High-Efficiency Electrocatalytic Equipment

Introduction to the High-Efficiency Self-Controlled Electrocatalytic Reactor:

The high-efficiency self-controlled electrocatalytic reactor accelerates the reaction of charges on the electrocatalytic medium through catalytically active DSA electrodes within a specific electrochemical reactor. Electrocatalytic technology can simultaneously and efficiently remove COD and ammonia nitrogen from wastewater, breaking through the technical barrier that oxidation technology cannot simultaneously remove COD and ammonia nitrogen in wastewater treatment. It degrades organic matter through direct anodic degradation or through oxidants such as hydroxyl radicals (·OH), ozone, and hypochlorous acid generated by anodic reactions, as well as a series of chemical reactions, electrochemical processes, or physical processes induced thereby, achieving the purpose of pollutant degradation and transformation. This degradation pathway makes organic matter decomposition more thorough, less likely to produce toxic intermediates, while the reactor equipment is relatively simple, occupies a small footprint, has low operation and maintenance costs, can effectively avoid secondary pollution, and offers a high degree of reaction controllability, facilitating industrial automation.

Reaction Mechanism:

The main process for organic wastewater treatment adopts the electrocatalytic oxidation method, which involves electrocatalytic degradation on the electrode surface. The electrodes can directly generate extremely strong oxidizing hydroxyl radicals [·OH] that are non-selective toward organic and inorganic substances to oxidize pollutants in water, causing pollutants to be completely mineralized, which is known as

the electrochemical combustion process; if the aqueous solution contains electrocatalytic media such as Cl-, SO42- using: sodium sulfate, chlorine gas, hypochlorite, and chlorate, etc. The generated peroxide H2O2, etc., catalytically oxidizes pollutants in water, and this process is called the electrochemical conversion process, whereby electro-oxidation effectively removes COD from wastewater. Some of the main reactions in the electrocatalytic process are as follows:

Anodic reaction: OH-→1/2O2 + H2O + 2e-

Cathodic reaction: O2 + H2O + 2e-→ HO2- + OH-

Overall reaction: 1/2O2 + OH- → HO2-

The hydroxyl radicals [·OH] generated by electrocatalysis cause secondary reactions in wastewater, causing pollutants to degrade or directly decompose into CO2, or convert into other simple compounds. The electrocatalytic process follows Faraday's law, i.e., the amount of substance deposited on the electrode is proportional to the current intensity passing through the solution and the duration of electrification. Similarly, the removal of organic pollutants from wastewater also conforms to Faraday's law. In the process of removing organic pollutants from wastewater, it is not necessary to completely oxidize them into final products, i.e., CO2 and H2O; it is only necessary to break the chains of organic pollutant molecules, tearing them into charged organic 'fragments,' and remove organic pollutants through electrocatalytic adsorption, flocculation, and sedimentation.

Technical Advantages:

1. High environmental compatibility: Electrochemical water treatment technology uses clean, effective electrons and does not require additional oxidants, reductants, flocculants, or other chemical agents during the electrocatalytic process, making it a 'green' treatment technology that is essentially non-polluting to the environment. Due to the extremely high potential gradient in the interfacial electric field, the electrode acts as a catalyst for heterogeneous reactions, thereby reducing environmental pollution that could be caused by adding catalysts. During the electrocatalytic process, the •OH radicals generated can directly react with organic pollutants in wastewater, degrading them into carbon dioxide, water, and simple organic compounds, with no or minimal secondary pollution. At the same time, the electrochemical process has high selectivity, which can prevent the formation of by-products and reduce the occurrence of pollutants.

2. Multifunctionality: The electrochemical process has functions such as direct and indirect oxidation and reduction, phase separation, concentration and dilution, and biological inactivation, with high energy efficiency. The electrochemical process can generally be carried out at ambient temperature and pressure.

3. Economical and applicable: Electrocatalytic equipment and its operation are generally relatively simple, with low costs and a small footprint, typically in modular combinations.

4. Extremely strong oxidizing capability: A. Hydroxyl radicals (OH) have extremely strong oxidizing power, second only to fluorine (F2), and much stronger than ozone (O3); B. The chemical reaction of OH radicals oxidizing and degrading organic matter is a chain reaction. Once the oxidation reaction occurs, as long as no inhibitor is added, the reaction will continue in a continuous cycle; C. The degradation of organic pollutant compounds is thorough (sometimes can be oxidized all the way to carbon dioxide and water) and broad-spectrum (any organic matter can be oxidized and degraded).