How quickly should samples for DO, pH, and temperature be processed after capture?

The correct response highlights the importance of processing samples for dissolved oxygen (DO), pH, and temperature within a specific timeframe to ensure accurate measurements. Processing samples within 15 minutes is optimal because these parameters can change quickly after collection. For instance, the levels of dissolved oxygen can decrease rapidly due to microbial activity, and variations in pH can also occur due to exposure to air or other environmental factors, such as temperature fluctuations.

In the case of temperature, while it is typically more stable than DO and pH, any delays might still introduce minor discrepancies in readings, depending on environmental conditions. By adhering to the 15-minute guideline, operators can ensure that the samples reflect the true water quality conditions of the source being tested, which is crucial for effective monitoring and management of wastewater treatment processes.