CN-118929883-B - Method for treating wastewater containing high-concentration Cu (II) -EDTA (ethylene diamine tetraacetic acid) by ball milling zero-valent manganese efficiently and at low cost

Abstract

The invention provides a method for efficiently and low-cost treatment of wastewater containing high-concentration Cu (II) -EDTA by ball milling of zero-valent manganese, which utilizes zero-valent manganese (ZVMn bm ) after simple mechanical ball milling and takes Cu (II) -EDTA as a target pollutant to study performance and mechanism. The concentration of Cu (II) -EDTA is 100ppm, the concentration of ZVMn bm is 1g/L, and after 5min of reaction, the removal rate of pollutants can reach more than 98%, and the recovery rate is up to 90%. By carrying out cost accounting on the system, the energy consumption of the zero-valent manganese after ball milling is reduced by 1.41 times compared with that of untreated zero-valent manganese. By adding different coexisting materials into the reaction system, the environmental adaptability of ZVMn bm is explored, and the pollutant removal rate reaches more than 90% after 5min, which shows that ZVMn bm can keep good removal effect under the influence of different coexisting materials and has better environmental adaptability.

Inventors

• MIAO JIE
• JIANG YUNYAO
• ZHOU WEI
• XU CHAO
• LV JINGWEN
• WANG XIXI

Assignees

• 南京工业大学

Dates

Publication Date

20260505

Application Date

20240724

Claims (17)

1. 1. The application of the zero-valent manganese in removing Cu (II) -EDTA is characterized in that the zero-valent manganese is prepared by ball milling manganese powder, and the mass ratio of the zero-valent manganese to the Cu (II) -EDTA is 8-12:1.
2. 2. The use according to claim 1, wherein the ball-milled ball-milling beads are stainless steel ball-milled beads.
3. 3. The use according to claim 2, wherein the ball-milling beads have a diameter of 2-6 mm.
4. 4. The use according to claim 2, wherein the ball-milling beads have a diameter of 2-4mm and 4.1-6 mm.
5. 5. The use according to claim 4, wherein the ratio of the number of ball-milling beads having a diameter of 2-4 mm to the number of ball-milling beads having a diameter of 4.1-6 mm is 1-3:1.
6. 6. The use according to claim 4, wherein the ratio of the number of ball-milling beads having a diameter of 2-4 mm to the number of ball-milling beads having a diameter of 4.1-6 mm is 2:1.
7. 7. The use according to claim 1, characterized in that between 15 and 25 ball-milling beads with a diameter of between 4.1 and 6mm and between 35 and 45 ball-milling beads with a diameter of between 2 and 4mm are used per 4 g manganese powder.
8. 8. The use according to claim 7, wherein 20 5mm ball-milling beads and 403 mm ball-milling beads are used per 4 g manganese powder.
9. 9. The use according to claim 1, wherein the total time of the ball milling is 0.5-4 h.
10. 10. The use according to claim 1, wherein the total time of the ball milling is 1.5-3 h.
11. 11. The use according to claim 1, wherein the total time of ball milling is 2h.
12. 12. The use according to claim 1, wherein the rotational speed of the ball mill is 200-800 rpm.
13. 13. The use according to claim 1, wherein the rotational speed of the ball mill is 300-600 rpm.
14. 14. The use according to claim 1, wherein the rotational speed of the ball mill is 350-500 rpm.
15. 15. The use according to claim 1, wherein the ball milling is performed by planetary ball milling, the direction of the ball milling being changed every 20-40 min a.
16. 16. The use according to claim 1, characterized in that the mass ratio of zero-valent manganese to Cu (II) -EDTA is 10:1.
17. 17. Use according to claim 1, characterized in that the zero-valent manganese removes Cu (II) -EDTA at a pH of 2-5.

Description

Method for treating wastewater containing high-concentration Cu (II) -EDTA (ethylene diamine tetraacetic acid) by ball milling zero-valent manganese efficiently and at low cost Technical Field The invention relates to the field of environmental remediation industrial heavy metal wastewater, in particular to a method for efficiently and low-cost treatment of wastewater containing high-concentration Cu (II) -EDTA by ball milling zero-valent manganese. Background This section provides merely background information related to the present disclosure and is not necessarily prior art. With the progress of industry and the development of society, heavy metal pollution has become a hotspot and a difficulty in national important treatment. According to statistics, the heavy metal wastewater generated by the electroplating industry in China only reaches about 40 hundred million tons each year, and mainly comprises copper (Cu), nickel (Ni), cadmium (Cd) and the like. The presence of complexing agents (pesticides, fertilizers, detergents, plasticizers, etc.) complicates the composition of industrial heavy metal wastewater. Heavy metal ions are easy to combine with organic ligands such as ethylenediamine tetraacetic acid (EDTA), nitrotriacetic acid (NTA), humic Acid (HA), citric Acid (CA) and the like to form stable metal complexes with different structures and toxicity. Thus, the heavy metals in the wastewater are more than 90% in complex form, except in ionic form. The stable heavy metal complex is not biodegradable, and has natural durability and biological enrichment. Once the biological enrichment is carried out, the biological enrichment is difficult to be naturally discharged or thoroughly cleared from the organism, and the biological enrichment can react with proteins or enzymes in the organism to deactivate the proteins or enzymes, destroy internal organs, cause acute, subacute and chronic poisoning and cause irreversible damage to the organism. Cu (II) -EDTA is a stable complex formed by complexing heavy metal Cu 2+ and EDTA according to a mole ratio of 1:1 as typical pollutant in electroplating wastewater. EDTA contains 4 carboxyl groups and 2 amine groups, and the stability constant of the complex formed with Cu 2+ is as high as 18.7. Copper is one of the essential elements for the human body, but excessive intake can lead to acute copper poisoning, and serious people can lead to hepatitis, hypotension, acute renal failure and even death. And complex copper, due to its stable coordination bond with EDTA, is more toxic to the environment and microorganisms than metal ions. In the previous studies, similar to the removal of most free heavy metals, the removal techniques of complex heavy metals also include electrolytic methods, adsorption methods, photocatalytic methods, and the like. However, in the actual operation process, the treatment effect and the operation cost are considered, and secondary pollutants are avoided being introduced. The electrolysis technology has high energy consumption and is easy to remain organic ligands to cause secondary pollution. The adsorption method has reliable effect, is economical and practical, has less sludge production compared with the coagulation-filtration method, and is widely used for treating and repairing the water body containing heavy metals, but the adsorbent can reach adsorption saturation, and the adsorbent must be regenerated. In addition, there are membrane separation methods such as reverse osmosis, but there are disadvantages such as high cost, high energy consumption, and difficult operation to various extents. The zero-valent metal is used as a green repair material, has large specific surface area and strong electron donating capability, and is widely applied to the water body purification treatment process. Manganese is one of the first superfluous series of high abundance elements and one of the most active and important geochemical elements. Mn element has rich valence states from 0 to +7, electronic structure of 3d 54s2, oxidation-reduction potential of-1.18V, strong affinity to oxygen and reduction fixation effect on most heavy metal ions in water. Mn 0 surface is easy to oxidize to form MnO x@Mn0 core-shell structure, and compared with manganese oxide, the Mn 0 has longer catalytic activity and strong adsorption capacity to heavy metals and organic matters. However, in practical applications, zero-valent manganese has many drawbacks, and the oxide layer on the surface greatly hinders the transfer of internal electrons to the outside, resulting in reduced reduction activity for the target pollutants. Compared with chemical modification, the method for carrying out surface modification on the zero-valent manganese by a mechanical ball milling method has the advantages of simple operation, lower cost and no waste liquid generation, and is easy to popularize and apply in large scale. Disclosure of Invention Aiming at the defects of the prior art, the i