COD dosage

Chemical Oxygen Demand (COD) is a fundamental parameter for assessing the pollutant load of a liquid effluent . It expresses the amount of oxygen (in mg/L) required to chemically oxidize the organic matter present in a water sample, whether it be domestic wastewater, industrial wastewater or process discharges.

This indicator is essential for monitoring water quality , sizing wastewater treatment plants and ensuring environmental compliance of discharges according to European regulations (Directive 91/271/EEC).

COD measurement provides a rapid and reliable measurement of biodegradable and non-biodegradable organic pollution.

Analytical method: spectrophotometry according to NF T90-101

COD analysis is carried out by standardized method (NF T90-101) based on oxidation with potassium dichromate (K₂Cr₂O₇) in acidic medium and in the presence of catalysts (silver sulfate, mercury sulfate).

The equivalent amount of oxygen consumed is determined by spectrophotometric measurement of dichromate reduction, which is proportional to the concentration of oxidizable organic matter.

This method is recognized for its accuracy and reproducibility , particularly in the context of monitoring industrial, urban and agricultural effluents .

Environmental and industrial applications

COD measurement is applicable to a wide range of fields:

• Industrial wastewater : pollution control before discharge or treatment.
• Surface and groundwater : assessment of ecological quality.
• Urban wastewater : monitoring of wastewater treatment plants.
• Food processing, chemical and paper industries : monitoring of production effluents.
• Environmental impact studies : diagnosis and modeling of the pollutant load.

This analysis can be complemented by the measurement of BOD5 (Biological Oxygen Demand) or the measurement of total organic carbon (TOC) for a complete characterization of organic pollution.

Affected matrices

Our partner laboratories perform COD analysis on different types of matrices:

• Domestic or industrial wastewater
• Surface waters (rivers, lakes, canals)
• Groundwater and drainage
• Effluents from processing or treatment facilities
• Sludge and leachate (on specific request)

Each protocol is adapted to the nature of the matrix , the expected concentration and the control objectives

YesWeLab expertise

At YesWeLab , we collaborate with a network of over 200 partner laboratories in France, Europe and internationally , rigorously selected for their analytical expertise and their ISO 17025 and COFRAC accreditations .

Our scientific team assists you in choosing the analytical protocol , selecting the most suitable laboratory , and monitoring your environmental analyses via our digital platform . You can centralize your requests , obtain quick quotes , and track your samples in real time .

Since 2020, many industrial companies, local authorities and environmental consulting firms have trusted us to monitor water quality and regulatory compliance of their discharges .

Order a COD analysis

Do you want to assess the organic load of your effluents or ensure the environmental compliance of your discharges ?
Submit your request via our platform or contact our scientific team for personalized support .

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