Preparation method of spherical composite material for innocent treatment of acid waste liquid

Abstract

The invention discloses a preparation method of a spherical composite material for innocent treatment of acidic waste liquid, the spherical composite material is prepared from cement, quartz sand, bentonite and deionized water, the preparation method comprises the following steps: sequentially adding the bentonite, the cement and the quartz sand into water, uniformly stirring, then preparing the uniformly mixed mixture into spherical particles, and carrying out spray drying on the spherical particles to obtain the spherical composite material for innocent treatment of acidic waste liquid. And finally drying the spherical particles to obtain the spherical composite material for innocent treatment of the acid waste liquid. The bentonite with alkalinity and adsorbability is selected as a main material, so that the cost for treating the acid wastewater is reduced, part of harmful substances can be effectively adsorbed, the defects of a neutralization method are overcome, and meanwhile, the situation that the circulation of the wastewater is blocked due to the fact that the bentonite is in contact with water to form gel or paste is avoided; the efficiency of neutralizing acid wastewater and adsorbing harmful substances can be effectively improved, the neutralizing and adsorbing effects are better, the cost is low, the environment is protected, and the manufacturing process is simple.

Description

Technical Field

[0001] This invention discloses a composite material for the harmless treatment of acidic waste liquid and its preparation method, particularly relating to a material for neutralizing the acidity of waste liquid and adsorbing toxic and harmful substances in acidic waste liquid, specifically relating to a composite material for treating acidic waste liquid using the alkalinity and adsorption properties of bentonite and its preparation method. Background Technology

[0002] Laboratory acidic waste liquids have complex compositions, numerous toxicological indicators, and are highly acidic, often classifying them as hazardous waste. The treatment cost for acidic waste liquids is high, with a market price of approximately 2000 yuan per ton. If acidic wastewater is discharged directly without proper treatment, it will corrode sewer pipes, damage the aquatic environment, and threaten human safety and health as well as the quality of laboratory equipment. The treatment of acidic waste liquids requires steps such as neutralization, precipitation, and separation. The treatment of acidic waste liquids containing heavy metals or organic pollutants is even more complex, and improper treatment may cause secondary environmental pollution.

[0003] Currently, the main methods for treating acidic laboratory wastewater include neutralization, precipitation, evaporation and concentration, biological treatment, incineration, and dilution. Neutralization is widely applicable and inexpensive, but the treated wastewater still contains large amounts of salts and difficult-to-treat toxic components. Precipitation, incineration, and evaporation and concentration can treat wastewater containing specific pollutants, but they are costly and pose a risk of secondary pollution. Biological treatment is an environmentally friendly and sustainable method, but its processing time is long and its application is limited. Dilution is simple to operate, but it is only suitable for small-scale wastewater treatment and has significant limitations.

[0004] Natural bentonite possesses both neutralizing and pollutant removal capabilities, and its abundant geological reserves further endow it with environmental friendliness and significant economic benefits. However, bentonite swells upon contact with water, leading to increased resistance to wastewater flow. To address this issue, this method incorporates cement-quartz sand composite curing to construct spherical porous composite materials, which can further improve the overall performance of the composite material. Summary of the Invention

[0005] The technical solution of the present invention is as follows: First, a bentonite suspension of a certain mass concentration is prepared, and then an appropriate amount of cement and quartz sand are added in sequence, mixed evenly and ultrasonically. Then, the mixture is granulated and dried to obtain a spherical composite material that can harmlessly treat acidic waste liquid.

[0006] The specific process for preparing the composite material for the harmless treatment of acidic wastewater is as follows:

[0007] (1) The mass concentration of bentonite in the bentonite suspension is 0.25–0.4 g / L;

[0008] (2) Add cement to the bentonite suspension, with a cement mass concentration of 0.4 to 0.6 g / L.

[0009] (3) After mixing evenly, add the quartz sand to the bentonite-cement suspension. The mass concentration of the quartz sand is 0.7-0.9 g / L, the SiO2 content is 80-90%, and the particle size is 40-60 mesh.

[0010] (4) After stirring the mixture obtained in step (3) evenly, it is subjected to ultrasound. The ultrasound frequency is 20-60 kHz and the ultrasound time is 30-60 min.

[0011] (5) The bentonite-cement-quartz sand mixture is put into a sealed bag, the air inside the bag is removed by vacuuming, a 1-5 mm discharge port is cut at the bottom of the bag, the material is squeezed out, and spherical particles of equal diameter are prepared with a diameter range of 1-5 mm.

[0012] (6) Dry the spherical particles obtained in step (5) at 30-60 °C for 1-6 h.

[0013] This invention also provides a real-world application of simulating composite material treatment of acidic wastewater, the method of which is as follows:

[0014] Prepare a 50mL syringe, remove the needle, place a 1cm thick cotton pad at the bottom of the container, then fill in a 5cm thick spherical composite material, and then cover the top with another 1cm thick cotton pad. Add acidic waste liquid from the top. The treatment effect of the composite material was tested, and the pH value stabilized at around 4.5 after treatment. Zeta potential results confirmed that the material has a certain adsorption capacity for heavy metal ions.

[0015] The beneficial effects of this invention are:

[0016] 1. Based on the fundamental principle of neutralization for treating acidic wastewater, bentonite, which possesses both alkalinity and adsorption properties, is selected as the main material. This material not only reduces the treatment cost of acidic wastewater but also effectively adsorbs some harmful substances in the wastewater, thus overcoming the shortcomings of traditional neutralization methods.

[0017] 2. To improve material performance, the bentonite-based neutralizing agent is immobilized using cement and quartz sand. This measure prevents the bentonite from forming a gel-like or pasty substance upon contact with water, thus avoiding the resulting decrease in neutralization and adsorption efficiency and obstruction of wastewater flow. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the preparation process of the spherical composite material for the harmless treatment of acidic wastewater according to the present invention.

[0019] Figure 2 pH values ​​of different volumes of acidic wastewater treated with spherical composite materials used for the harmless treatment of acidic wastewater.

[0020] Figure 3 Zeta potential diagram of spherical composite material used for the harmless treatment of acidic waste liquid. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments. These specific embodiments are only used to explain the present invention and are not intended to limit the scope of the invention.

[0022] Example 1:

[0023] (1) Add 33 g of bentonite to 100 mL of deionized water and mix well;

[0024] (2) Add 83 g of cement to the mixture in step (1), mix evenly, and then add 50 g of 40 mesh quartz sand with a SiO2 content of 85%;

[0025] (3) After stirring the mixture obtained in step (2) evenly, it is subjected to ultrasound. The ultrasound frequency is 40 KHz, the ultrasound temperature is 25 ℃, and the ultrasound time is 40 min.

[0026] (4) The mixture obtained in step (3) is put into a sealed bag, and the air inside the bag is removed by vacuuming (to prevent residual air bubbles from affecting the material molding accuracy and structural stability). A 2 mm discharge port is cut at the bottom of the bag, and the material is squeezed out to prepare spherical particles with a diameter of about 2 mm.

[0027] (5) The spherical composite material obtained in step (4) is placed in an oven and dried at a temperature of 50 °C for 1 hour. After drying, a composite material for the harmless treatment of acidic waste liquid is obtained.

[0028] Example 2:

[0029] The steps are the same as in Example 1, except that a 5 mm discharge port is cut in step (3).

[0030] Example 3:

[0031] The steps are the same as in Example 1, except that the drying time in step (5) is 5 hours.

[0032] Comparative Example 1:

[0033] The steps are the same as in Example 1, except that 100g of cement is added in step (2).

[0034] Comparative Example 2:

[0035] The steps are the same as in Example 1, except that 20g of quartz sand is added in step (2).

[0036] Comparative Example 3:

[0037] The steps are the same as in Example 1, except that in step (1), cement is first added to deionized water.

[0038]

Claims

1. A spherical composite material for the harmless treatment of acidic wastewater, the preparation method of which includes the following steps: (1) Prepare a bentonite suspension with a certain mass concentration; (2) Add cement and quartz sand to the bentonite suspension in step (1) in sequence, and perform ultrasound to ensure that the bentonite, cement and quartz sand are fully and evenly mixed to obtain a bentonite-cement-quartz sand mixed slurry. (3) The mixed slurry obtained in step (2) is granulated and dried in sequence to obtain a spherical composite material.

2. The spherical composite material according to claim 1, characterized in that, In step (1), the mass concentration of bentonite in the bentonite suspension is 0.25–0.4 g / L.

3. The spherical composite material according to claim 1, characterized in that, In step (2), cement is added to the bentonite suspension, and the mass concentration of cement is 0.4 to 0.6 g / L.

4. The spherical composite material according to claim 1, characterized in that, In step (2), quartz sand is added to bentonite-cement suspension. The mass concentration of quartz sand is 0.7-0.9 g / L, the SiO2 content is 80-90%, and the particle size is 40-60 mesh.

5. The spherical composite material according to claim 1, characterized in that, In step (2), the ultrasonic frequency is 20-60 kHz and the ultrasonic time is 30-60 min.

6. The spherical composite material according to claim 1, characterized in that, In step (3), the bentonite-cement-quartz sand mixture is put into a sealed bag, the air inside the bag is removed by vacuuming, a 1-5mm discharge port is cut at the bottom of the bag, the material is squeezed out, and spherical particles of equal diameter with a diameter range of 1-5mm are prepared.

7. The spherical composite material according to claim 1, characterized in that, In step (3), the spherical particles are dried at 30-60 °C for 1-6 h.

8. A spherical composite material for the harmless treatment of acidic wastewater, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 6.

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