Standard 5-day biochemical oxygen demand (BOD5) measurements are conducted at a constant temperature of_________________?
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Answer: C. 20°C
Explanation
Biological oxygen demand tests measure the dissolved oxygen consumed by bacteria during organic breakdown. Standardized testing protocols require consistent incubation conditions to yield comparable analytical results. The international standard for biochemical oxygen demand incubation specifies a constant temperature of twenty degrees Celsius. Biochemical oxygen demand is a crucial environmental parameter used to assess wastewater organic strength. Microbial metabolic rates depend heavily on temperature, making standardized incubation essential. Five-day incubation periods allow laboratories to measure rapid oxygen depletion reliably.
Environmental regulatory agencies enforce strict BOD limits on industrial effluent discharges into rivers. Wastewater treatment plant operators monitor BOD values daily to evaluate biological process efficiency. High biochemical oxygen demand values indicate severe organic pollution in natural aquatic ecosystems. Incubation at zero degrees Celsius would slow microbial activity too much to measure oxygen demand. Fifteen degrees Celsius is not the internationally recognized standard temperature for BOD five testing. Twenty-five degrees Celsius exceeds the standard protocol temperature specified for reliable BOD analysis.
- Subject
- Engineering
- Category
- Civil Engineering
- Topic
- —
- Difficulty
- medium
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