Biological filter device for removing and recycling mercury in wastewater

Abstract

The utility model relates to a biological filter device for removing and recycling mercury in wastewater. The device comprises a water quality regulating tank (I), a charcoal-based biological filter (II), a mercury reduction microorganism culture adding device (III) and a mercury trapping device (IV), the water quality adjusting tank (I) is a cylinder with an open top; a water outlet pipe A (7) is arranged at the bottom of the water quality adjusting tank (I); a switch B (6) with a flow meter is arranged on the water outlet pipe A (7); the water quality regulating tank (I) is connected with the charcoal-based biological filter tank (II) through a water outlet pipe A (7); and the like. The device can effectively remove mercury in the wastewater, prevents formed gaseous mercury from polluting the atmospheric environment, is low in cost, and can realize recovery of mercury in the wastewater.

Description

Technical Field

[0001] The utility model relates to the technical field of biological filter sewage ecological treatment, in particular to a device for removing and recovering mercury in wastewater by using mercury-reducing bacterial strains to strengthen a biochar-based biological filter. Background Art

[0002] Mercury is a non-essential metal element with strong biological toxicity for organisms. It may be discharged into the environment as a by-product or pollutant in many industrial processes such as plastic production, non-ferrous metal refining, mining, chemical industry, chemical fiber, fertilizer, pesticide, instrument manufacturing, pigment industry, etc. If the mercury-containing wastewater generated by these industrial activities is not properly treated, it will pose a major threat to the environment, ecosystem and public health. Aquatic ecological environments such as wetlands, lakes, and biofilters are a major area for mercury deposition. They can absorb mercury input from atmospheric deposition and surface runoff and are active reservoirs of mercury. However, in this process, inorganic mercury may be converted into methylmercury by microorganisms such as sulfate-reducing bacteria. Methylmercury is easily absorbed by organisms due to its fat solubility and bioavailability, and can be accumulated and amplified along the food chain in the ecosystem, leading to biological mercury poisoning, causing damage to various systems and organs of humans and animals, and in severe cases, it can be fatal. However, although traditional mercury-containing wastewater treatment technologies such as sulfide precipitation can remove mercury to a certain extent, they have problems such as high cost, incomplete treatment, difficulty in meeting increasingly stringent environmental protection standards, large amount of sediment, and easy secondary generation of methylmercury.

[0003] Biofilter technology, as an ecological engineering strategy for sewage treatment that imitates natural wetlands, integrates multiple pollutant purification mechanisms such as physical filtration, chemical reactions and biological metabolism to achieve effective degradation and transformation of pollutants in sewage. In the treatment of mercury-containing wastewater, this technology mainly uses the action of specific microbial communities and their ability to adsorb heavy metals to fix dissolved mercury ions on the cell surface, and then changes its chemical form through the biological transformation process, and finally removes it from the wastewater through physical processes such as precipitation separation. In addition, high-level organisms in the biofilter, such as micro-animals, may directly or indirectly remove mercury through feeding. However, the bioaccumulation of mercury inevitably leads to the accumulation of toxicity of microorganisms and other biological entities in the filter ecosystem. Once the tolerance threshold of the organism is exceeded, it will cause biological death, have an irreversible impact on the treatment performance of the filter, and may even lead to the functional collapse of the entire system. Some microorganisms can convert high-valent mercury into zero-valent mercury, which overflows directly from the water and enters the atmosphere, thereby reducing mercury pollution in the water body, but this process will cause atmospheric mercury pollution.

[0004] Therefore, how to alleviate the toxic effects of mercury-containing wastewater on the filter ecosystem, effectively improve the treatment effect of the biological filter on mercury-containing wastewater, ensure the efficient and stable operation of the biological filter system, and realize the recovery of mercury discharged from the filter is still a problem to be solved. Summary of the invention

[0005] The present utility model is designed to solve the above-mentioned problems and defects, and provides a biofilter device for removing and recovering mercury in wastewater. The utility model adds mercury-reducing strains into a biochar-based biofilter and operates it in an intermittent aeration environment. The strain can reduce the mercury in the system to a gaseous state under an aerobic environment, which can effectively reduce the toxicity and content of mercury in the biofilter. In addition, a mercury capture device is installed above the biofilter to effectively recover mercury, avoid mercury pollution to the atmospheric environment, and realize the resource utilization of mercury at the same time. In addition, biochar, as a biofilter matrix, can not only provide a carbon source for mercury-reducing microorganisms, but also cooperate with mercury-reducing microorganisms to promote the volatilization of mercury in the biofilter system.

[0006] The utility model is implemented by the following technical solution.

[0007] A biofilter device for removing and recovering mercury from wastewater, the device of the utility model comprises a water quality regulating tank I, a biochar-based biofilter II, a mercury-reducing microbial culture and addition device III and a mercury capture device IV;

[0008] The water quality regulating tank I is configured as a cylinder with an open top;

[0009] A water outlet pipe A7 is provided at the bottom of the water quality regulating tank I, and a switch B6 with a flow meter is provided on the water outlet pipe A7; the water quality regulating tank I is connected to the biochar-based biofilter II through the water outlet pipe A7;

[0010] The biochar-based biofilter II is also configured as a cylinder with an open top; a water outlet pipe B11 is provided at the bottom of the biochar-based biofilter II, and a switch C12 with a flow meter is provided on the water outlet pipe B11;

[0011] The mercury-reducing microorganism culture and addition device III is arranged on the upper side of the biochar-based biofilter II;

[0012] A flow guide pipe 15 is arranged at the bottom of the mercury-reducing microorganism culture and addition device III, and a switch D 16 with a flow meter is arranged on the flow guide pipe 15; the end of the flow guide pipe 15 is arranged above the biochar-based biofilter II;

[0013] The mercury capture device IV is also arranged above the biochar-based biofilter II.

[0014] Furthermore, an alkali dosing device 1 is provided on the upper part of one side of the water quality regulating tank 1 of the utility model, and the alkali dosing device 1 adds alkali solution into the water quality regulating tank 1 through a switch A 2 with a flow meter.

[0015] Furthermore, the water quality regulating tank I of the utility model is provided with an agitator A3 inside, and the agitator A3 is connected to a timing switch A4.

[0016] Furthermore, a pH meter 5 is installed inside the water quality regulating tank 1 of the utility model, and the end of the pH meter 5 is arranged near the water outlet pipe A 7.

[0017] Furthermore, the biochar-based biofilter II of the utility model is filled with a matrix 9.

[0018] Furthermore, the matrix 9 of the present invention is biochar with a particle size of 2-4 mm.

[0019] Furthermore, an aeration device 10 is provided at the bottom of the biochar-based biological filter II of the utility model; the aeration device 10 is connected to the timing switch B8.

[0020] Furthermore, the mercury-reducing microorganism culture and addition device III of the utility model is internally provided with a stirrer B13; the stirrer B13 is connected to a timer switch C14.

[0021] Furthermore, the lower end of the mercury-reducing microorganism culture adding device III of the utility model is set to be funnel-shaped; the rotating shape of the agitator B13 matches the shape of the lower end of the mercury-reducing microorganism culture adding device III.

[0022] Furthermore, the mercury capture device IV of the utility model is composed of an outer shell and porous activated carbon 17 filled in the outer shell.

[0023] The beneficial effects of the utility model are as follows: (1) the utility model can effectively remove mercury in wastewater and can effectively volatilize mercury from the filter system into the atmosphere in gaseous form, thereby reducing the pressure of mercury in the filter on organisms and improving the stability of the ecosystem.

[0024] (2) The utility model uses biochar as the biofilter matrix, which is a cost-effective biological raw material, environmentally friendly, and can realize the resource utilization of agricultural waste. In addition, biochar is alkaline, which can neutralize the acidity of wastewater and provide an environment conducive to the growth of microorganisms. The large pores provide a good carrier for the growth of microorganisms.

[0025] (3) The mercury capture device used in the utility model can adsorb the gaseous mercury volatilized from the filter tank to avoid the pollution of the atmospheric environment by the gaseous mercury, and the adsorption material can be reused after elution, thus realizing the resource utilization of mercury at low cost and high efficiency.

[0026] The utility model is further explained below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the utility model.

[0028] The numbers in the figure are: I-water quality regulating tank, II-biochar-based biological filter, III-mercury-reducing microorganism culture addition device, IV-mercury capture device, 1-alkali addition device, 2-switch A with flow meter, 3-agitator A, 4-timing switch A, 5-pH meter, 6-switch B with flow meter, 7-outlet pipe A, 8-timing switch B, 9-substrate, 10-aeration device, 11-outlet pipe B, 12-switch C with flow meter, 13-agitator B, 14-timing switch C, 15-flow guide pipe, 16-switch D with flow meter, 17-activated carbon. DETAILED DESCRIPTION

[0029] The following embodiments are only a part of the technical solution of the present utility model, and are not intended to limit the entire technical solution of the present utility model. The embodiments of the present utility model are provided to further explain and illustrate the details of the technical solution of the present utility model.

[0030] Embodiment 1:

[0031] like Figure 1 As shown, a device for removing and recovering mercury from wastewater by strengthening a biochar-based biofilter with mercury-reducing strains, the structure of which includes a water quality regulating tank I, a biochar-based biofilter II, a mercury-reducing microorganism culture and addition device III and a mercury capture device IV connected in sequence. The outlet pipe 7 of the water quality regulating tank I is connected to the water inlet pipe of the biochar-based biofilter II; the outlet pipe 11 of the biochar-based biofilter II is located at the middle position of the bottom of the biochar-based biofilter II; the mercury capture device IV is located directly above the biochar-based biofilter II. An alkali dosing device 1 is installed above the water quality regulating tank I, and an agitator 3 is installed in the water quality regulating tank I; the mercury-reducing microorganism culture and addition device III is located at the upper right of the biochar-based biofilter II, and the bottom is connected to the biochar-based biofilter II through a guide pipe 15; the mercury-reducing microorganism culture and addition device III is installed with an agitator 13.

[0032] The water quality regulating tank I is a vertical flow regulating tank, on which an alkali dosing device 1 is installed and connected to a switch 2 with a flow meter, a stirrer 3 is installed inside the water quality regulating tank I and connected to a timing switch 4, and a pH meter 5 is installed in the water quality regulating tank I. A switch 6 with a flow meter is installed on the outlet pipe 7 of the water quality regulating tank I to control the amount of mercury-containing wastewater entering the biochar-based biological filter II.

[0033] The biochar-based biofilter II is a vertical flow biofilter, and the filling matrix 9 is biochar; an aeration device 10 is installed at the bottom of the biofilter, and an intermittent aeration mode is adopted, which is controlled by a timing switch 8; the bottom of the biofilter is an outlet pipe 11, which is controlled by a switch 12 with a flow meter.

[0034] The mercury-reducing microorganism culture and addition device III is funnel-shaped, and an agitator 13 is installed inside it, which is controlled by a timing switch 14; a switch 16 with a flow meter is installed at the bottom guide pipe 15 of the mercury-reducing microorganism culture and addition device III.

[0035] A gaseous mercury capture device IV is installed directly above the biochar-based biofilter II, and the interior is filled with porous material activated carbon 17, which can effectively capture the gaseous mercury volatilized from the biofilter.

[0036] Embodiment 2:

[0037] like Figure 1 As shown, the biofilter of the device for removing and recovering mercury from wastewater by strengthening the biochar-based biofilter with mercury-reducing strains includes a water quality regulating tank I, a biochar-based biofilter II, a mercury-reducing microorganism culture and addition device III and a mercury capture device IV connected in sequence. The mercury-containing wastewater enters the water quality regulating tank I. According to the value displayed by the pH meter 5, the alkali dosing device 1 is controlled by the switch 2 with a flow meter to add alkaline substances to the water quality regulating tank. The alkaline substances are generally sodium bicarbonate. At the same time, the stirrer 3 is turned on by the timer switch 4, and the stirring rate is 60 r / min. When the value of the pH meter 5 is 7, the addition of alkaline substances is turned off by the switch 2 with a flow meter, and the stirrer 3 is turned off by the timer switch 4.

[0038] The outlet of the water quality regulating tank I is opened by using a switch 6 with a flow meter, so that the mercury-containing wastewater in the water quality regulating tank I enters the biochar-based biofilter II through the outlet pipe 7. The biochar-based biofilter II is a vertical flow biofilter, and the filling matrix 9 is biochar, which is made by shredding nut shells and walnut shells and burning them at 300°C under anaerobic conditions, with a particle size of 2-4 mm; an aeration device 10 is installed at the bottom of the biochar-based biofilter II, which is controlled by a timer switch 8 and adopts an intermittent aeration mode, with aeration: rest time = 0.5:2.5 h; the bottom of the biochar-based biofilter II is an outlet pipe 11, which is controlled by a switch 12 with a flow meter, and the hydraulic retention time is 24 h.

[0039] A mercury-reducing microorganism culture addition device III is installed on the upper right side of the biochar-based biological filter II. The device is funnel-shaped and has an agitator 13 installed inside. The stirring rate is 60 r / min and is controlled by a timing switch 14. A switch 16 with a flow meter is installed on the bottom guide pipe 15 of the mercury-reducing microorganism culture addition device III to control the amount of mercury-reducing microorganisms added to the biochar-based biological filter III.

[0040] A mercury capture device IV is installed directly above the biochar-based biofilter III, and is filled with porous material activated carbon 17. The activated carbon is generally made by burning fruit shells, etc., and can effectively capture gaseous mercury volatilized from the biofilter.

[0041] The above is only a specific embodiment of the utility model, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A biofilter device for removing and recovering mercury from wastewater, characterized in that: The device comprises a water quality regulating tank (I), a biochar-based biofilter (II), a mercury-reducing microbial culture and addition device (III) and a mercury capture device (IV); The water quality regulating tank (I) is configured as a cylinder with an open top; A water outlet pipe A (7) is provided at the bottom of the water quality regulating tank (I), and a switch B (6) with a flow meter is provided on the water outlet pipe A (7); the water quality regulating tank (I) is connected to the biochar-based biological filter tank (II) through the water outlet pipe A (7); The biochar-based biofilter (II) is also configured as a cylinder with an open top; a water outlet pipe B (11) is provided at the bottom of the biochar-based biofilter (II), and a switch C (12) with a flow meter is provided on the water outlet pipe B (11); The mercury-reducing microorganism culture addition device (III) is arranged on the upper side of the biochar-based biofilter (II); A flow guide pipe (15) is arranged at the bottom of the mercury-reducing microorganism culture and addition device (III), and a switch D (16) with a flow meter is arranged on the flow guide pipe (15); the end of the flow guide pipe (15) is arranged above the biochar-based biological filter (II); The mercury capture device (IV) is also arranged above the biochar-based biofilter (II).

2. A biofilter device for removing and recovering mercury from wastewater according to claim 1, characterized in that: An alkali dosing device (1) is provided at an upper portion of one side of the water quality regulating tank (I). The alkali dosing device (1) adds alkali solution into the water quality regulating tank (I) via a switch A (2) provided with a flow meter.

3. A biofilter device for removing and recovering mercury from wastewater according to claim 1, characterized in that: The water quality regulating tank (I) is provided with an agitator A (3) inside, and the agitator A (3) is connected to a timer switch A (4).

4. A biofilter device for removing and recovering mercury from wastewater according to claim 1, characterized in that: A pH meter (5) is installed inside the water quality regulating tank (I), and the end of the pH meter (5) is arranged near the water outlet pipe A (7).

5. The biofilter device for removing and recovering mercury from wastewater according to claim 1, characterized in that: The biochar-based biofilter (II) is filled with a matrix (9).

6. A biofilter device for removing and recovering mercury from wastewater according to claim 5, characterized in that: The matrix (9) is biochar with a particle size of 2-4 mm.

7. The biofilter device for removing and recovering mercury from wastewater according to claim 1, characterized in that: An aeration device (10) is provided at the bottom of the biochar-based biofilter (II); the aeration device (10) is connected to a timer switch B (8).

8. The biofilter device for removing and recovering mercury from wastewater according to claim 1, characterized in that: The mercury-reducing microorganism culture and addition device (III) is provided with a stirrer B (13) inside; the stirrer B (13) is connected to a timer switch C (14).

9. A biofilter device for removing and recovering mercury from wastewater according to claim 8, characterized in that: The lower end of the mercury-reducing microorganism culture adding device (III) is configured to be funnel-shaped; the rotating shape of the agitator B (13) matches the shape of the lower end of the mercury-reducing microorganism culture adding device (III).

10. The biofilter device for removing and recovering mercury from wastewater according to claim 1, characterized in that: The mercury capture device (IV) is composed of an outer shell and porous activated carbon (17) filled in the outer shell.

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