What are Organics in Water?
Organics (UV 254) in water refers to the measurement of the absorption of ultraviolet light at a wavelength of 254 nanometers by organic compounds present in a water sample. This parameter is particularly sensitive to aromatic organic molecules, which are common in natural organic matter (NOM). The UV 254 absorbance value is used as an indicator of the concentration of these organic materials in water. Since many organic compounds can react during water disinfection processes to form potentially harmful by-products, the UV 254 measurement serves as a critical tool for assessing water quality and treatment efficiency. It provides a rapid, non-destructive means to monitor the presence and changes in organic content, aiding in the management of water treatment processes to ensure the safety and palatability of drinking water.
Monitoring Organics in Potable Water
Monitoring organic matter in potable water is essential for maintaining water quality, optimising treatment processes and protecting public health. Organic compounds may include naturally occurring materials, such as humic and fulvic substances, as well as contaminants introduced through agricultural, industrial or urban activity. These compounds can enter water supplies from rivers, lakes, reservoirs and aquifers, affecting the taste, odour, colour and treatability of drinking water.
A UVT analyser provides continuous measurement of ultraviolet transmittance, typically at a wavelength of 254 nm. UV transmittance indicates how much UV light passes through the water and can provide a useful indication of changes in dissolved organic matter. Lower UVT values generally indicate that more UV-absorbing material is present, which may affect the performance of UV disinfection systems.
Organic matter can also be monitored using the Spectral Absorption Coefficient at 254 nm, commonly referred to as SAC254. While UVT measures the percentage of UV light transmitted through the sample, SAC254 measures the amount of UV light absorbed. Both parameters can help water treatment operators monitor changes in natural organic matter, assess treatment performance and identify variations in source water quality.
Continuous monitoring with a UVT analyser or SAC254 analyser allows operators to respond quickly to changing conditions, optimise processes such as coagulation and UV disinfection, and maintain consistent potable water quality. It can also support more efficient chemical dosing, help protect treatment equipment and contribute to more sustainable water management.
Online Organics UVT Analyser
