A high salinity wastewater treatment reagent and method

Abstract

The application discloses a kind of high salinity wastewater treatment reagent and treatment method, wherein the treatment reagent is one or several of any combination of isobutyl alcohol, acetylacetone, 2-methyltetrahydrofuran. The application is suitable for a wide range of PH values, and there is no need to control the PH value of high-salinity wastewater. The application uses alcohol, ketone and ether compounds as desalination reagents, and good results are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, in particular to a treatment reagent and method for high-salinity wastewater. BACKGROUND

[0002] High-salinity wastewater mainly comes from coal gas washing wastewater, circulating water system discharge water, chemical water station drainage and a small amount of organic wastewater after biochemical treatment in industrial production process. It is characterized by high concentrations of suspended solids (SS) and total dissolved solids (TDS), and contains a large amount of calcium and magnesium scale ions, heavy metal ions and other special substances (i.e. high water hardness). Direct discharge into rivers will cause changes in the distribution of water salinity, affecting the physiological functions, growth and reproduction of plants and animals, and even causing death.

[0003] High-salinity wastewater poses a great threat to the environment. Some high-salinity wastewater contains irritating odors. If discharged into the atmosphere without treatment, it will pollute the air quality. If discharged into water bodies without treatment, it will pollute the water environment and exacerbate the degree of water eutrophication. It can cause changes in the distribution of surface water or soil salinity, exacerbate land salinization, and affect the normal growth and reproduction of plants and animals. Moreover, high-salinity wastewater is difficult to process economically. To control the pollution of such high-salinity wastewater, it is not only necessary to reduce the content of COD, but more importantly, to completely separate the soluble salt substances from the wastewater. Therefore, there is an urgent need for new strategies for brine desalination.

[0004] A Chinese invention patent with application number 202310943018.4 discloses a treatment reagent for high-salinity wastewater, its application and a treatment method. The treatment reagent uses an organic reagent with variable hydrophilicity and hydrophobicity to extract fresh water from high-salinity wastewater. The reagent provided by the invention includes N,N-dimethylethanolamine, N,N-dimethylbutylamine, 3,5-dimethylpiperidine and any combination thereof. However, the method has the following shortcomings:

[0005] 1. Loss problem: Since the treatment reagent uses amine solvents, acid-base neutralization reactions will occur when mixed with acidic high-salinity wastewater, resulting in the loss of the treatment reagent. This means that the efficiency of the reagent is low when treating high-salinity wastewater;

[0006] 2. Heat release: Acid-base neutralization reactions are accompanied by the release of a large amount of heat, especially when the acidity of high-salinity wastewater is strong, the reaction is more intense, resulting in the release of a large amount of heat. This may cause safety hazards and also limits the application of the reagent under certain conditions;

[0007] 3. Limitations of acidic high-salinity wastewater: Due to the limitations of acidic high-salinity wastewater, the application range of the reagent in such wastewater is greatly limited, reducing its actual usability. SUMMARY

[0008] In view of the above deficiencies in the prior art, the purpose of the present application is to provide a high-salinity wastewater treatment reagent and a treatment method. The present application uses alcohol, ketone and ether compounds as treatment reagents, which are relatively stable under acidic and alkaline conditions and do not react. Therefore, this improvement can effectively solve the problems of consumption and heat release, and improve the efficiency and safety of the reagent. At the same time, since the new treatment reagent is stable under acidic conditions, it is not limited by the acidity of high-salinity wastewater, greatly widening the application range of the reagent in treating high-salinity wastewater. These improvements make the technical solution more flexible and efficient, and can be more widely applied to wastewater treatment needs under different conditions.

[0009] In order to achieve the above-mentioned purpose of the application, the technical solution adopted by the present application is:

[0010] On the one hand, a high-salinity wastewater treatment reagent is provided, which is any combination of one or more of isobutyl alcohol, acetylacetone and 2-methyltetrahydrofuran.

[0011] On the other hand, a high-salinity wastewater treatment method is provided, which uses the above-mentioned treatment reagent, and specifically includes the following steps:

[0012] Step 1, mix the treatment reagent with the high-salinity wastewater uniformly, then let the solution stand and divide it into two layers, remove the lower layer of salt water phase, and collect the upper layer of solvent phase;

[0013] Step 2, heat the solvent phase, after heating, recover the upper layer of solvent phase, and collect the lower layer of water, which completes the treatment of high-salinity wastewater.

[0014] Further, the heating temperature of the solvent phase is 50℃, and the heating time is 60min.

[0015] Further, the difference between the mixing temperature of the treatment reagent with the high-salinity wastewater and the heating temperature of the solvent phase is 30℃.

[0016] Further, the volume ratio of the treatment reagent to the high-salinity wastewater is 30:1.

[0017] The beneficial effects of the present application are:

[0018] The present application is suitable for a wide range of pH values, and does not need to control the pH value of high-salinity wastewater due to acid-base neutralization reaction, significantly widening the application range of the reagent in high-salinity wastewater. The present application uses alcohol, ketone and ether compounds as desalination reagents, all of which have good effects. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The water production rate and desalination rate (PH=1) of isobutyl alcohol in Example 1 of the present application are shown in the diagram;

[0020] Figure 2 Figure for water production rate and desalination rate (PH = 1) of acetylacetone in the embodiment 2 of the present application;

[0021] Figure 3 Figure for water production rate and desalination rate (PH = 1) of 2-methyltetrahydrofuran in the embodiment 3 of the present application;

[0022] Figure 4 Figure for water production rate and desalination rate (PH = 12) of NaCl solution and various reagents in the embodiment 4 of the present application. DETAILED DESCRIPTION

[0023] The specific embodiments of the present application are described below to facilitate the understanding of the present application for those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, it is obvious that various changes are within the spirit and scope of the present application defined and determined by the appended claims, and all the inventions utilizing the concept of the present application are within the scope of protection.

[0024] In the embodiments of the present application, high-salinity wastewater and landfill leachate are used for testing, and the high-salinity wastewater is simulated high-salinity wastewater. The salt concentration of the simulated high-salinity wastewater is 0.34 mol / L except for the landfill leachate.

[0025] The parameters are shown in the following table.

[0026]

[0027]

[0028] Embodiment 1

[0029] A method for treating high-salinity wastewater, specifically comprising the following steps:

[0030] Step 1, uniformly mix 30 ml of treatment reagent (isobutyl alcohol) with 1 ml of high-salinity wastewater at 20℃, and then let the solution stand to divide into upper and lower layers, discharge the lower salt water phase, and collect the upper solvent phase;

[0031] Step 2, heat the solvent phase (the heating temperature of the solvent phase is 50℃, and the heating time is 60 min), after heating, recover the upper solvent phase, and collect the lower water, which completes the treatment of high-salinity wastewater.

[0032] In this embodiment, the high-salinity wastewater is acidic, and the acidic condition is adjusted to PH = 1 by using 1 mol / L hydrochloric acid solution. The test results are shown in the following table and the following table. Figure 1

[0033]

[0034] ​Example 2

[0035] In the method steps of Example 2, the same as Example 1 will not be described here, only the different from Example 1. The difference between Example 2 and Example 1 is that the treatment reagent used in Example 2 is acetylacetone, the rest is described in Example 1. The test results are as follows Figure 2 and the following table.

[0036]

[0037] Example 3

[0038] In the method steps of Example 3, the same as Example 1 will not be described here, only the different from Example 1. The difference between Example 3 and Example 1 is that the treatment reagent used in Example 3 is 2-methyltetrahydrofuran, the rest is described in Example 1. The test results are as follows Figure 3 and the following table.

[0039]

[0040] Example 4

[0041] A method for treating high-salinity wastewater, specifically comprising the following steps:

[0042] Step 1, 30ml treatment reagent (isobutyl alcohol, acetylacetone, 2-methyltetrahydrofuran) is mixed with 1ml high-salinity wastewater at 20℃, and the solution is divided into two layers, the lower layer of salt water is discharged, and the upper layer of solvent is collected;

[0043] Step 2, heat the solvent phase (the heating temperature of the solvent phase is 50℃, and the heating time is 60min), after heating, recover the upper layer of solvent, collect the lower layer of water, and the treatment of high-salinity wastewater is completed.

[0044] In this embodiment, the high-salinity wastewater is alkaline, and the alkaline condition is adjusted to PH=12 with triethylamine. The test results are as follows Figure 4 and the following table.

[0045]

[0046] Example 5

[0047] A method for treating high-salinity wastewater, specifically comprising the following steps:

[0048] Step 1, 10ml treatment reagent (isobutyl alcohol) is mixed with 1ml landfill leachate at 20℃, and the solution is divided into two layers, the lower layer of salt water is discharged, and the upper layer of solvent is collected;

[0049] Step 2, heat the solvent phase (the solvent phase heating temperature is 50℃, the heating time is 60min), after heating, recover the upper solvent phase, collect the lower water, which completes the treatment of high-salinity wastewater. The test results are shown in the following table.

[0050]

[0051] Generally, the formation of hydrogen bonds involves the interaction between a polar molecule with a hydrogen atom and another polar molecule (usually with strong electronegative atoms such as oxygen, nitrogen or fluorine). In Chinese invention patent application No. 202310943018.4, the hydrogen bond formed between the N atom and the H atom in the high-salinity wastewater causes the absorption of water, thereby reducing the water content in the high-salinity wastewater. On the other hand, the desalination agent that absorbs water is heated, and due to the strengthening of the random motion between molecules, the hydrogen bond becomes unstable and even breaks, causing the water in the desalination agent to be released again. Similarly, in the present application, alcohol, ketone and ether compounds are selected as desalination reagents because these reagents contain O atoms that can form hydrogen bonds with H atoms in high-salinity wastewater, absorb water in high-salinity wastewater, and release water after heating.

[0052] The present application is suitable for a wide range of pH values, and does not require control of the pH value of high-salinity wastewater due to acid-base neutralization reactions, significantly broadening the application range of the reagent in high-salinity wastewater. The present application uses alcohol, ketone and ether compounds as desalination reagents, all of which have good results.

[0053] It is apparent to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered as exemplary and non-limiting, and the scope of the present application is defined by the appended claims, not the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.

[0054] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method for treating high salinity wastewater, characterized by, The acid high-salinity wastewater is treated by using acetylacetone or 2-methyltetrahydrofuran as a treatment reagent, and the treatment process specifically comprises the following steps: Step 1, after the treatment reagent is uniformly mixed with the high-salinity wastewater, the solution is divided into upper and lower layers, the lower salt water phase is discharged, and the upper solvent phase is collected; Step 2, the solvent phase is heated, after heating, the upper solvent phase is recovered, and the lower water is collected, thereby completing the treatment of the high-salinity wastewater; The heating temperature of the solvent phase is 50 DEG C, and the heating time is 60 min; The difference between the mixing temperature of the treatment reagent and the high-salinity wastewater and the heating temperature of the solvent phase is 30 DEG C; The volume ratio of the treatment reagent to the high-salinity wastewater is 30:1.

Images