CN117209094A - Printing and dyeing wastewater treatment process - Google Patents

Abstract

The application relates to a printing and dyeing wastewater treatment process, which comprises the following process steps: waste water is collected, and the waste water generated in the printing and dyeing process is collected and mixed; waste water is regulated, and the pH value of the mixed waste water is neutralized and regulated; air floatation flocculation, adding an air floatation flocculating agent into the mixed wastewater to obtain air floatation wastewater, and conveying floating sludge to a sludge pond for collection; separating mud and water, and precipitating and filtering the air-float wastewater in a separation tank; anaerobic treatment, namely placing the sludge-removed wastewater in an anaerobic tank, and adding an anaerobic microbial agent to obtain anaerobic treatment wastewater; aerobic treatment, namely aerating and oxygenating anaerobic treatment wastewater in an aeration tank; settling flocculation treatment, namely adding a settling flocculant into the aerobic treatment wastewater to obtain settling wastewater, and sending and collecting sludge; ozone treatment, namely, enabling the supernatant to be in contact reaction with ozone gas in an ozone tank to obtain supernatant; sand filtering, filtering the supernatant in a sand filter, and delivering the obtained reclaimed water into a reuse pond. The application has the advantage of better benefit effect on printing and dyeing wastewater.

Description

A printing and dyeing wastewater treatment process

Technical field

This application relates to the technical field of wastewater treatment, and in particular to a printing and dyeing wastewater treatment process.

Background technique

Printing and dyeing wastewater is wastewater generated and discharged during printing and dyeing, mainly processing cotton, linen, fiber and blended products. The printing and dyeing industry consumes a very large amount of water, and 80-90% of the production water becomes printing and dyeing wastewater. In addition to acids and alkalis, the various dyes and chemical pulps used in printing and dyeing wastewater will produce a large amount of organic materials that are difficult to biodegrade and have poor biodegradability in the wastewater. Moreover, the printing and dyeing wastewater has a high content of organic pollutants, high alkalinity, and chemical impurities. It is a kind of industrial wastewater that is difficult to treat. In the actual treatment of various printing and dyeing wastewater, printing and dyeing wastewater contains dyes, slurries, additives, oils, acids and alkalis, fiber impurities, and sand substances. , inorganic salts, etc.

The existing technology for the treatment of printing and dyeing wastewater or the treatment methods and treatment processes currently configured and implemented in the printing and dyeing industry basically adopt a unified multi-process collection method. When the printing and dyeing wastewater is treated in a single beat process, or the printing and dyeing wastewater is processed in In a single-beat treatment tank, multiple methods are implemented at the same time or in time intervals. It is basically difficult for printing and dyeing wastewater treated in similar ways to make the polluting impurities contained in the printing and dyeing wastewater reach the point where it can be recycled and reused as industrial water. index of,

For example, the Chinese invention patent application with announcement number CN111943447B discloses a treatment process for printing and dyeing wastewater, which specifically includes the following steps: S1. Collect wastewater, that is, collect the printing and dyeing wastewater generated from different processes in the printing and dyeing process into a regulating tank. Mix to obtain mixed wastewater; S2, air flotation flocculation, that is, transport the mixed wastewater in step S1 to the air flotation tank, add air flotation flocculant to obtain air flotation wastewater, and transport the floating sludge to the sludge tank; S3, biochemical treatment , that is, transporting the flotation wastewater in step S2 to the biochemical treatment tank for biochemical treatment to obtain biochemical treatment wastewater; S4, sedimentation flocculation, that is, transporting the biochemical treatment wastewater in step S3 to the sedimentation tank, and adding sedimentation flocculant to obtain sedimentation wastewater , transport the sinking sludge to the sludge tank; S5, post-processing, that is, take the precipitated wastewater in step S4 and perform post-processing to obtain post-treatment wastewater.

Regarding the above-mentioned related technologies, the inventor believes that there are the following shortcomings: it is difficult to fully meet the different needs of printing and dyeing wastewater during implementation through collective S3 and biochemical treatment to achieve anaerobic treatment, aerobic treatment, and ozone treatment of printing and dyeing wastewater. Property impurities cannot achieve good treatment results.

Contents of the invention

In order to solve the above problems, this application provides a printing and dyeing wastewater treatment process, which includes the following process steps: S1. Wastewater collection, collect the wastewater generated during the printing and dyeing process into a regulating tank to obtain mixed wastewater; S2. Wastewater conditioning, mix the wastewater The wastewater is neutralized and adjusted to obtain pH-neutralized wastewater; S3, air flotation flocculation, transports the mixed wastewater to the air flotation tank, adds air flotation flocculant, obtains air flotation wastewater, and transports the floating sludge to the sludge tank. Collect sludge in the process; S4. Separation of mud and water, transport the flotation wastewater to the mud-water separation tank for sedimentation and filtration, and obtain desilting wastewater; S5. Anaerobic treatment, transport the desilting wastewater to the anaerobic tank, and add anaerobic Bacteria are used to obtain anaerobic wastewater; S6, aerobic treatment, transport the anaerobic wastewater to the aeration tank for aeration and oxygenation, and obtain aerobic wastewater; S7, sedimentation and flocculation treatment, transport the aerobic wastewater to In the sedimentation tank, sedimentation wastewater is obtained after adding sedimentation flocculant, and the sinking sludge is transported to the sludge tank for collection; S8, ozone treatment, the supernatant liquid is contacted and reacted with ozone gas in the ozone tank to obtain supernatant water; S9, For sand filtration treatment, the supernatant water is transported to the sand filter tank. The sand filtration treatment system is used for sand filtration to obtain reusable gray water and send it to the reuse tank. This application has the advantage of better treatment effect on printing and dyeing wastewater.

A printing and dyeing wastewater treatment process provided by this application adopts the following technical solution:

A printing and dyeing wastewater treatment process specifically includes the following process steps:

S1. Wastewater collection. The printing and dyeing wastewater generated from different processes in the printing and dyeing process is collected uniformly into the regulating tank for mixing to obtain mixed wastewater;

S2. Wastewater adjustment: neutralize and adjust the pH value of the mixed wastewater in step S1 in the adjustment tank to obtain wastewater with neutralized pH value;

Mix and dilute the mixed wastewater in the regulating tank to obtain wastewater with reduced concentration;

Adjust the oxidation and reduction of the mixed wastewater in the conditioning tank, convert the pollutants in the printing and dyeing wastewater into simple compounds, and remove the dyes in the printing and dyeing wastewater;

S3, air flotation flocculation, transport the mixed wastewater adjusted in step S2 to the air flotation tank, add air flotation flocculant, and mix the air flotation flocculant with the mixed wastewater;

Air is injected to generate bubbles, which come into contact with the flocculated suspended solids and floating solids and bring them to the liquid surface to obtain air-floating sludge. The floating sludge is transported to the sludge tank for sludge collection;

S4. Separate mud and water. Transport the flotation wastewater in step S3 to the mud and water separation tank for sedimentation and filtration to obtain desilting wastewater;

The suspended solids and particulate matter separated from the air flotation wastewater after solid-liquid separation are obtained to obtain the original sludge. Collect and isolate through physical methods of precipitation, filtration, and centrifugation;

S5. Anaerobic treatment: transport the desilting wastewater in step S4 to an anaerobic tank, add anaerobic bacteria, and subject the desilting wastewater to anaerobic treatment to obtain anaerobic treatment wastewater;

The gas generated by the anaerobic bacteria decomposing organic matter is collected and discharged through external pipelines;

The dissolved matter and sediment produced by the decomposition of organic matter by the anaerobic bacteria are transported into the pipeline of the desilting wastewater in step S4 and transported to the transport pipe of the anaerobic tank;

S6. Aerobic treatment, transport the anaerobic treatment wastewater in step S5 to the aeration tank;

An aerator is provided in the aeration tank. The aerator stirs and aerates the anaerobic wastewater to continuously generate bubbles and absorb oxygen in the anaerobic wastewater;

Add aerobic bacteria to the aeration tank to aerobically treat the anaerobic wastewater to obtain aerobic wastewater;

S7. Sedimentation and flocculation treatment, transport the aerobic treatment wastewater in step S6 to the sedimentation tank;

That is, transporting the aerobic treatment wastewater in step S6 to the sedimentation tank, adding sedimentation flocculant to obtain sedimentation wastewater, transporting the sinking sludge to the sludge tank, and collecting the sludge;

S8. Ozone treatment, transport the supernatant obtained after the sedimentation and flocculation treatment in step S7 to the ozone tank;

The ozone gas generated by the ozone generator can be transported to the ozone pool through the delivery system;

The ozone gas contacts and reacts with the supernatant liquid to be treated in the ozone tank;

After ozone treatment, the sediments and oxidation products produced in the ozone tank are precipitated through the sedimentation tank at the bottom of the ozone tank, and solid-liquid separation is performed through physical precipitation, filtration, centrifugation, etc., and the supernatant water is obtained in the ozone tank;

S9. Sand filtration treatment, transport the supernatant water obtained after the ozone treatment in step S8 to the sand filter;

The sand filter is equipped with a sand filter treatment system;

A water storage tank is provided at the lower end of the sand filter treatment system of the sand filter tank. After the supernatant water is filtered through sand filtration, the gray water obtained flows into the water storage tank for collection. The external pipeline of the water storage tank is connected to the reuse tank;

S10. Reuse of reclaimed water. The reclaimed water in step S9 is collected in a reuse tank for reclaimed water reuse.

By adopting the above technical solution, wastewater from different processes in the printing and dyeing process is collected and mixed, and then neutralized and adjusted for pH, and then air flotation flocculation is used to use small bubbles as carriers to absorb and float the polluting impurities in the flocculation areas of the printing and dyeing wastewater. After initial treatment, mud-water separation, anaerobic treatment, aerobic treatment, sedimentation and flocculation treatment, ozone treatment, and sand filtration treatment are implemented step by step. The step-by-step wastewater treatment stage sedimentation and filtration of the air flotation wastewater in the separation tank, and then The organic matter in the wastewater is degraded by anaerobic microorganisms. The degraded organic matter is metabolized and degraded by aerobic microorganisms in an aerobic environment, converting the organic matter into carbon dioxide, water and biological substances. The efficient oxidation ability of ozone is widely used. The application range of the spectrum can effectively remove organic matter, heterochromatic substances and microorganisms in wastewater, improve the water quality and environmental impact of wastewater, and then send it to the sand filter for sand filtration. The gray water obtained is sent to the reuse tank and used in The fixed-point treatment method corresponding to the impurity population contained in a single section of sewage, the subtractive method, and the single-step corresponding treatment of a single section of sewage, so that all indicators of the treated reused reclaimed water can meet the discharge requirements of the reuse association.

Optionally, the mud-water separation tank in step S4 is equipped with an air flotation wastewater sedimentation bin, a filter device for solid-liquid separation, a centrifugal dehydration device, an original sludge isolation bin, and a desludge wastewater bin.

By adopting the above technical solution, the solid particles suspended in the wastewater settle to the bottom through gravity, thereby achieving mud-water separation. This can speed up the sedimentation process by adding a precipitant to the wastewater. Commonly used precipitants include polymeric iron, polymeric aluminum, etc. Once the solid particles settle to the bottom, various methods can be used to separate the supernatant liquid and the mud layer; filter media can also be used to intercept the solid particles in the wastewater and allow water to pass through to achieve mud-water separation.

Optionally, the anaerobic tank in step S5 is a closed container, and the anaerobic tank is connected to the anaerobic agent input device through an interface;

The anaerobic bacteria agent includes one or several types of methane bacteria, pseudomonas, lactic acid bacteria, yeast, and denitrifying bacteria.

By adopting the above technical solution, the anaerobic microorganisms decompose the organic matter in the desludging wastewater and convert it into dissolved matter and sediment in a suitable anaerobic environment for the desludging wastewater. The generated methane or carbon dioxide is discharged through special pipelines. Or collect, effectively treat high-concentration organic wastewater, and also produce renewable energy such as methane and lower consumption.

Optionally, the aeration tank in step S6 is an open container, and several aerators are installed in the aeration tank. The aerator is located at the liquid level of the anaerobic treatment wastewater in the aeration tank. The aerator The stirring blade is located under the liquid surface of the anaerobic treatment wastewater;

The aerobic bacteria added and used in the aeration tank include aerobic bacteria, aerobic fungi, biofilm bacteria and composite bacteria;

The aerobic bacterial agent includes nitrite-oxidizing bacteria, nitric acid-oxidizing bacteria, nitrifying bacteria; Bacillus, yeast, Micrococcus, Nitrosomonas, Nitrobacter, Pseudomonas, and Acinetobacter.

By adopting the above technical solution, an aerator is used to provide sufficient oxygen and suspension conditions for the anaerobically treated wastewater under the conditions of aeration, oxygenation and stirring. The aeration supplies aerobic bacteria through the blowing and diffusion of air. Agents, aerobic microbial respiration, and biodegradation and oxidation reactions, converting the organic matter reserved in the sewage into relatively simple compounds to achieve the purification function, the treatment effect is stable, the treatment time is relatively short, and the operation is relatively simple.

Optionally, the sedimentation flocculant added to the sedimentation tank in step S7 includes one or several types of inorganic flocculants, organic flocculants, and organic-inorganic composite flocculants.

By adopting the above technical solution and adding the sedimentation flocculant, the sedimentation flocculant interacts with the suspended solids and colloidal substances in the wastewater to form larger flocs. Flocs can be formed through physical effects including adsorption, aggregation and bridging, which aggregate fine suspended solids and colloidal substances into larger clumps for subsequent precipitation. After coagulation and flocculation, the flocs in the wastewater become It is larger and heavier and has enough mass to settle.

Clear and solid-liquid separation: After the precipitation process, the flocs that settle to the bottom form a clear supernatant. The supernatant can be collected through the upper overflow tank or water outlet. Solid-liquid separation can be carried out by physical methods, such as precipitation, filtration or centrifugation. Through solid-liquid separation, suspended solids in wastewater can be separated from the supernatant to achieve the purpose of purifying wastewater.

Optionally, the ozone input pipeline of the ozone pool in step S8 is connected to an external ozone generator, and the ozone gas input into the ozone pool contacts and reacts with the wastewater to be treated. The contact method includes bubble aeration, gas diffusion, In the spray contact method, ozone reacts with organic matter in the wastewater to cause oxidation, causing the organic matter to decompose into simple compounds.

By adopting the above technical solution, ozone and wastewater are fully mixed. During the contact process, ozone undergoes an oxidation reaction with the organic matter in the wastewater, causing it to decompose into simpler compounds.

Optionally, a sand filter treatment system is laid in the sand filter in step S9. The sand bed in the sand filter treatment system is composed of sand layers of different particle sizes. Coarse sand is arranged in sequence according to the direction in which the supernatant water enters. , medium sand and fine sand.

By adopting the above technical solution, water enters evenly from the top of the sand bed and is filtered through the penetration and filtration of the sand layer. When passing through the sand bed, suspended solids, colloids, microorganisms, etc. will be absorbed by various species in the sand layer. Mechanical removal, such as precipitation, adsorption, interception, etc.

Optionally, the air flotation flocculant used in step S3 is inorganic, including polyaluminum chloride, iron salt or aluminum salt;

0.4-3.5 parts of polyaluminum chloride per 1000 parts of water;

For every 1000 parts of water, 0.4-5.5 parts of iron salt or aluminum salt.

By adopting the above technical solution, the polyaluminum ferric chloride added to the wastewater can be hydrolyzed into multinuclear polymeric hydroxyl complex ions, and electrically neutralize, adsorb, and sweep up the suspended colloids in the wastewater, and the flocs float.

In addition, because iron salts or aluminum salts are added to the air flotation flocculant, they can form struvite with phosphorus and ammonia nitrogen in the wastewater, and can also decolorize the water, thereby greatly reducing the processing pressure during subsequent treatment.

Optionally, the precipitation flocculation treatment in step S7 adds precipitation flocculants including polyaluminum chloride (PAC) and aluminum sulfate;

0.4-3.5 parts polyaluminum chloride (PAC) per 1000 parts water;

0.5-4 parts polyferric chloride (PCl) per 1000 parts water;

150-200 parts aluminum sulfate per 1000 parts water.

By adopting the above technical solutions, the agglomeration and precipitation of suspended solids and colloidal substances can be effectively agglomerated, and the color in wastewater can be removed. Some sedimentation flocculants can coagulate and aggregate suspended solids and colloidal particles in water treatment and wastewater treatment. It forms larger agglomerates, making them easy to settle and separate, achieving water purification and solid-liquid separation.

To sum up, this application includes at least one of the following beneficial technical effects:

1. Comprehensive treatment effect: This application uses a series of process steps to comprehensively treat printing and dyeing wastewater, including adjusting the pH of wastewater, redox adjustment, air flotation flocculation, mud water separation, anaerobic treatment, aerobic treatment, sedimentation flocculation treatment, Ozone treatment, sand filter treatment, etc. This comprehensive treatment method can effectively remove pollutants and dyes in wastewater and achieve high treatment effects.

2. Wastewater reuse: This application introduces the step of reclaimed water, collecting and storing the treated supernatant water in a reuse pool for reuse. This method of resource reuse can reduce the demand for natural water resources, save water resources, and also reduce the impact of wastewater discharge on the environment.

3. Sludge treatment and utilization: In the mud-water separation process, this application sets up facilities such as air flotation wastewater sedimentation bins, solid-liquid separation filtering devices, centrifugal dehydration devices, original sludge isolation bins, and desilting wastewater bins. The separated sludge is processed and collected. This treatment method can effectively treat and reduce the sludge generated, and facilitates the subsequent treatment and utilization of sludge.

4. Use a variety of bacteria and flocculants: Different types of bacteria and flocculants are used in this application, including anaerobic bacteria, aerobic bacteria and sedimentation flocculants. The use of these bacterial agents and flocculants can accelerate the degradation of organic matter and the removal of pollutants in wastewater, and improve the treatment efficiency and water purification effect.

5. Bubble aeration and ozone treatment: This application introduces the method of bubble aeration and ozone gas contact reaction in the aerobic treatment and ozone treatment steps. This treatment method can increase the contact area of the gas-liquid interface, promote the dissolution of oxygen and the oxidative decomposition of organic matter, and improve the purification effect of wastewater.

The printing and dyeing wastewater treatment method of this application adopts comprehensive treatment, resource recycling, sludge treatment and utilization, the use of a variety of bacterial agents and flocculants, as well as bubble aeration and ozone treatment and other technical means, which has high treatment effect and is environmentally friendly. sex.

Description of drawings

Figure 1 is a process flow diagram of the wastewater treatment method in Embodiment 1 of the present application.

Figure 2 is a hardware connection diagram of the wastewater treatment method in Embodiment 1 of the present application.

Detailed ways

The present application will be further described in detail below in conjunction with Figures 1-2.

Embodiment 1

As shown in Figures 1 and 2, the embodiment of the present application discloses a printing and dyeing wastewater treatment process, which specifically includes the following process steps:

S1. Wastewater collection. The printing and dyeing wastewater generated from different processes in the printing and dyeing process is collected uniformly into the regulating tank for mixing to obtain mixed wastewater;

S2. Wastewater adjustment: neutralize and adjust the pH value of the mixed wastewater in step S1 in the adjustment tank to obtain wastewater with neutralized pH value;

Mix and dilute the mixed wastewater in the regulating tank to obtain wastewater with reduced concentration;

Adjust the oxidation and reduction of the mixed wastewater in the conditioning tank, convert the pollutants in the printing and dyeing wastewater into simple compounds, and remove the dyes in the printing and dyeing wastewater;

S3, air flotation flocculation, transport the mixed wastewater adjusted in step S2 to the air flotation tank, add air flotation flocculant, and mix the air flotation flocculant with the mixed wastewater;

Air is injected to generate bubbles, which come into contact with the flocculated suspended solids and floating solids and bring them to the liquid surface to obtain air-floating sludge. The floating sludge is transported to the sludge tank for sludge collection;

S4. Separate mud and water. Transport the flotation wastewater in step S3 to the mud and water separation tank for sedimentation and filtration to obtain desilting wastewater;

The suspended solids and particulate matter separated from the air flotation wastewater after solid-liquid separation are obtained to obtain the original sludge. Collect and isolate through physical methods of precipitation, filtration, and centrifugation;

S5. Anaerobic treatment: transport the desilting wastewater in step S4 to an anaerobic tank, add anaerobic bacteria, and subject the desilting wastewater to anaerobic treatment to obtain anaerobic treatment wastewater;

The gas generated by the anaerobic bacteria decomposing organic matter is collected and discharged through external pipelines;

The dissolved matter and sediment produced by the decomposition of organic matter by the anaerobic bacteria are transported into the pipeline of the desilting wastewater in step S4 and transported to the transport pipe of the anaerobic tank;

S6. Aerobic treatment, transport the anaerobic treatment wastewater in step S5 to the aeration tank;

An aerator is provided in the aeration tank. The aerator stirs and aerates the anaerobic wastewater to continuously generate bubbles and absorb oxygen in the anaerobic wastewater;

Add aerobic bacteria to the aeration tank to aerobically treat the anaerobic wastewater to obtain aerobic wastewater;

S7. Sedimentation and flocculation treatment, transport the aerobic treatment wastewater in step S5 to the sedimentation tank;

That is, transporting the aerobic treatment wastewater in step S6 to the sedimentation tank, adding sedimentation flocculant to obtain sedimentation wastewater, transporting the sinking sludge to the sludge tank, and collecting the sludge;

S8. Ozone treatment, transport the supernatant obtained after the sedimentation and flocculation treatment in step S7 to the ozone tank;

The ozone gas generated by the ozone generator can be transported to the ozone pool through the delivery system;

The ozone gas contacts and reacts with the supernatant liquid to be treated in the ozone tank;

After ozone treatment, the sediments and oxidation products produced in the ozone tank are precipitated through the sedimentation tank at the bottom of the ozone tank, and solid-liquid separation is performed through physical precipitation, filtration, centrifugation, etc., and the supernatant water is obtained in the ozone tank;

S9. Sand filtration treatment, transport the supernatant water obtained after the ozone treatment in step S8 to the sand filter;

The sand filter is equipped with a sand filter treatment system;

A water storage tank is provided at the lower end of the sand filter treatment system of the sand filter tank. After the supernatant water is filtered through sand filtration, the gray water obtained flows into the water storage tank for collection. The external pipeline of the water storage tank is connected to the reuse tank;

S10. Reuse of reclaimed water. The reclaimed water in step S9 is collected in a reuse tank for reclaimed water reuse.

Through comprehensive treatment, resource recycling, sludge treatment and utilization, the use of a variety of bacterial agents and flocculants, as well as bubble aeration and ozone treatment and other technical means, this application corresponds to the impurity populations and categories contained in the sewage and has relatively high performance. High processing effect and environmental friendliness.

Embodiment 2

Referring to the wastewater adjustment in Figure 1, according to the nature of the printing and dyeing wastewater, the adjustment methods used include pH neutralization adjustment, mixing and dilution and redox adjustment, and the input of adjustment consumables is pretended to be connected to the adjustment pool;

Oxidation-reduction adjustment: neutralize the pH value of the mixed wastewater in the adjustment pool to achieve neutralization of pH, and add acidic or alkaline substances to adjust the pH value of the wastewater to make it close to the neutral range, usually pH 6-9 , through neutralization treatment, the effectiveness of subsequent treatment steps can be improved and the wastewater will not cause further damage to the environment;

Mixing and dilution: In the regulating tank, the mixed wastewater is mixed and diluted to evenly mix the pollutants in the wastewater, and dilute the concentration of the wastewater by adding a certain amount of clean water. Mixing and dilution help to improve the uniformity of wastewater treatment. performance and processing efficiency, and reduce the load on subsequent processing units;

Redox conditioning: In the conditioning tank, the mixed wastewater is subjected to redox conditioning to convert the pollutants in the printing and dyeing wastewater into simpler compounds, thereby reducing its impact on the environment. Redox conditioning uses oxidants or reducing agents to trigger chemical Reaction to decompose or convert organic pollutants in wastewater into less toxic compounds, and can also be used to remove dyes from wastewater to improve the quality of wastewater;

The purpose of the wastewater conditioning step is to purify the wastewater during the printing and dyeing wastewater treatment process to make it more in line with environmental discharge standards or reusability requirements. These treatment steps are the preliminary treatment steps in the entire printing and dyeing wastewater treatment system, providing information for subsequent treatment units. Better wastewater quality for more thorough treatment and purification.

Embodiment 3

Referring to Figure 2, the air flotation tank is made of corrosion-resistant materials such as fiberglass and stainless steel to ensure that it can withstand the chemical properties and operating conditions of the wastewater. The location and structure of the water inlet connecting the regulating tank must consider the uniform distribution and flow settings of the wastewater so that To achieve effective flocculation and separation, the air flotation tank is equipped with a mixing and regulating device, a mixing and flocculation area, and a scum collection system;

The mixing and adjusting device can pass through the reaction tank after the stirrer and spray system to achieve optimal treatment conditions before wastewater air flotation treatment;

Mixing and flocculation zone: In the air flotation flocculation tank, the wastewater is mixed and flocculated with the injected air bubbles. This area is usually achieved through mechanical stirring or a bubble dispersion system to ensure that the bubbles fully contact and interact with suspended solids and contaminants in the wastewater;

Scum collection system _: As the flocs form, the flocs will gather into larger clumps and rise to the liquid surface to form scum. The scum collection system includes devices such as scrapers, tilting plates or chain collectors, which are used to collect the scum. The scum is scraped off the liquid surface and collected from the external sludge pipe at the upper end of the air flotation tank, which is output into the sludge tank;

Referring to the air flotation flocculation in step S3 in Figure 2, the gas injection system: the air flotation flocculation tank needs to inject gas (usually air) to form tiny bubbles. Gas injection systems typically include gas nozzles, bubble generators, or gas dispersion systems to evenly distribute the gas throughout the wastewater

Referring to step S3 and air flotation flocculation in Figure 1, during implementation, the mixed wastewater adjusted in step S2 is transported to the air flotation tank, and the air flotation flocculant is added to mix the air flotation flocculant and the mixed wastewater;

Injecting air creates bubbles, which come into contact with the flocculated suspended solids and floating matter, and the bubbles come into contact with the flocs: Due to the buoyancy and adhesion properties of the bubbles, they will interact with suspended solids, suspended particles and pollutants in the wastewater. The bubbles will attach to the suspended solids and cause them to float to the surface of the liquid to form flocs. As the flocs grow, they will gather into larger clumps to form scum, which will be brought to the liquid surface to obtain air-floating sludge. The floating sludge will be transported to the sludge tank for sludge collection.

Embodiment 4

Referring to the mud-water separation tank in Figure 2, the main part is the tank body that contains sludge and water. It is usually made of corrosion-resistant materials and contains a sludge collection system and a sludge discharge device. In the mud-water separation tank, air flotation The flocculated sludge will settle to the bottom of the tank. The sludge collection system includes a sludge pit or sludge hopper for collecting and storing sludge. The sludge collection system usually includes a stirring device or a scraper to promote the sludge. deposition and concentration;

Sludge discharge device: In order to remove accumulated sludge in time, a sludge discharge device is installed in the mud-water separation tank. This can be a sludge pump, screw conveyor or other type of sludge conveying device used to remove sludge from the bottom of the tank;

The mud-water separation tank is equipped with an overflow port to control water level and flow. Excess water is drained from the system through the overflow port to maintain a stable water level in the pool.

Embodiment 5

Referring to Figure 2, the anaerobic tank used for step S5 and anaerobic treatment is a closed container used to provide an anaerobic environment to promote microbial degradation of organic matter; the anaerobic tank is usually made of corrosion-resistant materials such as concrete or fiberglass. And has a certain thermal insulation performance. A stirring device is usually installed inside the pool to promote the contact and mixing of wastewater and microorganisms. The desilted wastewater in step S4 is transported to the anaerobic pool, and anaerobic bacteria are added to make it Conduct anaerobic treatment of desilting wastewater to obtain anaerobic treated wastewater;

Referring to the anaerobic treatment in step S5 of the anaerobic treatment in Figure 1, in order to promote the degradation of wastewater, it is usually necessary to add appropriate microbial inoculum to the anaerobic tank. These inoculants can be specific anaerobic bacteria or complex inoculants, which have strong degradation capabilities. Microbial inoculation is usually added to the water inlet system and evenly distributed into the anaerobic tank through a stirring device. The wastewater contacts the microorganisms and undergoes a mixing reaction. Anaerobic bacteria decompose organic matter under anaerobic conditions to produce methane and other combustible gases and water. The operation of the stirring device during the mixing process can maintain the uniform distribution of wastewater in the pool and promote the contact between microorganisms and wastewater.

The gas generated by the decomposition of organic matter by anaerobic bacteria is collected and discharged through external pipelines; the dissolved matter and sediment produced by the decomposition of organic matter by anaerobic bacteria are transported through pipelines to the desilting wastewater in step S4 and transported to the anaerobic tank. in the tube;

The sludge produced in anaerobic tanks needs to be treated. There are usually two treatment methods; one is internal circulation, in which the sludge generated in the return part flows back to the anaerobic tank to increase the degradation ability of the sludge and maintain good microbial activity; the other is sludge dehydration, which uses centrifugation Machines and filter presses are used to dewater the sludge and reduce the moisture content to facilitate subsequent processing and disposal.

After anaerobic treatment, the wastewater produces lower concentrations of organic pollutants and products in anaerobic tanks. The water outlet system is used to discharge the treated water from the anaerobic tank for further subsequent aerobic treatment.

Embodiment 6

Referring to the aeration tank in step S6 of the aerobic treatment in Figure 2, the aeration tank is an open container. There are several aerators in the aeration tank. The aerator is located at the liquid level of the anaerobic treatment wastewater in the aeration tank. The stirring blade of the machine is located under the liquid surface of the anaerobic treatment wastewater;

The aerobic bacteria added to the aeration tank include aerobic bacteria, aerobic fungi, biofilm bacteria and compound bacteria. The aerator is used to make the anaerobically treated wastewater aerate, oxygenate and stir. Under certain conditions, sufficient oxygen and suspension conditions are provided. Through the blowing and diffusion of air, aeration supplies aerobic bacteria and aerobic microorganisms for respiration, and performs biodegradation and oxidation reactions, converting the organic matter reserved in the sewage into Relatively simple compounds achieve the function of purification, with stable treatment effects, relatively short treatment times, and relatively simple operations.

Embodiment 7

Referring to the sedimentation tank where step S7 wastewater sedimentation and flocculation treatment is performed in Figure 2, the sedimentation flocculant is added, and the sedimentation flocculant interacts with the suspended solids and colloidal substances in the wastewater in the sedimentation tank to form larger flocs. Flocs can be formed through physical effects including adsorption, aggregation and bridging, which aggregate fine suspended solids and colloidal substances into larger clumps for subsequent precipitation. After coagulation and flocculation, the flocs in the wastewater become It is larger and heavier, and has enough mass to make it settle. The sinking sludge is transported to the sludge tank and the sludge is collected.

Embodiment 8

Referring to Figure 2 and Figure 1, in the ozone pool where wastewater step S8 ozone treatment is performed, the ozone gas generated by the external ozone generator can be transported to the ozone pool through the transportation system, and the ozone gas comes into contact with the supernatant liquid to be treated in the ozone pool. reaction, which can effectively remove organic pollutants, colors and odors,

The effect of ozone treatment is closely related to the reaction time. A longer reaction time can provide more time for ozone to react with pollutants in wastewater, thereby increasing the treatment effect. The reaction time is usually controlled by adjusting the entry rate and mixing of ozone gas. With the design of the contact device, when ozone comes into contact with organic pollutants, an oxidative degradation reaction will occur, decomposing the organic matter into smaller harmless substances. Ozone treatment can effectively remove dyes, organic solvents and other refractory organic pollutants in printing and dyeing wastewater.

After ozone treatment, the sediments and oxidation products produced in the ozone tank are precipitated through the sedimentation tank at the bottom of the ozone tank, and solid-liquid separation is performed through physical precipitation, filtration, centrifugation, etc., and the supernatant water is obtained in the ozone tank;

After ozone treatment, the treated supernatant water is discharged through the water outlet system and sent to the sand filter.

Embodiment 9

Referring to Figure 2, the sand filter for performing wastewater step S9 and sand filtration treatment is equipped with a sand filter treatment system. The lower end of the sand filter treatment system is equipped with a water storage tank. After the super clear water is sand filtered, the gray water obtained flows into the water storage tank for collection. The external pipeline of the water storage tank is connected back to the water tank. use pool;

A sand filter is a container with multiple layers of filter media, usually made of concrete or fiberglass. The upper part of the sand filter is usually equipped with a water inlet pipe and distributor to evenly distribute wastewater to the sand layer;

The sand layer in the sand filter is a key component to achieve the filtration effect. The sand layer is usually composed of quartz sand of different particle sizes and has a gradually finer hierarchical structure, which helps to capture suspended solids and color substances in the wastewater while maintaining Higher flow rate and low pressure loss;

Filtration process: Wastewater enters the sand filter through the water inlet pipe and is filtered through the sand layer. During the sand filtration process, suspended solids, color substances and some organic matter in the wastewater are intercepted by the sand layer and form a filter layer; filtration During the process, the flow rate of wastewater will gradually decrease, thereby increasing the capture efficiency of solid particles and color substances;

After sand filtration, the treated water is discharged from the sand filter. The water outlet system usually includes outlet pipes, water tanks and disinfection equipment. The disinfection equipment uses ultraviolet lamps to ensure that the effluent meets environmental discharge standards or reuse requirements;

A backwash device can be installed at the bottom of the sand layer. Pressure clean water is input from the outlet pipe of the sand filter. The pressure clean water backwashes the sand layer in the opposite direction to backwash out the solid particles and colored substances accumulated in the sand layer. , the backwashed mixed wastewater is output from the external drain port of the sand filter and sent into the collection container.

Example 10

Referring to the reclaimed water reuse in step S10 in Figure 1, the reclaimed water in step S9 is collected in the reuse pool for reclaimed water reuse, including greening spray, cooling water for printing and dyeing operations, etc., to achieve repeated reuse of water resources. And save energy and reduce emissions.

The implementation principle of a printing and dyeing wastewater treatment process in the embodiment of this application is:

S1. Wastewater collection. The printing and dyeing wastewater generated from different processes in the printing and dyeing process is collected uniformly into the regulating tank for mixing to obtain mixed wastewater.

S2. Wastewater adjustment: neutralize the pH value of the mixed wastewater in step S1 in the adjustment tank to obtain wastewater with neutral pH value. Mix and dilute the mixed wastewater in the adjustment tank to obtain wastewater with reduced concentration; The mixed wastewater redox adjustment in the regulating tank converts the pollutants in the printing and dyeing wastewater into simple compounds and removes the dyes in the printing and dyeing wastewater.

S3. Air flotation flocculation, transport the mixed wastewater adjusted in step S2 to the air flotation tank, add air flotation flocculant to mix the air flotation flocculant with the mixed wastewater; inject air to generate bubbles, and the bubbles will mix with the flocculated suspended matter and floating matter. The objects come into contact and are brought to the liquid surface to obtain air-floating sludge. The floating sludge is transported to the sludge tank for sludge collection.

S4. Separation of mud and water. Transport the air flotation wastewater in step S3 to the mud and water separation tank for sedimentation and filtration to obtain desilted wastewater; the suspended solids and particulate matter separated from the air flotation wastewater after solid-liquid separation are used to obtain the original sludge. Collect and isolate through physical methods of precipitation, filtration, and centrifugation.

S5. Anaerobic treatment: transport the desilting wastewater in step S4 to an anaerobic tank, add anaerobic bacteria to cause the desilting wastewater to undergo anaerobic treatment, and obtain anaerobic treatment wastewater; the anaerobic bacteria decompose organic matter to produce The gas is collected and discharged through external pipelines; the dissolved matter and sediment produced by the decomposition of organic matter by the anaerobic bacteria are transported through the pipeline into the desilting wastewater in step S4 and transported to the transportation pipe of the anaerobic tank.

S6. Aerobic treatment, transport the anaerobic treatment wastewater in step S5 to the aeration tank;

An aerator is installed in the aeration tank. The aerator stirs and aerates the anaerobic wastewater to continuously generate bubbles and absorb oxygen in the anaerobic wastewater. Aerobic bacteria are added to the aeration tank. The anaerobic treatment wastewater is subjected to aerobic treatment to obtain aerobic treatment wastewater.

S7, sedimentation flocculation treatment, transport the aerobic treatment wastewater in step S6 to the sedimentation tank; that is, transport the aerobic treatment wastewater in step S6 to the sedimentation tank, add sedimentation flocculant to obtain sedimentation wastewater, and remove the sinking sludge Transport it to the sludge tank and collect the sludge.

S8. Ozone treatment, transport the supernatant obtained after the sedimentation and flocculation treatment in step S7 to the ozone pool; the ozone gas generated by the ozone generator can be transported to the ozone pool through the transport system; the ozone gas and the ozone pool to be treated The supernatant liquid undergoes contact reaction; after ozone treatment, the sediment and oxidation products produced in the ozone tank are precipitated through the sedimentation tank at the bottom of the ozone tank, and solid-liquid separation is performed through physical precipitation, filtration, centrifugation, etc., and the supernatant water is obtained in the ozone tank .

S9. Sand filter treatment, transport the supernatant water obtained after the ozone treatment in step S8 to the sand filter;

A sand filter processing system is installed inside the sand filter; a water storage tank is installed at the lower end of the sand filter processing system of the sand filter. After the supernatant is filtered through sand filtration, the gray water obtained flows into the water storage tank for collection. The external pipeline of the water storage tank is connected to the reuse tank.

S10. Reuse of reclaimed water. The reclaimed water in step S9 is collected in the reuse pool for reclaimed water reuse.

By adopting the above technical solution, wastewater from different processes in the printing and dyeing process is collected and mixed, and then neutralized and adjusted for pH, and then air flotation and flocculation are used to allow small bubbles to be used as carriers to absorb and float polluting impurities in the flocculation areas of the printing and dyeing wastewater. , achieved initial treatment, and then implemented step-by-step mud-water separation, anaerobic treatment, aerobic treatment, sedimentation and flocculation treatment, ozone treatment, and sand filtration treatment. The step-by-step wastewater treatment staged the flotation wastewater to sediment and filter in the separation tank. , the organic matter in the wastewater is degraded by anaerobic microorganisms. The degraded organic matter is metabolized and degraded by aerobic microorganisms in an aerobic environment, and the organic matter is converted into carbon dioxide, water and biological substances. The efficient oxidation ability of ozone , broad spectrum application range, effectively remove organic matter, heterochromatic substances and microorganisms in wastewater, improve the water quality and environmental impact of wastewater, and then send it to the sand filter for sand filtration, and the gray water obtained is sent to the reuse tank. Adopt fixed-point treatment methods corresponding to the impurity populations contained in a single section of sewage, a subtractive method, and a single step corresponding to the corresponding treatment of a single section of sewage, so that all indicators of the treated reused reclaimed water can meet the discharge requirements of the reuse association.

The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application shall be covered by the scope of protection of the present application. Inside.

Claims (9)

1. The printing and dyeing wastewater treatment process is characterized by comprising the following steps of:

s1, collecting waste water, namely uniformly collecting printing and dyeing waste water generated in different working procedures in the printing and dyeing process into an adjusting tank for mixing to obtain mixed waste water;

s2, regulating the wastewater, namely neutralizing and regulating the pH value of the mixed wastewater in the step S1 in a regulating tank to obtain pH value and pH value neutralized wastewater;

mixing and diluting the mixed wastewater in the regulating tank to obtain wastewater with reduced concentration;

the mixed wastewater in the regulating tank is subjected to redox regulation, pollutants in the printing and dyeing wastewater are converted into simple compounds, and dyes in the printing and dyeing wastewater are removed;

s3, air floatation flocculation, namely conveying the mixed wastewater regulated in the step S2 into an air floatation tank, and adding an air floatation flocculant to mix the air floatation flocculant with the mixed wastewater;

injecting air to generate bubbles, enabling the bubbles to contact with flocculated suspended matters and bring the bubbles to the liquid surface, obtaining air-floating sludge, and conveying the floating sludge into a sludge tank for sludge collection;

s4, mud-water separation, namely conveying the air floatation wastewater in the step S3 into a mud-water separation tank for precipitation and filtration to obtain mud-removed wastewater;

suspended matters and particulate matters separated from the air-float wastewater after solid-liquid separation are collected and isolated by physical methods of precipitation, filtration and centrifugation;

s5, anaerobic treatment, namely conveying the sludge-removed wastewater in the step S4 into an anaerobic tank, and adding an anaerobic microbial agent to perform anaerobic treatment on the sludge-removed wastewater to obtain anaerobic treatment wastewater;

the gas generated by decomposing organic substances by anaerobic bacteria is collected and discharged through an external pipeline;

conveying a dissolved matter and a sediment pipeline generated by decomposing organic matters by anaerobic bacteria into the sludge-removing wastewater in the step S4, and conveying the sludge-removing wastewater into a conveying pipe of an anaerobic tank;

s6, carrying out aerobic treatment, and conveying the anaerobic treatment wastewater in the step S5 into an aeration tank;

an aerator is arranged in the aeration tank, and the aerator continuously generates bubbles and continuously absorbs oxygen in the anaerobic treatment wastewater in a stirring and aerating way;

an aerobic bacteria agent is added into the aeration tank to make anaerobic treatment wastewater undergo aerobic treatment to obtain aerobic treatment wastewater;

s7, sedimentation flocculation treatment, namely conveying the aerobic treatment wastewater in the step S6 into a sedimentation tank;

conveying the aerobic treatment wastewater in the step S6 into a sedimentation tank, adding a sedimentation flocculant to obtain sedimentation wastewater, conveying the settled sludge into a sludge tank, and collecting the sludge;

s8, carrying out ozone treatment, and conveying the supernatant obtained after the precipitation flocculation treatment in the step S7 into an ozone pool;

ozone gas generated by the ozone generator can be conveyed into the ozone pool through a conveying system;

carrying out contact reaction on ozone gas and supernatant to be treated in an ozone pool;

after ozone treatment, sediment and oxidation products generated in the ozone tank are precipitated through a precipitation tank at the bottom of the ozone tank, and solid-liquid separation such as physical precipitation, filtration, centrifugation and the like is carried out, so that supernatant water is obtained in the ozone tank;

s9, sand filtering treatment, namely conveying the supernatant obtained after the ozone treatment in the step S8 into a sand filter;

a sand filter treatment system is arranged in the sand filter;

the lower end of the sand filtering treatment system of the sand filtering pond is provided with a water storage bin, the supernatant water is filtered by the sand to obtain reclaimed water, the reclaimed water flows into the water storage bin for collection, and the water storage bin is externally connected with a pipeline and is communicated with a recycling pond;

s10, recycling the reclaimed water, wherein the reclaimed water in the step S9 is collected in a recycling pool for recycling the reclaimed water.

2. A process for treating printing and dyeing wastewater as claimed in claim 1, wherein: and the sludge-water separation tank in the step S4 is internally provided with an air floatation wastewater precipitation bin, a solid-liquid separation filtering device, a centrifugal dehydration device, a raw sludge isolation bin and a sludge removal wastewater bin.

3. A process for treating printing and dyeing wastewater as claimed in claim 1, wherein: the anaerobic tank in the step S5 is a closed container and is communicated with an anaerobic microbial agent input device through an interface;

the anaerobic bacteria agent comprises one or a plurality of methane bacteria, pseudomonas, lactobacillus, saccharomycetes and denitrifying bacillus.

4. A process for treating printing and dyeing wastewater as claimed in claim 1, wherein: the aeration tank in the step S6 is an open container, a plurality of aeration machines are arranged in the aeration tank, the aeration machines are positioned on the liquid level of anaerobic treatment wastewater in the aeration tank, and stirring blades of the aeration machines are positioned below the liquid level of anaerobic treatment wastewater;

the aerobic bacteria agent added in the aeration tank comprises an aerobic bacteria agent, an aerobic fungus agent, a biological film bacteria agent and a composite bacteria agent;

the aerobic bacterial agent comprises nitrous acid oxidizing bacteria, nitric acid oxidizing bacteria and nitrifying bacteria; bacillus, saccharomycetes, micrococcus, nitromonas, nitrifying bacillus, pseudomonas, acinetobacter.

5. A process for treating printing and dyeing wastewater as claimed in claim 1, wherein: the sedimentation flocculant added and used in the sedimentation tank in the step S7 comprises one or a plurality of inorganic flocculant, organic flocculant and organic-inorganic composite flocculant.

6. A process for treating printing and dyeing wastewater as claimed in claim 1, wherein: the ozone input pipeline of the ozone tank in the step S8 is communicated with an external ozone generator, ozone gas input into the ozone tank is in contact reaction with wastewater to be treated, the contact modes comprise a bubble aeration mode, a gas diffusion mode and a spraying contact mode, and the ozone is subjected to oxidation reaction with organic substances in the wastewater to decompose the organic substances into simple compounds.

7. A process for treating printing and dyeing wastewater as claimed in claim 1, wherein: and a sand filtering treatment system is paved in the sand filtering tank in the step S9, sand beds in the sand filtering treatment system are composed of sand layers with different particle sizes, and coarse sand, medium sand and fine sand are sequentially arranged according to the inlet direction of the supernatant water.

8. A process for treating printing and dyeing wastewater as claimed in claim 1, wherein: the air flotation flocculant used in the step S3 is inorganic matters, including polyaluminum chloride (PAC), ferric salt or aluminum salt;

0.4-3.5 parts of polyaluminum chloride (PAC) per 1000 parts of water;

0.4-5.5 parts of ferric salt or aluminum salt per 1000 parts of water.

9. A process for treating printing and dyeing wastewater as claimed in claim 1, wherein: the precipitation flocculation treatment in the step S7 adds a precipitation flocculant comprising polyaluminum chloride (PAC) and aluminum sulfate;

0.4-3.5 parts of polyaluminum chloride (PAC) per 1000 parts of water;

0.5-4 parts of polymeric ferric chloride (PCl) per 1000 parts of water;

150-200 parts of aluminum sulfate per 1000 parts of water.