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

Abstract

The application discloses a method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions, which comprises the following steps: adding alkaline printing and dyeing wastewater to a potassium ferrate solution and mixing and standing, organic matters in the alkaline printing and dyeing wastewater induce the potassium ferrate to occur redox reaction, so that the hexavalent iron ions are reduced into tetravalent iron ions, and a solution containing tetravalent iron ions is formed; and the prepared solution containing tetravalent iron ions is poured into 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 organic pollutants in the alkaline printing and dyeing wastewater to be treated, and the alkaline printing and dyeing wastewater is degraded and treated. The method significantly improves the water treatment effect of the potassium ferrate on wastewater, the TOC removal rate is increased by 10%-20% compared with the method of directly treating wastewater by using a potassium ferrate solution, and the decolorization rate of the wastewater is also obviously improved, and can reach more than 70%, so that the pollution degree of the alkaline printing and dyeing wastewater is effectively reduced, and the method is more suitable for environmental protection emission requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, and particularly relates to a method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions. BACKGROUND

[0002] As a key link in the textile industry chain, the printing and dyeing industry produces printing and dyeing wastewater with complex composition, containing a large amount of dyes, auxiliaries and other organic pollutants, and such wastewater is usually alkaline. At present, as a strong oxidizing agent, potassium ferrate has been applied in the field of water treatment, and the ferric ion in the hexavalent state 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, because the alkaline environment will have a certain influence on the redox process of potassium ferrate, limiting its ability to decompose pollutants, so there is an urgent need for a method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions to optimize the performance of potassium ferrate in the treatment of alkaline printing and dyeing wastewater. SUMMARY

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

[0005] In order to achieve the above purpose, the technical scheme of the present application is:

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

[0007] S1: adding alkaline printing and dyeing wastewater to a potassium ferrate solution, mixing and standing, the organic matter in the alkaline printing and dyeing wastewater induces the redox reaction of potassium ferrate, so that the hexavalent iron ion is reduced to tetravalent iron ion, forming a solution containing tetravalent iron ion;

[0008] S2: putting the solution containing tetravalent iron ion prepared in S1 into the alkaline printing and dyeing wastewater to be treated, so that the tetravalent iron ion in the solution containing tetravalent iron ion fully contacts and reacts with the organic pollutants in the alkaline printing and dyeing wastewater to be treated, and the alkaline printing and dyeing wastewater is degraded and treated.

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

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

[0011] Further, in S1, the temperature of the mixing and standing is 20-25 DEG C.

[0012] Further, the standing time of the mixing is 30 min.

[0013] Further, in S2, the reaction time of the ferric ion with the alkaline printing and dyeing wastewater is not less than 30 min.

[0014] The present application has the following advantages:

[0015] The present application discloses a method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions. The present application significantly improves the water treatment effect of potassium ferrate on wastewater by using a solution containing tetravalent iron ions. Experimental verification shows that, under the same treatment time and initial pollutant concentration of alkaline printing and dyeing wastewater samples, the TOC removal rate of the wastewater treated by the present method is 10%-20% higher than that of the wastewater treated by directly using potassium ferrate solution, 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 meeting the environmental protection discharge requirements. DETAILED DESCRIPTION

[0016] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0017] The specific principle of the present application is as follows:

[0018] The iron ion in potassium ferrate is in a hexavalent state and is a strong oxidizing agent, which can oxidize and decompose organic pollutants in wastewater in water treatment. However, in the alkaline printing and dyeing wastewater environment, the oxidation-reduction process is affected to some extent, and the ability to decompose pollutants is limited. The present method first prepares a potassium ferrate solution with a certain concentration, takes a small amount of alkaline printing and dyeing wastewater and adds it to the potassium ferrate solution, uses the organic matter in the alkaline printing and dyeing wastewater to induce the potassium ferrate to react, and the hexavalent iron ion is quickly converted into tetravalent iron ion.

[0019] Since the tetravalent iron ion has high oxidizing properties under alkaline conditions, it can improve the degradation effect of organic pollutants when it comes into contact with organic pollutants, so that the removal rate of organic matter can reach more than 70%, and the decolorization rate of wastewater can be increased to more than 65%.

[0020] Embodiment 1

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

[0022] S1: accurately take a certain amount of solid potassium ferrate, dissolve it in deionized water, continuously stir, and prepare a potassium ferrate solution with a concentration of 0.2 mol / L. Take 0.8 mL of alkaline printing and dyeing wastewater with pH of 12-13, add it to 40 mL of the prepared potassium ferrate solution. Place it in an environment at 20°C for 30 min of reaction. Use the organic matter in the alkaline printing and dyeing wastewater to induce the redox reaction of potassium ferrate, so that the hexavalent iron ion is quickly reduced to the tetravalent iron ion, forming a solution containing tetravalent iron ions;

[0023] S2: the prepared solution containing tetravalent iron ions is poured into the alkaline printing and dyeing wastewater to be treated, fully stirred and uniformly mixed, so that the tetravalent iron ions fully contact with various types of organic pollutants in the printing and dyeing wastewater. After 30 min of reaction, the TOC removal rate, organic matter removal rate and decolorization rate are detected. Under the same treatment time and the same initial pollutant concentration of the alkaline printing and dyeing wastewater sample, the TOC removal rate of the wastewater treated by the method is increased by 10% compared with 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] Example 2

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

[0026] S1: accurately take a certain amount of solid potassium ferrate, dissolve it in deionized water, continuously stir, and prepare a potassium ferrate solution with a concentration of 0.2 mol / L. Take 0.8 mL of alkaline printing and dyeing wastewater with pH of 12-13, add it to 40 mL of the prepared potassium ferrate solution. Place it in an environment at 20°C for 30 min of reaction. Use the organic matter in the alkaline printing and dyeing wastewater to induce the redox reaction of potassium ferrate, so that the hexavalent iron ion is quickly reduced to the tetravalent iron ion, forming a solution containing tetravalent iron ions;

[0027] S2: the prepared solution containing tetravalent iron ions is poured into the alkaline printing and dyeing wastewater to be treated, fully stirred and uniformly mixed, so that the tetravalent iron ions fully contact with various types of organic pollutants in the printing and dyeing wastewater. After 30 min of reaction, the TOC removal rate, organic matter removal rate and decolorization rate are detected. Under the same treatment time and the same initial pollutant concentration of the alkaline printing and dyeing wastewater sample, the TOC removal rate of the wastewater treated by the method is increased by 10% compared with 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%.

[0028] Example 3

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

[0030] S1: accurately take a certain amount of solid potassium ferrate, dissolve it in deionized water, continuously stir, and 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 prepared potassium ferrate solution. Place it in an environment at 20°C and let it react for 30 min. The organic matter in the alkaline printing and dyeing wastewater induces the redox reaction of potassium ferrate, causing the rapid reduction of hexavalent iron ions to tetravalent iron ions, forming a solution containing tetravalent iron ions;

[0031] S2: The prepared solution containing tetravalent iron ions is poured into the alkaline printing and dyeing wastewater to be treated, and fully stirred to make the tetravalent iron ions fully contact with various organic pollutants in the printing and dyeing wastewater. After 30 min of reaction, the TOC removal rate, organic matter removal rate, and decolorization rate are detected. Under the same treatment time and initial pollutant concentration, the TOC removal rate of the wastewater treated by this method is increased by 16% compared with the potassium ferrate solution containing only hexavalent iron ions, the organic matter removal rate is 72%, and the decolorization rate of the wastewater is 74%.

[0032] Example 4:

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

[0034] S1: accurately take a certain amount of solid potassium ferrate, dissolve it in deionized water, continuously stir, and 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 prepared potassium ferrate solution. Place it in an environment at 20°C and let it react for 30 min. The organic matter in the alkaline printing and dyeing wastewater induces the redox reaction of potassium ferrate, causing the rapid reduction of hexavalent iron ions to tetravalent iron ions, forming a solution containing tetravalent iron ions;

[0035] S2: The prepared solution containing tetravalent iron ions is poured into the alkaline printing and dyeing wastewater to be treated, and fully stirred to make the tetravalent iron ions fully contact with various organic pollutants in the printing and dyeing wastewater. After 30 min of reaction, the TOC removal rate, organic matter removal rate, and decolorization rate are detected. Under the same treatment time and initial pollutant concentration, the TOC removal rate of the wastewater treated by this method is increased by 20% compared with the potassium ferrate solution containing only hexavalent iron ions, the organic matter removal rate is 75%, and the decolorization rate of the wastewater is 78%.

[0036] Comparative Example 1:

[0037] Accurately weigh a certain amount of potassium ferrate solid, dissolve it in deionized water, continuously stir, and 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 prepared potassium ferrate solution. After the addition is complete, the mixture is left to stand at 20°C for 30 min, and it is found that tetravalent iron ions cannot be generated (no green liquid is generated by visual observation, the solution color is yellow-brown of trivalent iron, and XRD and ultraviolet tests also prove that only trivalent iron ions are generated, and tetravalent iron ions are not generated.)

[0038] Comparative Example 2:

[0039] Accurately weigh a certain amount of potassium ferrate solid, dissolve it in deionized water, continuously stir, and 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 prepared potassium ferrate solution. After the addition is complete, the mixture is left to stand at 20°C for 30 min, and it is found that tetravalent iron cannot be generated.

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

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limiting; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions, characterized in that, Includes the following steps: S1: Add alkaline dyeing wastewater with a pH of 12-13 to the potassium ferrate solution, mix and let stand. The organic matter in the alkaline dyeing wastewater induces potassium ferrate to undergo a redox reaction, which reduces hexavalent iron ions to tetravalent iron ions, forming a solution containing tetravalent iron ions. S2: The solution containing tetravalent iron ions obtained in S1 is added to the alkaline dyeing and printing wastewater to be treated, so that the tetravalent iron ions in the solution containing tetravalent iron ions can fully contact and react with the organic pollutants in the alkaline dyeing and printing wastewater to be treated, thereby degrading the alkaline dyeing and printing wastewater. In S1, the concentration of the potassium ferrate solution is not less than 0.2 mol / L; In S1, the volume ratio of the alkaline dyeing wastewater to the potassium ferrate solution is 1:40 - 1:

50.

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 temperature for mixing and settling is 20℃-25℃.

3. The method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions according to claim 1, characterized in that, The mixing and settling time is 30 minutes.

4. The method for rapidly improving the water treatment effect of potassium ferrate under alkaline conditions according to claim 1, characterized in that, In S2, the reaction time between the solution containing tetravalent iron ions and the alkaline dyeing wastewater to be treated is not less than 30 minutes.