A method for treating high-chloride tetracycline hydrochloride wastewater by using nitrogen self-doped ruthenium-based biochar coupled with electrodialysis
By using nitrogen-doped ruthenium-based biochar electrodes in the dilute chamber of electrodialysis, the problems of decreased conductivity and membrane fouling in electrodialysis technology were solved, achieving efficient desalination and simultaneous degradation of organic pollutants.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING TECH & BUSINESS UNIV
- Filing Date
- 2025-01-02
- Publication Date
- 2026-05-19
AI Technical Summary
When treating high-chloride tetracycline hydrochloride wastewater, electrodialysis technology suffers from concentration polarization caused by decreased conductivity in the dilute chamber and membrane fouling caused by tetracycline hydrochloride in the dilute chamber, which affects desalination efficiency and effluent quality.
Nitrogen-doped ruthenium-based biochar was used as the electrode material and combined with an electrodialysis reactor. Ruthenium oxide was loaded onto nitrogen-doped tea residue biochar as the active material to improve the conductivity and catalytic ability of the dilute chamber and simultaneously degrade tetracycline hydrochloride.
It stabilizes the conductivity of the dilute chamber in electrodialysis, improves desalination efficiency, and simultaneously degrades tetracycline hydrochloride, reducing membrane fouling and organic load in the effluent.
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Figure CN119774716B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for the simultaneous dechlorination and degradation of tetracycline hydrochloride in water, and more particularly to an improved electrodialysis desalination chamber reaction system for the simultaneous desalination and pollution reduction of high-salt organic wastewater. Background Technology
[0002] With the increasing demand for seafood in my country, the scale of the aquaculture industry is also expanding. The annual volume of aquaculture wastewater exceeds 5 billion tons, and its high salinity increases the difficulty of wastewater treatment. On the other hand, to ensure the safety of seafood supply, antibiotics are added to feed to kill pathogenic bacteria, prevent seafood diseases, and increase yield. In my country, tetracycline hydrochloride is the most widely used antibiotic in aquaculture, used to treat diseases such as vibriosis in fish, blind eye disease in shrimp, and septicemia in shrimp. However, only a small portion of the tetracycline hydrochloride added to aquaculture water is utilized; over 75% remains in the water, leading to excessive antibiotic levels in the aquatic environment and causing environmental pollution. The tetracycline residue in the water can not only cause deformities or death of algae, fish, and other aquatic organisms, but also induce the emergence of drug-resistant bacteria, directly threatening human health. Therefore, conducting research on water bodies polluted by high-chloride tetracycline hydrochloride wastewater can not only provide a reference for the treatment of marine aquaculture wastewater, but also help to address the urgent need for the resource utilization of high-salt organic wastewater.
[0003] Electrodialysis, a common desalination technology, has the advantage of operating at ambient temperature and pressure, avoiding energy consumption caused by temperature and pressure changes, and is widely used in the desalination treatment of high-salinity organic wastewater. However, when treating wastewater containing high levels of chloride ions and tetracycline hydrochloride, the conductivity of the dilute chamber decreases due to the continuous transfer of chloride ions to the concentrate chamber, exacerbating concentration polarization. Furthermore, tetracycline hydrochloride in the dilute chamber not only causes membrane fouling but also increases the difficulty and cost of subsequent treatment. Therefore, mitigating the concentration polarization phenomenon caused by the decreased conductivity of the dilute chamber during electrodialysis desalination, and addressing membrane fouling and organic load issues in the effluent caused by organic pollutants in the dilute chamber, are current research challenges.
[0004] To address the concentration polarization problem exacerbated by low conductivity in the dilute chamber of electrodialysis, particulate electrode materials with conductivity, catalytic activity, and chlorine evolution selectivity can be added to the dilute chamber. This stabilizes the conductivity while enhancing the degradation capacity of organic pollutants. Biochar itself is conductive and can stabilize the conductivity of the dilute chamber. Nitrogen doping improves the electrochemical and catalytic performance of biochar. Nitrogen atoms are more electronegative than carbon atoms, and the tendency for electrons to transfer from carbon to nitrogen atoms enhances biochar performance. Under the concept of green chemistry, nitrogen-rich biomass resources can be used to prepare various high-performance nitrogen-doped biochars without the need for an external nitrogen source. Tea residue itself has a high nitrogen content, and a high mass ratio of nitrogen can be detected in biochar prepared from tea residue. Utilizing tea residue, which is rich in nitrogen, has the potential to prepare nitrogen-doped biochar materials without the need for an external nitrogen source. Ruthenium oxide, as a noble metal oxide, has extremely high catalytic activity, mainly due to its excellent proton transfer ability and excellent reversible redox transformation performance. Studies have demonstrated that using ruthenium oxide as an electrode component can improve the selectivity for chlorine evolution reactions. Therefore, using nitrogen-doped biochar prepared from tea residue as a carrier material and loading ruthenium oxide, which has chlorine evolution selectivity, as the active substance, a nitrogen-doped ruthenium-based biochar with good conductivity, catalytic ability, and chlorine evolution selectivity can be obtained. This biochar can stabilize the conductivity of the dilute chamber in electrodialysis and simultaneously degrade tetracycline hydrochloride in high-chloride tetracycline hydrochloride wastewater. Summary of the Invention
[0005] To address the issues of decreased conductivity in the dilute chamber, membrane fouling caused by organic pollutants, and organic load in the effluent during electrodialysis treatment of high-chloride tetracycline hydrochloride wastewater, this invention provides a nitrogen-doped ruthenium-based biochar coupled electrodialysis reaction method that can be used for simultaneous desalination and pollution reduction of high-chloride tetracycline hydrochloride wastewater.
[0006] The technical solution adopted in this invention is as follows.
[0007] This invention provides a nitrogen-doped ruthenium-based biochar coupled with electrodialysis method for simultaneous desalination and pollution reduction of high-chloride tetracycline hydrochloride wastewater. The specific steps are as follows:
[0008] (1) 5.0 g of tea residue and KOH activator were mixed in 50 mL of deionized water at ratios of 1:2, 1:1 and 2:1 respectively. The mixture was magnetically stirred for 4 h to ensure thorough mixing. The activated tea residue was placed in a tube furnace and dried at 80 °C. The dried tea residue was placed in a tube furnace and filled with nitrogen. The temperature was maintained at 300–600 °C for 0.5–2.0 h. The residue was repeatedly washed with ultrapure water and dried in an oven to obtain nitrogen-doped tea residue biochar.
[0009] (2) Take 5 g of nitrogen-doped tea residue biochar and put it into a water bath; pour in 200 mL of water bath containing 0.5, 1, 2, and 4 mg / L of nitrogen-doped tea residue biochar. -1 The ruthenium chloride solution was used to soak the biochar particles in a water bath at 40°C for 48 hours. The soaked biochar particles were then placed in a muffle furnace filled with nitrogen. The temperature of the muffle furnace was adjusted to 300–600°C and heated for 2–4 hours to obtain nitrogen-doped ruthenium-based tea residue biochar.
[0010] (3) The electrodialysis reactor uses one set of membrane stacks (10–30 pairs of membranes). The electrodialysis cation membrane is made of sulfonated resin, the anion membrane is made of quaternized resin, and the electrode materials at both ends are ruthenium-iridium electrodes. The reaction voltage is 5–25 V, and the initial NaCl concentration of the water entering the dilute chamber is 10–30 g / L. -1 The initial tetracycline hydrochloride concentration in the desalination chamber was 0.05–10 g / L. -1 The initial NaCl concentration in the concentration chamber is 0–20 g / L. -1 The electrolyte in the electrode chamber is 20 g / L. -1 Na2SO4.
[0011] (4) Nitrogen-doped ruthenium-based tea residue biochar granular electrodes were added to different dilute chambers. Quartz sand and nitrogen-doped ruthenium-based tea residue biochar granular electrodes were placed in the dilute chambers in different proportions. The ratio of quartz sand to granular electrodes was set to 1:5, 1:3, 1:2, 1:1, 2:1, 3:1 and only nitrogen-doped ruthenium-based tea residue biochar granular electrodes were added. The water circulation flow rate of the dilute and concentrate chambers was set to 4–20 L / h. -1 The water circulation velocity in the polar chamber is 25 L / h. -1 .
[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The nitrogen self-doped ruthenium-based biochar coupled electrodialysis system constructed by the present invention, by adding nitrogen self-doped ruthenium-based biochar particle electrodes with conductivity, electrocatalytic activity and chlorine evolution selectivity in the electrodialysis dilute chamber, can stabilize the conductivity of the electrodialysis dilute chamber and efficiently convert chloride ions into active substances to degrade tetracycline hydrochloride during the desalination process. This not only ensures the electrodialysis desalination efficiency, but also simultaneously degrades organic pollutants in the dilute chamber. Attached Figure Description
[0013] Figure 1 This describes the preparation process of nitrogen-doped ruthenium-based tea residue biochar granular electrodes.
[0014] Figure 2The reaction principle involves adding nitrogen-doped ruthenium-based biochar as a particulate electrode to the dilute chamber of an electrodialysis reactor. The solutions in the dilute and concentrate chambers are injected and extracted using peristaltic pumps. The concentrate chamber is the reaction zone where cations and anions continuously enter and their concentrations continuously increase during the reaction. The dilute chamber is the reaction zone where cations and anions continuously flow out and their concentrations continuously decrease during the reaction. The large outflow of cations and anions in the dilute chamber leads to a sharp drop in ion concentration, reducing the conductivity of the entire electrodialysis system and decreasing the desalination effect. Furthermore, tetracycline hydrochloride in the dilute chamber can cause membrane fouling, increasing the difficulty and cost of subsequent treatment. Adding a biochar-supported particulate electrode to the dilute chamber can mitigate the concentration polarization effect and stabilize the conductivity. Using nitrogen self-doping to prepare the particulate electrode can improve its electrocatalytic activity, and loading it with ruthenium-based materials with chloride evolution selectivity can enhance the particulate electrode's ability to convert chloride ions into active substances, thereby improving the simultaneous removal of chloride ions and tetracycline hydrochloride from the dilute chamber of the electrodialysis reaction system.
[0015] Figure 3 The change in tetracycline hydrochloride concentration in the dilute chamber of the nitrogen-doped ruthenium-based biochar coupled electrodialysis reaction system in Example 1 is shown.
[0016] Figure 4 This refers to the change in chloride ion concentration in the dilute chamber of the nitrogen-doped ruthenium-based biochar coupled electrodialysis reaction system in Example 2.
[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The nitrogen self-doped ruthenium-based biochar coupled electrodialysis system constructed by the present invention, by adding nitrogen self-doped ruthenium-based biochar particle electrodes with conductivity, electrocatalytic activity and chlorine evolution selectivity in the electrodialysis dilute chamber, can stabilize the conductivity of the electrodialysis dilute chamber and efficiently convert chloride ions into active substances to degrade tetracycline hydrochloride during the desalination process. This not only ensures the electrodialysis desalination efficiency, but also simultaneously degrades organic pollutants in the dilute chamber. Detailed Implementation
[0018] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0019] like Figure 2 As shown, Figure 2The principle involves adding nitrogen-doped ruthenium-based biochar as a granular electrode to the dilute compartment of an electrodialysis system. During the reaction, cations and anions in the dilute compartment can enter the concentrate compartment, leading to a decrease in the conductivity of the entire electrodialysis system and affecting the desalination effect. Furthermore, tetracycline hydrochloride in the dilute compartment can cause membrane fouling, increasing the difficulty of effluent treatment. Adding a biochar-supported granular electrode to the dilute compartment can reduce the influence of concentration polarization and stabilize the conductivity. Using nitrogen self-doping to prepare the granular electrode can improve its electrocatalytic activity, and loading it with ruthenium-based materials exhibiting chlorine evolution selectivity can enhance the granular electrode's ability to convert chloride ions into active substances, thereby improving the simultaneous removal of chloride ions and tetracycline hydrochloride from the dilute compartment of the electrodialysis reaction system.
[0020] Example 1
[0021] (1) 5.0 g of tea residue and KOH activator were mixed in 50 mL of deionized water at a ratio of 1:2. The mixture was magnetically stirred for 4 h to ensure thorough mixing. The activated tea residue was placed in a tube furnace and dried at 80 °C. The dried tea residue was then placed in a tube furnace and filled with nitrogen. The furnace was carbonized at 300 °C for 1.5 h. The residue was repeatedly washed with ultrapure water and dried in an oven to obtain nitrogen-doped tea residue biochar.
[0022] (2) Take 5 g of nitrogen-doped tea residue biochar and put it into a water bath. Pour in 200 mL of water containing 4 mg L of nitrogen-doped tea residue biochar. -1 The ruthenium chloride solution was used to soak the biochar particles in a water bath at 40°C for 48 hours. The soaked biochar particles were then placed in a muffle furnace filled with nitrogen and heated at 300°C for 2 hours to obtain nitrogen-doped ruthenium-based tea residue biochar.
[0023] (3) The electrodialysis reactor uses one set of membrane stacks (10 pairs of membranes). The electrodialysis cation membrane is made of sulfonated resin, the anion membrane is made of quaternized resin, the electrode materials at both ends are ruthenium-iridium electrodes, the reaction voltage is 10 V, and the initial NaCl concentration of the water entering the desalination chamber is 10 g / L. -1 The initial tetracycline hydrochloride concentration in the desalination chamber was 1 g / L. -1 The initial NaCl concentration in the concentration chamber was 10 g / L. -1 The electrolyte in the electrode chamber is 20 g / L. -1 Na2SO4.
[0024] (4) Nitrogen-doped ruthenium-based tea residue biochar granular electrodes were added to different dilute chambers. Quartz sand and nitrogen-doped ruthenium-based tea residue biochar granular electrodes were placed in the dilute chambers in different proportions. The ratio of quartz sand to granular electrode was set to 1:1 and only nitrogen-doped ruthenium-based tea residue biochar granular electrodes were added. The water circulation flow rate of the dilute and concentrate chambers was set to 10 L / h respectively. -1The water circulation velocity in the polar chamber is 25 L / h. -1 .
[0025] In Example 1, the nitrogen-doped biochar prepared by carbonization at 300℃ for 1.5 h had a high nitrogen content, with a concentration of 4 mg / L in 200 mL of the solution. -1 Ruthenium chloride solution can increase the loading of ruthenium oxide, thereby obtaining a particulate electrode with strong electrocatalytic and chlorine evolution performance, which is suitable for water treatment with high chloride ion content and high tetracycline hydrochloride concentration.
[0026] Example 2
[0027] (1) 5.0 g of tea residue and KOH activator were mixed in 50 mL of deionized water at a ratio of 2:1. The mixture was magnetically stirred for 4 h to ensure thorough mixing. The activated tea residue was placed in a tube furnace and dried at 80°C. The dried tea residue was then placed in a tube furnace and filled with nitrogen. The furnace was carbonized at 500°C for 2.0 h. The residue was repeatedly washed with ultrapure water and dried in an oven to obtain nitrogen-doped tea residue biochar.
[0028] (2) Take 5 g of nitrogen-doped tea residue biochar and put it into a water bath. Pour in 200 mL of water containing 4 mg L of nitrogen-doped tea residue biochar. -1 The ruthenium chloride solution was used to soak the biochar particles in a water bath at 40°C for 48 hours. The soaked biochar particles were then placed in a muffle furnace filled with nitrogen and heated at 500°C for 3 hours to obtain nitrogen-doped ruthenium-based tea residue biochar.
[0029] (3) The electrodialysis reactor uses one set of membrane stacks (30 pairs of membranes). The electrodialysis cation membrane is made of sulfonated resin, the anion membrane is made of quaternized resin, the electrode materials at both ends are ruthenium-iridium electrodes, the reaction voltage is 25 V, and the initial NaCl concentration of the water entering the desalination chamber is 30 g / L. -1 The initial tetracycline hydrochloride concentration in the desalination chamber was 1 g / L. -1 The initial NaCl concentration in the concentration chamber was 20 g / L. -1 The electrolyte in the electrode chamber is 20 g / L. -1 Na2SO4.
[0030] (4) Nitrogen-doped ruthenium-based tea residue biochar granular electrodes were added to different dilute chambers. Quartz sand and nitrogen-doped ruthenium-based tea residue biochar granular electrodes were placed in the dilute chambers in different proportions. The ratio of quartz sand to granular electrode was set to 1:1 and only nitrogen-doped ruthenium-based tea residue biochar granular electrodes were added. The water circulation flow rate of the dilute and concentrate chambers was set to 20 L / h respectively. -1 The water circulation velocity in the polar chamber is 25 L / h. -1 .
[0031] like Figure 3 and Figure 4 As shown, the rice husk control group represents the treatment effect of replacing rice husk biochar with nitrogen-doped ruthenium-based tea residue biochar in the dilute chamber. The rice husk preparation conditions were: nitrogen heating at 500℃ for 2 hours. Example 2 increased the reactor membrane stack, and the water circulation flow rates in the dilute and concentrate chambers, which can increase the treatment capacity per unit time, making it suitable for pollution scenarios with high demand for treating tetracycline hydrochloride wastewater with high chloride ion concentrations.
[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for treating high-chloride tetracycline hydrochloride wastewater using nitrogen-doped ruthenium-based biochar coupled with electrodialysis, characterized in that, The specific steps are as follows: 5.0 g of tea residue was mixed with KOH activator in ratios of 1:2, 1:1, and 2:1 in 50 mL of deionized water. The mixture was magnetically stirred for 4 h to ensure thorough mixing. The activated tea residue was then dried in a tube furnace at 80 °C. The dried tea residue was then placed in a tube furnace filled with nitrogen and carbonized at 300–600 °C for 0.5–2.0 h. The residue was repeatedly washed with ultrapure water and dried in an oven to obtain nitrogen-doped tea residue biochar. 5 g of nitrogen-doped tea residue biochar was placed in a water bath, and 200 mL of KOH activator at concentrations of 0.5, 1, 2, and 4 mg L⁻¹ were added. -1 A ruthenium chloride solution was used to soak the biochar particles in a water bath at 40°C for 48 hours. The soaked biochar particles were then placed in a nitrogen-filled muffle furnace and heated at 300–600°C for 2–4 hours to obtain nitrogen-doped ruthenium-based tea residue biochar. The electrodialysis-three-dimensional electrode reactor used a single membrane stack. The cation exchange membrane was made of sulfonated resin, the anion exchange membrane was made of quaternized resin, and the electrodes at both ends were ruthenium-iridium electrodes. The reaction voltage was 5–25 V, and the initial NaCl concentration in the dilute chamber was 10–30 g / L. -1 The initial tetracycline hydrochloride concentration in the desalination chamber was 0.05–10 g / L. -1 The initial NaCl concentration in the concentration chamber is 0–20 g / L. -1 The electrolyte in the electrode chamber is 20 g / L. -1 Na₂SO₄; Nitrogen-doped ruthenium-based tea residue biochar granular electrodes were added to different dilute chambers. Quartz sand and nitrogen-doped ruthenium-based tea residue biochar granular electrodes were placed in the dilute chambers at different ratios: 1:5, 1:3, 1:2, 1:1, 2:1, 3:1, and only nitrogen-doped ruthenium-based tea residue biochar granular electrodes were added. The water circulation flow rates in the dilute and concentrate chambers were set to 4–20 L / h. -1 The water circulation velocity in the polar chamber is 25 L / h. -1 Adding nitrogen-doped ruthenium-based biochar to the dilute chamber of electrodialysis can stabilize the conductivity of the dilute chamber and avoid the reduction in desalination efficiency caused by the sharp drop in conductivity during electrodialysis desalination. Biochar-based materials can make the granular electrodes conductive, nitrogen self-doping can give the granular electrodes better electrocatalytic performance, and ruthenium-based materials can improve the chlorine evolution selectivity of the granular electrodes. The granular electrodes added to the dilute chamber can stabilize the conductivity of the dilute chamber and utilize the chloride ions in the dilute chamber to degrade tetracycline hydrochloride, thereby achieving the purpose of simultaneous desalination and degradation of organic pollutants in the dilute chamber.