Cationic heavy metal scavenger and its preparation method and application

Abstract

The invention relates to the technical field of wastewater treatment, and discloses a cationic heavy metal scavenger and a preparation method and application thereof. A cationic heavy metal scavenger comprises the following preparation raw materials: an alcohol amine compound, a methane halide and carbon disulfide; the mass ratio of the alcohol amine compound, the methane halide and the carbon disulfide is 10:(4-8):(7-9). In the cationic heavy metal scavenger provided by the invention, which takes the alcohol amine compound, the methane halide and the carbon disulfide as main raw materials, the thiol group can chelate and coordinate with the heavy metal ions in the wastewater to form a precipitate, and the quaternary ammonium salt cation structure formed by the substitution reaction between the methane halide and the alcohol amine compound can be electrically neutralized with the negatively charged colloidal particles in the wastewater, so that the heavy metal flocculent particles are destabilized, aggregated to form a larger precipitate, and quickly separated by sedimentation, so as to achieve deep removal of heavy metal ions.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a cationic heavy metal scavenger and a preparation method and application thereof. Background Art

[0002] The production and use of hardware electroplating products will be accompanied by a large amount of heavy metal wastewater. This type of wastewater usually has a low pH value and is extremely toxic and harmful even at low concentrations. Heavy metal ions can enter the human body through air, soil, and water, and have an adverse effect on human health. Therefore, how to effectively treat heavy metals in wastewater from the electronic electroplating industry to prevent it from causing harm to the environment and human health has become an environmental problem that needs to be solved urgently.

[0003] In recent years, the research and application of new heavy metal scavengers have gradually become an important means of treating such wastewater. At present, the most widely used heavy metal scavengers on the market are dithiocarbamates (DTC) and trithiothiotriazine trisodium salts (TMT). The above-mentioned treatment agents chelate with heavy metal ions in wastewater through the dithiocarbamate groups in the molecular structure to form water-insoluble precipitation, thereby removing heavy metals. Although this method has greater technical advantages than the traditional calcium hydroxide / calcium oxide neutralization method and sodium sulfide precipitation method, it still has the disadvantages of fine alum flakes, slow sedimentation rate, poor treatment effect under acidic conditions, and low efficiency in removing complexed heavy metal ions. In particular, the wastewater generated during chemical nickel plating cannot be stably treated by traditional organic sulfur heavy metal scavengers to meet the relevant local emission standards and industry emission standard limits. In addition, the composite heavy metal chelating agents in the prior art also have large steric hindrance, difficulty in capturing heavy metals, high reaction temperature and high comprehensive energy consumption during the preparation process, and low heavy metal ion removal efficiency when applied to heavy metal wastewater treatment, and cannot achieve technical defects such as deep treatment. Summary of the invention

[0004] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, one of the purposes of the present invention is to provide a cationic heavy metal scavenger; the second purpose of the present invention is to provide a method for preparing the cationic heavy metal scavenger; the third purpose of the present invention is to provide a method for treating heavy metal-contaminated wastewater.

[0005] The invention provides a cationic heavy metal scavenger prepared by taking alcohol amine compounds, methane halides and carbon disulfide as main raw materials. The thiol group introduced by carbon disulfide can chelate and coordinate with heavy metal ions in wastewater to form precipitation. The methane halides undergo substitution reaction with the alcohol amine compounds to replace halogen atoms with amine groups, so that the cationic heavy metal scavenger has a quaternary ammonium salt cation structure, and can undergo electrical neutralization with negatively charged colloidal particles in wastewater, destabilize heavy metal flocculent particles, aggregate to form larger precipitation, and quickly settle and separate, so as to achieve deep removal of heavy metals. The cationic heavy metal scavenger has a molecular weight of 180-227 Da, a relatively small molecular weight and a linear structure, and has a small intermolecular steric hindrance, so that it can be more freely combined with heavy metal ions, thereby improving the capture efficiency. During the preparation of the cationic heavy metal scavenger, the reaction temperature and the carbon disulfide dropping speed are strictly controlled to ensure that the carbon disulfide added to the system can preferentially participate in the main reaction, thereby reducing the situation in which the carbon disulfide does not have time to participate in the main reaction due to excessively fast dropping speed, and reacts with the alkali used to adjust the pH value of the system, thereby reducing the amount of by-products such as sodium trithiocarbonate and potassium trithiocarbonate generated, reducing their influence on the heavy metal capture effect, and making the obtained cationic heavy metal scavenger show excellent performance in the treatment of heavy metal contaminated wastewater.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The first aspect of the present invention provides a cationic heavy metal scavenger, comprising the following raw materials: an alcohol amine compound, a methane halide and carbon disulfide; the mass ratio of the alcohol amine compound, the methane halide and the carbon disulfide is 10:(4-8):(7-9).

[0008] Preferably, the mass ratio of the alcohol amine compound, methane halide and carbon disulfide is 10:(4-6):(7.2-8.2).

[0009] Preferably, the molecular weight of the cationic heavy metal scavenger is 180-227 Da; further preferably, the molecular weight of the cationic heavy metal scavenger is 182-202 Da.

[0010] Preferably, the alcoholamine compound includes at least one of 3-dimethylamino-1-propanol and 3-dimethylamino-1-butanol.

[0011] Preferably, the methane halide includes at least one of methyl chloride, methyl iodide and methyl bromide.

[0012] Preferably, the preparation raw materials also include an ether organic solvent.

[0013] Preferably, the concentration of the ether organic solvent is 97-99 wt %; further preferably, the concentration of the ether organic solvent is 98-99 wt %.

[0014] Preferably, the ether organic solvent includes at least one of tetrahydrofuran, ethylene glycol dimethyl ether and diethyl ether.

[0015] The second aspect of the present invention provides a method for preparing the cationic heavy metal scavenger according to the first aspect of the present invention, comprising the following steps:

[0016] S1, mixing an alcohol amine compound, an ether organic solvent and a methane halide, heating and reacting to obtain a solid product;

[0017] S2, dissolving the solid product in an ether organic solvent, adjusting the pH value to alkaline, and obtaining a mixed solution;

[0018] S3, adding carbon disulfide dropwise to the mixed solution for purification to obtain the product.

[0019] Preferably, in step S1, the mass ratio of the alcoholamine compound to the ether organic solvent is 1:(10-20); further preferably, the mass ratio of the alcoholamine compound to the ether organic solvent is 1:(10-15).

[0020] Preferably, in step S1, the methane halide participates in the reaction in the form of a solution; the concentration of the methane halide solution is 97-99 wt %; further preferably, the concentration of the methane halide solution is 98-99 wt %.

[0021] Preferably, in step S1, the temperature of the heating reaction is 40-55°C; further preferably, the temperature of the heating reaction is 45-55°C.

[0022] Preferably, in step S1, the heating reaction time is 1 to 3 hours; further preferably, the heating reaction time is 1 to 2 hours.

[0023] Preferably, in the step S1, after the heating reaction is completed, a cooling step is also included.

[0024] Preferably, in step S1, the cooling temperature is 15-35°C; further preferably, the cooling temperature is 15-25°C.

[0025] Preferably, in step S1, the heating reaction process is assisted by stirring.

[0026] Preferably, in the step S1, after cooling, centrifugation is performed to obtain a solid product; the solid product is light yellow.

[0027] Preferably, in step S2, the mass ratio of the solid product to the ether organic solvent is 1:(15-25); further preferably, the mass ratio of the solid product to the ether organic solvent is 1:(15-20).

[0028] Preferably, in the step S2, after the solid product is dissolved in the ether organic solvent, a cooling step is further included.

[0029] Preferably, in step S2, the cooling temperature is -1.0 to 8.0°C; further preferably, the cooling temperature is -1.0 to 5.0°C.

[0030] Preferably, in step S2, the pH value of the mixed solution is 10-13; further preferably, the pH value of the mixed solution is 12-13.

[0031] Preferably, in step S2, the pH value is adjusted to alkaline by adding alkali solution; the alkali source of the alkali solution includes alkali metal hydroxide; the alkali metal hydroxide includes at least one of potassium hydroxide and sodium hydroxide.

[0032] Preferably, in step S2, the concentration of the alkali solution is 5 to 15 wt %; further preferably, the concentration of the alkali solution is 10 to 15 wt %.

[0033] Preferably, in step S2, the mass ratio of the alkali solution to the alcoholamine compound is (1-3):1; further preferably, the mass ratio of the alkali solution to the alcoholamine compound is (1-2.5):1.

[0034] Preferably, in step S3, the concentration of carbon disulfide is 97-99 wt %; further preferably, the concentration of carbon disulfide is 98-99 wt %.

[0035] Preferably, in step S3, the dropping speed of the carbon disulfide is 0.05 to 1.5 mL / min; further preferably, the dropping speed of the carbon disulfide is 0.05 to 1.0 mL / min.

[0036] Preferably, in step S3, the temperature of the dropping process is 0-18°C; more preferably, the temperature of the dropping process is 0-15°C.

[0037] Preferably, in the step S3, the purification further includes a step of concentrating and removing the solvent.

[0038] Preferably, in step S3, an alcohol solvent is added to carry out the purification; the alcohol solvent includes at least one of anhydrous methanol, anhydrous ethanol and isopropanol.

[0039] Preferably, in step S3, the mass ratio of the alcohol solvent to the alcohol amine compound is (25-55):1; further preferably, the mass ratio of the alcohol solvent to the alcohol amine compound is (30-50):1.

[0040] The third aspect of the present invention provides a method for treating heavy metal-contaminated wastewater, comprising removing pollutants using the cationic heavy metal scavenger described in the first aspect of the present invention.

[0041] Preferably, the water quality parameters of the heavy metal polluted wastewater include at least one of the following: Ni 2+ The content is 0.5~1.5mg / L; Zn 2+ The content is 1.5~2.0mg / L; Cu 2+ The content is 0.8-3.0 mg / L; further preferably, the water quality parameters of the heavy metal polluted wastewater include at least one of the following: Ni 2+ The content is 0.5~1.2mg / L; Zn 2+ The content is 1.5~2.0mg / L; Cu 2+ The content is 0.8~2.6mg / L.

[0042] Preferably, the solid-liquid ratio of the cationic heavy metal scavenger to the wastewater is (70-80) mg:1L; further preferably, the solid-liquid ratio of the cationic heavy metal scavenger to the wastewater is (75-80) mg:1L.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1) In the cationic heavy metal scavenger provided by the present invention, which uses alcohol amine compounds, methane halides and carbon disulfide as main raw materials, the thiol group can chelate and coordinate with heavy metal ions in wastewater to form precipitation, and the quaternary ammonium salt cation structure formed by the substitution reaction between methane halides and alcohol amine compounds can have an electrical neutralization effect with negatively charged colloidal particles in the wastewater, so that the heavy metal flocculent particles are destabilized, aggregated to form a larger precipitation, and quickly separated by sedimentation, thereby achieving deep removal of heavy metal ions; the cationic heavy metal scavenger has a small molecular weight and a linear structure, and has a small steric hindrance between molecules, which is helpful to improve the heavy metal ion capture efficiency.

[0045] 2) The preparation method of the cationic heavy metal scavenger provided by the present invention has simple steps, low heating temperature, and low energy consumption. The preparation process reduces side reactions and ensures product performance by strictly controlling the reaction temperature and the dripping speed of carbon disulfide.

[0046] 3) The method for treating heavy metal polluted wastewater provided by the present invention, under the action of a cationic heavy metal scavenger, Ni 2+ 、Zn 2+ and Cu2+ The removal rate of heavy metal ions is greater than 70%, and stable Ni 2+ 、Zn 2+ , Cu 2+ The removal effect is good, the heavy metal polluted wastewater treatment effect is good, and the practicability is strong. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below by specific examples. Unless otherwise specified, the raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial sources or can be obtained by prior art methods. Unless otherwise specified, the experiments or test methods are conventional methods in the art.

[0048] Example 1

[0049] This embodiment provides a cationic heavy metal scavenger, and the preparation method comprises the following steps:

[0050] (1) 30 g of 3-dimethylamino-1-propanol was added to 305 mL of 99 wt% tetrahydrofuran, and the mixture was stirred evenly. Then, 15 g of 99 wt% iodomethane solution was added, and the temperature of the reactor was raised to 55° C., and the mixture was stirred and reacted for 1.5 hours under the temperature condition;

[0051] (2) cooling the reaction solution synthesized in step (1) to 18° C. by cooling circulating water, generating a solid precipitate in the reactor, and then centrifugally filtering to obtain a light yellow solid product;

[0052] (3) adding the solid product generated in step (2) to 320 mL of 99 wt% diethyl ether, cooling the system to 5.0° C., then adding 45 g of 10 wt% sodium hydroxide solution, and adjusting the pH value of the mixed solution in the reactor to 12.5;

[0053] (4) 17.44 mL of a 99 wt% carbon disulfide solution was slowly added dropwise to the mixed solution obtained in step (3) in batches, the carbon disulfide addition rate was adjusted to 1.0 mL / min, and the temperature of the entire dropping process was controlled to be 0-15° C., then the ether and water were removed by concentration, and finally recrystallization was performed with anhydrous ethanol to obtain a cationic heavy metal scavenger.

[0054] In the cationic heavy metal scavenger provided in this embodiment, the mass ratio of 3-dimethylamino-1-propanol, methyl iodide and carbon disulfide is 10:4.95:7.29.

[0055] Example 2

[0056] This embodiment provides a cationic heavy metal scavenger, and the preparation method comprises the following steps:

[0057] (1) 30 g of 3-dimethylamino-1-butanol was added to 360 mL of 99 wt% tetrahydrofuran, stirred evenly, and then 18 g of 99 wt% monochloromethane solution was added. The reactor was heated to 50° C. and stirred for 1.5 hours at this temperature.

[0058] (2) cooling the reaction solution synthesized in step (1) to 15° C. by cooling circulating water, generating a solid precipitate in the reactor, and then centrifugally filtering to obtain a light yellow solid product;

[0059] (3) adding the solid product generated in step (2) to 350 mL of 99 wt% ethylene glycol dimethyl ether, cooling the system to 5.0° C., then adding 30 g of 15 wt% sodium hydroxide solution, and adjusting the pH value of the mixed solution in the reactor to 13;

[0060] (4) 19.60 mL of a 99 wt% carbon disulfide solution was slowly added dropwise to the mixed solution obtained in step (3) in batches, the carbon disulfide addition rate was adjusted to 1.0 mL / min, and the temperature of the entire dropping process was controlled to be 0-15° C., then the ethylene glycol dimethyl ether and water were removed by concentration, and finally recrystallization was performed with anhydrous methanol to obtain a cationic heavy metal scavenger.

[0061] In the cationic heavy metal scavenger provided in this embodiment, the mass ratio of 3-dimethylamino-1-butanol, methyl chloride and carbon disulfide is 10:5.94:8.19.

[0062] Example 3

[0063] This comparative example provides a cationic heavy metal scavenger, and the preparation method comprises the following steps, which is different from Example 1 only in that the dropping speed of carbon disulfide in step (4) is 2.0 mL / min:

[0064] (1) 30 g of 3-dimethylamino-1-propanol was added to 305 mL of 99 wt% tetrahydrofuran, and the mixture was stirred evenly. Then, 15 g of 99 wt% iodomethane solution was added, and the temperature of the reactor was raised to 55° C., and the mixture was stirred and reacted for 1.5 hours under the temperature condition;

[0065] (2) cooling the reaction solution synthesized in step (1) to 18° C. by cooling circulating water, generating a solid precipitate in the reactor, and then centrifugally filtering to obtain a light yellow solid product;

[0066] (3) adding the solid product generated in step (2) to 320 mL of 99 wt% diethyl ether, cooling the system to 5.0° C., then adding 45 g of 10 wt% sodium hydroxide solution, and adjusting the pH value of the mixed solution in the reactor to 12.5;

[0067] (4) 17.44 mL of a 99 wt% carbon disulfide solution was slowly added dropwise to the mixed solution obtained in step (3) in batches, the carbon disulfide addition rate was adjusted to 2.0 mL / min, and the temperature of the entire dropping process was controlled to be 0-15° C., then the ether and water were removed by concentration, and finally recrystallization was performed with anhydrous ethanol to obtain a cationic heavy metal scavenger.

[0068] In the cationic heavy metal scavenger provided in this embodiment, the mass ratio of 3-dimethylamino-1-propanol, methyl iodide and carbon disulfide is 10:4.95:7.29.

[0069] Example 4

[0070] This comparative example provides a cationic heavy metal scavenger, and the preparation method comprises the following steps, which is different from Example 2 only in that the dropping speed of carbon disulfide in step (4) is 2.0 mL / min:

[0071] (1) 30 g of 3-dimethylamino-1-butanol was added to 360 mL of 99 wt% tetrahydrofuran, stirred evenly, and then 18 g of 99 wt% monochloromethane solution was added. The reactor was heated to 50° C. and stirred for 1.5 hours at this temperature.

[0072] (2) cooling the reaction solution synthesized in step (1) to 15° C. by cooling circulating water, generating a solid precipitate in the reactor, and then centrifugally filtering to obtain a light yellow solid product;

[0073] (3) adding the solid product generated in step (2) to 350 mL of 99 wt% ethylene glycol dimethyl ether, cooling the system to 5.0° C., then adding 30 g of 15 wt% sodium hydroxide solution, and adjusting the pH value of the mixed solution in the reactor to 13;

[0074] (4) 19.60 mL of a 99 wt% carbon disulfide solution was slowly added dropwise to the mixed solution obtained in step (3) in batches, the carbon disulfide addition rate was adjusted to 2.0 mL / min, and the temperature of the entire dropping process was controlled to be 0-15° C., then the ethylene glycol dimethyl ether and water were removed by concentration, and finally recrystallization was performed with anhydrous methanol to obtain a cationic heavy metal scavenger.

[0075] In the cationic heavy metal scavenger provided in this embodiment, the mass ratio of 3-dimethylamino-1-butanol, methyl chloride and carbon disulfide is 10:5.94:8.19.

[0076] Comparative Example 1

[0077] Taking the commercially available organic sulfur TMT-15 water treatment agent as a comparison, the agent can react rapidly with various heavy metal ions (mercury, lead, copper, cadmium, nickel, manganese, zinc, chromium, etc.) in wastewater at room temperature to generate chelates that are insoluble in water and have good chemical stability, thereby achieving the purpose of capturing and removing heavy metals. TMT-15 water treatment agent was purchased from Shandong Huamei Water Treatment and Environmental Protection Co., Ltd.

[0078] Comparative Example 2

[0079] The commercially available 40% sodium furam solution was used as a comparison. Sodium furam (sodium dimethyldithiocarbamate) is used for heavy metal wastewater treatment and can precipitate heavy metal ions in water. The 40% sodium furam solution was purchased from Hunan Fuercheng Technology Co., Ltd.

[0080] Application Example 1

[0081] The cationic heavy metal scavengers in Examples 1 to 4 and Comparative Examples 1 to 2 were used to treat electroplating wastewater. The treated electroplating wastewater was mixed drainage from an electroplating factory in Tangxiayong, Bao'an District, Shenzhen City, Guangdong Province. The water quality parameters of the electroplating wastewater tested by ICP are shown in Table 1:

[0082] Table 1 Water quality parameters of electroplating wastewater before treatment in the application example

[0083] Pollutants <![CDATA[Ni 2+ ]]> <![CDATA[Zn 2+ ]]> <![CDATA[Cu 2+ ]]> concentration 0.54mg / L 1.78mg / L 0.97mg / L

[0084] Table 1 shows the water quality parameters of electroplating wastewater before treatment in the application example. It can be seen from Table 1 that the main heavy metal pollutants in the wastewater are Ni 2+ 、Zn 2+ and Cu 2+ , and their concentrations exceed the limit values ​​in the Guangdong Provincial Local Standard "Electroplating Water Pollutant Discharge Standard (DB44 / 1597-2015)" (Ni 2+ ≤0.1mg / L, Zn 2+ ≤1.0mg / L, Cu 2+ ≤0.3mg / L).

[0085] 500 mL of the above wastewater was measured and placed in 6 1000 ml beakers, and 40 mg of the cationic heavy metal scavenger in Examples 1 to 4 and Comparative Examples 1 to 2 was added respectively. After magnetic stirring for 5 minutes, the mixture was allowed to stand for 30 minutes and filtered with a 0.45 μm filter membrane. The concentration of each heavy metal ion in the filtrate was detected. The test results are shown in Table 2:

[0086] Table 2 Water quality parameters of electroplating wastewater after treatment in Application Example 1

[0087]

[0088]

[0089] Table 2 shows the water quality parameters of the electroplating wastewater after treatment in Application Example 1. It can be seen from Table 2 that under the same dosage, the electroplating wastewater treated with the cationic heavy metal scavenger in Examples 1 and 2 has Ni 2+ The removal rates were higher than 85%, Zn 2+ The removal rates were all above 70%, Cu 2+ The removal rates were higher than 84%, Ni 2+ 、Zn 2+ and Cu 2+ The residual concentrations of Ni 2+ ≤0.1mg / L, Zn 2+ ≤1.0mg / L, Cu 2+ ≤0.3mg / L), the heavy metal wastewater treatment effect is better. In Examples 3 and 4, the drop rate of carbon disulfide in the preparation process of the cationic heavy metal scavenger is changed. Compared with Examples 1 and 2, the cationic heavy metal scavenger has a better effect on the heavy metal ion Ni 2+ 、Zn 2 + and Cu 2+ The capture effect of Ni 2+ 、Zn 2+ and Cu 2+ The residual concentrations of the wastewater treatment agents are all higher than the standard limit, and the wastewater treatment effect is not up to standard, indicating that the carbon disulfide dripping speed has a great influence on the occurrence of side reactions. When the dripping speed is too fast, the carbon disulfide in the system cannot participate in the main reaction. Some carbon disulfide reacts with the alkali (sodium hydroxide or potassium hydroxide) used to adjust the pH to produce third-generation sodium carbonate or third-generation potassium carbonate, which affects the heavy metal removal effect and makes the performance of the cationic heavy metal scavenger worse. Comparative Examples 1 and 2 are commercially available metal ion capture water treatment agents. It can be seen that the two commercially available water treatment agents have a negative effect on Ni 2+ 、Zn 2+ and Cu 2+ The removal effects of Examples 1 and 2 are far worse than those of Examples 1 and 2, indicating that compared with the existing treatment agents, the cationic heavy metal scavenger provided by the present invention has a better treatment effect on heavy metal polluted wastewater.

[0090] Application Example 2

[0091] Preparation of simulated wastewater: Use copper sulfate pentahydrate and nickel sulfate hexahydrate to prepare Cu2+ Concentration 2.58mg / L, Ni 2+ The concentration of heavy metal wastewater is 1.17 mg / L, and then the pH value of the wastewater is adjusted to 2.5 with sulfuric acid and sodium hydroxide solution. The water quality parameters of the simulated wastewater tested by ICP are shown in Table 3:

[0092] Table 3 Water quality parameters before simulated wastewater treatment in Application Example 2

[0093]

[0094] Table 3 shows the water quality parameters of the simulated wastewater before treatment in Application Example 2. It can be seen from Table 3 that the main heavy metal pollutants in the wastewater are Ni 2+ and Cu 2+ , and the simulated wastewater is strongly acidic.

[0095] 500 mL of the above simulated wastewater was taken and placed in 4 1000 ml beakers, and 40 mg of the cationic heavy metal scavenger in Examples 1-2 and Comparative Examples 1-2 was added to simulate the treatment of heavy metal polluted wastewater. After 5 minutes of magnetic stirring, the mixture was allowed to stand for 30 minutes and filtered with a 0.45 μm filter membrane. The concentration of each heavy metal ion in the filtrate was detected. The test results are shown in Table 4:

[0096] Table 4 Water quality parameters after simulated wastewater treatment in Application Example 2

[0097] Example 1 Example 2 Comparative Example 1 Comparative Example 2 <![CDATA[Ni 2+ Residual concentration (mg / L)]]> 0.15 0.13 0.48 0.69 <![CDATA[Ni 2+ Removal rate]]> 87.2％ 88.9％ 59.0％ 41.0％ <![CDATA[Cu 2+ Residual concentration (mg / L)]]> 0.28 0.25 0.42 0.51 <![CDATA[Cu 2+ Removal rate]]> 89.1％ 90.3％ 83.7％ 80.2％

[0098] Table 4 shows the water quality parameters of the simulated wastewater after treatment in Application Example 2. It can be seen from Table 4 that under the same dosage, the strongly acidic heavy metal polluted simulated wastewater is treated with the cationic heavy metal scavenger in Examples 1 and 2. 2+ The removal rates were higher than 87%, Cu 2+ The removal rates were higher than 89% in Comparative Examples 1 and 2. The commercially available water treatment agent organic sulfur TMT-15 and 40% sodium thiamethoxam solution were used to remove Ni 2+ The removal rates of Cu 2+ The removal rates of the two commercially available water treatment agents were ≥83.7% and ≥80.2% respectively. 2+ The removal effect of Cu 2+ The removal effect can reach 80%, but the removal effect is still not as good as the cationic heavy metal scavengers in Examples 1 and 2. It can be seen that compared with commercially available treatment agents, the cationic heavy metal scavenger provided by the present invention has a better treatment effect on heavy metal polluted wastewater under strong acid conditions.

[0099] The cationic heavy metal scavenger provided by the present invention is effective for Ni 2+ 、Zn 2+ and Cu2+ The removal rates of heavy metal ions such as Hg 2+ 、Cd 2+ , Pb 2+ The cationic heavy metal scavenger can play a good role in heavy metal capture under strong acidic conditions and has strong practicality. The preparation process of the cationic heavy metal scavenger is simple, the reaction temperature is low, the energy consumption is low, and the organic solvents after filtration or concentration in each step can be reused, which is conducive to reducing costs and meeting green process requirements.

Claims

1. A cationic heavy metal scavenger, characterized in that: The preparation method comprises the following raw materials: an alcoholamine compound, a methane halide, carbon disulfide and an ether organic solvent; the mass ratio of the alcoholamine compound, the methane halide and the carbon disulfide is 10: (4-8): (7-9); the alcoholamine compound comprises at least one of 3-dimethylamino-1-propanol and 3-dimethylamino-1-butanol; The cationic heavy metal scavenger is prepared by a method comprising the following steps: S1, mixing an alcohol amine compound, an ether organic solvent and a methane halide, heating and reacting to obtain a solid product; S2, dissolving the solid product in an ether organic solvent, adjusting the pH value to alkaline, and obtaining a mixed solution; S3, adding carbon disulfide dropwise to the mixed solution for purification to obtain the product.

2. The cationic heavy metal scavenger according to claim 1, characterized in that: The molecular weight of the cationic heavy metal scavenger is 180-227 Da.

3. The cationic heavy metal scavenger according to claim 1, characterized in that: The methane halide includes at least one of methyl chloride, methyl iodide and methyl bromide.

4. The cationic heavy metal scavenger according to claim 1, characterized in that: In the step S1, the mass ratio of the alcohol amine compound to the ether organic solvent is 1: (10-20); And / or, the temperature of the heating reaction is 40-55° C. and the time is 1-3 hours.

5. The cationic heavy metal scavenger according to claim 1, characterized in that: In the step S2, the mass ratio of the solid product to the ether organic solvent is 1: (15-25); And / or, the pH value of the mixed solution is 10-13.

6. The cationic heavy metal scavenger according to claim 1, characterized in that: In step S3, the dropping speed of carbon disulfide is 0.05-1.5 mL / min; And / or, the temperature of the dropping process is 0-18°C.

7. A method for treating heavy metal contaminated wastewater, characterized in that: The method comprises using the cationic heavy metal collector according to any one of claims 1 to 6 to remove pollutants.

8. The processing method according to claim 7, characterized in that: The water quality parameters of the heavy metal polluted wastewater include at least one of the following: Ni 2+ The content is 0.5~1.5mg / L; Zn 2+ The content is 1.5~2.0mg / L; Cu 2+ The content is 0.8~3.0mg / L.

9. The processing method according to claim 7, characterized in that: The solid-liquid ratio of the cationic heavy metal scavenger to the wastewater is (70-80) mg: 1L.

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