Fluorescence spectroscopy as a tool for determining microbial quality in potable water applications

• Published in: Environmental technology Vol. 33; no. 6; pp. 687 - 693
• Main Authors: Cumberland, Susan, Bridgeman, John, Baker, Andy, Sterling, Mark, Ward, David
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 01.03.2012; Taylor & Francis Ltd
• Subjects: Applied sciences; Atmospheric pollution; Bacteria; Bacterial Typing Techniques - methods; coliform bacteria; Coliforms; Continental surface waters; Diluents; Dilution; Drinking water; Drinking Water - analysis; Drinking Water - microbiology; Drinking water and swimming-pool water. Desalination; drinking water quality; E coli; Enumeration; environmental technology; Escherichia coli; Exact sciences and technology; faecal contamination; Feces; Fluorescence; fluorescence emission spectroscopy; Fluorescence spectroscopy; General purification processes; Heterotrophic bacteria; Indoles; infrastructure; Light-emitting diodes; microbiological quality; Microorganisms; Microscopy, Fluorescence - methods; Natural water pollution; Pollution; Portability; portable fluorescence; river water; Rivers; Sanitation; Sewage; Spectrophotometers; Spectroscopy; Spectrum analysis; Spring water; tap water; Tryptophan; wastewater; Wastewaters; Water analysis; Water Microbiology; Water Pollutants - analysis; Water quality; Water sampling; Water treatment and pollution; wavelengths; British Isles; Drinking water; Correlation; Microbiology; Fluorescence; Pollutant emission; Fluorescence spectrometry; Waste water; Pathogenic; Bacteria; Stream; Feces; Biological contamination; E. coli; tryptophan; portable fluorescence; faecal contamination; Buildings; drinking water quality; Coliforms; Tap water; Dilution; Correlation analysis; Surface water; Water quality; Air pollution
• ISSN: 1479-487X; 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2011.588401

Building on previous work where fluorescence spectroscopy has been used to detect sewage in rivers, a portable LED spectrophotometer was used for the first time to establish bacterial numbers in a range of water samples. A mixed-method approach was used with standard bacteria enumeration techniques on diluted river water and sewage works final effluent using a number of diluents (Ringer's solution, tap water and potable spring water). Fluorescence from uncultured dilutions was detected at a 280 nm excitation/360 nm emission wavelength (corresponding to the region of tryptophan and indole fluorescence) and compared with bacteria numbers on the same cultured sample. Good correlations were obtained for total coliforms, E. coli and heterotrophic bacteria with the portable LED spectrophotometer (R²=0.78, 0.72 and 0.81 respectively). The results indicate that the portable spectrophotometer could be applied to establish the quality of drinking water in areas of poor sanitation that are subject to faecal contamination, where infrastructure failure has occurred in the supply of clean drinking water. This would be particularly useful where laboratory facilities are not at hand.