Composite water purifying agent for purifying cold rolled steel production wastewater and preparation method of composite water purifying agent

Abstract

The invention discloses a composite water purifying agent for purifying cold rolled steel production wastewater and a preparation method of the composite water purifying agent, and belongs to the technical field of industrial wastewater treatment. An accelerant is added into polyaluminum chloride liquid to obtain the composite water purifying agent, the accelerant is composed of a component A and a component B, the component A is composed of dimethylamine, allyl chloride and sodium hydroxide, and the component B is composed of dicyandiamide, ammonium chloride and formaldehyde. The compound water purifying agent is obtained through formula improvement, the water treatment function of the water purifying agent is enriched through compounding of the components in the compound water purifying agent, soluble grease pollutants in cold rolled steel production wastewater can be more effectively separated from the wastewater through a coagulation reaction, and the purposes of removal and purification are achieved; the removal rate of pollutants such as COD (Chemical Oxygen Demand) and suspended matters is higher, the sewage purification effect is good by matching with the polyacrylamide flocculant, and the use cost is low.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial wastewater treatment, and specifically relates to a composite water purifier for purifying wastewater from cold-rolled steel production and a preparation method thereof. Background Art

[0002] As production units have increasingly higher requirements for strip surface quality, the chemical components in productive agents such as emulsions, leveling liquids, and coating passivation liquids used in the production process are becoming more and more stable. A large number of soluble pollutants are extremely difficult to separate and remove in the water body, which greatly increases the difficulty of treating emulsion wastewater, leveling liquid wastewater, concentrated alkali wastewater, weak oil and dilute alkali wastewater, and chromium-containing wastewater in cold-rolled steel production lines.

[0003] The existing water treatment agents commonly used in industrial wastewater treatment have a single function and weak adsorption capacity for heavy metal ions, so it is necessary to add multiple agents such as flocculants, corrosion inhibitors and demulsifiers separately in the water treatment system to effectively treat the sewage. However, this will lead to many problems such as large dosage of sewage treatment agents, complex treatment processes, many required equipment, and high sewage treatment costs. In addition, some chemical reactions will occur between the multiple agents and resist each other, resulting in reduced sewage treatment effects.

[0004] At present, conventional polyaluminum, polyiron and other flocculants have a poor treatment effect on these cold-rolled steel production wastewaters due to their single flocculation components, especially for the removal of soluble pollutants in the water. Therefore, for cold-rolled steel production wastewater, there is currently a lack of a water purifier with broad spectrum, high efficiency, good stability, strong specificity, excellent flocculation performance, and moderate performance-price ratio. Summary of the invention

[0005] In view of the above problems existing in the prior art, the technical problem to be solved by the present invention is to provide a composite water purifier for purifying wastewater from cold-rolled steel production, which can effectively remove organic pollutants in wastewater from cold-rolled steel production. Another technical problem to be solved by the present invention is to provide a preparation method of a composite water purifier for purifying wastewater from cold-rolled steel production, which has low requirements on production equipment and is easy to operate in the production process.

[0006] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] A composite water purifier for purifying wastewater from cold-rolled steel production is obtained by adding an accelerator to a polyaluminium chloride liquid, wherein the accelerator consists of a component A and a component B, the component A consists of dimethylamine, allyl chloride and sodium hydroxide, and the component B consists of dicyandiamide, ammonium chloride and formaldehyde.

[0008] Preferably, in the accelerator, the mass ratio of component A to component B is 0.5~1.5:0.5~1.5.

[0009] Preferably, in the accelerator, the mass ratio of component A to component B is 1:1.

[0010] Preferably, in the component A, the mass ratio of dimethylamine, allyl chloride and sodium hydroxide is 0.5-2:1-3:0.5-2; and in the component B, the mass ratio of dicyandiamide, formaldehyde and ammonium chloride is 0.5-1.5:1-3:0.1-2.

[0011] Preferably, in the component A, the mass ratio of dimethylamine, allyl chloride and sodium hydroxide is 1:1-1.5:1; and in the component B, the mass ratio of dicyandiamide, formaldehyde and ammonium chloride is 1:1.5-2:0.1-1.

[0012] Preferably, in the component A, the mass ratio of dimethylamine, allyl chloride and sodium hydroxide is 1:1.2:1; and in the component B, the mass ratio of dicyandiamide, formaldehyde and ammonium chloride is 1:1.8:0.9.

[0013] Preferably, the amount of the accelerator added is 0.5-1%.

[0014] A method for preparing the composite water purifier for purifying cold-rolled steel production wastewater comprises the following steps:

[0015] 1) Mix dimethylamine, allyl chloride and sodium hydroxide at room temperature to obtain component A; mix dicyandiamide, ammonium chloride and formaldehyde, react at high temperature and then cool to room temperature to obtain component B;

[0016] 2) Mix component A and component B at 20-25°C and stir for 1 hour to obtain an accelerator;

[0017] 3) Add 1% accelerator to the polyaluminium chloride liquid and stir for 30 minutes at 20-25°C to obtain a composite water purifier.

[0018] Preferably, in step 1), the temperature of the high temperature reaction is 80° C. and the reaction time is 3 h.

[0019] Preferably, in step 1), dimethylamine and allyl chloride are mixed and then sodium hydroxide is added.

[0020] The composite water purifier is used in the water purifier used for cold-rolled steel production wastewater.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention obtains a composite water purifier by improving the formula. The compounding of the components in the composite water purifier enriches the water treatment function of the water purifier, and can more effectively separate the soluble oil and heavy metal pollutants in the cold-rolled steel production wastewater from the wastewater through coagulation reaction, thereby achieving the purpose of removal and purification, with good sewage purification effect and low use cost;

[0023] (2) The composite water purifier of the present invention is suitable for the treatment of wastewater from cold-rolled steel production. It has a high removal rate for oil, suspended matter and organic pollutants in water and has a wide range of applications. It overcomes the technical problems of existing water treatment agents, such as single function, large dosage of agents, complex treatment process and poor water treatment effect.

[0024] (3) The composite water purifier of the present invention has a simple preparation process. When the prepared water purifier is used to treat cold-rolled steel production wastewater, the COD removal rate is not less than 70%, and the oil removal rate is not less than 75%. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described below in conjunction with specific embodiments. In the following embodiments, unless otherwise specified, the technical means used are conventional means well known to those skilled in the art.

[0026] Example 1

[0027] A method for preparing a composite water purifier for purifying wastewater from cold-rolled steel production, comprising the following steps:

[0028] 1) Dimethylamine, allyl chloride and sodium hydroxide are prepared in a mass ratio of 1:1.2:1. Dimethylamine and allyl chloride are first mixed, and then sodium hydroxide is added. The mixture is mixed and stirred at room temperature to obtain component A;

[0029] 2) Prepare according to the mass ratio of dicyandiamide, formaldehyde and ammonium chloride of 1:1.8:0.9, first mix dicyandiamide and ammonium chloride, then add formaldehyde, mix dicyandiamide, ammonium chloride and formaldehyde, react at 80°C for 3h and then cool to room temperature to obtain component B;

[0030] 3) Component A and component B were mixed in a mass ratio of 1:1, and the mixture was stirred at 25°C for 1 hour to obtain an accelerator; 1% of the accelerator was added to the polyaluminium chloride liquid, and the mixture was stirred at 25°C for 30 minutes to obtain a composite water purifier.

[0031] Example 2

[0032] A method for preparing a composite water purifier for purifying wastewater from cold-rolled steel production, comprising the following steps:

[0033] 1) Dimethylamine, allyl chloride and sodium hydroxide are prepared in a mass ratio of 1:1.5:1. Dimethylamine and allyl chloride are first mixed, and then sodium hydroxide is added. The mixture is mixed and stirred at room temperature to obtain component A;

[0034] 2) Prepare dicyandiamide, formaldehyde and ammonium chloride in a mass ratio of 1:2:1, first mix dicyandiamide and ammonium chloride, then add formaldehyde, mix dicyandiamide, ammonium chloride and formaldehyde, react at 80°C for 3h, and then cool to room temperature to obtain component B;

[0035] 3) Component A and component B were mixed in a mass ratio of 1:1, and the mixture was stirred at 25°C for 1 hour to obtain an accelerator; 1% of the accelerator was added to the polyaluminium chloride liquid, and the mixture was stirred at 25°C for 30 minutes to obtain a composite water purifier.

[0036] Example 3

[0037] A method for preparing a composite water purifier for purifying wastewater from cold-rolled steel production, comprising the following steps:

[0038] 1) Dimethylamine, allyl chloride and sodium hydroxide are prepared in a mass ratio of 1:1.5:1. Dimethylamine and allyl chloride are first mixed, and then sodium hydroxide is added. The mixture is mixed and stirred at room temperature to obtain component A;

[0039] 2) Prepare dicyandiamide, formaldehyde and ammonium chloride in a mass ratio of 1:2:1, first mix dicyandiamide and ammonium chloride, then add formaldehyde, mix dicyandiamide, ammonium chloride and formaldehyde, react at 80°C for 3h, and then cool to room temperature to obtain component B;

[0040] 3) Component A and component B were mixed in a mass ratio of 1:2, and the mixture was stirred at 25°C for 1 hour to obtain an accelerator; 1% of the accelerator was added to the polyaluminium chloride liquid, and the mixture was stirred at 25°C for 30 minutes to obtain a composite water purifier.

[0041] Example 4

[0042] A method for preparing a composite water purifier for purifying wastewater from cold-rolled steel production, comprising the following steps:

[0043] 1) Dimethylamine, allyl chloride and sodium hydroxide are prepared in a mass ratio of 1:1.5:1. Dimethylamine and allyl chloride are first mixed, and then sodium hydroxide is added. The mixture is mixed and stirred at room temperature to obtain component A;

[0044] 2) Prepare dicyandiamide, formaldehyde and ammonium chloride in a mass ratio of 1:2:1, first mix dicyandiamide and ammonium chloride, then add formaldehyde, mix dicyandiamide, ammonium chloride and formaldehyde, react at 80°C for 3h, and then cool to room temperature to obtain component B;

[0045] 3) Component A and component B were mixed in a mass ratio of 2:1, and the mixture was stirred at 25°C for 1 hour to obtain an accelerator; 1% of the accelerator was added to the polyaluminium chloride liquid, and the mixture was stirred at 25°C for 30 minutes to obtain a composite water purifier.

[0046] Example 5

[0047] A method for preparing a composite water purifier for purifying wastewater from cold-rolled steel production, comprising the following steps:

[0048] 1) Dimethylamine, allyl chloride and sodium hydroxide are prepared in a mass ratio of 1:1.2:1. Dimethylamine and allyl chloride are first mixed, and then sodium hydroxide is added. The mixture is mixed and stirred at room temperature to obtain component A;

[0049] 2) Prepare dicyandiamide, formaldehyde and ammonium chloride in a mass ratio of 1:1.5:1, first mix dicyandiamide and ammonium chloride, then add formaldehyde, mix dicyandiamide, ammonium chloride and formaldehyde, react at 80°C for 3h, and then cool to room temperature to obtain component B;

[0050] 3) Component A and component B were mixed in a mass ratio of 1:1, and the mixture was stirred at 25°C for 1 hour to obtain an accelerator; 1% of the accelerator was added to the polyaluminium chloride liquid, and the mixture was stirred at 25°C for 30 minutes to obtain a composite water purifier.

[0051] Comparative Example 1

[0052] Compared with Example 1, no accelerator is added, only polyaluminium chloride is contained, and the rest of the preparation process is the same as that of Example 1.

[0053] Comparative Example 2

[0054] Compared with Example 1, component A was not added, and the remaining ingredients and preparation process were the same as those in Example 1.

[0055] Comparative Example 3

[0056] Compared with Example 1, component B is not added, and the remaining ingredients and preparation process are the same as those of Example 1.

[0057] Comparative Example 4

[0058] Compared with Example 1, 5% of an accelerator is added to the polyaluminium chloride liquid, and the remaining components and preparation process are the same as those in Example 1.

[0059] Example 6

[0060] The products prepared in the above Examples 1 to 5 and Comparative Examples 1 to 4 were subjected to water treatment tests, as follows:

[0061] Weigh 5 mL of the water purifier prepared in Examples 1 to 5 and Comparative Examples 1 to 4, respectively, and add them into 1000 mL of cold-rolled steel production wastewater at a temperature of 20°C, stir at room temperature for 2 minutes, and after the reaction, take each clear liquid to measure its turbidity, COD value, oil content, solid suspended matter content and other indicators.

[0062] The raw water indicators of different cold-rolled steel production wastewater are:

[0063]

[0064] The test results are shown in Tables 1 to 6, and the removal rate calculation formula is: Removal rate = (content before treatment - content after treatment) / content before treatment × 100%.

[0065] Table 1 Emulsion wastewater treatment test results

[0066]

[0067] Table 2 Test results of leveling fluid wastewater treatment

[0068]

[0069] Table 3 Test results of concentrated alkaline wastewater treatment

[0070]

[0071] Table 4 Test results of weak oil and dilute alkali wastewater treatment

[0072]

[0073] Table 5 Acidic wastewater treatment test results

[0074]

[0075] Table 6 Test results of chromium-containing wastewater treatment

[0076]

[0077] As shown in Tables 1 to 6, the present invention shows excellent removal effects in different wastewater treatments, and each index is significantly better than the comparative example, which verifies the superiority and practicality of the method of the present invention. In particular, in chromium-containing wastewater, the total chromium removal rate is as high as 99.98%, and the suspended solids removal rate is also 97.1%, which fully proves the excellent ability of the present invention in treating complex pollutants.

[0078] In addition, when treating different types of wastewater, the removal rate of the present invention fluctuates less, showing good adaptability and reliability. The compounding of the components of the composite water purifier of the present invention will produce a synergistic effect, making the water treatment function of the water purifier stronger. When it lacks some components, its water purification effect is significantly reduced. This synergistic effect not only improves the effectiveness of the water purifier, but also reduces the treatment cost, providing an efficient and economical solution for the environmental protection field. Through multiple experimental verifications, the present invention has shown excellent stability and efficiency in various types of wastewater treatment and has broad application prospects. Its unique component compounding technology ensures efficient purification under different water quality conditions and provides reliable protection for industrial wastewater treatment. At the same time, the present invention is simple to operate and easy to promote, and is expected to play an important role in the environmental protection industry and help achieve green and sustainable development goals.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A composite water purifier for purifying wastewater from cold-rolled steel production, characterized in that: A composite water purifier is obtained by adding an accelerator to a polyaluminium chloride liquid, wherein the accelerator consists of a component A and a component B, the component A consists of dimethylamine, allyl chloride and sodium hydroxide, and the component B consists of dicyandiamide, ammonium chloride and formaldehyde.

2. The composite water purifier for purifying cold-rolled steel production wastewater according to claim 1, characterized in that: In the accelerator, the mass ratio of component A to component B is 0.5-1.5:0.5-1.

5.

3. The composite water purifier for purifying cold-rolled steel production wastewater according to claim 2, characterized in that: In the accelerator, the mass ratio of component A to component B is 1:

1.

4. The composite water purifier for purifying cold-rolled steel production wastewater according to claim 1, characterized in that: In the component A, the mass ratio of dimethylamine, allyl chloride and sodium hydroxide is 0.5-2:1-3:0.5-2; in the component B, the mass ratio of dicyandiamide, formaldehyde and ammonium chloride is 0.5-1.5:1-3:0.1-2.

5. The composite water purifier for purifying cold-rolled steel production wastewater according to claim 4, characterized in that: In the component A, the mass ratio of dimethylamine, allyl chloride and sodium hydroxide is 1:1-1.5:1; in the component B, the mass ratio of dicyandiamide, formaldehyde and ammonium chloride is 1:1.5-2:0.1-1.

6. The composite water purifier for purifying cold-rolled steel production wastewater according to claim 5, characterized in that: In the component A, the mass ratio of dimethylamine, allyl chloride and sodium hydroxide is 1:1.2:1; in the component B, the mass ratio of dicyandiamide, formaldehyde and ammonium chloride is 1:1.8:0.

9.

7. The composite water purifier for purifying cold-rolled steel production wastewater according to claim 1, characterized in that: The amount of the accelerator added is 0.5-1%.

8. A method for preparing the composite water purifier for purifying cold-rolled steel production wastewater according to claim 1, characterized in that: The following steps are involved: 1) Mix dimethylamine, allyl chloride and sodium hydroxide at room temperature to obtain component A; mix dicyandiamide, ammonium chloride and formaldehyde, react at high temperature and then cool to room temperature to obtain component B; 2) Mix component A and component B at 20-25°C and stir for 1 hour to obtain an accelerator; 3) Add 1% accelerator to the polyaluminium chloride liquid and stir for 30 minutes at 20-25°C to obtain a composite water purifier.

9. The method for preparing a composite water purifier for purifying cold-rolled steel production wastewater according to claim 8, characterized in that: In the step 1), the temperature of the high temperature reaction is 80° C. and the reaction time is 3 hours.

10. Use of the composite water purifier according to claim 1 in a water purifier for treating wastewater from cold-rolled steel production.

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