-S'-(α,α'-dimethyl-α”-acetic acid) trithiocarbonate, with an amount of 0.5%.

10. The method for preparing a reverse osmosis antiscalant for coking wastewater reuse according to claim 5, characterized in that, The method for preparing the modified polyepoxysuccinic acid includes: dissolving polyepoxysuccinic acid in deionized water and stirring until completely dissolved; slowly adding 1M KOH solution to maintain the pH at 10.3-10.7; adding dropwise 60% glycidyltrimethylammonium chloride aqueous solution, with a molar ratio of polyepoxysuccinic acid to glycidyltrimethylammonium chloride of 1:(0.5-0.8); controlling the temperature at 50±2℃; maintaining the pH at 10-11; and reacting for 6-8 hours to obtain the modified polyepoxysuccinic acid.

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