Title : Validation of an online rapid in-situ detection sensor for Escherichia coli in surface and drinking water
Events of faecal contamination in surface, drinking water and distribution systems can have a large impact on human health. To reduce the impact of these events it is crucial to have monitoring techniques to measure faecal contamination, such as faecal indicators (e.g. E. coli), that combine fast results with low detection limits. Conventional analytical methods take at least 24h to produce results, with a lack of in situ monitoring capability (Offenbaume et al, 2020, Vergine et al, 2017, Tiwari et al, 2016, Chukwuka et al, 2022) resulting in late detection of a contamination event or no detection of the event at all. Several sensors have been developed in the last years that tackle this issue by detecting Escherichia coli (E. coli) and delivering results within a couple of minutes or hours (Jing et al, 2020, Lopez et al, 2013). Further research on the sensitivity, specificity, implementation of these sensors and interpretation of results is still needed before they can be used in practice. The objective of this study is to validate the portable rapid online sensor BACTcontrol for E. coli detection, compare it with the MPN-method Colilert, study the quality of the data and how best to implement it in practice.
BACTcontrol (microLAN) is a water quality sensor for the quantification of bacteria. The technology combines the analysis of the beta-glucuronidase enzymatic reaction, which produces fluorescence, with a mathematical predictive method to determine the activity of E. coli in a sample in 32 minutes. The results are expressed in pmol/min.
Two laboratories (in Spain (Barcelona) and in the Netherlands (Nieuwegein)) performed tests with the BACTcontrol sensor on different water matrices. A baseline was initially established for each non-contaminated water matrix by continuously performing measurements with BACTcontrol. For each water matrix at least duplicate tests with Colilert were performed to determine the concentration of E. coli. In Spain, treated drinking water prior to chlorination (DW1), treated drinking water after chlorination (DW2), reverse osmosis (RO1) were used. In the Netherlands non-chlorinated drinking water (DW3), and surface water from two different rivers (SW1 & SW2) were used. In addition, in the Netherlands seven sources of non-chlorinated drinking water (of different production locations) were tested with BACTcontrol.
Audience Take Away:
- Explain how the audience will be able to use what they learn? The presentation will deepen in the benefits and limitations of a new method to quantify continuously E. coli in real time.
- How will this help the audience in their job? Method for E. coli detection in 30 minutes.
- Does this provide a practical solution to a problem that could simplify or make a designer’s job more efficient? Yes, an event detection system for fecal contamination in drinking water