COD is an important measure that can be used to determine wastewater treatment plant efficiency as it can determine the amount of oxidizable pollutants in wastewater and track the effectiveness of wastewater treatment processes.
It can also be used as an index for water quality, as a higher COD indicates a higher proportion of oxidizable material and therefore greater demand on the pre-existing oxygen content in the water.
Unlike its biochemical counterpart, COD testing can be completed within hours however it still requires a rigorous laboratory protocol.
COD testing involves using a strong oxidising agent on the sample to almost oxidise almost all organic compounds present to carbon dioxide, which takes place under extremely acidic conditions. Common oxidising agents include Potassium Dichromate and or Potassium iodate.
Once all the compounds have oxidised, the COD reported is the amount of oxygen that is required to chemically oxidise all the organic compounds in the water. The test typically takes around 2-3 hours in a laboratory, requiring specific protocols and reagents.
Proteus uses the intrinsic fluorescence of the organic matter in the system to correlate to a range of COD readings; because of the established relationship between fluorescence and COD, The Proteus can then output COD readings in real-time, based on the fluorescence output. This allows high accuracy reading with a flexible data return period from real-time to user specified intervals, removing the dependency on laboratory methods. Real-time COD is a game changer for improving efficiency through feed-forward and feed-back controls of water treatment facilities.
