Electrochemical wastewater treatment equipment: used for removing biological toxins from wastewater

Electrochemical oxidation wastewater treatment equipment | Removes microbial toxicity, improves biodegradability, and prevents scale and clogging of electrode modules.

This equipment employs advanced electrochemical oxidation technology, specifically designed to remove toxic substances from wastewater that inhibit or kill microorganisms (activated sludge, nitrifying bacteria, anaerobic bacteria, etc.). Typical sources include: antibiotic wastewater, pesticide wastewater, chemical synthesis wastewater, industrial wastewater containing bactericides/preservatives, and landfill leachate. Direct entry of these wastewaters into the biological treatment system would lead to microbial death, sludge disintegration, and a collapse in treatment efficiency. Electrochemical oxidation generates strong oxide species (hydroxyl radicals·OH, active chlorine, etc.) at the anode, destroying the molecular structure of toxic substances and converting them into non-toxic or low-toxic, biodegradable small-molecule organic compounds. This eliminates the inhibitory effect on microorganisms and simultaneously increases the BOD/COD ratio, creating safer conditions for subsequent biological treatment. The system consists of a pre-filter, an electrochemical motor module, a dedicated high-frequency DC power supply, and a circulating water tank. It offers advantages such as no chemical additives, no residual solid waste, no electrode scaling or clogging, thorough toxicity removal, and no secondary pollution.

core components

Pre-filter: Basket-type or self-cleaning filter to remove large suspended solids and debris, protecting the electrodes and circulation pump.

Electrochemical electrode module: Employs corrosion-resistant, high-performance electrodes with internal flow guiding and water distribution structures.

High-frequency DC power supply: High-power regulated/constant-current power supply with overload, short-circuit, and overheat protection; continuously adjustable current/voltage density.

Circulating water tank: Made of PE or PP material, equipped with level control and a circulation pump, supporting batch circulation or continuous flow processing.

Control cabinet: PLC fully automatic control, touchscreen HMI, interlocked control of liquid inlet, circulation, and discharge, fault alarm, and remote monitoring support.

Working principle

Wastewater containing microbial toxins enters a circulating water tank after pre-filtration and is then pumped into an electrochemical reactor. Under the influence of an electric field:

Direct electro-oxidation: Toxic organic compounds (such as antibiotics, cyanides, phenols, and heterocyclic compounds) directly lose electrons at the anode surface, their molecular structure is destroyed, and toxic groups break down.

Indirect electro-oxidation: The anode electrolyzes chloride ions in water or wastewater to generate strong oxidizing free radicals (·OH, O₃, HClO/ClO⁻, etc.). These reactive species diffuse into the solution, non-selectively attacking toxic substances, converting them into low-molecular-weight organic acids, CO₂, and water, or into biodegradable intermediates.

Toxicity elimination: After electrochemical treatment, the growth inhibition rate of activated sludge bacteria by the wastewater significantly decreases (typically from >80% to <20%), allowing microorganisms to grow and metabolize normally.

Improved biodegradability: Recalcitrant macromolecular toxic substances are decomposed into smaller molecules, increasing the BOD₅/CODcr ratio by more than 0.2, facilitating subsequent biochemical treatment.

The system circulates the treatment until the toxicity levels meet the standards, after which it can proceed to subsequent biochemical units or be directly discharged.

Main advantages

Precise Removal of Microbial Toxicity: Targets activated sludge inhibition, nitrification inhibition, and anaerobic bacterial toxicity, achieving a removal rate of 80%-95%. The treated wastewater has no inhibitory effect on the biological system.

Protecting the Stability of the Biological System: As a pretreatment unit, it prevents the biological treatment tank from being paralyzed by the impact of toxic wastewater, significantly improving the operational reliability of wastewater treatment plants or industrial wastewater treatment stations.

Improving Biodegradability: Converts recalcitrant organic matter into readily biodegradable substances, increasing the B/C ratio by 0.2-0.4, creating favorable conditions for subsequent hydrolysis acidification, aerobic or anaerobic treatment.

Chemical-Free: No chemical reagents are added to the treated wastewater, and no residual solid waste is generated.

Broad-Spectrum Applicability: Effective against typical microbial toxic substances such as antibiotics, bactericides, cyanides, phenols, formaldehyde, pyridine, and quinoline.

Easy Operation: PLC automatic control allows for flexible response to water quality fluctuations by adjusting current/voltage, eliminating the need for frequent testing and reagent adjustments.

Long electrode life: The electrode modules are non-consumable, scale-free, and non-clogging; they are corrosion-resistant and passivation-resistant, and can last for more than 2 years under normal use.

Modular skid-mounted: They have a small footprint and can be flexibly integrated into existing pretreatment sections.

Technical parameters

Processing capacity: 1 – 50 m³/h

Rated power: 5 – 200 kW (customizable based on water quality)

Voltage: 0 – 20 V (adjustable)

Hydraulic retention time (HRT): Customizable based on water quality

Microbial toxicity removal rate: ≥80% (can reduce toxicity to non-inhibitory levels)

BOD₅/CODcr improvement: Can be increased to 0.2 – 0.4

COD removal rate: 40% – 75% (partially converted into biodegradable intermediates)

Circulating water tank volume: 1 – 30 m³

Main material: PP / FRP / 304/316L stainless steel

Power supply: Customizable upon request

Application areas

Pharmaceutical wastewater (inhibition of activated sludge by antibiotics and synthetic medicine intermediates)

Pesticide and herbicide wastewater (toxicity to nitrifying bacteria and aerobic bacteria)

Chemical synthesis wastewater (containing cyanide, phenol, and heterocyclic compounds)

Landfill leachate (inhibition of microorganisms by high concentrations of ammonia nitrogen and organic toxins)

Dyeing and printing wastewater (biotoxicity of certain recalcitrant dyes and auxiliaries)

Hospital and medical center wastewater (impact of disinfectant residues on biochemical systems)

Industrial wastewater containing inhibitors such as bactericides, preservatives, and surfactants

We can provide electrode selection, current density, and treatment time based on the wastewater's inhibition rate test results on activated sludge. We welcome you to send water samples or provide microbial toxicity data for customized solutions.