Novel bentonite water treatment agent and method for preparing the same

Abstract

The application discloses a new type of bentonite water treatment agent and a preparation method thereof, wherein the water treatment agent comprises the following components in a mass ratio: 93%-98% of sodium-based bentonite, 1%-2% of aluminum inorganic salt, 0-2% of lime slurry powder and 1%-3% of cationic acrylate, the swelling capacity of the bentonite is greater than or equal to 40 ml / g, the particle size distribution of the bentonite is between 30 mesh and 200 mesh standard screens, and at least 50% of the bentonite is in a 50 mesh standard screen. The bentonite water treatment agent of the application uses bentonite as a main raw material, utilizes the high adsorption of the bentonite, combines other small amounts of inorganic and organic materials, and can achieve one-step treatment effect, is simple to use and operate, has small land occupation, has low equipment requirement, and has remarkable treatment effect on high-concentration pollutant wastewater.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to a novel bentonite water treatment agent and its preparation method. Background Technology

[0002] In recent years, the government has introduced a series of stringent wastewater discharge and water resource usage standards, requiring enterprises to increase investment in wastewater treatment, adopt more advanced and efficient treatment technologies and environmentally friendly treatment materials, and rationally and appropriately utilize water resources. In particular, policies have been implemented to postpone certain water-intensive projects. The implementation of these policies has transformed wastewater treatment from an additional responsibility for enterprises into a mandatory legal obligation. Consequently, many enterprises have begun to increase their research and development and application of wastewater treatment technologies and materials, which has driven continuous innovation and progress in wastewater treatment technology.

[0003] Currently, traditional treatment materials include quartz sand, anthracite, and activated carbon. However, these materials have relatively simple compositions and effects, and their applications are limited. Furthermore, they cannot achieve the required standards in a single treatment, typically requiring significant investment in facilities and equipment. They also suffer from numerous drawbacks, such as large material consumption, generation of large amounts of sludge, difficulties in subsequent treatment, low efficiency in treating complex water qualities, and ineffectiveness in treating high-concentration wastewater. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a novel bentonite water treatment agent and its preparation method, which can achieve a one-step treatment effect and has a significant effect on the treatment of wastewater with high concentrations of pollutants.

[0005] The objective of this invention is achieved through the following technical solution: A novel bentonite water treatment agent comprises the following components in the following mass ratio: 93%-98% sodium-based bentonite, 1%-2% aluminum inorganic salt, 0-2% lime slurry powder, and 1%-3% cationic acrylate. The bentonite has an expansion capacity ≥40 ml / g and a particle size distribution between 30 mesh and 200 mesh standard sieves, wherein at least 50% is within a 50 mesh standard sieve.

[0006] Preferably, the water treatment agent comprises, by mass ratio: 95% sodium bentonite, 2% aluminum inorganic salt, 1% lime slurry powder, and 2% cationic polyacrylamide.

[0007] Preferably, the aluminum inorganic salt is industrial-grade aluminum sulfate.

[0008] Preferably, the cationic polyacrylamide has a molecular weight of 7 million to 12 million and its particle size meets the requirement of passing 100% of a 40-mesh standard sieve.

[0009] Preferably, the bentonite has an expansion ratio of ≥24ml / 2g, a water content of ≤12%, and an impurity content of no more than 4%.

[0010] A method for preparing a novel bentonite water treatment agent as described above, characterized by comprising the following steps: S1. Raw material processing: The natural sodium-based bentonite ore is crushed, dried, and baked to control the moisture content of the bentonite to within 12%, and its expansion ratio and expansion capacity are tested to ensure that the required indicators are met. S2. Screening: The sodium-based bentonite that meets the index after treatment in S1 is subjected to particle size distribution so that the particle size is distributed between 30 mesh and 200 mesh standard sieves, of which at least 50% is in 50 mesh standard sieves; and it is further purified by air classification to control the impurity content in the bentonite powder to within 4%. S3. Raw material mixing: The lime slurry powder, aluminum inorganic salt and polyacrylamide are mixed evenly according to the proportion. Then, the mixture is fed into the mixer by a uniform feeder and mixed with the sodium bentonite in S2 to form a water treatment agent.

[0011] The beneficial effects of this invention are as follows: The bentonite water treatment agent uses bentonite as the main raw material. By utilizing the high adsorption properties of bentonite and combining it with other small amounts of inorganic and organic materials, it can achieve a one-step treatment effect. It is simple to use and operate, requires little space, and has low equipment requirements. It is especially effective for treating wastewater with high concentrations of pollutants. Attached Figure Description

[0012] Figure 1 : Schematic diagram of the mixing of components contained in the bentonite water treatment agent of the present invention. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the following description is provided in conjunction with the appendix. Figure 1 The present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0014] This invention discloses a novel bentonite water treatment agent, comprising the following components in the following mass ratio: 93%-98% sodium-based bentonite, 1%-2% aluminum inorganic salt, 0-2% lime slurry powder, and 1%-3% cationic acrylate. The bentonite has an expansion capacity ≥40 ml / g, an expansion ratio ≥24 ml / 2g, a water content ≤12%, an impurity content not exceeding 4%, and a particle size distribution between 30 mesh and 200 mesh standard sieves, with at least 50% within a 50 mesh standard sieve. The particle size distribution and performance limitations of the bentonite in this invention significantly shorten the contact reaction time between the agent and wastewater. Experimental verification shows that the water treatment agent of this invention can rapidly complete the reaction and settle within 5 minutes.

[0015] Experiments have shown that the treatment effect is not significant regardless of whether the bentonite particle size is large or small. The specific results are shown in the table below: Using a variety of different particle sizes is also to quickly adsorb pollutants in the water, and at the same time, under the action of stirring, it can form stable precipitates, which is beneficial to improving the water treatment effect.

[0016] The particle size distribution ranges from 30 mesh to 200 mesh standard sieves, as shown in Table 1 below. Different particle size distributions can rapidly hydrate and adsorb pollutants in water, and at the same time, they can form stable flocculent precipitates under stirring.

[0017] Table 1: The relationship between bentonite particle size distribution and residue distribution is shown in the table below. In the most preferred embodiment, the water treatment agent comprises: 95% sodium bentonite, 2% aluminum inorganic salt, 1% lime slurry powder, and 2% cationic polyacrylamide. The aluminum inorganic salt is industrial-grade aluminum sulfate, with a particle size that ensures 100% passes through a 50-mesh standard sieve. The lime slurry powder also has a particle size that ensures 100% passes through a 50-mesh standard sieve.

[0018] In this invention, sodium-based bentonite is used as the main matrix. Aluminum sulfate is used to work with bentonite to remove color, suspended solids, and organic pollutants from water. Its particle size is such that 100% passes through a 50-mesh standard sieve. To ensure effective wastewater treatment, the dosage of aluminum sulfate is controlled at approximately 1-2%. Too much or too little will affect the pH value of the wastewater and the adsorption effect of the water treatment agent. The cationic polyacrylamide has a molecular weight of 7 million to 12 million, and its particle size is such that 100% passes through a 40-mesh standard sieve. Experiments have shown that polymers with a molecular weight below 7 million have negligible flocculation effects, while those above 12 million increase water viscosity. Therefore, cationic polyacrylamide is the most effective choice.

[0019] This invention also discloses a method for preparing a novel bentonite water treatment agent as described above, comprising the following steps: S1. Raw material processing: The natural sodium-based bentonite ore is crushed, dried, and baked to control the moisture content of the bentonite to within 12%, and its expansion ratio and expansion capacity are tested to ensure that the required indicators are met. S2. Screening: The sodium-based bentonite that meets the index after treatment in S1 is subjected to particle size distribution so that the particle size is distributed between 30 mesh and 200 mesh standard sieves, of which at least 50% is in 50 mesh standard sieves; and it is further purified by air classification to control the impurity content in the bentonite powder to within 4%. S3. Raw material mixing: The lime slurry powder, sodium inorganic salt and polyacrylamide are mixed evenly according to the proportion. Then, the mixture is fed into the mixer by a uniform feeder and mixed with the sodium bentonite in S2 to form a water treatment agent. Example 1:

[0020] The components and their contents in the water treatment agent are as follows: bentonite 950 kg / ton, aluminum sulfate 30 kg / ton, and cationic polyacrylamide 20 kg / ton. When using this water treatment agent in the above proportions to treat fluorescent liquid wastewater, the addition amount is only 2%~5% of the wastewater volume. After physical stirring for 5-10 minutes, the COD of the wastewater is reduced from 6000 ppm to a level suitable for direct discharge, demonstrating an extremely high removal rate. Example 2:

[0021] The components and their contents in the water treatment agent are as follows: bentonite 950 kg / ton, aluminum sulfate 20 kg / ton, cationic polyacrylamide 20 kg / ton, and lime slurry powder 10 kg / ton. When using the above water treatment agent to treat wastewater generated from the painting process, the agent dosage is approximately 1.5% of the wastewater volume. After physical stirring for 5-10 minutes and settling, the COD of the supernatant decreases from 3000 ppm to 165 ppm, allowing for direct discharge. Simultaneously, hexavalent chromium decreases from 40 ppm to 0.4 ppm, reaching a dischargeable level. Example 3:

[0022] The components and their contents in the water treatment agent are as follows: bentonite 950 kg / ton, aluminum sulfate 20 kg / ton, cationic polyacrylamide 20 kg / ton, and lime slurry powder 10 kg / ton. This water treatment agent is used in wastewater generated from metal mold casting and cutting cleaning processes. The dosage is approximately 3% of the wastewater volume. After physical stirring for 5-10 minutes and settling, the COD of the supernatant decreases from 3670 ppm to 200 ppm. After filtration, the oil content decreases from 26200 to 3, resulting in highly efficient water treatment that meets discharge standards.

[0023] The water treatment agent of this invention can effectively treat wastewater with high COD and metal ion content. The principle is that bentonite has a very high surface porosity, and it expands after absorbing water, with the expansion number reaching more than 30 times its own volume. By combining with inorganic salts and cationic polymeric polyacrylamide, it can quickly form long-chain porous flowers after entering the water body, adsorbing more than 90% of COD, color, suspended solids and metal ions in the water. The water treatment agent of this invention can be well applied to the treatment of high COD sewage and metal ion wastewater, especially with significant results in hexavalent chromium wastewater projects.

[0024] There are many specific application examples of this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A novel bentonite water treatment agent, characterized in that, The product comprises the following components in the following mass ratio: 93%-98% sodium-based bentonite, 1%-2% aluminum inorganic salt, 0-2% lime slurry powder, and 1%-3% cationic acrylate. The bentonite has an expansion capacity ≥40 ml / g and a particle size distribution between 30 mesh and 200 mesh standard sieves, of which at least 50% is within a 50 mesh standard sieve.

2. The novel bentonite water treatment agent according to claim 1, characterized in that, The water treatment agent comprises, by mass ratio: 95% sodium bentonite, 2% aluminum inorganic salt, 1% lime slurry powder, and 2% cationic polyacrylamide.

3. The novel bentonite water treatment agent according to claim 2, characterized in that, The aluminum inorganic salt is industrial-grade aluminum sulfate.

4. The novel bentonite water treatment agent according to claim 3, characterized in that, The cationic polyacrylamide has a molecular weight of 7 million to 12 million and its particle size meets the requirement of passing 100% of a 40-mesh standard sieve.

5. A novel bentonite water treatment agent according to claim 4, characterized in that, The bentonite has an expansion ratio of ≥24ml / 2g, a water content of ≤12%, and an impurity content of no more than 4%.

6. A method for preparing a novel bentonite water treatment agent according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Raw material processing: The natural sodium-based bentonite ore is crushed, dried, and baked to control the moisture content of the bentonite to within 12%, and its expansion ratio and expansion capacity are tested to ensure that the required indicators are met. S2. Screening: The sodium-based bentonite that meets the index after treatment in S1 is subjected to particle size distribution so that the particle size is distributed between 30 mesh and 200 mesh standard sieves, of which at least 50% is in 50 mesh standard sieves; and it is further purified by air classification to control the impurity content in the bentonite powder to within 4%. S3. Raw material mixing: Aluminum inorganic salt, lime slurry powder and polyacrylamide are mixed evenly according to the proportion. Then, the mixture is fed into the mixer by a uniform feeder and mixed with sodium bentonite in S2 to form a water treatment agent.

Images