What is used to measure biodegradable organics in wastewater?

The measurement of biodegradable organics in wastewater is primarily accomplished using BOD, which stands for Biochemical Oxygen Demand. BOD measures the amount of oxygen that microorganisms will consume while decomposing organic matter in a water sample over a specified period, typically five days at 20 degrees Celsius. This metric is crucial for assessing the potential impact of wastewater on receiving water bodies, as higher BOD values indicate a greater concentration of organic material that can cause oxygen depletion in the water, leading to harm to aquatic life.

COD, or Chemical Oxygen Demand, is also relevant for understanding the total oxygen demand exerted by both biodegradable and non-biodegradable organics. However, since the question specifically asks about measuring biodegradable organics, BOD is the most direct indicator of the amount of organic matter available for biological decomposition.

In the context of the other options, pH levels are important for assessing the acidity or alkalinity of the wastewater but do not provide information about the organic content. Total Dissolved Solids (TDS) indicate the concentration of dissolved substances but do not specifically target organic matter. Nutrient ratios, while valuable for understanding the balance of nutrients such as nitrogen and phosphorus, do not directly measure biodegradable organics. Thus, BOD is the correct