Method for rapidly improving potassium ferrate water treatment effect under alkaline condition

Abstract

The invention discloses a method for rapidly improving potassium ferrate water treatment effect under alkaline conditions, which comprises the following steps: adding alkaline printing and dyeing wastewater into a potassium ferrate solution, mixing and standing, inducing potassium ferrate to generate oxidation-reduction reaction by organic matters in the alkaline printing and dyeing wastewater, reducing hexavalent iron ions into tetravalent iron ions, and separating the tetravalent iron ions from the potassium ferrate solution. Forming a solution containing tetravalent iron ions; the prepared solution containing the tetravalent iron ions is put into the alkaline printing and dyeing wastewater to be treated, so that the tetravalent iron ions in the solution containing the tetravalent iron ions and organic pollutants in the alkaline printing and dyeing wastewater to be treated are subjected to full contact reaction, and the alkaline printing and dyeing wastewater is degraded. According to the method, the water treatment effect of the potassium ferrate on the wastewater is remarkably improved, the TOC removal rate is improved by 10%-20% compared with that of a method for directly treating the wastewater through a potassium ferrate solution, the decolorization rate of the wastewater is also remarkably improved and can reach 70% or above, the pollution degree of the alkaline printing and dyeing wastewater is effectively reduced, and the method better meets the environment-friendly emission requirement.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a method for rapidly improving the treatment effect of potassium ferrate water under alkaline conditions. Background Art

[0002] As a key link in the textile industry chain, the printing and dyeing industry produces printing and dyeing wastewater with complex components, containing a large amount of dyes, auxiliaries and other organic pollutants, and this type of wastewater is usually alkaline. At present, potassium ferrate, as a strong oxidant, has been used in the field of water treatment. Its hexavalent iron ions can oxidize and decompose organic pollutants in wastewater.

[0003] However, when treating alkaline printing and dyeing wastewater, the treatment efficiency and effect of using conventional potassium ferrate solution still need to be improved. This is because the alkaline environment will have a certain impact on the redox process of potassium ferrate, limiting its ability to decompose pollutants. Therefore, there is an urgent need for a method to quickly improve the treatment effect of potassium ferrate water under alkaline conditions to optimize the performance of potassium ferrate in alkaline printing and dyeing wastewater treatment. Summary of the invention

[0004] The present invention provides a method for rapidly improving the treatment effect of potassium ferrate water under alkaline conditions to solve the above problems.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A method for rapidly improving the treatment effect of potassium ferrate water under alkaline conditions comprises the following steps:

[0007] S1: adding alkaline printing and dyeing wastewater to the potassium ferrate solution, mixing and standing, the organic matter in the alkaline printing and dyeing wastewater induces the potassium ferrate to undergo an oxidation-reduction reaction, so that the hexavalent iron ions are reduced to tetravalent iron ions, forming a solution containing tetravalent iron ions;

[0008] S2: adding the solution containing tetravalent iron ions obtained in S1 into the alkaline printing and dyeing wastewater to be treated, so that the tetravalent iron ions in the solution containing tetravalent iron ions fully contact and react with the organic pollutants in the alkaline printing and dyeing wastewater to be treated, thereby degrading the alkaline printing and dyeing wastewater.

[0009] Furthermore, in S1, the concentration of the potassium ferrate solution is not less than 0.2 mol / L.

[0010] Furthermore, the volume ratio of the alkaline printing and dyeing wastewater to the potassium ferrate solution is 1:40-1:50.

[0011] Furthermore, in S1, the temperature at which the mixture is allowed to stand is 20°C-25°C.

[0012] Furthermore, the mixing is allowed to stand for 30 minutes.

[0013] Furthermore, in S2, the reaction time of the tetravalent iron ions and the alkaline printing and dyeing wastewater to be treated is not less than 30 minutes.

[0014] The beneficial effects of the present invention are:

[0015] The present invention discloses a method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions. The present invention utilizes a method of pre-preparing a solution containing tetravalent iron ions to significantly improve the water treatment effect of potassium ferrate on wastewater. Experimental verification shows that under the same treatment time and the same initial pollutant concentration of alkaline printing and dyeing wastewater samples, the TOC removal rate of the wastewater treated by the method is increased by 10%-20% compared with the method of directly using potassium ferrate solution to treat the wastewater, and the decolorization rate of the wastewater is also significantly improved, which can reach more than 70%, effectively reducing the pollution degree of alkaline printing and dyeing wastewater, and more in line with environmental protection emission requirements. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] The specific principles of this application are:

[0018] The iron ions in potassium ferrate are hexavalent and are a strong oxidant. They can oxidize and decompose organic pollutants in wastewater during water treatment. However, in the alkaline printing and dyeing wastewater environment, its redox process will be affected to a certain extent, and its ability to decompose pollutants is limited. This method first prepares a potassium ferrate solution of a certain concentration, takes a trace amount of alkaline printing and dyeing wastewater and adds it to the potassium ferrate solution, and uses the organic matter in the alkaline printing and dyeing wastewater to induce potassium ferrate to react, and the hexavalent iron ions quickly generate tetravalent iron ions.

[0019] Since tetravalent iron ions have high oxidizing properties under alkaline conditions, they can improve the degradation effect of organic pollutants when in contact with them, thereby increasing the organic matter removal rate to more than 70%, and also increasing the decolorization rate of wastewater to more than 65%.

[0020] Embodiment 1:

[0021] A method for rapidly improving the treatment effect of potassium ferrate water under alkaline conditions comprises the following steps:

[0022] S1: Accurately weigh an appropriate amount of potassium ferrate solid, dissolve it in deionized water, and continue stirring to prepare a potassium ferrate solution with a concentration of 0.2 mol / L. Take 0.8 mL of alkaline printing and dyeing wastewater with a pH of 12-13, and add it to 40 mL of the above-prepared potassium ferrate solution. Let the reaction stand at 20°C for 30 minutes, and use the organic matter in the alkaline printing and dyeing wastewater to induce the potassium ferrate to undergo a redox reaction, so that the hexavalent iron ions are quickly reduced to tetravalent iron ions, forming a solution containing tetravalent iron ions;

[0023] S2: Add the prepared solution containing tetravalent iron ions into the alkaline printing and dyeing wastewater to be treated, stir it thoroughly to allow the tetravalent iron ions to fully contact with various organic pollutants in the printing and dyeing wastewater. After reacting for 30 minutes, detect the TOC removal rate, organic matter removal rate and decolorization rate. Under the conditions of the same treatment time and the same initial pollutant concentration of the alkaline printing and dyeing wastewater samples, the TOC removal rate of the wastewater treated by this method is 10% higher than that of the potassium ferrate solution containing only hexavalent iron ions, the organic matter removal rate is 66%, and the decolorization rate of the wastewater reaches 70%.

[0024] Embodiment 2:

[0025] A method for rapidly improving the treatment effect of potassium ferrate water under alkaline conditions comprises the following steps:

[0026] S1: Accurately weigh an appropriate amount of potassium ferrate solid, dissolve it in deionized water, and continue stirring to prepare a potassium ferrate solution with a concentration of 0.25 mol / L. Take 1.25 mL of alkaline printing and dyeing wastewater with a pH of 12-13, and add it to 50 mL of the above-prepared potassium ferrate solution. Let the reaction stand at 20°C for 30 minutes, and use the organic matter in the alkaline printing and dyeing wastewater to induce the redox reaction of potassium ferrate, so that the hexavalent iron ions are quickly reduced to tetravalent iron ions, forming a solution containing tetravalent iron ions;

[0027] S2: Add the prepared solution containing tetravalent iron ions into the alkaline printing and dyeing wastewater to be treated, stir it thoroughly to allow the tetravalent iron ions to fully contact with various organic pollutants in the printing and dyeing wastewater. After reacting for 30 minutes, detect the TOC removal rate, organic matter removal rate and decolorization rate. Under the conditions of the same treatment time and the same initial pollutant concentration of the alkaline printing and dyeing wastewater samples, the TOC removal rate of the wastewater treated by this method is 15% higher than that of the wastewater treated with potassium ferrate solution containing only hexavalent iron ions, the organic matter removal rate is 70%, and the decolorization rate of the wastewater reaches 73%.

[0028] Example 3

[0029] A method for rapidly improving the treatment effect of potassium ferrate water under alkaline conditions comprises the following steps:

[0030] S1: Accurately weigh an appropriate amount of potassium ferrate solid, dissolve it in deionized water, and continue stirring to prepare a potassium ferrate solution with a concentration of 0.3 mol / L. Take 1.25 mL of alkaline printing and dyeing wastewater with a pH of 12-13, and add it to 50 mL of the above-prepared potassium ferrate solution. Let the reaction stand at 20°C for 30 minutes, and use the organic matter in the alkaline printing and dyeing wastewater to induce the potassium ferrate to undergo a redox reaction, so that the hexavalent iron ions are quickly reduced to tetravalent iron ions, forming a solution containing tetravalent iron ions;

[0031] S2: Add the prepared solution containing tetravalent iron ions into the alkaline printing and dyeing wastewater to be treated, stir it thoroughly to allow the tetravalent iron ions to fully contact with various organic pollutants in the printing and dyeing wastewater. After reacting for 30 minutes, detect the TOC removal rate, organic matter removal rate and decolorization rate. Under the conditions of the same treatment time and the same initial pollutant concentration of the alkaline printing and dyeing wastewater samples, the TOC removal rate of the wastewater treated by this method is 16% higher than that of the wastewater treated with potassium ferrate solution containing only hexavalent iron ions, the organic matter removal rate is 72%, and the decolorization rate of the wastewater reaches 74%.

[0032] Embodiment 4:

[0033] A method for rapidly improving the treatment effect of potassium ferrate water under alkaline conditions comprises the following steps:

[0034] S1: Accurately weigh an appropriate amount of potassium ferrate solid, dissolve it in deionized water, and continue stirring to prepare a potassium ferrate solution with a concentration of 0.35 mol / L. Take 4 mL of alkaline printing and dyeing wastewater with a pH of 12-13, and add it to 50 mL of the above-prepared potassium ferrate solution. Let the reaction stand at 20°C for 30 minutes, and use the organic matter in the alkaline printing and dyeing wastewater to induce the redox reaction of potassium ferrate, so that the hexavalent iron ions are quickly reduced to tetravalent iron ions, forming a solution containing tetravalent iron ions;

[0035] S2: Add the prepared solution containing tetravalent iron ions into the alkaline printing and dyeing wastewater to be treated, stir it thoroughly to allow the tetravalent iron ions to fully contact with various organic pollutants in the printing and dyeing wastewater. After reacting for 30 minutes, detect the TOC removal rate, organic matter removal rate and decolorization rate. Under the conditions of the same treatment time and the same initial pollutant concentration of the alkaline printing and dyeing wastewater samples, the TOC removal rate of the wastewater treated by this method is 20% higher than that of the potassium ferrate solution containing only hexavalent iron ions, the organic matter removal rate is 75%, and the decolorization rate of the wastewater reaches 78%.

[0036] Comparative Example 1:

[0037] Accurately weigh an appropriate amount of potassium ferrate solid, dissolve it in deionized water, and stir continuously to prepare a potassium ferrate solution with a concentration of 0.15 mol / L. Take 1 mL of alkaline printing and dyeing wastewater with a pH of 12-13 and add it to 50 mL of the above-prepared potassium ferrate solution. After the addition is completed, the mixed solution is allowed to react at 20°C for 30 minutes, and it is found that tetravalent iron ions cannot be generated (no green liquid is generated by naked eye, and the solution color is yellow-brown of trivalent iron. After XRD and UV testing, it is also proved that only trivalent iron ions are generated, and no tetravalent iron ions are generated.)

[0038] Comparative Example 2:

[0039] Accurately weigh an appropriate amount of potassium ferrate solid, dissolve it in deionized water, and stir continuously to prepare a potassium ferrate solution with a concentration of 0.20 mol / L. Take 10 mL of alkaline printing and dyeing wastewater with a pH of 12-13 and add it to 50 mL of the above-prepared potassium ferrate solution. After the addition is completed, the mixed solution is allowed to react at 20°C for 30 minutes, and it is found that tetravalent iron cannot be generated.

[0040] In summary, compared with the prior art of using hexavalent iron ions to treat alkaline printing and dyeing wastewater, the present method first uses alkaline printing and dyeing wastewater to induce partial reduction of hexavalent iron ions in a specific concentration of potassium ferrate to generate tetravalent iron ions, and then uses tetravalent iron ions to treat the wastewater, thereby optimizing the oxidation process, solving the disadvantage that hexavalent iron has weak oxidation ability under alkaline conditions, and significantly improving the treatment effect. Under the same conditions, within 30 minutes, the TOC removal rate is 10%-20% higher than that of using a potassium ferrate solution containing only hexavalent iron ions, the decolorization rate is significantly improved, and can reach more than 70%, and the organic matter removal rate is not less than 66%, which effectively reduces the pollution degree of alkaline printing and dyeing wastewater and meets environmental protection emission requirements.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions, characterized in that: The following steps are involved: S1: adding alkaline printing and dyeing wastewater to the potassium ferrate solution, mixing and standing, the organic matter in the alkaline printing and dyeing wastewater induces the potassium ferrate to undergo an oxidation-reduction reaction, so that the hexavalent iron ions are reduced to tetravalent iron ions, forming a solution containing tetravalent iron ions; S2: adding the solution containing tetravalent iron ions prepared in S1 into the alkaline printing and dyeing wastewater to be treated, so that the tetravalent iron ions in the solution containing tetravalent iron ions fully contact and react with the organic pollutants in the alkaline printing and dyeing wastewater to be treated, and degrading the alkaline printing and dyeing wastewater.

2. The method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions according to claim 1, characterized in that: In S1, the concentration of the potassium ferrate solution is not less than 0.2 mol / L.

3. The method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions according to claim 1, characterized in that: The volume ratio of the alkaline printing and dyeing wastewater to the potassium ferrate solution is 1:40-1:

50.

4. The method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions according to claim 1, characterized in that: In S1, the temperature of the mixing and standing is 20°C-25°C.

5. The method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions according to claim 1, characterized in that: The mixing was allowed to stand for 30 min.

6. The method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions according to claim 3, characterized in that: In S2, the reaction time of the tetravalent iron ions and the alkaline printing and dyeing wastewater to be treated is not less than 30 minutes.