Biochemical Oxygen Demand" is an essential educational resource tailored for environmental science and engineering students, aiming to deepen their understanding of water quality assessment and pollution control. This unit comprises a series of engaging lessons, each meticulously designed to explore the dynamics of Biological Oxygen Demand (BOD) and its implications for aquatic ecosystems.Beginning with foundational concepts of dissolved oxygen and BOD, learners progress to advanced topics such as the Dissolved Oxygen Model and SAG (Submerged Aquatic Growth) curve analysis. Through interactive discussions and problem-solving exercises, students develop proficiency in calculating key parameters related to water quality, including DO concentrations and BOD levels.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"The characteristics of the world around us vary from one location to the next. This is also true of aquatic environments, where bottom-dwelling microorganisms must cope with variation in temperature, salinity, dissolved oxygen, and nutrients. Unfortunately, little is known about how these microbial communities and their functional genes respond to environmental changes. A team of researchers at Stockholm University recently set out to do just that by collecting samples of sediment at 59 sites spanning 1,145 km across the Baltic Sea. They characterized the environmental attributes and microbial community at each site using genetic sequencing and other laboratory techniques. The researchers found that salinity and dissolved oxygen content had the greatest effects on the microbes making up each community with the communities in oxygen-deficient “dead” zones being particularly dissimilar to those with higher dissolved oxygen content..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This activity focuses on getting students to think about bacteria, water quality and water treatment processes. Students develop and test their hypotheses about the "cleanliness" of three water samples prepared by the teacher. Then they grow bacteria in Petri dishes from the water samples. They learn how private septic systems and community sewage and wastewater treatment plants work, the consequences to the surrounding environment and wildlife from human wastewater, and what measurements of the released "clean" water are monitored to minimize harm to receiving rivers and lakes.