Deep copper ion capture agent suitable for wide pH range, its preparation and application

Abstract

This invention discloses a copper ion scavenging agent suitable for a wide pH range, its preparation method, and its application. The scavenging agent comprises the following components by mass: 10-30 parts trithiocarbonate, 5-20 parts N,N-dimethylaminodithiocarbamate, and 1-5 parts sodium citrate. The preparation method is as follows: (1) Add water to a sodium citrate solution and stir to prepare a buffer solution A; (2) Add trithiocarbonate and N,N-dimethylaminodithiocarbamate to buffer solution A, stir until completely dissolved, and filter to obtain the final product. This invention has the advantages of a wider pH range, copper removal effect that varies with water quality, stable copper removal effect, fast reaction speed, and rapid floc settling. After treatment, the concentration of each copper ion is less than 0.1 mg / L, the iron content is less than 0.0001%, and the lead content is less than 0.0001%, meeting the environmental emission requirements.

Description

Technical Field

[0001] This invention relates to a copper ion scavenging agent for treating copper wastewater, its preparation method and application, and more particularly to a copper ion scavenging agent adaptable to a wide pH range and depth, its preparation method and application. Background Technology

[0002] With the rapid development of industrial production and urban modernization, copper wastewater is commonly found in the electroplating, electronics, and metallurgical industries. Copper wastewater has a complex composition; besides cyanide-containing wastewater and acid / alkali wastewater, it can be classified according to the copper content, generally into chromium-containing wastewater, nickel-containing wastewater, cadmium-containing wastewater, copper-containing wastewater, zinc-containing wastewater, gold-containing wastewater, and silver-containing wastewater. The discharge of copper wastewater poses serious threats to the environment and human health.

[0003] Currently, there are many methods for treating copper wastewater, such as chemical precipitation, electrochemical methods, membrane separation, and ion exchange. However, these methods have drawbacks such as high investment costs, high operating costs, easy generation of secondary pollution, narrow pH range, and unsatisfactory copper removal effect.

[0004] Among the many methods for treating copper-containing wastewater, the copper scavenging agent method is widely used due to its advantages such as high reaction efficiency, fast sludge sedimentation speed and good selectivity. However, in practical engineering applications, copper scavenging agents have disadvantages such as a narrow applicable pH range, large fluctuations in effluent copper content with changes in water quality, and loose flocs after treatment that are not easy to settle. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a copper ion scavenging agent that can effectively and stably remove copper under fluctuating water quality conditions, and whose copper scavenging agent flocs are not easily loosened and easily settled, and is adaptable to a wide pH range and depth.

[0006] A second objective of this invention is to provide a method for preparing the above-mentioned copper ion scavenger with a wide pH range adaptability.

[0007] A third objective of this invention is to provide applications of the aforementioned copper ion scavenger adapted to a wide pH range.

[0008] Technical solution: The copper ion capture agent adapted to a wide pH range of the present invention comprises the following components by mass: 10-30 parts of trithiocarbonate and 5-20 parts of N,N-dimethylaminodithiocarbamate, and 1-5 parts of sodium dihydrogen citrate.

[0009] It also includes a coagulant aid, which comprises 0.2-0.5 parts sodium carboxymethyl cellulose and 0.5-2 parts dextran.

[0010] It also includes 1 to 2 parts of sodium hydrosulfide.

[0011] The above-mentioned method for preparing a deep copper ion scavenger with a wide pH range includes the following steps:

[0012] (1) Add water to sodium citrate solution and stir to prepare buffer solution A;

[0013] (2) Add trithiocarbonate and N,N-dimethylaminodithiocarbamate to buffer solution A, stir until completely dissolved, and filter to obtain the pH wide-range depth copper ion scavenger.

[0014] In step (2), 1-2 parts of sodium carboxymethyl cellulose, 0.5-2 parts of dextran, and 1-2 parts of sodium hydrosulfide are added to the dissolved system and mixed and dissolved to obtain a pH-wide-range deep copper ion scavenger.

[0015] The above-mentioned copper ion capture agent with a wide pH range adaptability is used in the treatment of copper-containing wastewater in the electronics industry.

[0016] Specifically, copper-containing waste liquid is taken, the pH value is adjusted to 7-11, and the pH wide-range deep copper capture agent is added to the copper-containing waste liquid.

[0017] The dosage of the pH-wide-range deep copper capture agent is 5 to 10 times the copper content per liter of copper waste liquid; the reaction time is 30-60 minutes.

[0018] Invention principle:

[0019] The pH of the water sample to be treated was adjusted to near neutral or above neutral. An appropriate amount of the copper ion scavenging agent of this invention was added, and the sample was buffered with sodium citrate to maintain pH stability. First, copper ions formed complexes with the -CS3 groups in trithiocarbonate and the N-CS2 groups in N,N-dimethylaminodithiocarbamate, respectively, resulting in two precipitates of varying sizes. Meanwhile, the S groups in sodium hydrosulfide... 2- The copper ions react to form relatively fine sulfide precipitates. These three types of fine precipitates, with uneven size distribution, more readily combine with the active groups such as hydroxyl and phenolic hydroxyl groups in sodium carboxymethyl cellulose and dextran. Through the action of the neutral coagulant aids sodium carboxymethyl cellulose and dextran, the fine flocs combine into larger, more easily settling flocs, resulting in rapid and stable settling. Compared to traditional copper scavengers, the copper removal efficiency is increased by 30-50%.

[0020] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects: (1) When the pH is adjusted to near neutral or above neutral, trithiocarbonate and N,N-dimethylaminodithiocarbamate are used to complex with copper ions to produce precipitates of different particle sizes, which fully complex copper ions, settle quickly, and the flocs are stable and can adapt to a wide pH range. (2) Under the condition of adding sodium hydrosulfide, three different particle sizes of precipitates are formed. At the same time, under the action of coagulant, the fine flocs combine into larger flocs that are easy to settle. Compared with traditional copper scavenging agents, the copper removal efficiency is increased by 30-50%. (3) The copper-containing wastewater is pumped into the pH adjustment tank, and the pH of the copper-containing wastewater entering the adjustment tank is adjusted to 7-11. The high-efficiency, deep copper scavenging agent is added. After reacting for 30 minutes, the electrolytic copper content in the wastewater with a copper content of 100ppm can be reduced to below 0.1mg / L, and the sedimentation is rapid and the effluent is clear. Compared with previous copper scavenging agents, it has the advantages of a wider pH range, copper removal effect that varies with water quality, stable copper removal effect, fast reaction speed, and rapid floc settling. (4) After the above copper-containing waste liquid was treated with a deep copper ion scavenging agent with a wide pH range, the concentration of each copper ion was less than 0.1 mg / L, the iron content was less than 0.0001%, and the lead content was less than 0.0001%, which met the environmental protection emission requirements. Attached Figure Description

[0021] Figure 1 This is a process flow diagram for the application of this invention. Detailed Implementation

[0022] The present invention will now be described in further detail.

[0023] Example 1

[0024] Preparation of a wide-range pH copper ion scavenger:

[0025] Formula 1: Prepare 1 part sodium citrate solution at room temperature; add 10 parts trithiocarbonate and 5 parts N,N-dimethylaminodithiocarbamate, stir thoroughly until the solid is completely dissolved, and filter with a 5µm filter bag to obtain a wide pH range depth copper ion scavenging agent.

[0026] Formula 2: Prepare 1 part sodium citrate solution at room temperature; add 20 parts trithiocarbonate and 5 parts N,N-dimethylaminodithiocarbamate, stir thoroughly until the solid is completely dissolved, and filter with a 5µm filter bag to obtain a wide pH range deep copper ion scavenging agent.

[0027] Formula 3: Prepare 1 part sodium citrate solution at room temperature; add 30 parts trithiocarbonate and 5 parts N,N-dimethylaminodithiocarbamate, stir thoroughly until the solid is completely dissolved, and filter with a 5µm filter bag to obtain a wide pH range deep copper ion scavenging agent.

[0028] Formula 4: Prepare 1 part sodium citrate solution at room temperature; add 10 parts trithiocarbonate and 10 parts N,N-dimethylaminodithiocarbamate, stir thoroughly until the solid is completely dissolved, and filter with a 5µm filter bag to obtain a wide pH range deep copper ion scavenging agent.

[0029] Formula 5: Prepare 1 part sodium citrate solution at room temperature; add 10 parts trithiocarbonate and 20 parts N,N-dimethylaminodithiocarbamate, stir thoroughly until the solid is completely dissolved, and filter with a 5µm filter bag to obtain a wide pH range deep copper ion scavenging agent.

[0030] Formula 6: Prepare 1.5 parts sodium citrate dihydrogen solution at room temperature; add 10 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, and 1 part sodium hydrosulfide, stir thoroughly until the solid is completely dissolved, and filter with a 5µm filter bag to obtain a wide pH range deep copper ion scavenging agent.

[0031] Formula 7: Prepare 1.5 parts sodium citrate dihydrogen solution at room temperature; add 20 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, and 1.5 parts sodium hydrosulfide, stir thoroughly until the solid is completely dissolved, and filter with a 5µm filter bag to obtain a wide pH range deep copper ion scavenging agent.

[0032] Formula 8: Prepare 1.5 parts sodium citrate dihydrogen solution at room temperature; add 30 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, and 2 parts sodium hydrosulfide, stir thoroughly until the solid is completely dissolved, and filter with a 5µm filter bag to obtain a wide pH range deep copper ion scavenging agent.

[0033] Formula 9: Prepare 3 parts sodium citrate dihydrogen solution at room temperature; add 20 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, and 2 parts sodium hydrosulfide, stir thoroughly until the solid is completely dissolved, and filter with a 5µm filter bag to obtain a wide pH range deep copper ion scavenging agent.

[0034] Formula 10: Prepare 5 parts sodium citrate solution at room temperature; add 30 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, 0.2 parts sodium carboxymethyl cellulose, 0.5 parts dextran, and 1 part sodium hydrosulfide. Stir thoroughly until the solid is completely dissolved. Filter with a 5µm filter bag to obtain a pH-wide depth copper ion scavenger.

[0035] Formula 11: Prepare 5 parts sodium citrate dihydrogen solution at room temperature; add 30 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, 0.3 parts sodium carboxymethyl cellulose, 0.5 parts dextran, and 1 part sodium hydrosulfide. Stir thoroughly until the solid is completely dissolved. Filter with a 5µm filter bag to obtain a pH-wide depth copper ion scavenging agent.

[0036] Formula 12: Prepare 5 parts sodium citrate solution at room temperature; add 30 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, 0.5 parts sodium carboxymethyl cellulose, 0.3 parts dextran, and 1 part sodium hydrosulfide. Stir thoroughly until the solid is completely dissolved. Filter with a 5µm filter bag to obtain a pH-wide depth copper ion scavenger.

[0037] Formula 13: Prepare 5 parts sodium citrate solution at room temperature; add 30 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, 0.3 parts sodium carboxymethyl cellulose, 1 part dextran, and 1 part sodium hydrosulfide. Stir thoroughly until the solid is completely dissolved. Filter with a 5µm filter bag to obtain a pH-wide-range deep copper ion scavenging agent.

[0038] Formula 14: Prepare 5 parts sodium citrate solution at room temperature; add 30 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, 1 part sodium carboxymethyl cellulose, 0.3 parts dextran, and 2 parts sodium hydrosulfide. Stir thoroughly until the solid is completely dissolved. Filter with a 5µm filter bag to obtain a pH-wide-range deep copper ion scavenging agent.

[0039] The wastewater from a semiconductor factory containing copper has the following characteristics: copper content 10.6 ppm, pH 2.3, and flow rate 20 m³ / h. 3 / d. For example... Figure 1 As shown, the method for treating the waste liquid using the above-mentioned capture agent formulations includes the following steps:

[0040] Step 1: Send the copper-containing wastewater with a copper content of 10.6 ppm to the pH adjustment tank, add 20 parts NaOH and 20 parts H2SO4, adjust the pH of the wastewater in the adjustment tank to 8±1, add the heavy removal and precipitating agent to a mass concentration of 100 ppm, stir rapidly, and react for 20 min.

[0041] Step 2: Send the effluent from the copper reaction tank to the copper flocculation tank, add 1‰ polyacrylamide to a mass concentration of 5ppm, stir at low speed, and react for 10 minutes.

[0042] Step 3: Send the effluent from the copper flocculation tank to the sedimentation tank and let it settle for 30 minutes.

[0043] Step 4: Return 15 parts of sludge from the bottom of the sedimentation tank to the deep copper reaction tank through the sludge return pipe, and discharge the remaining 85 parts of sludge.

[0044] Step 5: The copper ion content in the wastewater after deep copper removal is <0.1mg / L, which meets the discharge standards. After being stored in a clear water tank, it is discharged.

[0045] The specific proportions of each of the above formulations and their effects on treating copper ions are shown in Tables 1 and 2 below.

[0046] Table 1 Specific quantities of each recipe

[0047]

[0048] Table 2. Effects of raw water and formulas one through fourteen on copper ion capture.

[0049] Copper ion concentration in effluent (ppm) Settlement velocity (s) alum flower size raw water 10.6 - none Formula 1 0.15 186 small Formula 2 0.12 176 small Formula 3 0.10 153 small Formula 4 0.08 156 small Formula 5 0.07 149 small Formula Six 0.01 136 smaller Formula Seven 0.01 132 smaller Formula 8 0.01 135 smaller Formula Nine 0.01 137 smaller Formula 10 0.02 52 block Formula Eleven 0.01 37 block Formula Twelve 0.01 32 block Formula Thirteen 0.01 35 block Formula Fourteen 0.01 33 block

[0050] As shown in Tables 1 and 2 above, the formulation consists of trithiocarbonate, N,N-dimethylaminodithiocarbamate, sodium dihydrogen citrate, a specially formulated coagulant aid: a mixture of sodium carboxymethyl cellulose and dextran, and sodium hydrosulfide. Increasing the amount of sodium trithiocarbonate improves the heavy metal removal effect, but the sedimentation rate is not ideal. Adding sodium hydrosulfide significantly increases the sedimentation rate, with the best effect observed at an addition amount of 1.5 parts or more. The addition of carboxymethyl cellulose and dextran forms flocs that are lumpy and easily settle; the effect is best within the specified dosage range. This invention's wide-range pH copper ion scavenging agent shows good copper removal efficiency from copper-containing wastewater in the electronics industry, with effluent metal ion concentrations less than 0.1 mg / L.

[0051] Example 2

[0052] Preparation of copper ion scavenging agent:

[0053] Formula: Prepare 1.5 parts sodium citrate solution at room temperature; add 25 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, 0.5 parts sodium carboxymethyl cellulose, 0.5 parts dextran, and 1 part sodium hydrosulfide, and stir thoroughly for 30 minutes until the solids are completely dissolved. Filter with a 5µm filter bag to obtain a pH-wide depth copper ion scavenging agent.

[0054] The wastewater from a semiconductor factory contains copper and has the following characteristics: copper content 73 ppm, nickel 46 ppm, and a flow rate of 30 m³ / h. 3 / d. The method for treating the waste liquid using the above-mentioned trapping agent formulation includes the following steps:

[0055] Reaction steps:

[0056] Step 1: Send the copper-containing wastewater with a copper content of 73ppm and a nickel content of 46ppm to the pH adjustment tank. Add 20% NaOH and 20% H2SO4 to adjust the pH of the wastewater in the tank to 9±1. Add the heavy removal and precipitating agent to a mass concentration of 1000ppm, stir rapidly, and react for 20 minutes.

[0057] Step 2: Send the effluent from the copper reaction tank to the copper flocculation tank, add 1‰ polyacrylamide to a mass concentration of 5ppm, stir at low speed, and react for 10 minutes.

[0058] Step 3: Send the effluent from the copper flocculation tank to the sedimentation tank and let it settle for 30 minutes.

[0059] Step 4: Return 15 parts of sludge from the bottom of the sedimentation tank to the deep copper reaction tank through the sludge return pipe, and discharge the remaining 85 parts of sludge.

[0060] Step 5: After deep copper removal, the copper ion content in the wastewater is <0.1mg / L and the nickel ion content is <0.05mg / L, which meets the discharge standards. After being stored in a clear water tank, the wastewater is discharged.

[0061] Example 3

[0062] Preparation of copper ion scavenging agent:

[0063] Formula: Prepare 1.5 parts sodium citrate solution at room temperature; add 25 parts trithiocarbonate, 10 parts N,N-dimethylaminodithiocarbamate, 0.5 parts carboxymethyl cellulose, 0.5 parts dextran, and 1 part sodium hydrosulfide, and stir thoroughly for 30 minutes until the solids are completely dissolved. Filter through a 5µm filter bag to obtain a pH-wide depth copper ion scavenging agent.

[0064] The wastewater from a TFT-LCD panel factory contains copper and has the following characteristics: copper acid content 35 ppm, wastewater flow rate 30 m³ / h. 3 / d. The method for treating the waste liquid using the above-mentioned capture agent formulations includes the following steps:

[0065] Step 1: Send the copper-containing wastewater to the pH adjustment tank, add 20 parts NaOH and 20 parts H2SO4, adjust the pH of the wastewater in the tank to 10±1, add the heavy removal and precipitating agent to a mass concentration of 300ppm, stir quickly, and react for 20min.

[0066] Step 2: Send the effluent from the copper reaction tank to the copper flocculation tank, add 1‰ polyacrylamide to a mass concentration of 5ppm, stir at low speed, and react for 10 minutes.

[0067] Step 3: Send the effluent from the copper flocculation tank to the sedimentation tank and let it settle for 30 minutes.

[0068] Step 4: Return 15 parts of sludge from the bottom of the sedimentation tank to the deep copper reaction tank through the sludge return pipe, and discharge the remaining 85 parts of sludge.

[0069] Step 5: The copper ion content in the wastewater after deep copper removal is 0.03 mg / L, which meets the discharge standard. After being stored in a clear water tank, it is discharged.

Claims

1. An application of a copper ion capture agent adaptable to a wide pH range in the treatment of copper-containing wastewater in the electronics industry, characterized in that, Take copper-containing wastewater, adjust the pH value to 7-11, and add a copper ion scavenging agent with a wide pH range to the copper-containing wastewater. The copper ion scavenging agent with a wide pH range includes the following components by mass: 10-30 parts trithiocarbonate, 5-20 parts N,N-dimethylaminodithiocarbamate, and 1-5 parts sodium dihydrogen citrate; it also includes a coagulant aid, which includes 0.2-0.5 parts sodium carboxymethyl cellulose and 0.5-2 parts dextran; and 1-2 parts sodium hydrosulfide.

2. The application of the copper ion capture agent with a wide pH range adaptability according to claim 1 in the treatment of copper-containing wastewater in the electronics industry, characterized in that, The preparation method of the copper ion scavenger with a wide pH range includes the following steps: (1) Add water to sodium citrate solution and stir to prepare buffer solution A; (2) Add trithiocarbonate and N,N-dimethylaminodithiocarbamate to buffer solution A and stir until completely dissolved; Sodium carboxymethyl cellulose, dextran, and sodium hydrosulfide were added to the dissolved system and mixed and dissolved; after filtration, the pH wide-range deep copper ion scavenging agent was obtained.

3. The application of the copper ion capture agent with a wide pH range adaptability according to claim 1 in the treatment of copper-containing wastewater in the electronics industry, characterized in that, The dosage of the pH-wide-range deep copper capture agent is 5 to 10 times the copper content per liter of copper waste liquid.

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