CN112624358A - Environment-friendly water treatment agent and preparation method thereof - Google Patents

Abstract

The invention provides an environment-friendly water treatment agent and a preparation method thereof, wherein the environment-friendly water treatment agent is prepared from SiO₂The chitosan Schiff base is used as a carrier, the Schiff base is generated by the reaction of chitosan and salicylaldehyde in a neutral medium, and the structure can generate a chelate with a very stable six-membered ring structure with most metals. The chitosan Schiff base is made of SiO₂Is used as carrier to improve its stability and slow corrosion effect. The water treatment agent is an environment-friendly nontoxic non-phosphorus agent, does not cause water eutrophication after being used, and is not easy to breed bacteria and algae; the integral scale inhibition effect is good, and the corrosion inhibition rate is high. And the original materials are simple and easy to obtain, the main raw material chitosan is low in price, the raw material formula is small in quantity, the preparation is convenient, the use is convenient, and the cost is low.

Description

Environment-friendly water treatment agent and preparation method thereof

Technical Field

The invention relates to a water treatment agent, and particularly provides an environment-friendly water treatment agent and a preparation method thereof.

Background

The biggest problem in the 21 st century is the global shortage of water resources, which has attracted much attention worldwide. The total amount of water resources in China is the sixth world, but the occupied amount of people is only one fourth of the number of people in the world, 88 people in the world are discharged, the water-deficient countries belong to the limited water resource distribution, 81 percent of the water resource distribution is uneven in the regions south of Yangtze river basin, and many cities belong to the serious water-deficient state. At the same time, followThe economic development of China is continuous, and the environmental burden is also continuously increased. On one hand, water resources are short in China, on the other hand, a large amount of precious water resources are wasted, the reuse rate of urban industrial water is only 30% on average, and the water intake amount per ten thousand yuan industrial production value is 500m on average³Water has a large gap compared to developed countries. With the increasingly sharp contradiction between water supply and demand, enterprises are faced with high water cost and pollution discharge cost, and how to improve the technical level of water treatment, save water and improve the reuse rate of industrial water is a problem that the enterprises need to solve urgently.

In industry, industrial circulating cooling water is used by large households, and circulating water is adopted for heat exchange in chemical industry, metallurgy, thermal power generation and large central air conditioners, so that the use efficiency of industrial or civil circulating water is improved, and an environment-friendly chemical agent is adopted, and the industrial circulating cooling water has important significance for saving water resources, reducing production cost and enhancing environmental protection.

In recent years, China invests a large amount of funds for water pollution treatment. In order to meet the requirement of sustainable development, it is urgent to develop water treatment agents with excellent performance, low cost and no pollution to the environment. The water treatment agent with excellent corrosion and scale inhibition performance can effectively inhibit the scaling and corrosion of the circulating cooling water, save the consumption of the circulating cooling water and prolong the service life of equipment.

The organic phosphine series medicament in the prior art has the advantages of good chemical stability, high temperature resistance, obvious threshold effect, good synergistic effect and the like, and is widely applied in recent years.

However, the phosphorus contained in the medicament can cause eutrophication of surrounding water areas, and cause excessive propagation of bacteria and algae, thereby causing water source pollution. Therefore, the use of organic phosphine water treatment agents will be gradually limited, and the development of novel corrosion and scale inhibitor which is phosphorus-free and has good biodegradability becomes the development direction of the current water treatment agents.

The Chinese patent with publication numbers CN1919752A, CN100509652 and CN101607763A discloses a formulation of a phosphorus-free corrosion and scale inhibitor, but most of the corrosion and scale inhibitors adopted at home and abroad at present are toxic or harmful to the environment or have poor corrosion and scale inhibition effects, and the organic compound corrosion inhibitor has better corrosion prevention effect but higher price, so that the development of an economic, efficient, novel and environment-friendly corrosion and scale inhibitor is the key point of the current research.

Chitin, also known as chitin and chitin, is a cationic polymer material in nature, is a biodegradable and widely distributed polymer material, and is abundantly present in the carapace of marine arthropods (shrimps and crabs) and also in the cell membranes of fungi, insects and algae of lower animals. Chitosan is a deacetylation product of chitin, also called chitosan or chitin, is the only basic polysaccharide in the current biological world, and chitosan and derivatives thereof are abundant natural resources, the storage amount is second to vitamins, and the annual generation amount on the earth reaches 100 hundred million tons. The chemical name of chitosan is: (1,4) -2-amino-2-deoxy- β -D-glucose. The structural formula is shown in figure 1.

Chitosan is a cationic natural high molecular polymer, has the characteristics of good flocculation, film formation, biocompatibility, biodegradability, no toxicity and the like, and has pharmacological actions of antibiosis, cancer resistance, virus resistance and the like, so the chitosan is widely applied to the fields of chemical industry, textile, food, cosmetics, biomedicine, sewage treatment, functional high molecular materials and the like. The chitosan can form stable chelate with most heavy metal ions through amino and hydroxyl in molecules, and can be applied to precious metal recovery and industrial wastewater treatment.

Schiff bases refer to organic compounds containing imino or methylimino, which are formed by addition elimination reaction of two substances containing aldehyde group and amino group, and the compounds are important organic ligands and can form complexes with a plurality of metal ions through coordination bonds. Various Schiff base ligands with different performances and variable structures can be synthesized from chain to ring, from monodentate to multidentate by changing the methods of connecting substituent groups and donor atoms. They can form complexes with most metal ions in the periodic table, and donor atoms such as O, N, S contained in the groups can be ligands which are favorable for forming heteronuclear complexes, so that the ligands have important functions in coordination chemistry. Schiff bases are widely applied in the fields of corrosion inhibitors, catalysts, organic synthesis, new material development and analytical chemistry. In the field of corrosion, certain aromatic schiff bases are often used as corrosion inhibitors for metals such as copper.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides an environment-friendly water treatment agent with economy, high efficiency and good corrosion and scale inhibition effects and a preparation method thereof, and solves the problem of environmental pollution caused by nitrite and phosphorus in the composite slow-release scale inhibitor of the existing water treatment agent.

The technical scheme adopted by the invention is as follows:

an environment-friendly water treatment agent is characterized in that chitosan reacts with salicylaldehyde in a neutral medium to generate Schiff base, the Schiff base can react with most metals to generate a chelate with a six-membered ring structure, and the structure is very stable, so that the effect of absorbing heavy metals in water is achieved.

The amino and hydroxyl of the chitosan are chemically modified, so that new chemical active groups can be introduced, the physical and chemical properties of the chitosan are changed, and a series of chitosan derivatives with good adsorption functions are obtained.

The environment-friendly water treatment agent is characterized in that the chitosan Schiff base takes SiO2 as a carrier to improve the stability and the corrosion-retarding effect of the chitosan Schiff base.

The invention provides a preparation method of an environment-friendly water treatment agent, which comprises the following specific steps:

the first step is as follows: stirring chitosan and acetic acid solution at room temperature to dissolve, adding a certain amount of SiO₂Adjusting pH value with NaOH solution, heating and stirring for a period of time, cooling and filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

The second step is that: taking SiO₂Sequentially adding a certain amount of salicylaldehyde, methanol and glacial acetic acid into chitosan, heating and stirring for a period of time, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan schiff base bright yellow powdery solid.

The environment-friendly waterThe preparation method of the treating agent comprises the following steps: chitosan, SiO₂The ratio of the salicylaldehyde is 1: (2-4): (4-8), more preferably 1: (2-3): (4-6).

The preparation method of the environment-friendly water treatment agent comprises the following steps: in the first step, the pH is adjusted to 7 to 14, more preferably 10 to 13, with NaOH solution.

The preparation method of the environment-friendly water treatment agent comprises the following steps: the stirring time in the first step is 2 to 8 hours, more preferably 4 to 6 hours.

The preparation method of the environment-friendly water treatment agent comprises the following steps: the stirring temperature in the first step is 50 to 90 ℃ and more preferably 60 to 80 ℃.

The preparation method of the environment-friendly water treatment agent comprises the following steps: the stirring time in the second step is 5 to 15 hours, and more preferably 8 to 12 hours.

The preparation method of the environment-friendly water treatment agent comprises the following steps: in the second step, the stirring temperature is 50 to 95 ℃, and more preferably 65 to 80 ℃.

The use method of the environment-friendly water treatment agent comprises the following steps:

firstly, regulating the pH value of water to be treated, then adding a certain mass fraction of water treatment agent into the water to be treated, stirring, and reacting at normal temperature for a period of time, wherein the scale inhibition rate of calcium ions and magnesium ions is up to more than 98%.

The use method of the environment-friendly water treatment agent is characterized by comprising the following steps: the mass fraction of the water treatment agent is 0.5-5%, preferably 1-2%.

The use method of the environment-friendly water treatment agent is characterized by comprising the following steps: the reaction time is 0 to 20 hours, and more preferably 4 to 15 hours.

The use method of the environment-friendly water treatment agent is characterized by comprising the following steps: the pH value of the water to be treated is 2-13, and the preferable pH value is 5-9.

The use method of the environment-friendly water treatment agent is characterized by comprising the following steps: the water to be treated can be various sewage, industrial water and oil field water, and is suitable for circulating cooling water of oil refineries, nuclear power plants, central air conditioners, freezers, thermal power plants, chemical plants, iron and steel plants and the like.

The invention has the beneficial effects that:

1. the water treatment agent is an environment-friendly nontoxic non-phosphorus agent, does not cause water eutrophication after being used, and is not easy to breed bacteria and algae.

2. The water treatment agent does not contain components with high toxicity, such as molybdate and the like, and belongs to an environment-friendly water treatment agent.

3. The water treatment agent has good integral scale inhibition effect and high corrosion inhibition rate. The corrosion rate of common carbon steel, stainless steel, copper materials and other metal materials is far lower than the national standard, and is greatly higher than the phosphorus-free medicament of the prior art.

4. The water treatment agent has the advantages of simple and easily-obtained raw materials, low price of the main raw material chitosan, small amount of raw material formulas, convenient preparation, convenient use and low cost.

Drawings

The invention is described in further detail below with reference to the following figures and embodiments:

FIG. 1 is a structural diagram of chitosan.

FIG. 2 is a structural view of a water treatment agent.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.

The invention provides an environment-friendly water treatment agent, which is characterized in that chitosan reacts with salicylaldehyde in a neutral medium to generate Schiff base, the special structure of the Schiff base can react with most metals to generate chelate with a six-membered ring structure, and the structure diagram of the Schiff base is shown in figure 1. The water treatment agent has a very stable structure, thereby playing a role in absorbing heavy metals in water.

The amino and hydroxyl of the chitosan are chemically modified, so that new chemical active groups can be introduced, the physical and chemical properties of the chitosan are changed, and a series of chitosan derivatives with good adsorption functions are obtained.

The environment-friendly water treatment agent is characterized in that the chitosan Schiff base takes SiO2 as a carrier to improve the stability and the corrosion-retarding effect of the chitosan Schiff base.

The invention also provides a preparation method of the environment-friendly water treatment agent, which comprises the following specific steps:

the first step is as follows: stirring chitosan and acetic acid solution at room temperature to dissolve, adding a certain amount of SiO₂Adjusting pH value with NaOH solution, heating and stirring for a period of time, cooling and filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

The second step is that: taking SiO₂Sequentially adding a certain amount of salicylaldehyde, methanol and glacial acetic acid into chitosan, heating and stirring for a period of time, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan schiff base bright yellow powdery solid.

The preparation method of the environment-friendly water treatment agent comprises the following steps: chitosan, SiO₂The ratio of the salicylaldehyde is 1: (2-4): (4-8), more preferably 1: (2-3): (4-6).

The preparation method of the environment-friendly water treatment agent comprises the following steps: in the first step, the pH is adjusted to 7 to 14, more preferably 10 to 13, with NaOH solution.

The preparation method of the environment-friendly water treatment agent comprises the following steps: the stirring time in the first step is 2 to 8 hours, more preferably 4 to 6 hours.

The preparation method of the environment-friendly water treatment agent comprises the following steps: the stirring temperature in the first step is 50 to 90 ℃ and more preferably 60 to 80 ℃.

The preparation method of the environment-friendly water treatment agent comprises the following steps: the stirring time in the second step is 5 to 15 hours, and more preferably 8 to 12 hours.

The preparation method of the environment-friendly water treatment agent comprises the following steps: in the second step, the stirring temperature is 50 to 95 ℃, and more preferably 65 to 80 ℃.

Example 1:

the preparation method of the environment-friendly water treatment agent comprises the following specific steps:

(1) mixing 4 parts of chitosan and acetic acid solution at room temperature, stirring for dissolving, and adding 8 parts of SiO₂Adjusting pH value to 13 with NaOH solution, heating and stirring at 60 deg.C for 2h, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

(2) Taking 10 parts of SiO₂Sequentially adding 18 parts of salicylaldehyde, methanol and glacial acetic acid into chitosan, heating and stirring at 65 ℃ for 8 hours, cooling, filtering, and drying in vacuum to obtain SiO₂-chitinSugar schiff base bright yellow powdery solid.

Example 2:

the preparation method of the environment-friendly water treatment agent comprises the following specific steps:

(1)4 parts of chitosan and acetic acid solution are stirred and dissolved at room temperature, and 12 parts of SiO is added₂Adjusting pH value to 10 with NaOH solution, heating and stirring at 60 deg.C for 6h, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

(2) Taking 10 parts of SiO₂Sequentially adding 20 parts of salicylaldehyde, methanol and glacial acetic acid into chitosan, heating and stirring at 80 ℃ for 12 hours, cooling, filtering, and drying in vacuum to obtain SiO₂-chitosan schiff base bright yellow powdery solid.

Example 3:

the preparation method of the environment-friendly water treatment agent comprises the following specific steps:

(1)4 parts of chitosan and acetic acid solution are stirred and dissolved at room temperature, and 10 parts of SiO is added₂Adjusting pH value to 12 with NaOH solution, heating and stirring at 70 deg.C for 5h, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

(2) Taking 10 parts of SiO₂Adding 15 parts of salicylaldehyde, methanol and glacial acetic acid into chitosan in sequence, heating and stirring at 70 ℃ for 12 hours, cooling, filtering, and drying in vacuum to obtain SiO₂-chitosan schiff base bright yellow powdery solid.

Example 4:

the preparation method of the environment-friendly water treatment agent comprises the following specific steps:

(1)4 parts of chitosan and acetic acid solution are stirred and dissolved at room temperature, and 10 parts of SiO is added₂Adjusting pH value to 12 with NaOH solution, heating and stirring at 70 ℃ for 6h, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

(2) Taking 10 parts of SiO₂Sequentially adding 10 parts of salicylaldehyde, methanol and glacial acetic acid into chitosan, heating and stirring at 70 ℃ for 10 hours, cooling, filtering, and drying in vacuum to obtain SiO₂-chitosan schiff base bright yellow powdery solid.

Example 5:

the preparation method of the environment-friendly water treatment agent comprises the following specific steps:

(1)10 parts of chitosan and acetic acid solution are stirred and dissolved at room temperature, and 20 parts of SiO is added₂Adjusting pH value to 12 with NaOH solution, heating and stirring at 80 ℃ for 8h, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

(2) Taking 10 parts of SiO₂Sequentially adding 32 parts of salicylaldehyde, methanol and glacial acetic acid into chitosan, heating and stirring at 70 ℃ for 18h, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan schiff base bright yellow powdery solid.

Example 6:

the preparation method of the environment-friendly water treatment agent comprises the following specific steps:

(1)6 parts of chitosan and acetic acid solution are stirred and dissolved at room temperature, and 14 parts of SiO is added₂Adjusting pH value to 12 with NaOH solution, heating and stirring at 60 deg.C for 5h, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

(2) Taking 10 parts of SiO₂Sequentially adding 20 parts of salicylaldehyde, methanol and glacial acetic acid into chitosan, heating and stirring at 80 ℃ for 12 hours, cooling, filtering, and drying in vacuum to obtain SiO₂-chitosan schiff base bright yellow powdery solid.

Use example of water treatment agent:

example 1:

the preparation method of the environment-friendly water treatment agent comprises the following specific steps:

(1) mixing 4 parts of chitosan and acetic acid solution at room temperature, stirring for dissolving, and adding 8 parts of SiO₂Adjusting pH value to 13 with NaOH solution, heating and stirring at 60 deg.C for 2h, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

(2) Taking 10 parts of SiO₂Sequentially adding 18 parts of salicylaldehyde, methanol and glacial acetic acid into chitosan, heating and stirring at 65 ℃ for 8 hours, cooling, filtering, and drying in vacuum to obtain SiO₂-chitosan schiff base bright yellow powdery solid.

Taking 1 part of circulating cooling water, adjusting the pH value of the circulating cooling water to be 7, adding the water treatment agent prepared by the method with the mass fraction of 1.5%, stirring, reacting at normal temperature for a period of time, and testing the scale inhibition rates of calcium ions and magnesium ions at different times.

Example 2:

1 part of circulating cooling water which is the same as that in the example 1 is taken, the PH value is adjusted to be 7, 3 percent of water treatment agent which is the same as that in the preparation method of the example 1 is added, stirred and reacted for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different times are tested.

Example 3:

1 part of circulating cooling water which is the same as that in the example 1 is taken, the PH value is adjusted to be 7, a water treatment agent which is 5 percent of the mass fraction and is the same as that in the preparation method of the example 1 is added, the mixture is stirred and reacts for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different times are tested.

Example 4:

1 part of industrial sewage is taken, the PH value is adjusted to be 7, a water treatment agent which is 1.5 percent of the mass fraction and is the same as the preparation method of the embodiment 1 is added into the industrial sewage, the industrial sewage is stirred and reacts for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different times are tested.

Example 5:

1 part of industrial sewage is taken, the PH value is adjusted to be 7, a water treatment agent which is 2.5 percent of the mass fraction and is the same as the preparation method of the embodiment 1 is added into the industrial sewage, the industrial sewage is stirred and reacts for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different times are tested.

Example 6:

1 part of industrial sewage is taken, the PH value is adjusted to be 7, a water treatment agent which is 4.5 percent by mass and is the same as the preparation method of the embodiment 1 is added into the industrial sewage, the industrial sewage is stirred and reacts for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different times are tested.

Example 7:

1 part of domestic sewage is taken, the PH value is adjusted to be 7, a water treatment agent with the mass fraction of 4.5 percent and the same as the preparation method of the embodiment 1 is added into the domestic sewage, the mixture is stirred and reacts for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different times are tested.

Example 8:

1 part of domestic sewage is taken, the PH value is adjusted to be 7, a water treatment agent with the mass fraction of 4.5 percent and the same as the preparation method of the embodiment 1 is added into the domestic sewage, the mixture is stirred and reacts for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different times are tested.

Example 9:

1 part of domestic sewage is taken, the PH value is adjusted to be 7, a water treatment agent with the mass fraction of 4.5 percent and the same as the preparation method of the embodiment 1 is added into the domestic sewage, the mixture is stirred and reacts for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different times are tested.

Example 10:

1 part of oil field water is taken, the PH value is adjusted to be 7, 1.5 percent by mass of water treatment agent which is the same as the preparation method of the embodiment 1 is added into the oil field water, the mixture is stirred and reacts for a period of time at normal temperature, and the scale inhibition rate of calcium ions and magnesium ions at different time is tested.

Example 11:

1 part of oil field water is taken, the PH value is adjusted to be 7, 3 percent of water treatment agent with the same mass percentage as that of the preparation method in the embodiment 1 is added, the mixture is stirred and reacts for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different time are tested.

Example 12:

1 part of oil field water is taken, the PH value is adjusted to be 7, 5 percent of water treatment agent which is the same as the preparation method of the embodiment 1 is added, the mixture is stirred and reacts for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions at different time are tested.

Comparative example 1:

1 part of the same circulating cooling water as in example 1 was taken, without adding a water treatment agent, stirred, reacted at normal temperature for a period of time, and the scale inhibition rates of calcium and magnesium ions thereof at different times were measured.

Comparative example 2:

taking 1 part of industrial sewage which is the same as that in the example 4, adding no water treatment agent, stirring, reacting for a period of time at normal temperature, and testing the scale inhibition rate of calcium ions and magnesium ions of the industrial sewage at different times.

Comparative example 3:

1 part of domestic sewage which is the same as that in the example 7 is taken, no water treatment agent is added, the mixture is stirred and reacted for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions of the mixture at different times are tested.

Comparative example 4:

1 part of oil field water which is the same as that in the example 10 is taken, no water treatment agent is added, stirring is carried out, the reaction is carried out for a period of time at normal temperature, and the scale inhibition rates of calcium ions and magnesium ions of the oil field water at different times are tested.

TABLE 1 Scale inhibition ratio of calcium and magnesium ions by adding water treatment agent with different mass fractions

As shown in Table 1, when different mass fractions of water treatment agents are added for different types of water to be treated (circulating cooling water, domestic sewage, industrial sewage and oil field water), the scale inhibition rates of calcium ions and magnesium ions are over 98%, and the scale inhibition rates are obviously different from those of comparative calcium ions and magnesium ions, so that the water treatment agent is good in overall scale inhibition effect and high in corrosion inhibition rate. The corrosion rate of the alloy on common carbon steel, stainless steel, copper materials and other metal materials is far lower than the national standard.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.

Claims (9)

1. An environment-friendly water treatment agent is characterized in that: the Schiff base is generated by the reaction of chitosan and salicylaldehyde in a neutral medium, and the Schiff base can generate a chelate with a six-membered ring structure with metal.

2. The environment-friendly water treatment agent according to claim 1, wherein: the Schiff base is made of SiO₂Is a carrier.

3. A method for preparing an environmentally friendly water treatment agent according to any one of claims 1 to 2, comprising the steps of:

stirring chitosan and acetic acid solution at room temperature to dissolve, adding a certain amount of SiO₂Adjusting pH value with NaOH solution, heating and stirring for a period of time, cooling and filtering, and vacuum drying to obtain SiO₂-chitosan white powdery solid.

Taking SiO₂Sequentially adding a certain amount of salicylaldehyde, methanol and glacial acetic acid into chitosan, heating and stirring for a period of time, cooling, filtering, and vacuum drying to obtain SiO₂-chitosan schiff base bright yellow powdery solid.

4. The method for producing an environmentally friendly water treatment agent according to claim 3: chitosan, SiO₂The ratio of the salicylaldehyde is 1: (2-4): (4-8).

5. The method for producing an environmentally friendly water treatment agent according to claim 3: the pH value is in the range of 7-14.

6. The method for producing an environmentally friendly water treatment agent according to claim 3: and when the pH value is adjusted by NaOH solution, stirring for 2-8 h.

7. The method for producing an environmentally friendly water treatment agent according to claim 3: when the pH value is adjusted by NaOH solution, the stirring temperature is 50-90 ℃.

8. The method for producing an environmentally friendly water treatment agent according to claim 3: the stirring time of the methanol and the glacial acetic acid is 5-15 h.

9. The method for producing an environmentally friendly water treatment agent according to claim 3: the stirring temperature of the methanol and the glacial acetic acid is 50-95 ℃.

Images