Abstract: Biochemical oxygen demand (BOD) is a critical indicator in scientific research related to water pollution control. The traditional BOD testing method, based on dissolved oxygen consumption, has several disadvantages, including a long testing period, significant errors, poor reproducibility, and complex procedures, which hinder the advancement of water environment and ecology research as well as its application in experimental teaching. This paper presents a new principle, method, and instrument for BOD detection, detailing the development of an innovative scientific instrument—the “BOD-Q Water Quality Analyzer”—and its application in laboratory teaching. The results indicate that this instrument reduces the BOD detection time from the conventional 5 days to just 0.5 to 5 hours, with a detection error of less than 10%. Integrating this instrument into laboratory teaching enriches the curriculum and enhances teaching quality.

Key words: Biochemical oxygen demand (BOD), Microbial coulometric method, BOD-Q water quality analyzer, Original innovative scientific instruments, Laboratory teaching