UV Absorbance (UV254) Monitoring

Continuous UV254 measurement for monitoring changes in organic content in water and wastewater.

UV254 Monitoring for Organic Content

UV absorbance at 254 nm (UV254) measures the absorption of ultraviolet light by compounds present in water. It is commonly used as an indicator of changes in organic content and, where a suitable correlation has been established, as a surrogate for parameters including COD, BOD, DOC and TOC. Continuous UV254 monitoring provides real-time data for process monitoring and treatment control.

Real-Time Organic Monitoring & Control

Continuous UV254 measurement allows changes in water quality to be identified as they occur, rather than relying solely on periodic laboratory samples. This can support process control, treatment optimisation and early identification of changes in organic loading.

Correlation with Key Water Quality Parameters

Where a reliable site-specific correlation has been established, UV254 can be used as a surrogate measurement for parameters associated with organic content, including:

  • Biochemical Oxygen Demand (BOD)
    Indicates the level of biodegradable organic matter in water
  • Chemical Oxygen Demand (COD)
    Measures the total oxygen required to oxidise organic material
  • Dissolved Organic Carbon (DOC)
    Estimates the concentration of dissolved organic compounds
  • Total Organic Carbon (TOC)
    Provides an overall indication of organic carbon content

What Does UV254 Measure?

UV254 measures the amount of ultraviolet light absorbed by a water sample at a wavelength of 254 nm. Compounds that absorb light at this wavelength contribute to the measured absorbance. Changes in UV254 can therefore be used to monitor changes in water composition and organic loading.

Benefits of Continuous UV254 Monitoring

  • Continuous indication of changes in organic load
  • Early identification of changes in water quality
  • Data to support treatment process control
  • Reduced dependence on frequent laboratory measurements where an appropriate correlation has been established
  • Continuous measurement between laboratory samples

 

UV254 provides a rapid, reagent-free measurement that can be used to monitor changes in organic content continuously. Where correlations with laboratory measurements have been established, it can also provide real-time surrogate data for parameters such as COD, BOD, DOC and TOC.