CA80COD

Chemical oxygen demand (COD) represents the total amount of oxygen required to completely oxidize all oxidizable substances in a sample and is therefore a comprehensive water quality parameter. Chloride ions interfere with COD measurement and must be removed before analysis. Mercury sulfate is added to eliminate chloride interference. The sample is then digested at 175 °C with sulfuric acid, silver sulfate, and potassium dichromate. Silver sulfate acts as a catalyst, while the high temperature and strong oxidizing properties of potassium dichromate ensure rapid and complete digestion. The CA80COD pressure reactor significantly shortens the digestion time. During the reaction, hexavalent chromium (Cr(VI)) is reduced to trivalent chromium (Cr(III)), causing the solution color to change from orange to green. The extent of chromate reduction and the resulting color change are directly proportional to the concentration of oxidizable substances in the sample. Therefore, optical quantification of the reduced chromate concentration can be used to determine the COD value.

Standard

Liquiline System CA80COD is a continuous online COD analyzer for reliable wastewater monitoring and process control. Automatic calibration and cleaning reduce operating costs, while advanced diagnostics and remote access support process documentation. Software-controlled safety functions provide a high level of workplace safety. Suitable for: • Wastewater treatment plant influent and effluent monitoring • Treatment performance evaluation and data archiving • Industrial wastewater discharge monitoring and discharge fee assessment • Process water monitoring