High-concentration agricultural wastewater degradation device and method

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a high-concentration agricultural wastewater degradation device and method.The high-concentration agricultural wastewater degradation device comprises an enrichment container, a water inlet, a water outlet, a water pump, a filter membrane, an ultraviolet lamp tube and a magnetic stirring device. According to the invention, large-particle substances in wastewater are filtered in a membrane filtration manner to realize pretreatment; large-particle substances can be filtered by using a common permeable membrane, small-particle substances in sewage can be filtered in a reverse osmosis manner, the particle substances in the sewage are effectively removed, and nicotine pesticides in the sewage are further treated; in addition, a large number of hydroxyl free radicals are generated through ultraviolet photolysis, at the moment, the hydroxyl free radicals can degrade residual pesticides in water, the degradation reaction is conducted through a photocatalyst, an oxidation-reduction reaction system is formed, the pesticides in the sewage are reduced to small molecular substances through the photocatalysis effect, and toxicity is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and particularly relates to a device and method for degrading high-concentration agricultural wastewater. Background Art

[0002] Neonicotinoids are a class of neuroactive pesticides. Their main insecticidal mechanism is to act on the nicotinic acetylcholine receptors (nAChRs) on the postsynaptic membrane of the insect nervous system and the surrounding nerves, causing the insects to remain excited, paralyzed and die. Compared with traditional pesticides such as organophosphates and carbamates, neonicotinoid pesticides have the advantages of high efficiency, broad spectrum and high selectivity, so they are widely used globally. Since 2010, neonicotinoids have become the most widely used class of pesticides in the world, and their sales volume has been increasing year by year in recent years. China is a major producer and user of neonicotinoid pesticides. In 2012, China produced 12,000 tons of imidacloprid, accounting for 2 / 3 of the global total production. Neonicotinoid pesticides have relatively high water solubility and are easily contaminated with water through surface runoff, underground drainage, wet and dry deposition and other ways. When the water source is close to agricultural land where neonicotinoids are applied, the water source is more likely to be contaminated. Existing research has found that neonicotinoids have widely polluted surface water, tap water and drinking water.

[0003] Due to the huge current usage of neonicotinoid pesticides, it is urgent to strengthen the research on the toxicity mechanism of neonicotinoid pesticides and the treatment of pesticide residue problems to reduce potential health risks.

[0004] In the prior art, the treatment of neonicotinoid pesticides is mainly through adsorption treatment. Adsorption treatment can only achieve a certain degree of enrichment and cannot completely eliminate pesticide residues, and still pollutes the environment. Summary of the Invention

[0005] Therefore, the present invention provides a device and method for degrading high-concentration agricultural wastewater to solve the above technical problems.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A device for degrading high-concentration agricultural wastewater includes an enrichment container, a water inlet, a water outlet, a water pump, a filter membrane, an ultraviolet lamp tube and a magnetic stirring device. The enrichment container is provided with a water inlet and a water outlet on both sides respectively. Filter membranes are installed at one end inside the enrichment container for both the water inlet and the water outlet. A water pump is provided on the water inlet. An ultraviolet lamp tube is provided above the interior of the enrichment container, and a magnetic stirring device is provided at the bottom inside the enrichment container.

[0007] Preferably, the enrichment container is made of transparent organic glass.

[0008] Preferably, the filter membrane is a mixed cellulose filter membrane.

[0009] Preferably, there are at least two groups of ultraviolet lamp tubes.

[0010] Preferably, the power of each ultraviolet lamp tube is 6-15W.

[0011] Preferably, two handles are provided at the upper ends of multiple groups of the ultraviolet lamp tubes.

[0012] The present invention provides a method for degrading high-concentration agricultural wastewater, which specifically includes the following steps:

[0013] S1. Pump the wastewater from the water inlet into the enrichment container through a water pump, and a filter membrane is provided at the end of the water inlet for filtration to achieve pretreatment of the wastewater.

[0014] S2. Then, add a photocatalyst to the enrichment container in a certain proportion to the mass volume of the wastewater.

[0015] S3. Use multiple groups of ultraviolet lamp tubes arranged above the enrichment container to irradiate and degrade the wastewater with ultraviolet light.

[0016] S4. During the degradation, use a magnetic stirring device arranged at the bottom of the enrichment container to continuously stir the wastewater and the photocatalyst.

[0017] S5. During the degradation process, the handles can be pulled to adjust the height of multiple groups of ultraviolet lamp tubes.

[0018] S6. The degraded wastewater can be discharged through the water outlet, and when the wastewater is discharged, it is filtered by the filter membrane at the inner end of the water outlet to block and recycle the photocatalyst, thereby completing the degradation work of the wastewater.

[0019] Preferably, in step S2, the photocatalyst exists in the enrichment container in a solid form, and the addition amount of the catalyst to the mass volume of the wastewater is 0.05-0.1:10 g / ml.

[0020] Preferably, in step S2, after adding the photocatalyst, ultrasonic treatment is carried out for 1 h.

[0021] Preferably, the stirring rate of the magnetic stirring device in step S4 is 500-600 rpm.

[0022] The beneficial effects of the present invention:

[0023] The present invention realizes pretreatment by filtering large particulate matters in the wastewater by means of membrane filtration; ordinary permeable membranes can be used to filter large particulate matters, and reverse osmosis is used to filter small particulate matters in the sewage, effectively removing particulate matters in the sewage and further treating nicotine pesticides in the sewage.

[0024] The present invention also uses ultraviolet photolysis to generate a large number of hydroxyl radicals. At this time, the hydroxyl radicals can degrade the remaining pesticides in the water, and utilize the photocatalyst degradation reaction to form an oxidation-reduction reaction system. Through the action of photocatalysis, the pesticides in the sewage are reduced to small molecule substances, reducing toxicity.

[0025] The enrichment container of the present invention is made of transparent plexiglass, which not only increases toughness but also can utilize sunlight to assist degradation, achieving a dual degradation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of the present invention;

[0027] Figure 2 is a comparative curve graph of absorbance of the examples and comparative examples of the present invention;

[0028] Figure 3 is a comparative bar graph of degradation rates of the examples and comparative examples of the present invention;

[0029] Figure 4 is a linear curve graph of the pesticide imidacloprid and ultraviolet absorbance values in the examples of the present invention.

[0030] Wherein: enrichment container - 1, water inlet - 2, water outlet - 3, water pump - 4, filter membrane - 5, ultraviolet lamp tube - 6, magnetic stirring device - 7, handle - 8. DETAILED DESCRIPTION OF THE INVENTION

[0031] In order to further explain the technical solution of the present invention, the following will be elaborated in detail through specific examples.

[0032] As Figure 1 shown, the present invention provides a high-concentration agricultural wastewater degradation device, including an enrichment container 1, a water inlet 2, a water outlet 3, a water pump 4, a filter membrane 5, an ultraviolet lamp tube 6, and a magnetic stirring device 7. The two sides of the enrichment container 1 are respectively provided with a water inlet 2 and a water outlet 3. Filter membranes 5 are installed at one end inside the enrichment container 1 for both the water inlet 2 and the water outlet 3. A water pump 4 is provided on the water inlet 2. An ultraviolet lamp tube 6 is provided above the inside of the enrichment container 1. A magnetic stirring device 7 is provided at the bottom inside the enrichment container 1. The provided magnetic stirring device 7 can ensure that the photocatalyst inside the enrichment container 1 always maintains uniformity. It should be noted that the magnetic stirring device 7 is an existing general magnetic stirring device, and its working principle is that a stirring rotor magnet is arranged at the bottom inside the enrichment container 1, and the magnet is rotated by the internal motor of the magnetic stirrer. Through the detailed action of magnetic force, the stirring rotor magnet arranged at the bottom inside the enrichment container 1 rotates to achieve the stirring work, and its specific structure will not be elaborated in the present invention.

[0033] As Figure 1As shown, in the enrichment container 1 of the present invention, transparent organic glass is used, which not only increases toughness but also can utilize sunlight to assist in degradation, achieving a dual degradation effect.

[0034] Among them, the filter membrane 5 uses a mixed cellulose filter membrane, which can effectively filter large particulate matter in the wastewater, and at the same time ensure that the photocatalyst inside the enrichment container 1 will not be discharged, reducing the loss of the photocatalyst and realizing the reuse of the photocatalyst.

[0035] As Figure 1 shown, in the present invention, there are no less than two groups of ultraviolet lamp tubes 6; and the power of each group of ultraviolet lamp tubes 6 is 6 - 15W. A large number of hydroxyl radicals are generated through ultraviolet photolysis. At this time, the hydroxyl radicals can degrade the pesticides remaining in the water. Utilizing the photocatalyst degradation reaction, an oxidation-reduction reaction system is formed, and the pesticides in the sewage are reduced to small molecule substances through the action of photocatalysis, reducing toxicity.

[0036] Among them, two handlebars 8 are provided at the upper ends of multiple groups of ultraviolet lamp tubes 6, and the height of the ultraviolet lamp tubes 6 can be adjusted according to the actual use situation to maintain an efficient degradation height.

[0037] The present invention provides a method for degrading high-concentration agricultural wastewater, which specifically includes the following steps:

[0038] S1. The wastewater is pumped from the water inlet 2 into the enrichment container 1 through the water pump 4, and a filter membrane 5 is provided at the end of the water inlet 2 for filtration to achieve wastewater pretreatment;

[0039] S2. Then, a photocatalyst is added to the enrichment container 1 in a certain proportion to the mass-volume of the wastewater;

[0040] S3. Multiple groups of ultraviolet lamp tubes 6 arranged above the enrichment container 1 are used to irradiate and degrade the wastewater with ultraviolet light;

[0041] S4. During the degradation, the magnetic stirring device 7 arranged at the bottom of the enrichment container 1 continuously stirs the wastewater and the photocatalyst;

[0042] S5. During the degradation process, the handlebars 8 can be pulled to adjust the height of multiple groups of ultraviolet lamp tubes 6;

[0043] S6. The degraded wastewater can be discharged through the water outlet 3. When the wastewater is discharged, it is filtered by the filter membrane 5 at the inner end of the water outlet 3 to block and recycle the photocatalyst, thereby completing the degradation work of the wastewater.

[0044] In step S2, the photocatalyst exists in the enrichment container 1 in a solid form, and the addition amount of the catalyst to the mass-volume ratio of the wastewater is 0.05 - 0.1:10 g / ml.

[0045] After adding the photocatalyst in step S2, ultrasonic treatment is carried out for 1 h to prevent the aggregation of the catalyst and increase the specific surface area.

[0046] In step S4, the stirring rate of the magnetic stirring device 7 is 500 - 600 rpm, and the stirring continues without stopping, which can ensure that the wastewater inside the enrichment container 1 is degraded fully and evenly.

[0047] The degradation rate is calculated by the formula:

[0048] The degradation rate of pesticides can be calculated by the following formula:

[0049] Degradation rate = (Co–Ct) / Co×100%

[0050] Where Co is the initial concentration and Ct is the concentration after a certain period of time.

[0051] Example 1

[0052] Titanium dioxide is added as a photocatalyst to the wastewater, and the addition amount is in a mass - volume ratio of 0.05:10 g / ml to the wastewater; continuous stirring is carried out, the power of the photolysis ultraviolet lamp is 10 W, and illumination is carried out at a distance of 10 cm from the liquid surface, and the pesticide degradation rates at different times are recorded.

[0053] Example 2

[0054] Titanium dioxide is added as a photocatalyst to the wastewater, and the addition amount is in a mass - volume ratio of 0.75:10 g / ml to the wastewater; continuous stirring is carried out, the power of the photolysis ultraviolet lamp is 10 W, and illumination is carried out at a distance of 10 cm from the liquid surface, and the pesticide degradation rates at different times are recorded.

[0055] Example 3

[0056] Titanium dioxide is added as a photocatalyst to the wastewater, and the addition amount is in a mass - volume ratio of 0.10:10 g / ml to the wastewater; continuous stirring is carried out, the power of the photolysis ultraviolet lamp is 10 W, and ultraviolet light illumination is carried out at a distance of 10 cm from the liquid surface, and the pesticide degradation rates at different times are recorded.

[0057] Comparative Example 1

[0058] Titanium dioxide is added as a photocatalyst to the wastewater, and the addition amount is in a mass - volume ratio of 0.05:10 g / ml to the wastewater; continuous stirring is carried out, and the ultraviolet lamp does not carry out illumination at a distance of 10 cm from the liquid surface, and the pesticide degradation rates at different times are recorded.

[0059] Comparative Example 2

[0060] Titanium dioxide is added as a photocatalyst to the wastewater, and the addition amount is in a mass - volume ratio of 0.75:10 g / ml to the wastewater; continuous stirring is carried out, and the ultraviolet lamp does not carry out illumination at a distance of 10 cm from the liquid surface, and the pesticide degradation rates at different times are recorded.

[0061] Comparative Example 3

[0062] Titanium dioxide was added to the wastewater as a photocatalyst, and the addition amount was in a mass - volume ratio of 0.10:10 g / ml to the wastewater; continuous stirring was carried out, and the ultraviolet lamp was not irradiated at a position 10 cm away from the liquid surface, and the pesticide degradation rate at different times was recorded.

[0063] Comparative Example 4

[0064] There was no need to add titanium dioxide as a photocatalyst to the wastewater, continuous stirring was carried out, and the ultraviolet lamp was irradiated at a position 10 cm away from the liquid surface, and the pesticide degradation rate at different times was recorded.

[0065] 4h degradation rate (%) 8h degradation rate (%) Example 1 64.64 67.84 Example 2 69.27 80.14 Example 3 71.05 80.67 Comparative Example 1 1.76 3.90 Comparative Example 2 3.90 4.61 Comparative Example 3 3.57 4.08 Comparative Example 4 0 0

[0066] The experimental data are as follows:

[0067] Referring to the experimental data in the above table, the addition amount of the oxidant can be controlled in the examples to control the residual content of the pesticide after the reaction, but there is an optimal addition amount. It is not that the more is added, the less the content is. At the same time, referring to the comparative example where no photolysis reaction device is added, it is found that the pesticide degradation rate is very low and the pesticide residue cannot be further removed. The experimental results show that the degradation of pesticide residue requires the simultaneous action of a photocatalyst and an ultraviolet lamp, indicating that this device can be used for the degradation of high - concentration agricultural wastewater and for purifying water sources. The specific comparison is as Figures 2 - 4 shown.

[0068] The above are only the preferred examples of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-concentration agricultural wastewater degradation device, characterized in that: It includes an enrichment container (1), a water inlet (2), a water outlet (3), a water pump (4), a filter membrane (5), an ultraviolet lamp tube (6) and a magnetic stirring device (7). The two sides of the enrichment container (1) are respectively provided with a water inlet (2) and a water outlet (3). Filter membranes (5) are installed at one end inside the enrichment container (1) for both the water inlet (2) and the water outlet (3). A water pump (4) is provided on the water inlet (2). An ultraviolet lamp tube (6) is arranged above the inside of the enrichment container (1), and a magnetic stirring device (7) is arranged at the bottom inside the enrichment container (1).

2. The high-concentration agricultural wastewater degradation device according to claim 1, characterized in that: The enrichment container (1) is made of transparent organic glass.

3. The high-concentration agricultural wastewater degradation device according to claim 2, wherein: The filter membrane (5) is a mixed cellulose ester filter membrane.

4. The high-concentration agricultural wastewater degradation device according to claim 3, wherein: There are no less than two groups of the ultraviolet lamp tubes (6).

5. The high-concentration agricultural wastewater degradation device according to claim 4, characterized in that: The power of each group of the ultraviolet lamp tubes (6) is 6 - 15 W.

6. The high-concentration agricultural wastewater degradation device according to claim 5, characterized in that: Two handle grips (8) are provided at the upper ends of multiple groups of the ultraviolet lamp tubes (6).

7. A method for degrading high-concentration agricultural wastewater, according to the high-concentration agricultural wastewater degradation device described in claim 6, characterized in that: Specifically, it includes the following steps: S1. The wastewater is pumped into the enrichment container (1) from the water inlet (2) through the water pump (4). A filter membrane (5) is provided at the end of the water inlet (2) for filtration to achieve the pretreatment of the wastewater. S2. Then, a photocatalyst is added into the enrichment container (1) in a certain proportion to the mass - volume of the wastewater. S3. Multiple groups of ultraviolet lamp tubes (6) arranged above the inside of the enrichment container (1) are used to irradiate and degrade the wastewater by ultraviolet light. S4. During the degradation, the magnetic stirring device (7) arranged at the bottom inside the enrichment container (1) continuously stirs the wastewater and the photocatalyst. S5. During the degradation process, the handle grips (8) can be pulled to adjust the height of multiple groups of ultraviolet lamp tubes (6). S6. The degraded wastewater can be discharged through the water outlet (3). When the wastewater is discharged, it is filtered by the filter membrane (5) at the inner end of the water outlet (3) to block and recycle the photocatalyst, thus completing the degradation work of the wastewater.

8. The method for degrading high-concentration agricultural wastewater according to claim 7, wherein: In step S2, the photocatalyst exists in the enrichment container (1) in a solid form, and the addition amount of the catalyst to the mass - volume ratio of the wastewater is 0.05 - 0.1:10 g / ml.

9. The method for degrading high-concentration agricultural wastewater according to claim 8, characterized in that: In step S2, after adding the photocatalyst, ultrasonic treatment is carried out for 1 h.

10. The method for degrading high-concentration agricultural wastewater according to claim 7, characterized in that: The stirring rate of the magnetic stirring device (7) in step S4 is 500 - 600 rpm.

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