A process and device for algae removal in the Yangtze River

Abstract

This invention discloses a process for algae removal from Yangtze River water, comprising the following steps: Yangtze River water enters a modified attapulgite adsorption tower via an inlet pump; modified attapulgite adsorbent is placed in the modified attapulgite adsorption tower; the residence time of the Yangtze River water in the modified attapulgite adsorption tower is 15–25 minutes; the modified attapulgite adsorbent occupies 80–85% of the internal volume of the modified attapulgite adsorption tower; after treatment, the algae content is 4.5–9.2 × 10⁻⁶. 3 The algae concentration was 36–55 cells / L, and the suspended solids concentration was 18–34 mg / L. Subsequently, the Yangtze River water was pumped into an electrochemical system containing modified carbon electrode plates. The electrochemical system voltage was 6–10V, the spacing between the modified carbon electrode plates was 8–12 cm, and the residence time of the Yangtze River water in the electrochemical system was 15–23 min. After treatment by the electrochemical system, the algae content was 36–55 cells / L, and the suspended solids concentration was 11–27 mg / L. This invention can effectively utilize Yangtze River water, especially showing good treatment effects for Yangtze River water with high algae and suspended solids content. It has good social and environmental benefits.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a technology and method for algae removal from the Yangtze River. Background Technology

[0002] The raw water conditions in the lower reaches of the Yangtze River are complex. Due to local pollution, eutrophication and other reasons, the water quality is complex and variable, with problems such as high algae content and high suspended solids. Research on these conditions can greatly develop the water resources of the lower reaches of the Yangtze River and promote the rational use of water resources.

[0003] Researching the raw water of the Yangtze River and converting it into usable industrial water can significantly reduce water costs for enterprises. Developing a process and device for algae removal from Yangtze River water, with green technology as the primary objective, and promoting comprehensive utilization. Summary of the Invention

[0004] Therefore, the technical problem to be solved by this invention is to effectively remove algae from the Yangtze River water based on the water quality and quantity conditions of the downstream Yangtze River, so as to ensure that the industrial water can be used for production.

[0005] The technical solution of this invention is a process for removing algae from the Yangtze River, comprising the following steps:

[0006] The water quality of the Yangtze River was described as having an algae content of 3.4–9.5 × 10⁻⁶. 5 The concentration of cells / L and suspended solids ranged from 234 to 456 mg / L.

[0007] a. Yangtze River water enters a modified attapulgite adsorption tower via an inlet pump. Modified attapulgite adsorbent is placed inside the tower. The residence time of the Yangtze River water in the tower is 15–25 minutes. The modified attapulgite adsorbent occupies 80–85% of the tower's internal volume. After treatment, the algae content is 4.5–9.2 × 10⁻⁶. 3 The concentration of particles / L and the suspended solids concentration are 18-34 mg / L; the modified attapulgite adsorbent is obtained by mixing attapulgite, carboxymethyl chitosan and sand particles in a mass ratio of 11-17:2-4:1, soaking them in a 1.1-2.3 mol / L aluminum sulfate solution and then heating them.

[0008] b. Subsequently, the Yangtze River water enters the electrochemical system via a booster pump, and modified carbon electrode plates are placed in the electrochemical system; the voltage of the electrochemical system is 6-10V, the spacing between the modified carbon electrode plates is 8-12cm, and the residence time of the Yangtze River water in the electrochemical system is 15-23min; 1-3g of diatomaceous earth and 0.1-0.3g of sodium carbonate are added to each liter of nitric acid and hydrochloric acid mixed acid solution to obtain a coating solution, which is then applied to the surface of the carbon electrode plates and heated to modify the carbon electrode plates.

[0009] After treatment by the electrochemical system, the algae content was 36–55 cells / L and the suspended solids were 11–27 mg / L.

[0010] According to the process for removing algae from Yangtze River water according to the present invention, preferably, the preparation method of the modified attapulgite adsorbent in step a includes: (1) screening attapulgite particles with a particle size of 100-200 mesh, washing them 2-3 times with a sodium hydroxide solution of 0.1-10% by mass, washing them 1-2 times with water, and drying them; (2) mixing the dried attapulgite with carboxymethyl chitosan and sand particles in a mass ratio of 11-17:2-4:1, stirring thoroughly to form a modified attapulgite mixture; (3) soaking the modified attapulgite mixture in a 1.1-2.3 mol / L aluminum sulfate solution for 5-9 hours, taking it out, placing the modified attapulgite mixture in a heating device, heating it to 235-275°C at a heating rate of 2-5°C / min, then holding it at a constant temperature for 25-55 minutes, and cooling it to prepare the modified attapulgite adsorbent. After the preparation process, the modified attapulgite adsorbent has an adsorption specific surface area of ​​123.1–137.6 m². 2 / g, greatly improving the ability to adsorb various algae and suspended solids. The modified attapulgite adsorbent was prepared and synthesized based on the characteristics of the Yangtze River water quality.

[0011] Furthermore, in the preparation method of the modified attapulgite adsorbent, the mass concentration of the sodium hydroxide solution in step (1) is 1.5-2.7%; the stirring in step (2) is mechanical stirring. Even further, the mechanical stirring time is 15-25 min. Preferably, the water used in step (1) is industrial water.

[0012] Furthermore, in the preparation method of the modified attapulgite adsorbent, the isothermal time in step (3) is 25 to 45 minutes.

[0013] According to the process for removing algae from Yangtze River water described in this invention, preferably, the modified titanium electrode plate in step b has a length and width of 0.2-0.5*0.4-1.0m and a thickness of 5-8mm.

[0014] According to the process for removing algae from Yangtze River water according to the present invention, preferably, the preparation method of the modified electrode plate in step b is as follows: (1) First, polish the carbon electrode plate, then soak the polished carbon electrode plate in a hydrochloric acid solution with a mass ratio of 1-10% for 10-60 minutes, then rinse with water and air dry; (2) Preparation of the coating solution: pure nitric acid and pure hydrochloric acid are mixed in a volume ratio of 5-7:1 to form a mixed acid solution, and 1-3g of diatomaceous earth and 0.1-0.3g of sodium carbonate are added to each liter of mixed acid solution, and the mixture is stirred thoroughly to form a coating solution; (3) The coating solution is evenly coated on the surface of the carbon electrode, and the coating is repeated 5-8 times. The electrode is then placed in a heating device and heated to 70-90℃ at a heating rate of 4-6℃ / min, held at a constant temperature for 30-58 minutes, carbonized, and then cooled to finally prepare a modified carbon electrode plate. Through modification, the electrode interface resistance is reduced, the actual surface area of ​​the electrode is increased, the number of active adsorption sites is increased, and the electrocatalytic activity is improved.

[0015] The modified carbon electrode plate of the present invention is prepared according to the characteristics of Yangtze River water.

[0016] Furthermore, in the method for preparing modified carbon electrode plates, the mass concentration of the hydrochloric acid solution in step (1) is 3-7%; the soaking time in step (1) is 20-50 min; and the water in step (1) is tap water.

[0017] Furthermore, in the method for preparing modified carbon electrode plates, the stirring time in step (2) is 10-30 min.

[0018] Furthermore, in the method for preparing modified carbon electrode plates, the isothermal time in step (3) is 35 to 55 minutes.

[0019] The present invention also provides an apparatus for the above-mentioned process of algae removal in Yangtze River water, wherein an inlet pump is connected to a modified attapulgite adsorption tower, and the modified attapulgite adsorption tower is provided with modified attapulgite adsorbent; the outlet of the modified attapulgite adsorption tower is connected to a booster pump, and the booster pump is connected to an electrochemical system; the electrochemical system is provided with modified carbon electrode plates, and the outlet of the electrochemical system is connected to a drain pump.

[0020] The beneficial effects of this invention are:

[0021] The Yangtze River water treated by the algae removal process of this invention meets the standards for algae and suspended solids content. The drainage pump then pumps the treated Yangtze River water into the industrial water use system for industrial use.

[0022] Therefore, this invention is an industrial water production process that can effectively utilize Yangtze River water, especially showing good treatment effects on Yangtze River water with high algae and suspended solids content. It has significant social and environmental benefits. Attached Figure Description

[0023] Figure 1 A schematic diagram of a process device for removing algae from the Yangtze River.

[0024] In the diagram, 1 is the inlet pump, 2 is the modified attapulgite adsorption tower, 3 is the modified attapulgite adsorbent, 4 is the booster pump, 5 is the electrochemical system, 6 is the modified carbon electrode plate, and 7 is the drain pump. Detailed Implementation

[0025] Example 1:

[0026] A process for algae removal from the Yangtze River includes an inlet pump, a modified attapulgite adsorption tower, a modified attapulgite adsorbent, a booster pump, an electrochemical system, modified carbon electrode plates, and a drain pump. See [link to details]. Figure 1 As shown.

[0027] The water quality of the Yangtze River was described as having an algae content of 9.5*10. 5 The concentration of the substance was 456 mg / L.

[0028] Yangtze River water enters a modified attapulgite adsorption tower via an inlet pump. Modified attapulgite adsorbent is placed inside the tower. The residence time in the tower is 25 minutes. The modified attapulgite adsorbent occupies 85% of the tower's internal volume. After treatment, the algae content is 7.2 × 10⁻⁶. 3 The concentration of the substance was 30 mg / L.

[0029] The modified attapulgite adsorbent was prepared and synthesized based on the characteristics of the Yangtze River water quality. The preparation process is as follows: (1) Attapulgite particles with a diameter of 200 mesh were screened, washed three times with sodium hydroxide at a mass ratio of 2.7%, and then washed twice with industrial water and dried. (2) The dried attapulgite, carboxymethyl chitosan, and sand particles were mixed in a mass ratio of 17:2:1 and mechanically stirred for 25 minutes to form a modified attapulgite mixture. (3) The modified attapulgite mixture was soaked in a 2.1 mol / L aluminum sulfate solution for 8 hours. After removal, the modified attapulgite mixture was placed in a muffle furnace and heated to 270°C at a heating rate of 5°C / min. Then, it was kept at a constant temperature for 40 minutes and cooled to prepare the modified attapulgite adsorbent. After the preparation process, the adsorption specific surface area of ​​the modified attapulgite adsorbent was 133.7 m². 2 / g, which greatly improves the ability to adsorb various algae and suspended matter.

[0030] Subsequently, the Yangtze River water is pumped into the electrochemical system, where modified carbon electrode plates are placed. The electrochemical system voltage is 10V, the spacing between the modified carbon electrode plates is 12cm, the modified titanium electrode plates have dimensions of 0.2*0.5m and a thickness of 8mm, and the Yangtze River water resides in the electrochemical system for 22 minutes.

[0031] The modified carbon electrode plate of this invention is prepared according to the characteristics of Yangtze River water. (1) First, the carbon electrode plate is polished, and then the polished carbon electrode plate is immersed in a 7% hydrochloric acid solution for 45 minutes, then rinsed with tap water and dried. (2) Preparation of coating solution: Analytical pure nitric acid and analytical pure hydrochloric acid are mixed at a volume ratio of 7:1 to form a mixed acid solution. 3g of diatomaceous earth and 0.3g of sodium carbonate are added to each liter of mixed acid solution, and the mixture is mechanically stirred for 20 minutes to form a coating solution. (3) The coating solution is evenly coated on the surface of the carbon electrode, and the coating is repeated 7 times. The electrode is placed in a muffle furnace and heated to 80°C at a heating rate of 6°C / min. The temperature is held for 55 minutes, and the plate is cooled after carbonization to finally prepare the modified carbon electrode plate. Through modification, the electrode interface resistance is reduced, the actual surface area of ​​the electrode is increased, the number of active adsorption sites is increased, and the electrocatalytic activity is improved.

[0032] After treatment by the electrochemical system, the algae content was 45 cells / L and the suspended solids were 25 mg / L.

[0033] Finally, the drainage pump pumps the treated Yangtze River water into the process water system for use as industrial water.

[0034] Example 2

[0035] A process for removing algae from Yangtze River water includes an inlet pump, a modified attapulgite adsorption tower, a modified attapulgite adsorbent, a booster pump, an electrochemical system, modified carbon electrode plates, and a drain pump.

[0036] The water quality of the Yangtze River was described as having an algae content of 3.7*10. 5 The concentration of the substance was 256 mg / L.

[0037] Yangtze River water enters a modified attapulgite adsorption tower via an inlet pump. Modified attapulgite adsorbent is placed inside the tower. The residence time in the tower is 15 minutes. The modified attapulgite adsorbent occupies 80% of the tower's internal volume. After treatment, the algae content is 5.2 × 10⁻⁶. 3 The concentration of the substance was 23 mg / L.

[0038] The modified attapulgite adsorbent was prepared and synthesized based on the characteristics of the Yangtze River water quality. The preparation process is as follows: (1) Attapulgite particles with a diameter of 100 mesh were screened, washed twice with sodium hydroxide at a mass ratio of 1.5%, and then washed once with industrial water and dried. (2) The dried attapulgite, carboxymethyl chitosan, and sand particles were mixed in a mass ratio of 11:3:1 and mechanically stirred for 18 minutes to form a modified attapulgite mixture. (3) The modified attapulgite mixture was soaked in a 1.1 mol / L aluminum sulfate solution for 6 hours. After removal, the modified attapulgite mixture was placed in a muffle furnace and heated to 245°C at a heating rate of 3°C / min. Then, it was kept at a constant temperature for 30 minutes and cooled to prepare the modified attapulgite adsorbent. After the preparation process, the adsorption specific surface area of ​​the modified attapulgite adsorbent was 126.3 m². 2 / g, which greatly improves the ability to adsorb various algae and suspended matter.

[0039] Subsequently, the Yangtze River water was pumped into the electrochemical system, where modified carbon electrode plates were placed. The electrochemical system voltage was 6V, the spacing between the modified carbon electrode plates was 9cm, the modified titanium electrode plates had dimensions of 0.2*0.5m and a thickness of 6mm, and the Yangtze River water resided in the electrochemical system for 17 minutes.

[0040] The modified carbon electrode plate of this invention is prepared based on the characteristics of Yangtze River water. (1) First, the carbon electrode plate is polished, and then the polished carbon electrode plate is immersed in a 3% hydrochloric acid solution for 25 minutes. Then, it is rinsed with tap water and dried. (2) Preparation of coating solution: Analytical pure nitric acid and analytical pure hydrochloric acid are mixed at a volume ratio of 5:1 to form a mixed acid solution. 2g of diatomaceous earth and 0.1g of sodium carbonate are added to each liter of mixed acid solution. After mechanical stirring for 20 minutes, a coating solution is formed. (3) The coating solution is evenly coated on the surface of the carbon electrode. The coating is repeated 5 times. The electrode is placed in a muffle furnace and heated to 80°C at a heating rate of 4°C / min. The temperature is held for 35 minutes. After carbonization, the electrode is cooled to finally prepare the modified carbon electrode plate. Through modification, the electrode interface resistance is reduced, the actual surface area of ​​the electrode is increased, the number of active adsorption sites is increased, and the electrocatalytic activity is improved.

[0041] After treatment by the electrochemical system, the algae content was 38 cells / L and the suspended solids were 12 mg / L.

[0042] Finally, the drainage pump pumps the treated Yangtze River water into the process water system for use as industrial water.

[0043] Example 3

[0044] A process for removing algae from Yangtze River water includes an inlet pump, a modified attapulgite adsorption tower, a modified attapulgite adsorbent, a booster pump, an electrochemical system, modified carbon electrode plates, and a drain pump.

[0045] The water quality of the Yangtze River was described as having an algae content of 7.2*10⁻⁶. 5 The concentration of the substance was 335 mg / L.

[0046] Yangtze River water enters a modified attapulgite adsorption tower via an inlet pump, where modified attapulgite adsorbent is placed. The residence time in the modified attapulgite adsorption tower is 21 minutes. The modified attapulgite adsorbent occupies 83% of the tower's internal volume. After treatment, the algae content is 6.1 × 10⁻⁶. 3 The concentration of the substance was 27 mg / L.

[0047] The modified attapulgite adsorbent was prepared and synthesized based on the characteristics of the Yangtze River water quality. The preparation process is as follows: (1) Attapulgite particles with a diameter of 150 mesh were screened, washed twice with sodium hydroxide at a mass ratio of 1.9%, and then washed twice with industrial water and dried. (2) The dried attapulgite, carboxymethyl chitosan, and sand particles were mixed in a mass ratio of 13:3:1 and mechanically stirred for 19 min to form a modified attapulgite mixture. (3) The modified attapulgite mixture was soaked in a 1.7 mol / L aluminum sulfate solution for 6 h. After removal, the modified attapulgite mixture was placed in a muffle furnace and heated to 252 °C at a heating rate of 4 °C / min. Then, it was kept at a constant temperature for 34 min and cooled to prepare the modified attapulgite adsorbent. After the preparation process, the adsorption specific surface area of ​​the modified attapulgite adsorbent was 130.6 m². 2 / g, which greatly improves the ability to adsorb various algae and suspended matter.

[0048] Subsequently, the Yangtze River water is pumped into the electrochemical system, where modified carbon electrode plates are placed. The electrochemical system voltage is 8V, the spacing between the modified carbon electrode plates is 10cm, the modified titanium electrode plates have dimensions of 0.2*0.5m and a thickness of 6mm, and the Yangtze River water resides in the electrochemical system for 18 minutes.

[0049] The modified carbon electrode plate of this invention is prepared based on the characteristics of Yangtze River water. (1) First, the carbon electrode plate is polished, and then the polished carbon electrode plate is immersed in a 4% hydrochloric acid solution for 36 minutes. Then, it is rinsed with tap water and dried. (2) Preparation of coating solution: Analytical pure nitric acid and analytical pure hydrochloric acid are mixed at a volume ratio of 6:1 to form a mixed acid solution. 2g of diatomaceous earth and 0.2g of sodium carbonate are added to each liter of mixed acid solution. After mechanical stirring for 20 minutes, a coating solution is formed. (3) The coating solution is evenly coated on the surface of the carbon electrode. The coating is repeated 6 times. The electrode is placed in a muffle furnace and heated to 80°C at a heating rate of 5°C / min. The temperature is held for 45 minutes. After carbonization, the electrode is cooled to finally prepare the modified carbon electrode plate. Through modification, the electrode interface resistance is reduced, the actual surface area of ​​the electrode is increased, the number of active adsorption sites is increased, and the electrocatalytic activity is improved.

[0050] After treatment by the electrochemical system, the algae content was 43 cells / L and the suspended solids were 17 mg / L.

[0051] Finally, the drainage pump pumps the treated Yangtze River water into the process water system for use as industrial water.

[0052] Of course, those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Any modifications or variations of the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A process for removing algae from Yangtze River water, characterized in that: Includes the following steps: The water quality of the Yangtze River was described as having an algae content of 3.4~9.5*10. 5 The concentration of particles per L was 234–456 mg / L, and the suspended solids were 234–456 mg / L. a. Yangtze River water enters a modified attapulgite adsorption tower via an inlet pump. Modified attapulgite adsorbent is placed inside the tower. The residence time of the Yangtze River water in the tower is 15-25 minutes. The modified attapulgite adsorbent occupies 80-85% of the tower's internal volume. After treatment, the algae content is 4.5-9.2 × 10⁻⁶. 3 The concentration of cells / L and suspended solids is 18~34 mg / L; The preparation method of the modified attapulgite adsorbent includes: (1) screening attapulgite particles with a size of 100-200 mesh, washing them 2-3 times with a sodium hydroxide solution of 0.1-10% by mass, washing them 1-2 times with water, and drying them; (2) mixing the dried attapulgite with attapulgite: carboxymethyl chitosan: sand particles in a mass ratio of 11-17:2-4:1, stirring thoroughly to form a modified attapulgite mixture; (3) soaking the modified attapulgite mixture in a 1.1-2.3 mol / L aluminum sulfate solution for 5-9 h, taking it out, placing the modified attapulgite mixture in a heating device, heating it to 235-275℃ at a heating rate of 2-5℃ / min, then holding it at a constant temperature for 25-55 min, and cooling it to prepare the modified attapulgite adsorbent; b. Subsequently, the Yangtze River water is introduced into the electrochemical system via a booster pump, and modified carbon electrode plates are placed in the electrochemical system; the voltage of the electrochemical system is 6~10 V, the spacing between the modified carbon electrode plates is 8~12 cm, and the residence time of the Yangtze River water in the electrochemical system is 15~23 min; The preparation method of the modified carbon electrode plate is as follows: (1) First, polish the carbon electrode plate, then soak the polished carbon electrode plate in a hydrochloric acid solution with a mass ratio of 1~10% for 10~60 min, then rinse with water and air dry; (2) Preparation of coating liquid: Analytical pure nitric acid and analytical pure hydrochloric acid are mixed in a volume ratio of 5~7:1 to form a mixed acid solution. Add 1~3 g of diatomaceous earth and 0.1~0.3 g of sodium carbonate to each liter of mixed acid solution, stir thoroughly to form a coating liquid; (3) Apply the coating liquid evenly to the surface of the carbon electrode plate, apply it repeatedly 5~8 times, put it in a heating device, heat it to 70-90℃ at a heating rate of 4~6℃ / min, keep it at a constant temperature for 30~58 min, cool it, and finally prepare the modified carbon electrode plate; After treatment by the electrochemical system, the algae content was 36-55 cells / L and the suspended solids were 11-27 mg / L.

2. The algae removal process for Yangtze River water according to claim 1, characterized in that: In step a, the mass concentration of the sodium hydroxide solution in step (1) is 1.5~2.7%; in step a, the stirring in step (2) is mechanical stirring.

3. The process for removing algae from Yangtze River water according to claim 1, characterized in that: In step a, the constant temperature time in step (3) is 25~45 min.

4. The process for removing algae from Yangtze River water according to claim 1, characterized in that: The modified carbon electrode plate described in step b has a length and width of 0.2-0.5*0.4-1.0 m and a thickness of 5~8 mm.

5. The process for removing algae from Yangtze River water according to claim 1, characterized in that: In step b, the mass concentration of the hydrochloric acid solution in step (1) is 3-7%; in step b, the soaking time in step (1) is 20-50 min; in step b, the rinsing water in step (1) is tap water.

6. The process for removing algae from Yangtze River water according to claim 1, characterized in that: In step b, the stirring time in step (2) is 10-30 min.

7. The process for removing algae from Yangtze River water according to claim 1, characterized in that: In step b, the constant temperature time mentioned in step (3) is 35~55 min.

8. An apparatus for implementing the algae removal process for Yangtze River water as described in claim 1, characterized in that: The inlet pump is connected to a modified attapulgite adsorption tower, which contains modified attapulgite adsorbent; the outlet of the modified attapulgite adsorption tower is connected to a booster pump, which is connected to an electrochemical system; the electrochemical system contains modified carbon electrode plates, and the outlet of the electrochemical system is connected to a drain pump.

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