Comparitive Study: Traditional Glass Vs. Disposable Plastic BOD Bottles

An Independent Study of Disposable Plastic vs. Traditional Glass BOD₅/CBOD₅ Bottles

Inspectors of wastewater treatment plants are well aware of the need for blanks to be run for most monitoring tests, and they are also well aware that the results for these blanks should be zero. Because of the emphasis put on the blank for the BOD test, analysts go to great extremes to make sure all labware used in the tests is scrupulously cleaned. BOD samples are typically incubated in 300-mL stoppered bottles. A typical wastewater treatment plant lab would have several dozen BOD bottles that are usually cleaned with detergent and water and rinsed several times with water including reagent grade water as the last step. The bottles have small openings making them difficult to clean. Most labs find it necessary to acid-rinse the bottles occasionally to make sure all contamination is removed. Keeping the bottles clean is labor intensive, costly and, if acid rinsing is required, potentially hazardous. Hence the dilema...