Iron-carbon micro-electrolysis decomposes refractory organic compounds.

In the field of industrial wastewater treatment, how to efficiently and economically decompose refractory organic compounds has always been a core technical challenge. These organic compounds are typically structurally stable (containing benzene rings, heterocyclic rings, etc.), highly toxic, and poorly biodegradable, making conventional biological methods almost ineffective. Iron-carbon micro-electrolysis catalytic oxidation technology is precisely a powerful tool to tackle this challenge.

Iron-carbon micro-electrolysis catalytic oxidation is an advanced oxidation technology based on electrochemical principles. It utilizes specific fillers composed of iron and carbon (often supplemented with catalysts) to form a vast, intrinsic "micro-battery" reaction system in wastewater. This system not only facilitates ordinary electrolytic reactions but also, through catalysis, stimulates the generation of highly oxidizing free radicals, thereby achieving efficient decomposition and mineralization of refractory organic compounds.

Simply put, it is a "self-powered" deep oxidation process that operates under normal temperature and pressure, specifically designed to "break down" those "hard-to-degrade" pollutants in wastewater.

The process of decomposing refractory organic compounds through iron-carbon micro-electrolysis catalytic oxidation is not a single mechanism but a multi-stage, multi-mechanism synergistic "combination punch." Its sophistication lies in its progressive, layer-by-layer destruction of the molecular structure of organic compounds.

When wastewater comes into contact with the iron-carbon micro-electrolysis filler, iron acts as the anode (losing electrons), and carbon acts as the cathode (gaining electrons), forming countless micro-galvanic cells. At the anode, ferrous ions (Fe²⁺) are produced, which are strong reducing agents; at the cathode, H⁺ or dissolved oxygen in the wastewater is reduced. This process itself can preliminarily破坏 the complex structures of some refractory organic compounds through redox reactions, such as breaking long-chain macromolecules or reducing certain chromophores, achieving initial COD removal and decolorization. This is the starting point and foundation of the decomposition process.

The core product of this reaction is the hydroxyl radical (·OH). ·OH is one of the most potent oxidizing active species known in water, with an oxidation potential as high as 2.8 eV.

Hydroxyl radicals (·OH) attack almost all refractory organic compounds non-selectively and indiscriminately. They decompose these compounds by extracting hydrogen atoms, transferring electrons, or through addition reactions:

Stable cyclic structures: They forcefully break open stable structures such as benzene rings and heterocyclic rings, effectively "shattering" them.

Long-chain molecules: They cut large organic molecules into smaller intermediate products like organic acids, aldehydes, and ketones.
Eventually, these intermediate products can be further oxidized into the most stable inorganic substances—carbon dioxide and water—a process known as "mineralization." At this stage, the toxic and hazardous refractory organic compounds are completely decomposed, losing their original toxicity and pollution characteristics.

Flocculation and sedimentation: The Fe³⁺ generated by the reaction hydrolyzes to form ferric hydroxide colloids, which possess strong flocculation and adsorption capabilities. These colloids can capture and co-precipitate the tiny particles and colloids formed after decomposition, creating flocs that settle, further purifying the water quality.

Improving biodegradability (B/C ratio): After pretreatment with iron-carbon micro-electrolysis catalytic oxidation, previously non-biodegradable refractory organic compounds are transformed into easily biodegradable small molecules, significantly increasing the wastewater's B/C ratio and clearing the way for subsequent biological treatment.

High efficiency and targeting: Specifically targets refractory organic compounds that traditional processes cannot handle, with high decomposition efficiency and significant results.

Broad applicability: Suitable for various high-difficulty industrial wastewaters, such as those from printing and dyeing, chemical, pharmaceutical, pesticide, coking, and landfill leachate industries.

Improved biodegradability: Not only an end-of-pipe removal method but also an efficient pretreatment手段 that lays the foundation for enhancing the efficiency of the entire treatment process.

Low operating costs: Utilizes waste to treat waste (consuming waste iron scraps), with low energy consumption and minimal chemical dosing, offering significant comprehensive cost advantages.

Environmentally friendly: Does not introduce secondary pollution, and the final products are safe and harmless.