Device and preparation method for resource-based modified cyanobacteria to purify printing and dyeing wastewater

Abstract

The invention discloses a device and preparation method for purifying printing and dyeing wastewater using resource-based modified cyanobacteria, relates to the technical field of water treatment, and aims to solve the problems of late-stage disposal of cyanobacteria and purification of printing and dyeing wastewater. The invention comprises at least one integrated modified cyanobacteria purification device, the interior of which is a cavity in which a plurality of structural filler plates are fixedly arranged, and the surface of each structural filler plate is covered with an immobilized iron ion-cyanobacteria membrane. The integrated modified cyanobacteria purification device is also provided with an aeration system, and aeration holes are distributed between every two adjacent structural filler plates. The preparation process of the structural filler plate covered with the immobilized iron ion-cyanobacteria membrane comprises first coating a layer of polyvinyl alcohol solution on the structural filler plate and drying it, then coating a layer of cross-linking agent, then pouring a mixed cyanobacteria liquid onto the structural filler plate for single-sided cross-linking and fixation, and finally fixing the other side of the mixed cyanobacteria liquid with a setting agent. The invention can not only recycle cyanobacteria in a resource-based manner, but also purify printing and dyeing wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, in particular to a device for purifying printing and dyeing wastewater using resource-based modified cyanobacteria and a preparation method thereof. Background Art

[0002] Algal blooms are a widespread global aquatic environmental disaster and the most common aquatic environmental problem in eutrophic water bodies in my country. In my country, algal blooms are mostly referred to as cyanobacterial blooms. When cyanobacteria form in water bodies, the water surface is covered with a thick blue-green algae, blocking oxygen from the air and causing hypoxia or even anaerobic conditions. The water body gradually becomes a reducing environment, leading to increased ammonia nitrogen concentrations, phosphorus release, and other deteriorating water quality. Furthermore, the subsequent disposal costs of cyanobacteria also account for a significant portion of engineering treatment costs.

[0003] The printing and dyeing industry is a major emitter of industrial wastewater. For every 100m of fabric produced, a printing and dyeing factory generates an average of 3 to 5m of wastewater. 3 The amount of printing and dyeing wastewater discharged in my country is about 3 to 4 million m 3 Anthraquinone dyes are the second most widely used dyes. Reactive Brilliant Blue KN-R is a typical anthraquinone dye. Its wastewater has the characteristics of high chroma, difficulty in degradation, difficulty in oxidation, and poor biodegradability.

[0004] In summary, if these two problems can be solved at the same time, the dual goals of resource conservation and environmental governance can be achieved while saving costs. Therefore, a device and preparation method for resource-based modified cyanobacteria to purify printing and dyeing wastewater is urgently needed to solve this problem. Summary of the Invention

[0005] The purpose of the present invention is to provide a device and preparation method for resource-based modified cyanobacteria to purify printing and dyeing wastewater, so as to solve the problems of late treatment of cyanobacteria and purification of printing and dyeing wastewater.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a resource-based modified cyanobacteria purification device for printing and dyeing wastewater, comprising at least one integrated modified cyanobacteria purification device, the interior of which is a cavity in which a plurality of structural filler plates are fixedly arranged, and the surface of each structural filler plate is covered with an immobilized iron ion-cyanobacteria membrane; an aeration system is also provided inside the integrated modified cyanobacteria purification device, and aeration holes are distributed between every two adjacent structural filler plates.

[0007] Preferably, the cavity lower end and both side walls of the integrated modified blue algae purification device are provided with a plurality of groups of structural filler slots, and the structural filler plates are detachably inserted into the structural filler slots.

[0008] Preferably, the structural filler plate is arranged vertically, and multiple structural filler plates are parallel and distributed at equal intervals; the structural filler plate is made of polyethylene plate, and its surface is densely covered with multiple polyethylene hairs to increase the adhesion to the immobilized iron ion-cyanobacteria film.

[0009] Preferably, the aeration system includes a main air supply pipe located above the plurality of structural filler plates and a plurality of branch pipes connected thereto, each branch pipe extending downward to between every two adjacent structural filler plates, and a plurality of aeration holes are provided on the sidewalls of the branch pipes.

[0010] Another technical solution provided by the present invention is a method for preparing the above-mentioned device, comprising first coating a layer of polyvinyl alcohol solution on the structured filler plate and drying it, then coating it with a layer of cross-linking agent, then pouring the mixed cyanobacteria liquid onto the structured filler plate for cross-linking and fixing on one side, and finally fixing the other side of the mixed cyanobacteria liquid with a setting agent to produce a structured filler plate with a surface covered with an immobilized iron ion-cyanobacteria film.

[0011] Preferably, the preparation process of the mixed cyanobacteria liquid includes: adding trivalent iron ions to the cyanobacteria liquid for modification so that the cyanobacteria cell surface carries more positive charge, thereby obtaining an iron ion-modified cyanobacteria liquid; adding a cross-linking agent to the sodium alginate and polyvinyl alcohol fixative to fully cross-link the molecular structure to make it stronger, adding the iron ion-modified cyanobacteria liquid to the cross-linked fixative and fixing the volume with the fixative; after fixing the volume, fully mixing and waiting for it to be fully cross-linked to obtain a mixed cyanobacteria liquid.

[0012] Preferably, the algae content in the cyanobacteria liquid used in the preparation process of the mixed cyanobacteria liquid is 100,000-300,000 mg / m 3 ; The concentration of trivalent iron ions after addition is 0.1-1 mol / L, and the mixture is stirred for 10-24 hours after addition; the mass ratio of sodium alginate to polyvinyl alcohol in the fixative is 1:, the cross-linking agent uses glutaraldehyde with a concentration of 3-6%, and the volume ratio of the fixative to the iron ion-modified cyanobacteria liquid in the mixed cyanobacteria liquid is 1:.

[0013] Preferably, a layer of polyvinyl alcohol solution is applied and dried, the concentration of the polyvinyl alcohol solution is 10%, and the coating is placed in a 40°C oven until the coating is completely dry, with a coating thickness of 0.5-5 mm; the crosslinking agent is glutaraldehyde with a concentration of 3-6%, and the mixed cyanobacteria solution poured on the structured filler plate is 10-1000 ml; the setting agent is a mixed solution of CaCl2 and boric acid, wherein the mass ratio of CaCl2 to boric acid is 1:.

[0014] Preferably, a cross-linking agent is added to the sodium alginate and polyvinyl alcohol fixatives and cross-linked for 10-24 hours before adding iron ions to modify the cyanobacteria liquid.

[0015] Preferably, the cyanobacteria liquid used in the preparation of the mixed cyanobacteria liquid is obtained by salvaging, culturing or purchasing, and the algae content is concentrated by centrifugation at 5000 r / min for 30 seconds.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The device and preparation method for resource-based modified cyanobacteria to purify printing and dyeing wastewater are specifically designed to target the characteristics of cyanobacteria that have pseudovacuoles and can be suspended or float on the water surface. At the same time, the surface of cyanobacteria has functional groups and is charged. By utilizing the principles of functional group adsorption and charge attraction, dyes in printing and dyeing wastewater in different water layers can be adsorbed and removed; by modifying the cyanobacteria with iron ions, this process can be strengthened and accelerated. This method not only recycles cyanobacteria in a resource-based manner, turning waste into treasure, is easy to use, does not require excessive capital investment, but can also purify printing and dyeing wastewater, killing two birds with one stone. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the integrated modified cyanobacteria purification device of the present invention;

[0019] Figure 2 Schematic diagram of the structure of the structural filler plate of the present invention.

[0020] In the figure: 1. Integrated modified cyanobacteria purification device; 2. Structural filler slot; 3. Structural filler plate; 4. Immobilized iron ion-cyanobacteria membrane; 5. Aeration system. DETAILED DESCRIPTION

[0021] As a type of algae, cyanobacteria have a certain effect on removing nitrogen, phosphorus and organic matter from water. At the same time, experiments have found that cyanobacteria have a large specific surface area and their cell wall surface has rich functional groups. At the same time, the surface is charged, which can remove heavy metal ions, reactive dyes and other pollutants from water through functional group bonding or adsorption. However, how to effectively utilize this function of cyanobacteria remains to be studied and developed. The present invention has conducted a large number of experiments on this specialized function and finally obtained a technical solution for effectively treating printing and dyeing wastewater as follows, refer to Figure 1 and Figure 2 A resource-based modified cyanobacteria purification device for printing and dyeing wastewater includes an integrated modified cyanobacteria purification device 1 (multiple devices can be set up for joint operation), the interior of which is a cavity in which multiple structural filler plates 3 are fixed, and the surface of each structural filler plate 3 is covered with an immobilized iron ion-cyanobacteria membrane 4; the integrated modified cyanobacteria purification device 1 is also provided with an aeration system 5, and aeration holes are distributed between every two adjacent structural filler plates 3.

[0022] The lower end and both side walls of the cavity of the integrated modified cyanobacteria purification device 1 can preferably be provided with multiple groups of structural filler slots 2, and the structural filler plates 3 can be removably inserted into the structural filler slots 2. For reference, the spacing between adjacent slots can be set smaller so that the entire cavity is filled with slots, so that the spacing of the structural filler plates 3 can be easily adjusted according to needs.

[0023] In a preferred embodiment, the structural filler plate 3 is vertically arranged, and multiple structural filler plates 3 are parallel and evenly spaced. The structural filler plate 3 is made of polyethylene plate, and its surface is densely covered with multiple polyethylene fluffs to increase the adhesion to the immobilized iron ion-cyanobacteria membrane 4.

[0024] For reference, such as Figure 1 As shown, the aeration system 5 includes a main air supply pipe located above a plurality of structural filler plates 3 and a plurality of branch pipes connected thereto. Each branch pipe extends downward to between every two adjacent structural filler plates 3, and a plurality of aeration holes are provided on the side wall of the branch pipe.

[0025] The method for preparing the above-mentioned device, particularly the structured filler plate 3, includes first coating the structured filler plate 3 with a layer of polyvinyl alcohol solution and drying it, then coating it with a layer of crosslinking agent, then pouring the mixed cyanobacteria solution onto the structured filler plate 3 and crosslinking and fixing it on one side, and finally fixing the other side of the mixed cyanobacteria solution with a setting agent, thereby producing a structured filler plate 3 with a surface covered with an immobilized iron ion-cyanobacteria membrane 4.

[0026] Preferably, a layer of polyvinyl alcohol solution is applied and dried, the concentration of the polyvinyl alcohol solution is preferably 10%, and the coating can be placed in a 40°C oven and dried until the coating is completely dry, for example, for 24 hours. Before pouring the mixed cyanobacteria solution, the coating thickness is preferably 0.5-5 mm; the cross-linking agent can be glutaraldehyde with a concentration of 3-6%, and the mixed cyanobacteria solution poured on the structured filler plate 3 can be 10-1000 ml; the setting agent is a commonly available mixed solution of CaCl2 and boric acid, wherein the mass ratio of CaCl2 to boric acid is 1:10-100.

[0027] Alternatively, the preparation process of the mixed cyanobacteria liquid used above includes: adding trivalent iron ions to the cyanobacteria liquid to modify it so that the cyanobacteria cell surface has more positive charges, thereby preparing the iron ion modified cyanobacteria liquid; adding a crosslinking agent to the sodium alginate and polyvinyl alcohol fixative to fully crosslink and make the molecular structure more solid, for example, crosslinking for 10-24 hours, adding the iron ion modified cyanobacteria liquid to the crosslinked fixative and fixing it to a fixed volume with the fixative; after fixing the volume, fully mixing and waiting for it to be fully crosslinked to prepare the mixed cyanobacteria liquid; wherein preferably, the algae content of the cyanobacteria liquid used in the preparation process of the mixed cyanobacteria liquid is 100,000-300,000 mg / m 3The concentration of trivalent iron ions after addition is 0.1-1 mol / L, and FeCl3 can be used. After addition, mixing and stirring should be carried out for 10-24 hours; the mass ratio of sodium alginate to polyvinyl alcohol in the fixative is 1:2-50, the mass ratio of sodium alginate to sterile water in the fixative can be 1:100-1000, and the cross-linking agent can still be glutaraldehyde with a concentration of 3-6%. The volume ratio of the fixative to the iron ion modified cyanobacteria liquid in the mixed cyanobacteria liquid is preferably 30-1000:1, and the volume ratio of the cross-linking agent to the fixative can be 1:10-100.

[0028] The above-mentioned cyanobacteria liquid can be obtained by salvaging, culturing or purchasing, and the algae content thereof can be concentrated by centrifugation at 5000 r / min for 30 seconds.

[0029] Example:

[0030] Preparation of iron ion modified cyanobacteria liquid: salvage the cyanobacteria bloom water, remove floating leaves, plant debris, etc., and centrifuge to concentrate the algae content to 100,000-300,000 mg / m 3 ; Add FeCl3 solution until the trivalent iron ion content reaches 1 mol / L, and stir slowly at 80 rpm for 24 h.

[0031] Prepare a mixed cyanobacteria solution: Purchase sodium alginate, polyvinyl alcohol fixative, and glutaraldehyde crosslinker. In the fixative, the mass ratio of sodium alginate to polyvinyl alcohol is 1:24, the mass ratio of sodium alginate to water is 1:340, and the concentration of glutaraldehyde in the crosslinker is 4%. Add iron ion-modified cyanobacteria solution to the crosslinked fixative, and calibrate the volume with the fixative. After calibrating the volume, further crosslink the fixative to fully mix and connect with the solution. The volume ratio of the fixative to the iron ion-modified cyanobacteria solution is 100:1, and the volume ratio of the crosslinker to the fixative is 1:70.

[0032] Filler plate coating: First, apply a layer of 10% polyvinyl alcohol on the surface of the structural filler plate and dry it at 40°C for 24 hours; then apply a layer of 4% glutaraldehyde cross-linking agent. The coating thickness is about 3mm. Pour the mixed cyanobacteria liquid on the surface for single-sided cross-linking and fixation. Then, spray the surface of the mixed cyanobacteria liquid with a setting agent for setting. The setting agent is a 4% calcium chloride saturated boric acid solution.

[0033] Insert multiple coated structural filler plates into corresponding slots, set branch pipes for microporous aeration between adjacent filler plates, and connect the main air supply pipe of the aeration system to the fan to form an integrated modified cyanobacteria purification device 1. In this embodiment, five integrated modified cyanobacteria purification devices 1 are used to work together.

[0034] Five integrated modified cyanobacteria purification devices 1 were set up in a simulated sewage tank with a sewage volume of 2m 3The dye KN-R concentration was 80 mg / L. After 3 days of operation, the KN-R concentration was reduced to 23.30 mg / L. After 10 days of operation, the KN-R concentration was reduced to 4.55 mg / L, with a removal rate of over 90%.

[0035] Furthermore, algae leakage was observed and recorded during the purification process. Chlorophyll was not detected in the initial water column, and was essentially absent in the final water column after 10 days of operation, indicating that algae leakage was minimal and the fixative was effective, eliminating the risk of secondary contamination.

[0036] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined by the claims.

[0037] Any matters not described in detail in the present invention are well-known technologies to those skilled in the art.

Claims

1. A device for purifying printing and dyeing wastewater using resource-based modified cyanobacteria, characterized by: The invention comprises at least one integrated modified cyanobacteria purification device (1), the interior of which is a cavity in which a plurality of structural filler plates (3) are fixedly arranged, and the surface of each structural filler plate (3) is covered with an immobilized iron ion-cyanobacteria membrane (4); an aeration system (5) is also provided inside the integrated modified cyanobacteria purification device (1), and aeration holes are distributed between every two adjacent structural filler plates (3); The method for covering the surface of the structured filler plate (3) with an immobilized iron ion-cyanobacteria film (4) comprises first coating a layer of polyvinyl alcohol solution on the structured filler plate (3) and drying it, then coating a layer of cross-linking agent, then pouring a mixed cyanobacteria liquid onto the structured filler plate (3) for cross-linking and fixing on one side, and finally fixing the other side of the mixed cyanobacteria liquid with a fixing agent; wherein the preparation process of the mixed cyanobacteria liquid comprises: adding trivalent iron ions to the cyanobacteria liquid for modification so that the surface of the cyanobacteria cells carries more positive charges, thereby obtaining an iron ion-modified cyanobacteria liquid; adding a cross-linking agent to sodium alginate and polyvinyl alcohol fixing agents for sufficient cross-linking to make the molecular structure more solid, adding the iron ion-modified cyanobacteria liquid to the cross-linked fixing agent and fixing the volume with the fixing agent; after fixing the volume, fully mixing and waiting for sufficient cross-linking to obtain a mixed cyanobacteria liquid.

2. The device for purifying printing and dyeing wastewater using resource-based modified cyanobacteria according to claim 1, characterized in that: The cavity lower end and both side walls of the integrated modified blue algae purification device (1) are provided with a plurality of groups of structural filler slots (2), and the structural filler plates (3) are detachably inserted into the structural filler slots (2).

3. The device for purifying printing and dyeing wastewater using resource-based modified cyanobacteria according to claim 2, characterized in that: The structural filler plate (3) is vertically arranged, and a plurality of structural filler plates (3) are parallel and evenly spaced. The structural filler plate (3) is a polyethylene plate, and a plurality of polyethylene hairs are densely distributed on its surface to increase the adhesion to the immobilized iron ion-cyanobacteria membrane (4).

4. The device for purifying printing and dyeing wastewater using resource-based modified cyanobacteria according to claim 3 is characterized by: The aeration system (5) comprises a main air supply pipe located above a plurality of structural filler plates (3) and a plurality of branch pipes connected thereto, each branch pipe extending downward to between each two adjacent structural filler plates (3), and a plurality of aeration holes are provided on the side walls of the branch pipes.

5. The device for purifying printing and dyeing wastewater using resource-based modified cyanobacteria according to claim 1 is characterized by: The algae content of the cyanobacteria liquid used in the preparation process of the mixed cyanobacteria liquid is 100,000-300,000 mg / m 3 The concentration of trivalent iron ions after addition is 0.1-1 mol / L, and the mixture is stirred for 10-24 hours. The mass ratio of sodium alginate to polyvinyl alcohol in the fixative is 1: (2-50), the cross-linking agent uses glutaraldehyde with a concentration of 3-6%, and the volume ratio of the fixative to the iron ion-modified cyanobacteria solution in the mixed cyanobacteria solution is (30-1000):

1.

6. The device for purifying printing and dyeing wastewater using resource-based modified cyanobacteria according to claim 1 is characterized by: The coating and drying process comprises applying a layer of polyvinyl alcohol solution, wherein the concentration of the polyvinyl alcohol solution is 10%, and the coating is placed in a 40°C oven and dried until the coating is completely dry, with a coating thickness of 0.5-5 mm; a cross-linking agent is glutaraldehyde with a concentration of 3-6%, and 10-1000 ml of the mixed cyanobacteria solution is poured onto the structured filler plate (3); and a setting agent is a mixed solution of CaCl2 and boric acid, wherein the mass ratio of CaCl2 to boric acid is 1:(10-100).

7. The device for purifying printing and dyeing wastewater using resource-based modified cyanobacteria according to claim 1 is characterized by: A cross-linking agent is added to the sodium alginate and polyvinyl alcohol fixative, and then cross-linked for 10-24 hours, and then iron ions are added to modify the cyanobacteria liquid.

8. The device for purifying printing and dyeing wastewater using resource-based modified cyanobacteria according to claim 1 is characterized by: The cyanobacteria liquid used in the preparation process of the mixed cyanobacteria liquid is obtained by salvaging, culturing or purchasing, and the algae content is concentrated by centrifugation at 5000 r / min for 30 seconds.

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