Specific Ultraviolet Absorbance: A Tool for Characterizing Total Organic Carbon in Water

Total Organic Carbon (TOC) is a key component of raw water that significantly influences water treatment processes and outcomes. Among the parameters used to evaluate TOC, Specific Ultraviolet Absorbance at 254 nm (UV-254) stands out as a crucial indicator. UV-254 measures the aromaticity of organic matter by normalizing UV absorbance at 254 nm to the organic carbon concentration in a water sample. This parameter provides valuable insights into the composition of organic matter, particularly the presence of aromatic compounds, which are more reactive with disinfectants during water treatment. For water operators, monitoring UV-254 is critical to ensuring effective water treatment and minimizing the formation of disinfection by-products (DBPs), such as trihalomethanes (THMs). These DBPs form when disinfectants, like chlorine, react with organic matter, particularly its aromatic components. Elevated levels of DBPs pose health risks and may lead to regulatory violations, making proactive monitoring of UV-254 essential for compliance with water quality standards.