Technical ArticlesSeptember 27, 2026

ECO Electrocatalytic Oxidation Equipment: An Advanced Treatment Solution for Refractory Wastewater Using Electricity Instead of Chemicals, Without Fenton Iron Sludge

Refractory organic compounds, high salinity, toxicity, and poor biodegradability often make traditional biological treatment "unable to digest" wastewater. Rihong Environmental launches the ECO electrocatalytic oxidation equipment, which directly mineralizes pollutants through electrocatalytic anodes, uses electricity instead of chemicals, and does not produce Fenton iron sludge as secondary hazardous waste. It is an ideal choice for advanced compliance and upgrading of wastewater from chemical, pharmaceutical, and electroplating industrial parks; it can also serve as a pretreatment stage to break toxicity and improve biodegradability, feeding the "hard bones" back into the biological system.

I. Product Positioning

ECO electrocatalytic oxidation equipment is an electrochemical advanced oxidation device centered on catalytic electrodes: driven by a direct current electric field, pollutants undergo direct electron transfer on the anode surface and are decomposed, or are indirectly mineralized by strong oxidants such as hydroxyl radicals (·OH) generated in situ at the anode, ultimately converting into CO₂ and H₂O. Rihong adopts a non-precious metal catalytic electrode route, balancing oxidation activity and service life, avoiding precious metal dissolution and high costs, and turning "electricity instead of chemicals" from a concept into engineering equipment capable of long-term stable operation.

II. Working Principle (Brief)

  1. Influent distribution: After homogenization and flow equalization, the wastewater enters the electrolytic reaction zone, where pH and conductivity are adjusted as needed to ensure stable reaction.

  2. Anodic direct oxidation: Pollutants undergo direct electron transfer on the catalytic anode surface and are gradually decomposed and mineralized.

  3. Indirect oxidation (·OH): Strong oxidants such as hydroxyl radicals are generated in situ at the anode, non-selectively mineralizing refractory organic compounds.

  4. Synergistic oxidation (high salinity): When chloride ions are present, active chlorine (HClO) is generated for synergistic oxidation; chlorate/perchlorate by-products need to be controlled.

  5. Effluent and subsequent stages: The ECO stage effluent enters subsequent sedimentation or biological treatment; this stage does not dose Fenton reagents and does not produce chemical iron sludge.

  6. Electrode cleaning: Pulse/periodic polarity reversal power supply suppresses electrode plate scaling, combined with regular online cleaning to maintain long-term efficiency.

Process schematic: Influent → distribution/conditioning → electrocatalytic oxidation (direct + indirect) → subsequent biological treatment/sedimentation → compliant effluent (ECO stage does not dose Fenton, no iron sludge)

The proportion of direct oxidation to indirect oxidation depends on the anode material: non-precious metal catalytic coatings achieve a balance between oxidation activity and service life, enabling ECO to deeply mineralize organic compounds without introducing external chemical sludge, which is the essential advantage distinguishing it from Fenton and other chemical agents.

III. Core Advantages

① Electricity instead of chemicals, no Fenton iron sludgeNo ferrous iron/hydrogen peroxide dosing, no iron-containing hazardous waste sludge, low disposal cost and low environmental compliance risk.

② Non-precious metal electrodes, long service lifeNon-precious metal catalytic coatings, no precious metal dissolution, stable operation and simple maintenance.

③ Thorough mineralization, clean effluent·OH strong oxidation deeply mineralizes organic compounds, reducing COD while decolorizing, detoxifying, and breaking complexation.

④ Small footprint, modularCompact skid-mounted/modular design, parallel expansion possible, adaptable to different water volumes and retrofit spaces.

⑤ Intelligent control, unattended operationPLC + remote monitoring, automatically adjusts current and operation according to water quality, reducing O&M dependence.

⑥ Flexible combination, front-to-back connectionCan serve as an advanced treatment stage or pretreatment to improve biodegradability, flexibly coupled with anaerobic/aerobic/MBR.

IV. Main Technical Parameters (Reference Range)

Item

Parameter Range / Description

Remarks

Treatment scale

Modular, configured according to water volume and COD load (parallel expansion possible)

Project-specific

Electrode type

Non-precious metal catalytic electrode (titanium-based catalytic coating)

No precious metal dissolution

Power supply form

DC stabilized / pulse / periodic polarity reversal

Scaling suppression, extended life

Applicable pH

Generally wide adaptability (specific depending on electrode and design)

Determined by design

COD removal (advanced treatment stage)

Typically 30% – 70% (depending on water quality and target)

Mainly refractory

Energy consumption per ton of water

Strongly correlated with pollutant load, calculated as kWh/kg COD

More economical as advanced/pretreatment stage

By-products

No external iron sludge; chlorate/perchlorate control required in high-salinity scenarios

Boundary reminder

Layout

Skid-mounted / modular, indoor or under shed

Convenient footprint

* The above are typical reference ranges. Actual removal performance and power consumption are affected by raw water quality, concentration, target removal rate, electrode and power supply selection, and operation management, and shall be determined by design calculation and on-site commissioning.

V. Typical Application Scenarios

Scenario

Adaptability Description

Chemical industrial park wastewater

Advanced treatment of refractory organic compounds, upgrading, and water reuse

Pharmaceutical / API wastewater

High toxicity, high salinity, poor biodegradability; ECO breaks toxicity and improves biodegradability

Electroplating / PCB wastewater

Breakdown of complexed heavy metals, advanced purification

Printing and dyeing / dye wastewater

Efficient decolorization and COD mineralization

Landfill leachate

Advanced reduction of refractory COD in mature leachate

Petrochemical / fine chemicals

Detoxification and compliance of toxic and hazardous organic compounds

VI. Applicable Boundaries and Selection Recommendations

ECO is suitable for wastewater that is refractory, high-salinity, toxic, and poorly biodegradable (B/C < 0.3), as an advanced treatment stage or pretreatment detoxification stage; forcing it on low-concentration, huge-volume scenarios is uneconomical, and recirculation to biological treatment is preferable. High-salinity wastewater requires assessment and control of active chlorine by-products (chlorate/perchlorate). Selection should be based on water quality testing and bench-scale tests to determine current density, retention time, and electrode configuration; cyanide-containing wastewater must first undergo cyanide destruction, and when heavy metals exist in complexed form, ECO can assist in breaking complexation but requires subsequent precipitation.

Electricity Instead of Chemicals, Making Refractory Wastewater Clean and Compliant

We can provide water quality assessment, bench-scale demonstration, electrode and power supply selection, and skid-mounted layout solutions. Welcome to call or leave a message to obtain ECO configuration recommendations tailored to your wastewater quality and discharge standards.

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