阅读说明：本技术 一种臭氧处理高浓度cod废水的方法 (Method for treating high-concentration COD wastewater by ozone ) 是由 蒲江 柳臻 于 2021-08-24 设计创作，主要内容包括：本发明公开了一种臭氧处理高浓度COD废水的方法,解决了现有技术中的臭氧处理废水方法,加入酸/碱调节pH值,会生成盐,增加出水中的盐含量,存在出水电导率过高的技术问题。它包括下述步骤：(1)将待处理的高浓度COD废水过滤除杂；(2)将除杂后的高浓度COD废水加入臭氧催化氧化反应器中,所述臭氧催化氧化反应器中添加有进行臭氧氧化的催化剂；(3)向高浓度COD废水中通入臭氧；(4)臭氧催化氧化。本发明在处理废水的过程中,大幅度降低了酸和/或碱的消耗,降低了高浓度COD废水的处理成本；并且不会增加出水中的盐含量,也避免了出水电导率过高的问题。(The invention discloses a method for treating high-concentration COD (chemical oxygen demand) wastewater by ozone, which solves the technical problems that in the method for treating wastewater by ozone in the prior art, salt is generated by adding acid/alkali to adjust the pH value, the salt content in effluent is increased, and the conductivity of the effluent is overhigh. It comprises the following steps: (1) filtering and removing impurities from high-concentration COD wastewater to be treated; (2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; (3) introducing ozone into the high-concentration COD wastewater; (4) and (4) carrying out catalytic oxidation by ozone. In the process of treating the wastewater, the invention greatly reduces the consumption of acid and/or alkali and reduces the treatment cost of the high-concentration COD wastewater; and the salt content in the effluent cannot be increased, and the problem of overhigh conductivity of the effluent is also avoided.)

1. A method for treating high-concentration COD wastewater by ozone is characterized by comprising the following steps: the method comprises the following steps:

(1) filtering and removing impurities from high-concentration COD wastewater to be treated;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor;

(3) introducing ozone into the high-concentration COD wastewater;

(4) and (4) carrying out catalytic oxidation by ozone.

2. The method for treating high concentration COD wastewater by ozone according to claim 1, characterized in that: in the step (1), a bag filter is adopted for filtering and removing impurities.

3. The method for treating high concentration COD wastewater by ozone according to claim 1, characterized in that: in the step (2), the adding amount of the catalyst is 75-85% of the effective volume of the ozone catalytic oxidation reactor.

4. The method for treating high concentration COD wastewater by ozone according to claim 1, characterized in that: in the step (2), when the pH value of the high-concentration COD wastewater is less than 7, the added catalyst is a titanium compound catalyst and/or an iron compound catalyst; when the pH value of the high-concentration COD wastewater is more than or equal to 7, the added catalyst is a silicon-aluminum compound catalyst and/or a manganese compound catalyst.

5. The method for treating high concentration COD wastewater by ozone according to claim 4, wherein: in the step (2), the titanium compound catalyst is titanium oxide, titanium sulfate or titanium chloride.

6. The method for treating high concentration COD wastewater by ozone according to claim 4, wherein: in the step (2), the iron compound is zero-valent iron, ferrous sulfate or ferric oxalate.

7. The method for treating high concentration COD wastewater by ozone according to claim 4, wherein: in the step (2), the silicon-aluminum compound catalyst is silicon-aluminum composite salt or aluminum oxide.

8. The method for treating high concentration COD wastewater by ozone according to claim 4, wherein: in the step (2), the manganese compound catalyst is manganese dioxide, potassium permanganate or manganese sulfate.

9. The method for treating high concentration COD wastewater by ozone according to claim 1, characterized in that: in the step (3), the volume ratio of the high-concentration COD wastewater to the ozone is 1: 10-1000.

10. The method for treating high concentration COD wastewater by ozone according to claim 1, characterized in that: in the step (4), the catalytic oxidation of ozone is carried out at normal temperature and normal pressure.

Technical Field

The invention relates to the field of wastewater treatment, in particular to a method for treating high-concentration COD wastewater by ozone.

Background

Ozone is an unstable, bluish gas with a particularly pungent odor at ambient temperature and pressure. Ozone has strong oxidation performance, has an oxidation potential of 2.07V in alkaline solution, and has the oxidation capacity second to fluorine and higher than chlorine and potassium permanganate. Based on the strong oxidizing property of ozone, the water can be automatically decomposed in a short time without secondary pollution, and the ozone is an ideal green oxidizing agent. Therefore, the ozone oxidation method has been gradually developed into an advanced oxidation technology, and the ozone technology has been applied in many aspects in the field of water treatment. The ozone is mainly used for deodorization, decoloration, sterilization and removal of organic matters in the water treatment process.

In the existing ozone wastewater treatment method, alkali liquor is needed to be used for regulating the acidity and the alkalinity of acid wastewater, sulfuric acid is needed to be used for regulating the acidity and the alkalinity of alkaline wastewater, the consumption of acid and/or alkali is high, and the wastewater treatment cost is high; in addition, the pH value is adjusted by adding acid/alkali, salt is generated, the salt content in the effluent is increased, and the problem of overhigh conductivity of the effluent is solved.

The applicant has found that the prior art has at least the following technical problems:

1. in the method for treating wastewater by ozone in the prior art, alkali liquor is needed to be used for regulating the acidity and the alkalinity of acidic wastewater, sulfuric acid is needed to be used for regulating the acidity and the alkalinity of alkaline wastewater, the consumption of acid and/or alkali is high, and the wastewater treatment cost is high;

2. in the method for treating wastewater by ozone in the prior art, acid/alkali is added to adjust the pH value, salt can be generated, the salt content in the effluent is increased, and the problem of overhigh conductivity of the effluent exists.

Disclosure of Invention

The invention aims to provide a method for treating high-concentration COD wastewater by ozone, and aims to solve the technical problems that in the method for treating wastewater by ozone in the prior art, salt is generated by adding acid/alkali to adjust the pH value, the salt content in effluent is increased, and the conductivity of the effluent is too high.

In order to achieve the purpose, the invention provides the following technical scheme:

the invention provides a method for treating high-concentration COD wastewater by ozone, which comprises the following steps:

(1) filtering and removing impurities from high-concentration COD wastewater to be treated;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor;

(3) introducing ozone into the high-concentration COD wastewater;

(4) and (4) carrying out catalytic oxidation by ozone.

Further, in the step (1), a bag filter is adopted to filter and remove impurities.

Further, in the step (2), the adding amount of the catalyst is 75-85% of the effective volume of the ozone catalytic oxidation reactor.

Further, in the step (2), when the pH value of the high-concentration COD wastewater is less than 7, the added catalyst is a titanium compound catalyst and/or an iron compound catalyst; when the pH value of the high-concentration COD wastewater is more than or equal to 7, the added catalyst is a silicon-aluminum compound catalyst and/or a manganese compound catalyst.

Further, in the step (2), the titanium compound catalyst is titanium oxide, titanium sulfate or titanium chloride.

Further, in the step (2), the iron compound catalyst is zero-valent iron, ferrous sulfate or ferric oxalate.

Further, in the step (2), the silicon-aluminum compound catalyst is silicon-aluminum composite salt or aluminum oxide.

Further, in the step (2), the manganese compound catalyst is manganese dioxide, potassium permanganate or manganese sulfate.

Further, in the step (3), the volume ratio of the high-concentration COD wastewater to the ozone is 1: 10-1000.

Further, in the step (4), the catalytic oxidation of ozone is carried out at normal temperature and normal pressure.

The ozone oxidation principle is as follows:

ozone exhibits strong oxidizing property because oxygen atoms in ozone molecules have strong electrophilic or nucleophilic properties, nascent oxygen atoms generated by ozone decomposition, and hydroxyl radical OH having strong oxidizing effect are formed in water, and their high activity is used for sterilization, disinfection, destruction of organic structures, etc. in water treatment, and its by-products are non-toxic, and basically have no secondary pollution, and have many advantages that other oxidants cannot match, and not only can sterilize, but also can oxidatively decompose pollutants in water.

Based on the technical scheme, the embodiment of the invention can at least produce the following technical effects:

(1) according to the method for treating high-concentration COD wastewater by using ozone, provided by the invention, in the process of treating wastewater, except for the catalyst, only one kind of ozone is used as a chemical substance; different from other ozone treatment methods, the method of the invention does not need to use alkali liquor to adjust the acidity and the alkalinity of the acid wastewater, and does not need to use sulfuric acid to adjust the acidity and the alkalinity of the alkaline wastewater, thereby greatly reducing the consumption of acid and/or alkali and reducing the treatment cost of high-concentration COD wastewater;

(2) according to the method for treating the high-concentration COD wastewater by using the ozone, provided by the invention, the pH value is not required to be adjusted by adding acid/alkali, so that the salt content in the effluent is not increased, the problem of overhigh conductivity of the effluent is avoided, and the subsequent continuous wastewater treatment is facilitated;

(3) according to the method for treating high-concentration COD wastewater by using ozone, when the pH value of the high-concentration COD wastewater is less than 7, the added catalyst is a titanium compound catalyst and/or an iron compound catalyst; when the pH value of the high-concentration COD wastewater is more than or equal to 7, the added catalyst is a silicon-aluminum compound catalyst and/or a manganese compound catalyst; the applied catalyst can be repeatedly used for many times and has good catalytic effect.

Detailed Description

First, an embodiment

Example 1:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 100g/L and the pH is 3) by adopting a bag filter;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; the adding amount of the catalyst is 80 percent of the effective volume of the ozone catalytic oxidation reactor;

in this embodiment, the added catalyst is a titanium compound catalyst, specifically selected is titanium oxide;

(3) introducing ozone into the high-concentration COD wastewater, wherein the volume ratio of the high-concentration COD wastewater to the ozone is 1: 25;

(4) carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Example 2:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 92g/L and the pH is 4) by using a bag filter;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; the adding amount of the catalyst is 75 percent of the effective volume of the ozone catalytic oxidation reactor;

in this embodiment, the added catalyst is a titanium compound catalyst, specifically selected is titanium sulfate;

(3) introducing ozone into the high-concentration COD wastewater; the volume ratio of the high-concentration COD wastewater to the ozone is 1: 22.

(4) Carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Example 3:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 60g/L and the pH is 5) by using a bag filter;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; the adding amount of the catalyst is 85 percent of the effective volume of the ozone catalytic oxidation reactor;

in this embodiment, the added catalyst is an iron compound catalyst, specifically, zero-valent iron is selected;

(3) introducing ozone into the high-concentration COD wastewater; the volume ratio of the high-concentration COD wastewater to the ozone is 1: 20.

(4) Carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Example 4:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 73g/L and the pH is 6) by adopting a bag filter;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; the adding amount of the catalyst is 82 percent of the effective volume of the ozone catalytic oxidation reactor;

in this embodiment, the added catalyst is an iron compound catalyst, specifically ferrous sulfate;

(3) introducing ozone into the high-concentration COD wastewater; the volume ratio of the high-concentration COD wastewater to the ozone is 1: 19.

(4) Carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Example 5:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 120g/L and the pH is 7) by using a bag filter;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; the adding amount of the catalyst is 77 percent of the effective volume of the ozone catalytic oxidation reactor;

in this embodiment, the added catalyst is a silicon-aluminum compound catalyst, specifically, a silicon-aluminum composite salt is selected;

(3) introducing ozone into the high-concentration COD wastewater; the volume ratio of the high-concentration COD wastewater to the ozone is 1: 30.

(4) carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Example 6:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 30g/L and the pH is 8) by adopting a bag filter;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; the adding amount of the catalyst is 80 percent of the effective volume of the ozone catalytic oxidation reactor;

in this embodiment, the added catalyst is a silicon-aluminum compound catalyst, specifically, alumina is selected;

(3) introducing ozone into the high-concentration COD wastewater; the volume ratio of the high-concentration COD wastewater to the ozone is 1: 21.

(4) Carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Example 7:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 52g/L and the pH is 9) by using a bag filter;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; the adding amount of the catalyst is 78 percent of the effective volume of the ozone catalytic oxidation reactor;

in this embodiment, the catalyst added is a manganese compound catalyst, specifically manganese dioxide;

(3) introducing ozone into the high-concentration COD wastewater; the volume ratio of the high-concentration COD wastewater to the ozone is 1: 15.

(4) Carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Example 8:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 66g/L and the pH is 10) by adopting a bag filter;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; the adding amount of the catalyst is 80 percent of the effective volume of the ozone catalytic oxidation reactor;

in this embodiment, the added catalyst is a manganese compound catalyst, specifically selected to be potassium permanganate;

(3) introducing ozone into the high-concentration COD wastewater; the volume ratio of the high-concentration COD wastewater to the ozone is 1: 33.

(4) Carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Example 9:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 50g/L and the pH is 11) by adopting a bag filter;

(2) adding the high-concentration COD wastewater subjected to impurity removal into an ozone catalytic oxidation reactor, wherein a catalyst for performing ozone oxidation is added into the ozone catalytic oxidation reactor; the adding amount of the catalyst is 80 percent of the effective volume of the ozone catalytic oxidation reactor;

in this embodiment, the added catalyst is a manganese compound catalyst, specifically, manganese sulfate is selected;

(3) introducing ozone into the high-concentration COD wastewater; the volume ratio of the high-concentration COD wastewater to the ozone is 1: 29;

(4) carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

II, comparison example:

comparative example 1:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 100g/L and the pH is 3) by adopting a bag filter;

(2) adjusting the pH of the high-concentration COD wastewater after impurity removal, wherein the adjusted pH is 9;

(3) introducing ozone into the high-concentration COD wastewater, wherein the volume ratio of the high-concentration COD wastewater to the ozone is 1: 25;

(4) carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Comparative example 2:

a method for treating high-concentration COD wastewater by ozone comprises the following steps:

(1) filtering impurities such as solid slag, suspended matters and the like in high-concentration COD wastewater to be treated (the COD concentration is 120g/L and the pH is 7) by using a bag filter;

(2) adjusting the pH of the high-concentration COD wastewater after impurity removal, wherein the adjusted pH is 9;

(3) introducing ozone into the high-concentration COD wastewater; the volume ratio of the high-concentration COD wastewater to the ozone is 1: 30.

(4) Carrying out catalytic ozonation for 1h at normal temperature and normal pressure to obtain treated wastewater, wherein the COD, the salt content and the conductivity of the treated wastewater are shown in Table 1.

Third, salt content and conductivity after high COD wastewater treatment in comparative examples and comparative examples:

the parameters of wastewater treatment and the treatment results in examples 1 to 9 and comparative examples 1 to 2 are shown in the following Table 1:

TABLE 1 examples and comparative examples wastewater treatment parameters and results

As can be seen from table 1, in examples 1 to 9 of the present invention, the catalytic ozonation can be directly performed by adding the catalyst to the high COD wastewater, and compared with the conventional catalytic ozonation after pH adjustment, the catalytic ozonation has low salt content and low conductivity, which is helpful for the subsequent wastewater treatment.