Method for recovering valuable metal copper from water while removing organic phosphorus

Abstract

The present application belongs to the technical field of wastewater resource treatment and disposal, and provides a method for recovering valuable metal copper in water and simultaneously removing organic phosphorus. In the present application, copper-containing wastewater is mixed with acid to convert metal copper in a complex state in the wastewater into a salt ion state; then, by adjusting the pH value, the remaining copper element is also in an ion state, while most of the phosphate exists in the form of anion, and an iron-carbon adsorbent is added to remove phosphate substances in the water; then, the iron-carbon adsorbent is separated by magnetic separation, and a mixture of iron oxide and copper oxide is obtained by calcination; finally, the iron oxide is removed by magnetic separation to obtain copper oxide. The results of the examples show that, after the wastewater with a copper ion content of 21.02 mg / L and a total phosphorus content of 1.107 mg / L is treated by the method provided in the present application, the concentration of copper ions in the filtrate is 0.6103 mg / L, and the concentration of total phosphorus is 0.59 mg / L.

Description

Technical Field

[0001] This invention relates to the field of wastewater resource utilization and treatment technology, and in particular to a method for recovering valuable copper metal from water while removing organophosphates. Background Technology

[0002] Textile dyeing and printing wastewater is characterized by high pollutant content, high alkalinity, and significant water quality fluctuations, making it one of the most difficult types of industrial wastewater to treat. Pollutants include dyes, sizing agents, auxiliaries, oils, acids and alkalis, fiber impurities, sand, and inorganic salts. Although dyeing and printing wastewater contains many types of pollutants, different dyeing and printing plants produce wastewater with their own unique characteristics. For example, wastewater from copper-containing dye plants primarily contains copper chelates and alkaline inorganic salts.

[0003] For wastewater generated by copper-containing dye factories, although the metallic copper in the water is precipitated in the flocculation sedimentation tank after aeration treatment, the heavy metal copper in the wastewater is not recovered and utilized. Most of it settles in the sludge and is treated and disposed of as hazardous waste, resulting in resource waste. At the same time, the phosphate substances in the wastewater after secondary treatment also require further treatment. Therefore, there is an urgent need for a method that can recover valuable metallic copper from water while removing organophosphates to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a method for recovering valuable copper from water while removing organophosphates. The method provided by this invention can recover valuable copper from wastewater and remove organophosphates therein.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for recovering valuable copper from water while simultaneously removing organophosphates, comprising the following steps:

[0007] (1) Mix copper-containing wastewater with acid to obtain acidified copper-containing wastewater;

[0008] (2) The acidified copper-containing wastewater obtained in step (1) is mixed with iron-carbon adsorbent and the pH value is adjusted. Then, adsorption and filtration are carried out in sequence to obtain low phosphorus filtrate and filter residue.

[0009] (3) The filter residue obtained in step (2) is subjected to a first magnetic separation and then calcined to obtain a mixture of iron oxide and copper oxide;

[0010] (4) The mixture of iron oxide and copper oxide obtained in step (3) is subjected to a second magnetic separation to obtain copper oxide.

[0011] Preferably, the copper content in the copper-containing wastewater in step (1) is 20-25 mg / L, and the total phosphorus content is 1.0-1.5 mg / L.

[0012] Preferably, the acid in step (1) includes sulfuric acid and / or nitric acid.

[0013] Preferably, the amount of acid used in step (1) is 80-100 mL / L.

[0014] Preferably, the iron-carbon adsorbent in step (2) includes paper-based biochar loaded with iron or biochar modified materials with similar paper-like properties that are easy to burn.

[0015] Preferably, the amount of iron-carbon adsorbent used in step (2) is 50-80 g / L.

[0016] Preferably, the pH value in step (2) is 5 to 6.5.

[0017] Preferably, the reagent for adjusting the pH value in step (2) is a sodium hydroxide solution.

[0018] Preferably, the mass concentration of the sodium hydroxide solution is 5-10%.

[0019] Preferably, the calcination in step (3) is carried out under aerobic conditions.

[0020] This invention provides a method for recovering valuable copper from water while removing organophosphates, comprising the following steps: (1) mixing copper-containing wastewater with acid to obtain acidified copper-containing wastewater; (2) mixing the acidified copper-containing wastewater obtained in step (1) with an iron-carbon adsorbent and adjusting the pH value, then performing adsorption and filtration sequentially to obtain a low-phosphorus filtrate and filter residue; (3) performing a first magnetic separation on the filter residue obtained in step (2), and then calcining it to obtain a mixture of iron oxides and copper oxides; (4) performing a second magnetic separation on the mixture of iron oxides and copper oxides obtained in step (3) to obtain copper oxides. This invention first converts the copper in the complexed state in the wastewater into a salt ion state by mixing copper-containing wastewater with acid; then, by adjusting the pH value, the remaining copper element is also in a copper ion state, while most of the phosphate exists in the form of anions, and an iron-carbon adsorbent is added to remove phosphate substances from the water; then, the iron-carbon adsorbent is separated by magnetic separation, and a mixture of iron oxides and copper oxides is obtained by calcination; finally, iron oxides are removed by magnetic separation to obtain copper oxides. The results of the examples show that after treating wastewater with a copper ion content of 21.02 mg / L and a total phosphorus content of 1.107 mg / L using the method provided by the present invention, the concentration of copper ions in the filtrate was measured to be 0.6103 mg / L and the concentration of total phosphorus was 0.59 mg / L.

[0021] The method for recovering valuable copper from water and simultaneously removing organophosphates provided by this invention can simultaneously achieve the recovery of heavy metal copper and the treatment of phosphates. Compared with the method of treating phosphates in water using iron and calcium salt flocculants, the method provided by this invention reduces the phosphate content in the water while allowing the copper in the flocculated sediment to be directly recovered, avoiding the formation of heavy metal copper as hazardous sludge waste that is difficult to separate and thus leads to resource waste. Furthermore, compared with the method of treating water with activated carbon to adsorb heavy metal copper, the method provided by this invention overcomes the disadvantage that activated carbon is ineffective against phosphates in water. Attached Figure Description

[0022] Figure 1 A flowchart of the method for recovering valuable copper metal from water and simultaneously removing organophosphorus compounds provided by the present invention;

[0023] Figure 2 This is a morphology diagram of the iron oxide obtained in Example 1 of the present invention;

[0024] Figure 3 This is a morphology diagram of the copper oxide obtained in Example 1 of the present invention;

[0025] Figure 4 The image shows the XRD pattern of the iron oxide obtained in Example 1 of this invention.

[0026] Figure 5 The image shows the XRD pattern of the copper oxide obtained in Example 1 of this invention. Detailed Implementation

[0027] This invention provides a method for recovering valuable copper from water while simultaneously removing organophosphates, comprising the following steps:

[0028] (1) Mix copper-containing wastewater with acid to obtain acidified copper-containing wastewater;

[0029] (2) The acidified copper-containing wastewater obtained in step (1) is mixed with iron-carbon adsorbent and the pH value is adjusted. Then, adsorption and filtration are carried out in sequence to obtain low phosphorus filtrate and filter residue.

[0030] (3) The filter residue obtained in step (2) is subjected to a first magnetic separation and then calcined to obtain a mixture of iron oxide and copper oxide;

[0031] (4) The mixture of iron oxide and copper oxide obtained in step (3) is subjected to a second magnetic separation to obtain copper oxide.

[0032] This invention mixes copper-containing wastewater with acid to obtain acidified copper-containing wastewater. This invention converts the complexed copper in the wastewater into salt ions by mixing the copper-containing wastewater with acid.

[0033] The method provided by this invention is applicable to the treatment of various copper-containing wastewaters. In this invention, the copper-containing wastewater is preferably copper-containing printing and dyeing wastewater.

[0034] In this invention, the copper content in the copper-containing wastewater is preferably 20-25 mg / L; the total phosphorus content in the copper-containing wastewater is preferably 1.0-1.5 mg / L.

[0035] In this invention, the acid preferably includes sulfuric acid and / or nitric acid. In this invention, the sulfuric acid is preferably concentrated sulfuric acid; the nitric acid is preferably concentrated nitric acid. This invention does not impose any particular limitation on the concentration of the concentrated sulfuric acid and concentrated nitric acid; concentrations commonly used in the art can be employed.

[0036] In this invention, the amount of acid used is preferably 80-100 mL / L, more preferably 90-100 mL / L. This invention preferably controls the amount of acid within the above range, which is beneficial for fully converting the complexed copper in the wastewater into salt ions.

[0037] In this invention, the mixing of the copper-containing wastewater and the acid is preferably carried out under stirring conditions. The stirring speed is preferably 800–1000 rpm / min; the stirring time is preferably 20–30 min.

[0038] In this invention, the preferred temperature for mixing the copper wastewater and acid is 40°C.

[0039] After obtaining acidified copper-containing wastewater, this invention mixes the acidified copper-containing wastewater with an iron-carbon adsorbent and adjusts the pH value, then performs adsorption and filtration sequentially to obtain a low-phosphorus filtrate and filter residue. This invention adjusts the pH value so that the remaining copper elements are also in a copper ion state, while most phosphates exist in anionic form. Simultaneously, the addition of an iron-carbon adsorbent removes phosphate substances from the water.

[0040] The present invention does not have any special limitations on the operation of mixing the acidified copper-containing wastewater and the iron-carbon adsorbent; any mixing technology known to those skilled in the art can be used.

[0041] In this invention, the iron-carbon adsorbent preferably includes paper-based biochar loaded with iron or similar easily combustible biochar modified materials, more preferably paper-based biochar loaded with iron. This invention uses the above-mentioned types of iron-carbon adsorbents, overcoming the disadvantage of activated carbon's ineffectiveness against phosphates in water, and is also a waste-to-waste treatment measure with low raw material costs.

[0042] In this invention, the preferred dosage of the iron-carbon adsorbent is 50-80 g / L, more preferably 50 g / L. This invention preferably controls the dosage of the iron-carbon adsorbent within the above range, ensuring both adsorption efficiency and avoiding waste of raw materials.

[0043] In this invention, the pH value is preferably 5 to 6.5, more preferably 6 to 6.2. This invention preferably controls the pH value within the above range to ensure that the remaining copper element is in the copper ion state, while most of the phosphate exists in the anionic form.

[0044] In this invention, the reagent used to adjust the pH value is preferably a sodium hydroxide solution. The mass concentration of the sodium hydroxide solution is preferably 5-10%.

[0045] In this invention, the adsorption is preferably carried out under stirring conditions; the stirring speed is preferably 150–800 rpm / min; and the stirring time is preferably 1–1.5 h. This invention preferably maintains a certain stirring speed during the adsorption process to ensure sufficient contact between the adsorbent and the solution. As time increases, the stirring speed decreases, and high-speed stirring is no longer maintained to prevent reverse reactions in the adsorption process.

[0046] The present invention does not impose any special limitations on the operation of the filtration, and any filtration technology solution known to those skilled in the art can be used.

[0047] After obtaining the filter residue, the present invention performs a first magnetic separation on the filter residue, followed by calcination to obtain a mixture of iron oxides and copper oxides. The present invention utilizes magnetic separation to separate iron-carbon adsorbents and obtains a mixture of iron oxides and copper oxides through calcination.

[0048] The present invention does not impose any special limitations on the operation of the first magnetic separation; any magnetic separation technology known to those skilled in the art can be used.

[0049] After the first magnetic separation, the product obtained from the first magnetic separation is preferably dried. The drying operation is not particularly limited in this invention; any drying technique well-known to those skilled in the art can be used. In this invention, the drying temperature is preferably 105°C. The drying time is not particularly limited in this invention, as long as the purpose of removing moisture is achieved.

[0050] This invention does not impose any special limitations on the calcination operation; any calcination technique well-known to those skilled in the art can be used. This invention uses calcination to oxidize, burn, and volatilize the carbon-based material in iron-carbon adsorbents, yielding iron oxides and copper oxides.

[0051] In this invention, the calcination is preferably carried out under aerobic conditions; the aerobic conditions are preferably air conditions.

[0052] After obtaining a mixture of iron oxide and copper oxide, the present invention performs a second magnetic separation on the mixture to obtain copper oxide. The present invention removes iron oxide through magnetic separation to obtain copper oxide.

[0053] The present invention does not impose any special limitations on the operation of the second magnetic separation; any magnetic separation technology solution known to those skilled in the art can be used.

[0054] The flowchart of the method for recovering valuable copper from water and simultaneously removing organophosphates provided by this invention is as follows: Figure 1 As shown, the wastewater is first acidified to obtain acidified wastewater; then iron-carbon adsorbents are added for adsorption and flocculation, followed by filtration to obtain filter residue and low-phosphorus filtrate; the filter residue is then separated from the iron-carbon adsorbents by magnetic separation, and then calcined to obtain iron oxides and copper oxides; finally, the iron oxides are removed by magnetic separation to obtain copper oxides.

[0055] This invention first converts the complexed copper in copper-containing wastewater into salt ions by mixing it with acid. Then, the pH value is adjusted so that the remaining copper elements are also in the copper ion state, while most of the phosphate exists in the form of anions. At the same time, an iron-carbon adsorbent is added to remove phosphate substances from the water. Then, the iron-carbon adsorbent is separated by magnetic separation, and a mixture of iron oxide and copper oxide is obtained by calcination. Finally, the iron oxide is removed by magnetic separation to obtain copper oxide.

[0056] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0057] Example 1

[0058] Wastewater samples were collected from the sedimentation tank of a dyeing and printing factory in Hebei Province. The results showed that the copper ion content in the wastewater was 21.02 mg / L and the total phosphorus content was 1.107 mg / L.

[0059] (1) Weigh 100 mL of the wastewater collected by the factory into a 250 mL beaker, measure 10 mL of concentrated nitric acid, and stir at 800 rpm / min for 30 min at 40 °C to obtain acidified copper-containing wastewater.

[0060] (2) Add 5.0000 g of iron-loaded paper-based biochar at a dosage of 50 g / L to the acidified copper-containing wastewater in step (1) at a speed of 800 rpm / min and adsorb for 30 min; reduce the stirring speed to 250 rpm / min, continue to add 5% sodium hydroxide to the solution to adjust the pH to 6.2, and continue the adsorption reaction for 60 min; then filter to obtain filter residue and low phosphorus filtrate; the concentration of copper ions in the filtrate was determined to be 0.8355 mg / L by inductively coupled plasma, and the concentration of total phosphorus was determined to be 0.41 mg / L by spectrophotometry.

[0061] (3) The filter residue obtained in step (2) is subjected to first magnetic separation, then dried at 105°C, and then calcined in air to obtain a mixture of iron oxide and copper oxide.

[0062] (4) The mixture of iron oxide and copper oxide obtained in step (3) is subjected to a second magnetic separation to obtain copper oxide.

[0063] Figure 2 This is a morphological diagram of the iron oxide obtained in this embodiment.

[0064] Figure 3 This is a morphological diagram of the copper oxide obtained in this embodiment.

[0065] Figure 4 This is the XRD pattern of the iron oxide obtained in this embodiment.

[0066] Figure 5 This is the XRD pattern of the copper oxide obtained in this embodiment.

[0067] Example 2

[0068] Wastewater samples were collected from the sedimentation tank of a dyeing and printing factory in Hebei Province. The results showed that the copper ion content in the wastewater was 21.02 mg / L and the total phosphorus content was 1.107 mg / L.

[0069] (1) Weigh 100 mL of the wastewater collected by the factory into a 250 mL beaker, measure 10 mL of concentrated sulfuric acid, and stir at 800 rpm / min for 20 min at 40 °C to obtain acidified copper-containing wastewater.

[0070] (2) Add 8.0000 g of paper-based biochar loaded with iron element at a ratio of 50 g / L and add it to the acidified copper-containing wastewater in step (1) at a speed of 800 rpm / min. Adsorb for 25 min, then continue to add 5% sodium hydroxide to the solution to adjust the pH to 6.0 and continue the adsorption reaction for 60 min. Then filter to obtain filter residue and low phosphorus filtrate. The concentration of copper ions in the filtrate was determined to be 0.6103 mg / L by inductively coupled plasma and the concentration of total phosphorus was determined to be 0.59 mg / L by spectrophotometry.

[0071] (3) The filter residue obtained in step (2) is subjected to first magnetic separation, then dried at 105°C, and then calcined in air to obtain a mixture of iron oxide and copper oxide.

[0072] (4) The mixture of iron oxide and copper oxide obtained in step (3) is subjected to a second magnetic separation to obtain copper oxide.

[0073] As can be seen from the above embodiments, the method provided by the present invention can recover valuable copper from wastewater and remove organic phosphorus. Furthermore, after treating wastewater with a copper ion content of 21.02 mg / L and a total phosphorus content of 1.107 mg / L using the method provided by the present invention, the concentration of copper ions in the filtrate was measured to be 0.6103 mg / L and the concentration of total phosphorus was 0.59 mg / L.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for recovering valuable copper from water while simultaneously removing organophosphates, comprising the following steps: (1) Mix copper-containing wastewater with acid to obtain acidified copper-containing wastewater; (2) The acidified copper-containing wastewater obtained in step (1) is mixed with iron-carbon adsorbent and the pH value is adjusted. Then, adsorption and filtration are carried out in sequence to obtain low-phosphorus filtrate and filter residue. (3) The filter residue obtained in step (2) is subjected to a first magnetic separation and then calcined in an aerobic environment to obtain a mixture of iron oxide and copper oxide; (4) The mixture of iron oxide and copper oxide obtained in step (3) is subjected to a second magnetic separation to obtain copper oxide.

2. The method according to claim 1, characterized in that, The acid in step (1) includes sulfuric acid and / or nitric acid.

3. The method according to claim 1, characterized in that, The amount of acid used in step (1) is 80~100mL / L.

4. The method according to claim 1, characterized in that, In step (2), the iron-carbon adsorbent includes paper-based biochar loaded with iron.

5. The method according to claim 1 or 4, characterized in that, In step (2), the amount of iron-carbon adsorbent used is 50~80g / L.

6. The method according to claim 1, characterized in that, The pH value in step (2) is 5~6.

5.

7. The method according to claim 1, characterized in that, The reagent used to adjust the pH value in step (2) is sodium hydroxide solution.

8. The method according to claim 7, characterized in that, The sodium hydroxide solution has a mass concentration of 5-10%.

Images