Rapid inline monitoring of microbiological water quality

Water is essential for a wide range of applications, from drinking and bathing to industrial processes and agriculture. Despite the varying quality requirements for each use, maintaining high water quality is critical for public health, environmental protection, and operational efficiency. Two key indicators of water quality are the microbial biomass and microbial growth potential of the water. An increase in microbial biomass often signals a change in the water system, while a high growth potential can lead to the proliferation of pathogens or cause aesthetic and technical issues.
Traditional methods for assessing microbial biomass and growth potential are labor-intensive, slow, and not suitable for continuous monitoring. In response, several inline sensors have been developed to provide real-time data. These include the BactoSense, which uses flow cytometry to count bacteria; the BugCount Online and Guardian, which measure ATP as a proxy for active biomass; and the BACTcontrol, which detects microbial enzymatic activity. Additionally, the Continuous Biofilm Monitor (CBM) assesses the potential for biofilm formation by measuring the biomass (ATP) accumulation rate on glass beads.
These sensors offer the advantage of high-frequency, inline monitoring, enabling faster responses to change(s) in water quality and reducing the risk of product quality issues or water waste. However, most of these sensors were originally designed for clean drinking water and may not perform as well in water with higher biomass, nutrient concentration or particulate content, such as industrial cooling or process water. As some of these sensor technologies are relatively new or not yet tested in more complex water matrices, further research is needed to determine their reliability and predictive value in diverse water systems.