Electrochemical wastewater treatment equipment for laboratory wastewater.

I. Product Overview

Laboratory wastewater primarily originates from experimental activities in universities, research institutes, testing and inspection agencies, pharmaceutical R&D centers, disease control centers, and environmental monitoring stations, covering multiple fields including chemistry, biomedicine, environmental testing, materials science, and food testing. Typical characteristics of laboratory wastewater include: a wide variety of wastewater types (organic waste liquid, inorganic waste liquid, biological waste liquid, acid and alkali waste liquid, etc.); extremely complex composition (including thousands of chemical reagents, solvents, intermediate products, and reaction byproducts); extremely wide COD concentration range (from hundreds of mg/L to tens of thousands of mg/L); the presence of recalcitrant organic matter (aromatics, halogenated hydrocarbons, polycyclic aromatic hydrocarbons, etc.) and biotoxic substances (pathogenic microorganisms, antibiotics, genetically engineered products, etc.); drastic fluctuations in water quality and quantity (significant differences between different experimental projects and time periods); and relatively small production volume but extremely high hazard.

Laboratory wastewater treatment has long faced a series of unique challenges:

1. Diverse wastewater types and extremely complex compositions after mixing: Wastewater from different laboratories and different experimental projects exhibits vastly different properties, resulting in hundreds of pollutants in the mixed wastewater, which traditional single-process treatment methods struggle to comprehensively address.

2. Contains high concentrations of toxic and harmful substances: The coexistence of organic solvents, strong acids and alkalis, and pathogenic microorganisms poses a serious threat to the environment and human health.

3. Significant biosafety issues: Biological/medical laboratory wastewater may contain pathogens, viruses, genetically engineered organisms, etc., requiring complete inactivation before discharge.

4. Extremely poor biodegradability: Large amounts of organic solvents and aromatic compounds... The compounds have stable structures, with a B/C ratio often below 0.10, making them virtually ineffective for conventional biological treatment. Water quality and quantity fluctuate wildly – ​​experiments are discontinuous, wastewater discharge is intermittent, and COD can jump from hundreds of mg/L to tens of thousands of mg/L within hours, making traditional biological systems unsuitable. Treatment facilities are limited by space constraints – laboratories are typically located in urban built-up areas or on campuses, with extremely limited available space, making large-scale treatment facilities impossible. Strict management requirements – wastewater containing Class I pollutants must be collected and treated separately, and direct discharge or diluted discharge is prohibited.

This system employs electrochemical oxidation technology, specifically optimized for the characteristics of laboratory wastewater: small volume (1~50 m³/d), complex composition, high toxicity, and large fluctuations. Through the synergistic effect of direct anodic oxidation and electrocatalytic generation of hydroxyl radicals (·OH) and active chlorine, it can simultaneously treat various organic pollutants, ammonia nitrogen, and pathogenic microorganisms (electrochemical disinfection) in laboratory wastewater, stabilizing the effluent COD to meet discharge standards, completely eliminating color, and ensuring biosafety.

The entire process consumes only electricity, without adding any chemical reagents. The equipment has a small footprint (it can be placed inside or next to the laboratory building), a high degree of automation, and is easy to operate and maintain. It is an ideal technical solution to solve the four core Key difficulties of laboratory wastewater: "complex composition, high toxicity, large fluctuations, and small footprint".

II. Difficulties in laboratory wastewater treatment and solutions with this equipment

III. Working Principle

After large particulate matter is removed by a screen or filter, the laboratory wastewater enters an electrochemical reactor, where multiple pollutants are synergistically removed under the action of electrodes:

(1) Oxidative Degradation of Organic Matter

A large amount of organic solvents (ketone‑based components, ethanol, diethyl special organic components, dichloromethane, benzene series compounds, etc.), aromatic compounds, and halogenated hydrocarbons in the laboratory wastewater are directly oxidized on the anode surface:

Aromatic Compounds: The benzene ring is hydroxylated on the anode surface, opening the ring and transforming into small molecule organic acids, which are eventually mineralized into CO₂ and H₂O

Halogenated Hydrocarbons (chloroform, dichloromethane, carbon tetrachloride, etc.) : The C-X bond breaks at the anode surface, halogens are removed in ionic form, and the organic skeleton is oxidized and decomposed.

Organic solvents (alcohols, ketones, esters, special organic components, etc.): are directly oxidized to CO₂ and H₂O at the anode surface.

Macromolecules (polymers, surfactants, etc.): long carbon chains and special organic components are oxidized and broken.

Anode electrolysis of water generates hydroxyl radicals (·OH), and simultaneously utilizes chloride ions present in the wastewater to generate active chlorine (Cl₂, HOCl, OCl⁻), supplementing the oxidation of pollutants that did not directly contact the anode.

(2) Ammonia nitrogen removal

Ammonia nitrogen in laboratory wastewater (from nitrogen-containing reagents, cleaning solutions, etc.) is removed through an indirect oxidation pathway—chloride ions are electrolyzed at the anode to generate active chlorine, which rapidly oxidizes ammonia nitrogen into nitrogen gas. (3) Disinfection and Sterilization: The active chlorine and hydroxyl radicals generated during the electrochemical oxidation process have a highly effective killing effect on pathogenic microorganisms in the wastewater—penetrating cell walls, oxidizing cell membrane proteins and intracellular enzyme systems, and destroying DNA/RNA structures, causing irreversible inactivation of microorganisms. The fecal coliform count in the effluent meets the corresponding discharge standards.

(2) Color Elimination: Dyes, colored reagents, and chromophores (azo bonds, quinone groups, conjugated double bonds, etc.) that may be present in the laboratory wastewater are oxidized and broken, resulting in colorless and transparent effluent.

IV. Core Advantages (Targeting Laboratory Wastewater)

V. Technical Parameters (Customizable)

VI. Process Location

Option 1: Integrated Wastewater Treatment

Laboratory wastewater (organic waste liquid, inorganic waste liquid, biological waste liquid, etc.) → Sorted collection → Mixing and equalization tank → Integrated electrochemical treatment equipment (COD degradation + ammonia nitrogen removal + disinfection and sterilization + decolorization) → Effluent meets discharge standards/is discharged into the municipal sewer system

Description: After sorting and collecting (meeting regulatory requirements), various types of laboratory wastewater enter the mixing and equalization tank for homogenization, and then enter the integrated electrochemical equipment for comprehensive treatment. One set of equipment simultaneously completes four major functions: organic matter oxidation, ammonia nitrogen removal, disinfection and sterilization, and decolorization, ensuring the effluent meets the corresponding standards. This option has the shortest process flow, the smallest footprint, and the simplest operation, making it the preferred configuration for most laboratory wastewater treatment systems.

Option 2: High-Concentration Waste Liquid Reduction (Alternative to Hazardous Waste Transportation)

Laboratory high-concentration waste liquid (expired reagents, reaction residues, chromatographic waste liquid, etc.) → Collection tank → Electrochemical treatment equipment (COD removal rate 60%~85%) → Effluent discharged into integrated wastewater system → Integrated treatment equipment → Discharge meeting standards

Explanation: Traditionally, high-concentration organic waste liquid generated in laboratories (such as expired organic solvents, chromatographic waste liquid, etc.) is disposed of as hazardous waste through transportation, which is extremely costly. Electrochemical treatment allows for on-site batch processing of this type of high-concentration waste liquid, significantly reducing COD before smoothly discharging it into the integrated wastewater treatment system. This reduces the amount of hazardous waste transported by 70%~90%, resulting in considerable annual savings in disposal costs.

Option 3: Disinfection Treatment of Biological Laboratory Wastewater

Biological/Medical Laboratory Wastewater → Separate Collection → Electrochemical Disinfection Unit (Active Chlorine + Hydroxyl Radical Synergistic Sterilization) → Effluent (Pathogenic Microorganism Inactivation) → Discharge into Integrated Wastewater System/Compliant Discharge

Note: Pathogenic microorganisms in biological laboratory wastewater must be completely inactivated before discharge. The electrochemical disinfection unit efficiently kills various pathogenic microorganisms through on-site electrolytic active chlorine and hydroxyl radicals, eliminating the need for storing and using chemical disinfectants (such as sodium hypochlorite), eliminating the risk of chemical leakage, and providing stable and reliable disinfection results.