Coal Coking Wastewater Treatment: 2500 T/D COD Reduction to Below 50 ppm with Chelating Resin Technology
August 20, 2026
Project Overview
A large coal coking facility faced a critical wastewater treatment challenge. Its coking effluent, produced at a continuous rate of 2,500 tons per day, carried a chemical oxygen demand (COD) of 180–220 ppm and exhibited a distinct tea-yellow coloration. This made direct discharge or process reuse impossible under modern environmental compliance standards.
The Challenge
The plant needed a reliable, cost-effective solution to meet strict discharge requirements while maintaining uninterrupted production. The key treatment targets were:
- Daily wastewater volume: 2,500 T/D
- Influent COD: 180–220 ppm
- Appearance: tea-yellow, requiring full decolorization
- Effluent target: COD below 50 ppm, colorless and crystal clear
Our Solution
After evaluating conventional biological and chemical treatment options, we deployed an advanced chelating resin adsorption process tailored to the specific composition of coal coking wastewater. The treatment train combines pretreatment with high-selectivity chelating resin columns, which efficiently capture organic pollutants, refractory compounds, and color-causing substances in a single integrated flow.
Key features of the applied process:
- High adsorption selectivity for organic contaminants and chromophoric groups
- Rapid COD removal, reducing load from 180–220 ppm to below 50 ppm
- Complete decolorization, transforming tea-yellow influent into colorless, crystal-clear effluent
- Stable long-cycle operation with efficient resin regeneration for low operating costs
- Compact footprint, easily integrated into existing plant infrastructure
Results & Benefits
The system has been operating stably, delivering consistent effluent quality that fully meets the discharge standard:
| Parameter | Influent | Effluent (After Treatment) | Requirement |
|---|---|---|---|
| COD | 180–220 ppm | < 50 ppm | < 50 ppm |
| Color | Tea-yellow | Colorless | Colorless & clear |
| Flow Rate | 2,500 T/D | ||
Beyond compliance, the project delivered measurable business value:
- Regulatory peace of mind — effluent consistently below the COD < 50 ppm threshold
- Water reuse potential — crystal-clear effluent suitable for further polishing and recycling
- Lower operating costs — minimized chemical consumption and sludge generation compared to conventional coagulation
- Minimal downtime — robust resin performance ensures continuous, uninterrupted operation
Why Choose Chelating Resin Technology?
Coal coking wastewater is notoriously difficult to treat due to its high organic load, complex refractory compounds, and intense color. Chelating resin technology offers a decisive advantage: it combines physical adsorption with selective binding of target pollutants, achieving deep COD removal and decolorization in one step — without the need for excessive chemical dosing or large-footprint biological stages.
This case demonstrates that even the most demanding industrial effluents can be treated to crystal-clear, low-COD quality with the right resin technology and process design.
Contact us to discuss how chelating resin solutions can be tailored to your wastewater treatment project.