What is referred to as BOD dilution water?

BOD dilution water refers to the water used in the biochemical oxygen demand (BOD) test to dilute a wastewater sample to a level that allows for accurate measurement of the oxygen consumed by microorganisms over a specified period. The correct choice here is aerated distilled water with nutrients and buffer.

This type of water is specifically prepared to create conditions that mimic natural environments, allowing for the growth of microorganisms during the test. The addition of nutrients ensures that these microorganisms have a source of food, leading to higher and more consistent microbial activity. The buffer component stabilizes the pH of the solution, ensuring that any changes in acidity or alkalinity do not affect the results of the test.

Other options do not provide the necessary conditions for the test. Untreated tap water may contain impurities or chemical constituents that could interfere with the BOD measurement. Purified water without additives lacks essential nutrients needed by the microorganisms. Water from reservoirs can vary in quality and composition, making it less reliable for standard testing purposes. Thus, using aerated distilled water with nutrients and buffer ensures that the BOD test yields accurate and reproducible results.