SOUR stands for which term?

• A. Standard Organic Uptake Rate
• B. Specific Oxygen Uptake Rate
• C. Sludge Oxygen Utilization Ratio
• D. Sulfur Oxygen Reduction

Answer: (B)

Specific Oxygen Uptake Rate measures the oxygen consumed by the microbial community per unit of biomass in a given time, typically mg O2 per g of volatile suspended solids per hour. This is what the acronym SOUR stands for. It’s a key indicator of how actively the sludge microorganisms are metabolizing available substrates; higher values mean higher metabolic activity, while lower values indicate lower activity or stressed/aging sludge. The other options are not standard terms used in wastewater practice to describe oxygen consumption by biomass.