Preparation method of anionic flocculant based on solid waste

Abstract

The invention aims to provide a preparation method of an anionic flocculant based on solid waste, and belongs to the technical field of water pollution remediation / governance, the preparation method comprises the following steps: by taking the solid waste as a raw material, mechanically mixing the solid waste with hydrophosphate, putting the mixture into a tubular furnace, calcining at high temperature in an N2 atmosphere, cooling to room temperature, washing the obtained material with deionized water to be neutral, and drying to obtain the anionic flocculant based on the solid waste. And drying to obtain the anionic flocculant. The preparation method is low in cost, simple, convenient and easy to operate, and the obtained flocculant has an efficient flocculation effect and can be recycled. The method has a wide application prospect in the field of wastewater treatment.

Description

Technical Field

[0001] This invention belongs to the field of water pollution remediation / treatment technology, specifically relating to a method for preparing an anionic flocculant based on solid waste. Background Technology

[0002] Chemical flocculation is widely used in the pretreatment of wastewater due to its simple equipment, convenient operation, and significant treatment effect. Flocculants neutralize the charge of colloidal particles in wastewater, enhancing particle collision and aggregation, thereby forming flocs that are easy to settle or filter, effectively removing organic pollutants from wastewater. This is of great significance for improving water quality and reducing the load on subsequent treatment processes.

[0003] Currently, the most common flocculants on the market are divided into two main categories: inorganic flocculants and organic flocculants. Inorganic flocculants, such as polyferric chloride and polyaluminum chloride, are relatively inexpensive, but their large usage increases treatment costs. Organic flocculants, such as polyacrylamide, offer superior flocculation effects, but their high synthesis cost means large-scale application significantly increases wastewater treatment costs for businesses. Furthermore, existing flocculants dissolve in water after being added and cannot be regenerated and recycled. This characteristic necessitates the addition of flocculants each time wastewater is treated, greatly increasing long-term operating costs and wasting resources.

[0004] Therefore, developing a low-cost, high-efficiency, and water-insoluble flocculant has become a technical problem that needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing anionic flocculants based on solid waste. The flocculants provided by this invention have low cost and good anionic dye flocculation effect.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing an anionic flocculant based on solid waste includes the following steps: S1. The solid waste material and hydrogen phosphate are ball-milled and mixed to obtain a mixed material; S2. Place the above-mentioned mixed material into a tube furnace and heat it from room temperature under a N2 atmosphere. After the heating reaction is completed, cool it to room temperature. Wash the resulting material with deionized water until it is neutral and dry it to obtain the anionic flocculant.

[0007] Furthermore, the mass ratio of the solid waste material to the hydrogen phosphate in S1 is 1:0.5-4.

[0008] Furthermore, the solid waste materials mentioned in S1 include one or a mixture of several of the following: industrial silicon slag, gasification slag, fly ash, coal gangue, liquefied slag extract residue, perlite, and biochar.

[0009] Furthermore, the hydrogen phosphate salt mentioned in S1 includes one or a mixture of several of potassium dihydrogen phosphate, sodium dihydrogen phosphate, ammonium dihydrogen phosphate, calcium dihydrogen phosphate, and magnesium dihydrogen phosphate.

[0010] Furthermore, the heating reaction in S2 is carried out at a temperature of 300-600°C for 1-4 hours.

[0011] An anionic flocculant based on solid waste is used for the flocculation treatment of cationic substances in wastewater.

[0012] The principle of this invention is as follows: Through the salt fusion method, the hydroxyl groups in the material dehydrate with the hydrogen in the hydrogen phosphate to form a phosphorus-containing polymer. This polymer has a large number of negative charges and can flocculate cationic substances in wastewater.

[0013] The beneficial effects of the invention are as follows: The novel anionic flocculant of the present invention has moderate hardness and volume of flocs, fast settling speed, and obvious separation after flocculation, which facilitates the recovery of flocs and supernatant.

[0014] The novel anionic flocculant of this invention uses only solid waste and phosphate as raw materials and can be prepared by a one-step salt fusion method. This significantly reduces the preparation cost of the flocculant.

[0015] The novel flocculant of this invention can be recovered by high-temperature calcination after the flocs are collected. High temperature does not destroy the original composition of the flocculant, and the recovered flocculant can be recycled multiple times. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1 By weight, take 100 parts of industrial silicon slag and 50 parts of potassium dihydrogen phosphate. Mechanically mix the industrial silicon slag and potassium dihydrogen phosphate particles (ball mill). Place the mixture in a tube furnace and calcine at 300°C for 2 hours under a nitrogen atmosphere. Wash, filter, and dry the resulting material to obtain a flocculant.

[0018] Example 2 By weight, take 100 parts fly ash and 50 parts sodium dihydrogen phosphate. Mechanically mix the fly ash and sodium dihydrogen phosphate particles (by ball milling). Place the mixture in a tube furnace and calcine at 400°C for 2 hours under a nitrogen atmosphere. Wash, filter, and dry the resulting material to obtain the flocculant.

[0019] Example 3 By weight, take 200 parts of coal gangue and 200 parts of ammonium dihydrogen phosphate. Mechanically mix the coal gangue and ammonium dihydrogen phosphate particles using a ball mill. Place the mixture in a tube furnace and calcine at 500°C for 3 hours under a nitrogen atmosphere. Wash, filter, and dry the resulting material to obtain the flocculant.

[0020] Example 4 By weight, 100 parts of gasification slag, 25 parts of calcium dihydrogen phosphate, and 25 parts of magnesium dihydrogen phosphate were taken. The gasification slag and the particles containing calcium dihydrogen phosphate and magnesium dihydrogen phosphate were mechanically (ball milled) and mixed. The mixture was placed in a tube furnace and calcined at 600°C for 4 hours under a nitrogen atmosphere. The resulting material was washed, filtered, and dried to obtain a flocculant.

[0021] Example 5 By weight, take 50 parts perlite, 50 parts pure silica, 25 parts potassium dihydrogen phosphate, and 25 parts sodium dihydrogen phosphate. Mechanically mix the perlite, pure silica, potassium dihydrogen phosphate, and sodium dihydrogen phosphate using a ball mill. Place the mixture in a tube furnace and calcine at 300°C for 1 hour under a nitrogen atmosphere. Wash, filter, and dry the resulting material to obtain the flocculant.

[0022] Example 6 By weight, take 50 parts of liquefied petroleum slag extract residue, 50 parts of biochar, 25 parts of potassium dihydrogen phosphate, and 25 parts of sodium dihydrogen phosphate. Mechanically mix the liquefied petroleum slag extract residue, biochar, potassium dihydrogen phosphate, and sodium dihydrogen phosphate using a ball mill. Place the mixture in a tube furnace and calcine at 300°C for 1 hour under a nitrogen atmosphere. Wash, filter, and dry the resulting material to obtain the flocculant.

[0023] Example 7 The flocculant prepared in Example 1 was calcined in a muffle furnace at 500°C for 3 hours. The resulting material could be used again for the flocculation of methylene blue (MB). After flocculation equilibrium, the flocculation amount of MB was 900 mg / g.

[0024] Experimental Example 1 0.01 g of the flocculant prepared in Example 1 was added to 100 mL of a 200 mg / L methylene blue (MB) solution and shaken on a shaking bed for 30 min. After equilibration, the concentration of MB in the solution was detected by ultraviolet spectrophotometry. The calculated MB adsorption capacity was 1789 mg / g.

[0025] Experimental Example 2 0.01 g of the flocculant prepared in Example 2 was added to 100 mL of a 200 mg / L toluidine blue solution and shaken on a shaking bed for 30 min. After equilibration, the concentration of toluidine blue in the solution was detected by ultraviolet spectrophotometry. The calculated adsorption capacity of toluidine blue was 1865 mg / g.

[0026] Experimental Example 3 0.01 g of the flocculant prepared in Example 3 was added to 100 mL of a 200 mg / L solution of azure A, and the solution was shaken on a shaking bed for 30 min. After equilibration, the concentration of azure A in the solution was detected by ultraviolet spectrophotometry. The calculated adsorption capacity of azure A was 1894 mg / g.

[0027] Experiment Example 4 0.01 g of the flocculant prepared in Example 4 was added to 100 mL of a 200 mg / L methyl violet solution and shaken on a shaking bed for 30 min. After equilibration, the concentration of methyl violet in the solution was detected by ultraviolet spectrophotometry. The calculated adsorption capacity of methyl violet was 1589 mg / g.

[0028] Experimental Example 5 0.01 g of the flocculant prepared in Example 5 was added to 100 mL of a 200 mg / L solution of Azure B, and the solution was shaken on a shaking bed for 30 min. After equilibration, the concentration of Azure B in the solution was detected by ultraviolet spectrophotometry. The calculated adsorption capacity of Azure B was 1789 mg / g.

[0029] Experimental Example 6 0.01 g of the flocculant prepared in Example 6 was added to 100 mL of a 200 mg / L neutral red solution and shaken on a shaking bed for 30 min. After equilibration, the concentration of neutral red in the solution was detected by ultraviolet spectrophotometry. The calculated neutral red adsorption capacity was 1679 mg / g.

[0030] Experimental Example 7 0.01 g of the flocculant prepared in Example 1 was added to 100 mL of a 200 mg / L cationic violet solution and shaken on a shaking bed for 30 min. After equilibration, the concentration of the cationic violet solution in the solution was detected by ultraviolet spectrophotometry. The calculated adsorption capacity of the cationic violet solution was 1546 mg / g.

[0031] Experimental Example 8 0.01 g of the flocculant prepared in Example 7 was added to 100 mL of a 200 mg / L cationic violet solution and shaken on a shaking bed for 30 min. After equilibration, the concentration of the cationic violet solution in the solution was detected by ultraviolet spectrophotometry. The calculated adsorption capacity of the cationic violet solution was 1651 mg / g.

[0032] Comparative Example 1 The temperature in Example 1 was changed from 300℃ to 200℃, with the rest remaining the same as in Example 1. 0.01 g of the material was added to 100 mL of a 200 mg / L methylene blue (MB) solution and shaken on a shaking bed for 30 min. After equilibration, the concentration of MB in the solution was detected using a UV spectrophotometer. The calculated MB flocculation amount was only 105 mg / g.

[0033] Comparative Example 2 Potassium dihydrogen phosphate in Example 1 was replaced with potassium phosphate, and the rest remained the same as in Example 1. 0.01 g of this material was added to 100 mL of a 200 mg / L methylene blue (MB) solution and shaken on a shaking bed for 30 min. After equilibration, the concentration of MB solution in the solution was detected by ultraviolet spectrophotometry. The calculated MB flocculation amount was only 61 mg / g.

[0034] Comparative Example 3 The potassium dihydrogen phosphate in Example 1 was replaced with potassium monohydrogen phosphate, and the rest remained the same as in Example 1. 0.01 g of this material was added to 100 mL of a 200 mg / L methylene blue (MB) solution and shaken on a shaking bed for 30 min. After equilibration, the concentration of MB solution in the solution was detected by ultraviolet spectrophotometry. The calculated MB flocculation amount was only 128 mg / g.

[0035] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing an anionic flocculant based on solid waste, characterized in that: Includes the following steps: S1. The solid waste material and hydrogen phosphate are ball-milled and mixed to obtain a mixed material; S2. Place the above-mentioned mixed material into a tube furnace and heat it from room temperature under a N2 atmosphere. After the heating reaction is completed, cool it to room temperature. Wash the resulting material with deionized water until it is neutral and dry it to obtain the anionic flocculant.

2. The method for preparing an anionic flocculant based on solid waste according to claim 1, characterized in that: The mass ratio of solid waste material to hydrogen phosphate in S1 is 1:0.5-4.

3. The method for preparing an anionic flocculant based on solid waste according to claim 1, characterized in that: The solid waste materials mentioned in S1 include one or a mixture of several of the following: industrial silicon slag, gasification slag, fly ash, coal gangue, liquefied slag extract residue, perlite, and biochar.

4. The method for preparing an anionic flocculant based on solid waste according to claim 1, characterized in that: The hydrogen phosphate salts mentioned in S1 include one or a mixture of several of potassium dihydrogen phosphate, sodium dihydrogen phosphate, ammonium dihydrogen phosphate, calcium dihydrogen phosphate, and magnesium dihydrogen phosphate.

5. The method for preparing an anionic flocculant based on solid waste according to claim 1, characterized in that: The heating reaction described in S2 is carried out at a temperature of 300-600℃ for 1-4 hours.

6. An anionic flocculant based on solid waste prepared by the preparation method as described in claim 1 is used for the flocculation treatment of cationic substances in wastewater.