Essential Parameters for Monitoring Coal Chemical Wastewater

Coal chemical wastewater, generated from processes like coal gasification, coking, liquefaction, and methanol/olefin production, is notoriously complex and highly polluted. Effective treatment and regulatory compliance hinge on comprehensive and accurate wastewater characterization. Systematic monitoring of specific parameters is crucial for assessing pollution load, guiding treatment processes, and ensuring discharge standards are met.

The core parameters can be categorized into physical, organic, inorganic, and toxic substance groups. The following table outlines the essential testing parameters as guided by industry standards and practice

Typical Concentration Ranges and Challenges
Coal chemical wastewater is characterized by extremely high concentrations of pollutants. For instance, COD can range from 2,000 to 5,000 mg/L, and ammonia nitrogen from 200 to 600 mg/L, which is tens to hundreds of times higher than in domestic sewage. Cyanide levels may range from 10 to 30 mg/L. These high levels, combined with the presence of refractory and toxic compounds, make pretreatment and specialized biological treatment processes essential.

Detection Methods
Standard methods are employed for accurate measurement:

COD and BOD: Standard dichromate and dilution methods are used. For high-chlorine samples, a chloride ion correction method may be necessary.

Ammonia Nitrogen: For the high concentrations typical in coking wastewater, the formaldehyde method (titrimetric) is a standard and reliable technique (GB/T 34532-2017). For lower concentrations, spectrophotometric methods like Nessler's reagent are common.

Inorganic Anions: Ion Chromatography (IC) is a highly effective and standard method for the simultaneous separation and detection of anions such as F⁻, Cl⁻, NO₃⁻, and SO₄²⁻, offering high sensitivity and accuracy.

Heavy Metals: Techniques like Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) or Atomic Absorption Spectroscopy (AAS) are typically used.

In summary, the effective management of coal chemical wastewater depends on a multi-parameter testing regime. Regular monitoring of the parameters listed above provides the data needed to design efficient treatment systems, optimize operational control, and ultimately achieve compliance with stringent environmental regulations for discharge or reuse. Adherence to established national and industry standards, such as *T/NAIA 0136—2022* and *GB/T 42866—2023*, is fundamental to this process.

If you are interested in the specific discharge limit values for these parameters or deeper insights into treatment technologies, I can provide further details.