What is a common method to determine the organic strength of wastes in the influent?

The biochemical oxygen demand (BOD) test is a standard method used to assess the organic strength of wastewater. BOD measures the amount of oxygen that microorganisms will consume while decomposing organic matter in a water sample over a specified time period, usually five days at a controlled temperature. This metric is critical, as it directly correlates to the level of organic pollutants present in the influent, indicating how much oxygen will be depleted from the water, which can adversely affect aquatic life and water quality if not managed properly.

In contrast, testing for pH level, suspended solids, or temperature does not provide a direct measure of the organic content in wastewater. While pH gives information regarding the acidity or alkalinity of the wastewater, and suspended solids measure the particulate matter present, neither of these metrics reflects the consumable organic materials that pose a demand for oxygen in treatment processes. Temperature can affect the rate of biological processes but does not directly measure organic load. Thus, BOD is the most relevant and widely used indicator for determining the organic strength of wastes in the influent.