CN101531440A - Printing and dyeing wastewater treatment method - Google Patents

Abstract

A method for treating printing and dyeing wastewater belongs to the technical field of printing and dyeing wastewater treatment, and comprises the following steps: the printing and dyeing wastewater is pre-adjusted and treated with water temperature, water volume and pH value by a pre-adjustment system; the printing and dyeing wastewater enters an ozone oxidation system for oxidation, ozone is introduced into the ozone oxidation system, and some high molecular organic matter in the printing and dyeing wastewater completes the ring-opening and bond-breaking process; the printing and dyeing wastewater enters a biochemical treatment system for biochemical treatment, and is treated by microorganisms to complete the hydrolysis, acidification, degradation and precipitation processes; the printing and dyeing wastewater enters an oxidation decolorization system, chlorine and ozone are introduced into the oxidation decolorization system to complete the oxidation decolorization process; the treated printing and dyeing wastewater meets the discharge standards. The present invention combines the advantages of both the ozone oxidation method and the biochemical method, and organically combines the two for the treatment of printing and dyeing wastewater, which can not only improve the effluent quality, but also achieve the purpose of energy saving.

Description

A kind of printing and dyeing wastewater treatment method

Technical field:

The invention belongs to the technical field of printing and dyeing wastewater treatment, and in particular relates to a method for treating printing and dyeing wastewater.

Background technique:

At present, printing and dyeing wastewater has the characteristics of large water volume, high content of organic pollutants, deep chroma, high alkalinity, and large changes in water quality. Moreover, there are various types of dyes used, and they are developing in the direction of anti-biological oxidation, which makes the treatment of printing and dyeing wastewater more difficult. bigger and bigger. Now the main treatment methods are ozone oxidation or biochemical method. As an advanced oxidation technology, ozone oxidation mainly utilizes the strong oxidizing properties of ozone, and ozone can decompose itself in a short period of time in water without secondary pollution. Ozone not only has a strong sterilizing effect, but also can use ozone to remove the chromaticity and refractory organic matter of dyes and printing and dyeing wastewater. Through the reaction of active hydroxyl radical OH with organic matter, the unsaturated bond in the dye chromogenic gene Fracture to generate small molecular weight and colorless organic acids, aldehydes, etc., to achieve the purpose of decolorization and degradation of organic matter. Molecular ozone has strong reaction selectivity and can directly add to double-bonded dyes to open rings and decolorize dyes, and improve the biochemical properties of wastewater. Although ozone has strong oxidizing properties, the cost of ozone treatment alone is high and the economy is poor. The biochemical method is mainly used in low-concentration sewage treatment and pretreatment of raw water micro-pollution, such as urban domestic sewage treatment and low-concentration industrial sewage treatment. It is a microbial contact growth system, through the absorption and degradation of microorganisms attached to the filler , oxidation, synthesis, etc., to remove biodegradable and soluble substances. However, the biochemical method can only remove biodegradable organic matter, and the treatment effect on wastewater containing refractory organic matter is often not good.

Invention content:

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a printing and dyeing wastewater treatment method that organically combines the ozone oxidation wastewater treatment method and the biochemical wastewater treatment method.

The purpose of the present invention is achieved through the following technical solutions:

A method for treating printing and dyeing wastewater, comprising the steps of:

a. The printing and dyeing wastewater is pre-adjusted by the pre-conditioning system for water temperature, water volume and PH value;

b. The printing and dyeing wastewater treated in step a enters the ozone oxidation system to be oxidized, and ozone is introduced into the ozone oxidation system, and part of the high molecular organic matter in the sewage completes the process of opening and breaking bonds;

c. After the oxidation treatment in step b, the printing and dyeing wastewater enters the biochemical treatment system for biochemical treatment, and is treated by microorganisms to complete the hydrolysis, acidification, degradation and precipitation processes;

d. The printing and dyeing wastewater treated in step c enters the oxidation decolorization system, and chlorine gas and ozone are introduced into the oxidation decolorization system to complete the oxidation decolorization process;

e. The treated printing and dyeing wastewater is discharged up to the standard.

Wherein the preconditioning system described in step a includes a front regulation pool, a cooling tower and a rear regulation pond; the front regulation pond, the cooling tower and the rear regulation pond are connected by pipelines in turn, and the printing and dyeing wastewater enters the preconditioning tank from the inlet of the front regulation pond system, the pre-regulation system flows out from the water outlet of the rear regulation pool.

Wherein, the ozone oxidation system described in step b is a pretreatment tank connected to an ozone generator pipeline, the pretreatment tank adopts a fully enclosed structure, and the water inlet of the pretreatment tank is connected to the water outlet of the preconditioning system by a pipeline.

Wherein the amount of ozone input into the ozone oxidation system is 10 grams of ozone per cubic meter of printing and dyeing wastewater.

Wherein the biochemical treatment system described in step c comprises a hydrolytic acidification pond, an aerobic pond, and a sedimentation pond; the hydrolytic acidification pond, an aerobic pond, and a sedimentation pond are sequentially connected by pipelines, and the printing and dyeing wastewater enters the biochemical treatment system from the water inlet of the hydrolytic acidification pond, The water from the outlet of the sedimentation tank flows into the biochemical treatment system; the water inlet of the hydrolytic acidification tank is connected with the outlet pipe of the ozone oxidation system.

Wherein the oxidation decolorization system described in the step d is an oxidation pool connected with the ozone generator pipeline, and a liquid chlorine pipeline is connected to the oxidation pool, and the water inlet of the oxidation pool is connected with the biochemical treatment system water outlet pipeline.

The amount of ozone input into the oxidation decolorization system is 10 grams of ozone per cubic meter of printing and dyeing wastewater.

The amount of chlorine gas input into the oxidation decolorization system is 20-30 grams of liquid chlorine per cubic meter of printing and dyeing wastewater.

The beneficial effects of the present invention are as follows: (1) The present invention realizes two processes of ozone oxidation printing and dyeing wastewater treatment method and biochemical printing and dyeing wastewater treatment method in a combined process, which effectively solves the difficulty of biochemical treatment of current printing and dyeing wastewater and the single use of high-grade ozone (2) It is not necessary to install an ozone destruction system after ozone oxidation, because ozone has to be fully dissolved in sewage and finally decomposed after passing through a biochemical treatment system.

Description of drawings:

Describe the present invention in detail below in conjunction with accompanying drawing:

Fig. 1 is a diagram of the production process of the embodiment of the present invention.

Detailed ways:

As shown in Figure 1, it is a process flow chart of a kind of printing and dyeing wastewater treatment method of the present invention, and each equipment and work flow are as follows:

The pre-conditioning system described in the present invention is composed of the front regulating pool 1, the cooling tower 2 and the rear regulating pool 3 which are sequentially connected by pipelines. The water outlet flows out of the pre-conditioning system. Because of the variety of dyes and chemicals used in the printing and dyeing process, the water quality of the printing and dyeing wastewater produced in the printing and dyeing production process fluctuates greatly. Therefore, it is best to treat the printing and dyeing wastewater before chemical and biological treatment. Wastewater is pre-conditioned to achieve better results in subsequent chemical and biological treatments. When using the present invention to pretreat printing and dyeing wastewater, the printing and dyeing wastewater is first discharged into the front-stage regulating tank 1 of the pre-conditioning system, and parameters such as water volume and pH value are adjusted. The purpose of water volume, the water volume requirement is mainly determined by the treatment volume of printing and dyeing wastewater; the PH value is mainly achieved by a certain amount of acid-base neutralization, and the pH value of the printing and dyeing wastewater regulated by the front adjustment tank 1 is generally 8-9. The printing and dyeing wastewater regulated by water volume and PH value enters the cooling tower 2 from the front adjustment pool 1 for temperature regulation, because the temperature of the printing and dyeing wastewater has a great influence on the microorganisms in the biochemical treatment process, so the suitable temperature is beneficial to the subsequent biochemical treatment , this program generally controls the temperature of the printing and dyeing wastewater within the range of 30°C-35°C; the printing and dyeing wastewater enters the rear regulation pool 3 from the cooling tower 2, and further adjusts the above parameters for the printing and dyeing wastewater to reach the best state to be treated.

The printing and dyeing wastewater stays in the front regulation pool 1 for about 6 hours; the air volume of the cooling tower 2 fan is: 135*10 ⁴ m ³ /h, the volume of the filler layer is 1700m ³ , and the contact time is about 30 minutes; The main function of the adjustment tank 3 is to finally stabilize the effluent quality of the printing and dyeing wastewater pretreated from the front adjustment tank 1 and the cooling tower 2, so that the printing and dyeing wastewater enters the subsequent treatment process with a relatively stable and uniform water quality.

The ozone oxidation system described in the present invention is a pretreatment pool 4, and the water inlet of the pretreatment pool 4 is connected with the outlet of the rear adjustment pool 3 with pipelines. In addition, the pretreatment pool 4 is connected with the ozone generator 5 pipelines, which is convenient for printing and dyeing. A certain amount of ozone is passed into the pretreatment pool 4 during the ozone oxidation treatment of wastewater; the pretreatment pool 4 adopts a fully enclosed structure, and the depth of the pretreatment pool 4 is 10 meters. In the process of ozone oxidation treatment, the dosage of ozone is 10g/m ³ wastewater, and the contact time is 20 minutes. The ozone gas and the printing and dyeing wastewater are fully contacted in a reverse way. The ozone oxidation system mainly uses the strong oxidizing property of ozone to fully oxidize the dyes and other unsaturated polymer compounds, so that the dyes and other unsaturated polymer compounds are opened and broken, and become small molecular substances, forming easy-to-bio Degraded substances, thereby improving the biodegradability of printing and dyeing wastewater.

The biochemical treatment system described in the present invention comprises the hydrolytic acidification pond 10, the aerobic pond 9 and the sedimentation pond 8 connected successively by pipeline; Biochemical treatment system. The water inlet of the hydrolytic acidification tank 10 is connected with the water outlet of the pretreatment tank 4 with a pipeline. The hydrolytic acidification tank 10 of the present invention is provided with fillers to ensure the microbial biomass in the hydrolytic acidification tank 10, and the effective volume is 8320m ³ . According to the two-stage action principle of hydrolysis and acidification, the printing and dyeing wastewater only undergoes hydrolysis and acidification reactions in the hydrolysis and acidification tank 10, so that the high-molecular organic matter becomes smaller molecules, and the purpose is to improve the biodegradability of the printing and dyeing wastewater. In addition, the printing and dyeing wastewater has a sufficiently long residence time in the hydrolytic acidification tank 10, generally about 20 hours. The printing and dyeing wastewater treated by the hydrolytic acidification pool 10 enters the aerobic pool 9 for treatment. The aerobic pool 9 is equipped with fillers and has an effective volume of 6240m ³ . The residence time of the printing and dyeing wastewater in the aerobic pool 9 is about 15 hours; in addition, The present invention feeds a certain amount of oxygen into the aerobic pool 9 through the fan 6 to meet the oxygen demand of the aerobic pool 9 . In the present invention, the excess sludge generated in the aerobic tank 9 is returned to the hydrolysis acidification tank 10 for recycling and reprocessing, and the organic pollutants contained in this part of the excess sludge are thoroughly digested. After part of the remaining sludge in the aerobic tank 9 is returned to the hydrolytic acidification tank 10 for sludge reduction, the N, P and other nutrient sources in the microorganisms can be partially released, which partially solves the problem of imbalanced nutrient ratios in printing and dyeing wastewater. Adding a small amount of nutrients such as N and P can meet the normal growth needs of microorganisms. The aerobic pool 9 mainly uses the microbial film attached to the filler to degrade the organic pollutants in the printing and dyeing wastewater. After the two-step treatment of the pretreatment pool 4 and the hydrolytic acidification pool 10, the pollutants in the printing and dyeing wastewater have become easily degradable substances. Provided with an appropriate amount of dissolved oxygen 2-3mg/L, the organic matter can be degraded more thoroughly. The printing and dyeing wastewater treated in the aerobic tank 9 enters the sedimentation tank 8 for further treatment. The effective volume of the sedimentation tank 8 is 1664m ³ , and the residence time of the printing and dyeing wastewater in the sedimentation tank 8 is 4 hours. The main function of the sedimentation tank 8 is to separate solids and liquids to reduce the COD in the printing and dyeing wastewater. A part of the excess sludge generated is returned to the hydrolytic acidification tank 10 for complete digestion, and a part is sent to the power station after being pressed by the mud press 11 incinerate.

The oxidative decolorization system described in the present invention is an oxidation pond 7, the water inlet of the oxidation pond 7 is connected with the 8 water outlet pipes of the sedimentation pond, and the oxidation pond 7 is connected with the ozone generator 5 pipes; in addition, the liquid chlorine pipe is also provided on the oxidation pond 7 , for adding liquid chlorine into the oxidation pool 7. The effective water depth of oxidation pool 8 is 4.5 meters, the dosage of ozone is 10g/ ^m3 of wastewater, the contact time is 10 minutes, and the dosage of liquid chlorine is 20-30 g/ ^m3 of wastewater, the purpose is to use the strong oxidation and decolorization of ozone In this procedure, because a certain amount of ozone is added, the amount of liquid chlorine will be reduced to reduce the by-products caused by the addition of liquid chlorine, so as to avoid secondary pollution. After being oxidized and decolorized in the oxidation pool 7, the waste water is discharged up to the standard.

Example 1

Taking the treatment of 10,000 m ³ /day printing and dyeing wastewater as an example, the combined process of ozone and biochemical treatment is used:

The printing and dyeing wastewater (40°C-45°C) in the workshop is pre-adjusted through the pretreatment system. The temperature of the printing and dyeing wastewater can be reduced to about 30°C-35°C, the pH is adjusted to 8-9, and the water volume is adjusted to 42m ³ /hour.

The printing and dyeing wastewater regulated by the pretreatment system enters the pretreatment pool 4, and some reducing substances that are easier to be oxidized are first oxidized. In the pretreatment tank 4, the dosage of ozone is 10g/m ³ wastewater, and the contact time is about 20 minutes. The ozone gas is in reverse contact with the printing and dyeing wastewater, and the biodegradability of the treated printing and dyeing wastewater is increased to about 0.4 (before ozone oxidation treatment is about 0.23), and the chroma of printing and dyeing wastewater also has 30% removal.

The printing and dyeing wastewater treated in the pretreatment tank 4 enters the hydrolytic acidification tank 10 for treatment. After the printing and dyeing wastewater is hydrolyzed and acidified, the biochemical property is increased to about 0.5, and the chroma of the printing and dyeing wastewater is also removed by about 50%. In addition, the hydrolytic acidification tank 10 has digested most of the remaining sludge in the aerobic tank and the sedimentation tank, realizing the reduction of sludge.

Due to the adequate pretreatment, the biodegradability of the sewage has been greatly improved, and the organic pollutants in the printing and dyeing wastewater in the aerobic pool 9 are more thoroughly degraded, and the COD removal rate reaches about 80%.

After the printing and dyeing wastewater enters the sedimentation tank 8, the printing and dyeing wastewater undergoes liquid-solid separation in the sedimentation tank 8, and most of the remaining sludge generated is returned to the hydrolysis acidification tank 10 for thorough digestion, and the rest is squeezed by the mud press 11 and then sent to the power station for incineration .

The printing and dyeing wastewater separated and treated by the sedimentation tank 8 enters the oxidation tank 7 for decolorization treatment. The decolorization process is mainly based on ozone decolorization, and the ozone gas is in reverse contact with the printing and dyeing wastewater. The dosage is 10g/m ³ wastewater, the contact time is 10 minutes, the auxiliary liquid chlorine is decolorized, the dosage is 20-30g/m ³ wastewater, and the chroma of printing and dyeing wastewater is completely removed. After the above treatment, the effluent water quality is as follows: COD is 60-70mg/L, chroma is 20-30 times, BOD is 10-20mg/L wastewater, and suspended solids is 10-20mg/L wastewater, which is better than the discharge standard. After calculation, the cost of increasing ozone is equal to the cost of saving fan power consumption and adding liquid chlorine. If the process operation parameters are adjusted properly, there is still room for reduction in operating costs. Therefore, the economic and social benefits obtained are huge.

The above is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the structure, features and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims (8)

1, a kind of treatment method of printing and dying wastewater is characterized in that, it comprises the steps:

A, dyeing waste water carry out water temperature, the water yield and pH value through the preconditioning system and regulate processing in advance;

B, the dyeing waste water after step a handles enter the oxidation of ozone oxidation system, feed ozone in the ozone oxidation system, and the part macromolecule organic is finished open loop scission of link process in the sewage;

C, dyeing waste water enters biochemical treatment system and carries out biochemistry after step b oxide treatment, through microbiological treatment, finishes hydrolysis, acidifying, degraded and precipitation process;

D, the dyeing waste water after step c handles enter the oxidative decoloration system, feed chlorine and ozone in the oxidative decoloration system, finish the oxidative decoloration process;

E, the discharging of printing and dyeing wastewater to reach standard after treatment.

2, a kind of treatment method of printing and dying wastewater according to claim 1 is characterized in that: preconditioning system described in a step comprises leading portion equalizing tank (1), cooling tower (2) and back segment equalizing tank (3); Described leading portion equalizing tank (1), cooling tower (2) and back segment equalizing tank (3) be pipe connection successively, and dyeing waste water enters the preconditioning system from leading portion equalizing tank (1) water inlet, flows out the preconditioning system from back segment equalizing tank (3) water outlet; Dyeing waste water pH value after the preconditioning system regulates is 8-9.

3, a kind of treatment method of printing and dying wastewater according to claim 1, it is characterized in that: ozone oxidation system described in the b step for the pretreatment pool (4) of ozonizer (5) pipe connection, pretreatment pool (4) adopts full-closed structure, the water-in of pretreatment pool (4) and preconditioning system water outlet pipe connection.

4, a kind of treatment method of printing and dying wastewater according to claim 3 is characterized in that: the ozone amount of described ozone oxidation system input is that every cubic metre of dyeing waste water drops into 10 gram ozone.

5, a kind of treatment method of printing and dying wastewater according to claim 1 is characterized in that: biochemical treatment system described in the c step comprises hydrolysis acidification pool (10), Aerobic Pond (9) and settling tank (8); Described hydrolysis acidification pool (10), Aerobic Pond (9) and settling tank (8) be pipe connection successively, and dyeing waste water enters biochemical treatment system by hydrolysis acidification pool (10) water inlet, flows out biochemical treatment system by settling tank (8) outlet water; The water inlet of hydrolysis acidification pool (10) and ozone oxidation system water outlet pipe connection.

6, a kind of treatment method of printing and dying wastewater according to claim 1, it is characterized in that: oxidative decoloration system described in the d step for the oxidation pond (7) of ozonizer (5) pipe connection, described oxidation pond is connected to the liquid chlorine pipeline on (7) in addition, the water inlet of oxidation pond (7) and biochemical treatment system water outlet pipe connection.

7, a kind of treatment method of printing and dying wastewater according to claim 6 is characterized in that: the ozone amount of described oxidative decoloration system input is that every cubic metre of dyeing waste water drops into 10 gram ozone.

8, a kind of treatment method of printing and dying wastewater according to claim 6 is characterized in that: the liquid chlorine amount of described oxidative decoloration system input is that every cubic metre of dyeing waste water drops into 20-30 gram liquid chlorine.

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