Which test is commonly used to measure the concentration of organic matter in wastewater?

The Biochemical Oxygen Demand (BOD) test is widely used to measure the concentration of organic matter in wastewater because it assesses the amount of oxygen that microorganisms will consume while decomposing organic matter under aerobic conditions over a specific period, typically five days. This makes BOD a key indicator of the strength of wastewater, as organic materials are a significant pollutant in wastewater treatment processes. A higher BOD value signifies a higher level of organic pollution, which necessitates more treatment to protect aquatic life and maintain environmental integrity.

In contrast, Chemical Oxygen Demand (COD) measures both biodegradable and non-biodegradable organic matter in wastewater, thus providing a comprehensive metric of organic matter but not specifically focusing on the biodegradable portion. Total Suspended Solids (TSS) quantifies the solid particles suspended in water, which can include organic and inorganic matter but does not directly measure organic content. The pH test indicates the acidity or alkalinity of the wastewater but does not provide any information about the concentration of organic matter.