According to data from the United Nations, 80% of global wastewater currently goes untreated. This exposes human populations and the natural environment to all manner of pollutants, ranging from human waste to toxic industrial discharges.
The presence of pathogens, organic matter, chemical pollutants and microplastics can all make water unsuitable for human use or consumption, as well as negatively impacting marine life and local ecosystems. As such, there is a great need to invest in and improve the current treatment and analytical infrastructure for wastewater to support public and environmental health in both developed and developing nations.
Historically, the most widely-used techniques for analyzing organic pollution in wastewater have been BOD and COD, both of which have been standard practice for wastewater operations and environmental science for many decades. However, both methods have clear limitations.
BOD testing works by measuring the amount of oxygen consumed by microorganisms in one liter of water over five days, which is why it is also known as the BOD5 method. Although this approach can deliver useful insights, the five-day cycle makes BOD the slowest and most expensive of the available methods; additionally, this process has very specific pH, nutrient and chemical requirements that make it difficult for many labs to perform.
The COD method is favored by many in the industry, as it does not rely on a temperamental microbial process and takes only two to four hours per measurement, overcoming the biggest limitations of BOD. However, the COD method also has major drawbacks, as it is dependent on highly toxic and dangerous substances that are difficult to handle and dispose of, and creates hazardous waste byproducts through the process.
As such, strong demand has emerged for a cleaner, faster, less wasteful and more efficient analysis method that can present a viable alternative to both BOD and COD.