Double-membrane sewage treatment method

Abstract

The invention discloses a double-membrane sewage treatment method. The whole treatment method and process are as follows: incoming water, a coarse screen, a fine screen, a high-density sedimentation tank, a V-shaped filter tank, an ultrafiltration membrane, a reverse osmosis membrane and blended water (produced water in the V-shaped filter tank and produced water in the reverse osmosis membrane) are recycled; wherein sludge water of the high-density sedimentation tank passes through the sludge concentration tank and the plate-and-frame filter, and sludge cakes are transported outwards. The invention aims to provide the double-membrane sewage treatment method, the treated sewage is industrial and domestic mixed wastewater and also comprises rainwater, and the sewage can be reused through treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a double-membrane sewage treatment method. Background Art

[0002] In today's society, with the acceleration of industrialization and urbanization.

[0003] Traditional sewage treatment methods have gradually revealed their limitations in response to increasingly complex sewage compositions and strict discharge standards. For example, some simple physical and chemical treatment methods may not be able to effectively remove pollutants such as dissolved organic matter, nitrogen, and phosphorus in sewage; biological treatment methods may be affected by factors such as water quality fluctuations and temperature changes, and the treatment effect is unstable.

[0004] In addition, with the increasing awareness of environmental protection, people's requirements for sewage treatment are not only to meet the discharge standards, but also to pay more attention to resource recycling and energy conservation. Therefore, it is imperative to develop more efficient, energy-saving and environmentally friendly sewage treatment systems and methods to achieve the goals of sustainable use of water resources and environmental protection.

[0005] Compared with the existing patent CN 209468220 U, the present invention introduces a stable operation method of a sewage treatment system of a double membrane method, and the water treatment equipment and facilities of the system include: a coarse grid, a fine grid, a high-density sedimentation tank, a V-type filter, an ultrafiltration system, a reverse osmosis system, a plate and frame filter, etc.; while the existing patent CN 209468220 U mainly introduces another sewage treatment system, which includes a regulating water tank, a regulating tank lifting pump, an air flotation sedimentation integrated machine, an inclined tube sedimentation tank, a clean water pump, a multi-media filter, an iron removal filter, an activated carbon filter, a filter backwash water pump, an ultrafiltration water supply pump, a self-cleaning filter, an ultrafiltration device, an ultrafiltration backwash water pump, a reverse osmosis water supply pump, a dosing device, a security filter, a reverse osmosis high-pressure pump, a reverse osmosis filtration device and a fan. Although a small part of the sewage treatment equipment and facilities are the same as the present invention, the process is very different. Summary of the invention

[0006] The purpose of the present invention is to provide a double-membrane sewage treatment method, wherein the sewage to be treated is mixed industrial and domestic wastewater and rainwater, and the sewage can be reused through treatment.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] The present invention discloses a double-membrane sewage treatment method, comprising:

[0009] 1). The incoming water is intercepted by the coarse and fine grids, and larger debris such as wood, beverage bottles, plastic bags, branches, and plastic sticks are intercepted;

[0010] 2). The water out of the fine screen is pumped into the high-density sedimentation tank for filtration through a lifting pump. PAM, lime, sodium chlorate and concentrated sulfuric acid are added to the high-density sedimentation tank. The dosage is dynamically adjusted according to the water quality and water volume of the incoming water;

[0011] 3). The effluent from the high-density sedimentation tank enters the V-type filter for the next stage of treatment. The V-type filter is backwashed regularly during the water treatment process, and the backwash cycle is dynamically adjusted according to the water quality and the degree of contamination of the filter material in the V-type filter;

[0012] 4). Part of the effluent from the V-type filter enters the V-filter water storage tank, and the other part enters the ultrafiltration membrane system through the booster pump. Chlorine dioxide is added to the ultrafiltration inlet pipe for sterilization;

[0013] 5). The produced water of the ultrafiltration membrane system enters the water reservoir, and then enters the reverse osmosis membrane system through a pressure pump. The water quality of the system requires SDI ≤ 4. The chemicals added during normal operation are scale inhibitors, bactericides, and reducing agents;

[0014] 6). The reverse osmosis water and the V-type filter water are blended, and the blending ratio and the conductivity of the blended water are dynamically adjusted according to production needs. The blended water is delivered to users for use.

[0015] Furthermore, the high-density sedimentation tank is regularly discharged, and the discharged sludge water is pumped into the sludge thickening tank through the sludge discharge pump. The sludge discharge time is dynamically adjusted according to the incoming water quality.

[0016] Furthermore, the ultrafiltration membrane system includes two backwashing modes during operation:

[0017] The first is conventional backwashing: usually once every 30 minutes, the added agent is sodium hypochlorite;

[0018] The second is chemical cleaning: generally once every 24 hours, chemical cleaning is divided into acid cleaning and alkaline cleaning.

[0019] Furthermore, citric acid is added for pickling, and sodium hydroxide and sodium hypochlorite are added for alkali washing.

[0020] Furthermore, after each set of reverse osmosis has been running for a period of time, chemical cleaning is performed according to changes in the reverse osmosis operating parameters.

[0021] Furthermore, chemical cleaning is divided into alkaline cleaning and acid cleaning, wherein the reagents added in alkaline cleaning are sodium polyphosphate, sodium dodecyl benzoate and sodium hydroxide, and the reagent added in acid cleaning is citric acid.

[0022] Furthermore, the sludge water discharged from the high-density sedimentation tank passes through a sludge concentration tank and a plate and frame filter, and finally the mud cake is transported out.

[0023] Compared with the prior art, the beneficial technical effects of the present invention are:

[0024] The water treatment equipment such as coarse screens, fine screens, high-density sedimentation tanks, V-type filters, ultrafiltration membranes, reverse osmosis membranes, sludge concentration tanks, plate and frame filters operate smoothly, and the entire sewage treatment system operates stably. The blended water is qualified for reuse, and the environmental protection indicators meet the standards, preventing sewage from being directly discharged into the natural environment, alleviating the pressure of water shortage, achieving sustainable use of water resources, ensuring that enterprises and social activities comply with relevant environmental protection laws and regulations, and avoiding penalties for illegal discharge. DETAILED DESCRIPTION

[0025] A double membrane sewage treatment method, comprising:

[0026] 1. The incoming water is intercepted by the coarse and fine screens, which can basically intercept some larger debris such as wood, beverage bottles, plastic bags, branches, plastic sticks, etc.

[0027] 2. The effluent from the fine screen is pumped into the high-density sedimentation tank for filtration through a lifting pump. The high-density sedimentation tank needs to be added with PAM, lime, sodium chlorate, and concentrated sulfuric acid. The dosage is dynamically adjusted according to the water quality and water volume of the incoming water. The high-density sedimentation tank is regularly drained of sludge, and the sludge water is pumped into the sludge concentration tank through a sludge pump. The sludge discharge time is dynamically adjusted according to the water quality of the incoming water.

[0028] 3. The effluent from the high-density sedimentation tank enters the V-type filter for the next stage of treatment. The V-type filter water treatment method requires regular backwashing, and the backwash cycle is dynamically adjusted according to the water quality and the degree of contamination of the V-filter filter material.

[0029] 4. Part of the effluent from the V-type filter enters the V-filter water storage tank, and the other part enters the ultrafiltration membrane system through the booster pump. Chlorine dioxide is added to the ultrafiltration water inlet pipe to play a sterilizing role. In addition, there are two backwashing methods in the operation of the ultrafiltration membrane system. The first is conventional backwashing, which is generally once every 30 minutes, and the added agent is sodium hypochlorite; the second is chemical cleaning, which is generally once every 24 hours. Chemical cleaning is divided into acid cleaning and alkaline cleaning. Acid cleaning requires the addition of citric acid, and alkaline cleaning requires the addition of sodium hydroxide and sodium hypochlorite.

[0030] 5. The water produced by the ultrafiltration membrane system enters the water reservoir and then enters the reverse osmosis membrane system through a pressure pump. The water quality of the system requires SDI ≤ 4. The chemicals that need to be added during normal operation are scale inhibitors, bactericides, and reducing agents. After each set of reverse osmosis has been running for a period of time, chemical cleaning is carried out according to the changes in the reverse osmosis operating parameters. Chemical cleaning is divided into alkaline cleaning and acid cleaning. The chemicals added for alkaline cleaning are sodium polyphosphate, sodium dodecyl benzoate, and sodium hydroxide, and the chemicals added for acid cleaning are citric acid.

[0031] 6. The reverse osmosis water and the water produced by the V-type filter are blended. The blending ratio and the conductivity of the blended water are dynamically adjusted according to production needs, and the blended water is delivered to users for use.

[0032] The double membrane sewage treatment method of the present invention has the following advantages:

[0033] 1. Environmental protection: Prevent sewage from being discharged directly into the natural environment, avoid pollution of water, soil and air, and protect ecological balance and biodiversity.

[0034] 2. Water resource protection: Through treatment, sewage can be reused to alleviate the pressure of water shortage and achieve sustainable use of water resources.

[0035] 3. Ecosystem maintenance: protect the stability and function of water ecosystems such as rivers, lakes, and oceans, and promote the self-repair and normal operation of ecosystems.

[0036] 4. Promote economic development: A good sewage treatment system helps improve the environmental quality of the region, attract investment, and promote the sustainable development of industry and agriculture.

[0037] 5. Comply with regulatory requirements: Ensure that corporate and social activities comply with relevant environmental protection laws and regulations to avoid penalties for illegal emissions.

[0038] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A double membrane sewage treatment method, characterized in that: include: 1). The incoming water is intercepted by the coarse and fine grids, and larger debris such as wood, beverage bottles, plastic bags, branches, and plastic sticks are intercepted; 2). The water out of the fine screen is pumped into the high-density sedimentation tank for filtration through a lifting pump. PAM, lime, sodium chlorate and concentrated sulfuric acid are added to the high-density sedimentation tank. The dosage is dynamically adjusted according to the water quality and water volume of the incoming water; 3). The effluent from the high-density sedimentation tank enters the V-type filter for the next stage of treatment. The V-type filter is backwashed regularly during the water treatment process, and the backwash cycle is dynamically adjusted according to the water quality and the degree of contamination of the filter material in the V-type filter; 4). Part of the effluent from the V-type filter enters the V-filter water storage tank, and the other part enters the ultrafiltration membrane system through the booster pump. Chlorine dioxide is added to the ultrafiltration inlet pipe for sterilization; 5). The produced water of the ultrafiltration membrane system enters the water reservoir, and then enters the reverse osmosis membrane system through a pressure pump. The water quality of the system requires SDI ≤ 4. The chemicals added during normal operation are scale inhibitors, bactericides, and reducing agents; 6). The reverse osmosis water and the V-type filter water are blended, and the blending ratio and the conductivity of the blended water are dynamically adjusted according to production needs. The blended water is delivered to users for use.

2. The method for treating sewage by double membrane method according to claim 1, characterized in that: The high-density sedimentation tank is discharged regularly, and the discharged sludge water is pumped into the sludge concentration tank through the sludge discharge pump. The sludge discharge time is dynamically adjusted according to the incoming water quality.

3. The method for double membrane wastewater treatment according to claim 1, characterized in that: The ultrafiltration membrane system includes two backwashing modes during operation: The first is conventional backwashing: usually once every 30 minutes, the added agent is sodium hypochlorite; The second is chemical cleaning: generally once every 24 hours, chemical cleaning is divided into acid cleaning and alkaline cleaning.

4. The method for treating sewage by double membrane method according to claim 3, characterized in that: Citric acid is added for pickling, and sodium hydroxide and sodium hypochlorite are added for alkaline washing.

5. The method for treating sewage by double membrane method according to claim 1, characterized in that: After each set of reverse osmosis has been running for a period of time, chemical cleaning is carried out according to the changes in the reverse osmosis operating parameters.

6. The method for treating sewage by double membrane method according to claim 5, characterized in that: The chemical cleaning is divided into alkali cleaning and acid cleaning, wherein the reagents added for alkali cleaning are sodium polyphosphate, sodium dodecyl benzoate and sodium hydroxide, and the reagent added for acid cleaning is citric acid.

7. The method for treating sewage by double membrane method according to claim 1, characterized in that: The sludge water discharged from the high-density sedimentation tank passes through a sludge concentration tank and a plate and frame filter, and finally the sludge cake is transported out.