Water & Wastewater Treatment Magazine
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www.wwtonline.co.uk | WWT | JULY 2016 | 21 In the know Research Notes: water quality Rapid, low cost water quality assessment for all Real-time water quality testing would be a significant step forward for water treatment and public health, both in the developed and developing world. Researchers at the University of Birmingham are developing an optical instrument which uses fluorescence to give a rapid, in- situ indicator of quality PRofessoR John BRidgeman Head of CiviL engineeRing UniveRsiTY of BiRmingHam In less developed countries, the length of time, expert analysis and relatively expensive reagents needed mean the use of such tests in community water management and disaster relief scenarios, such as refugee camps, is problematic and infrequent. Furthermore, these techniques are beyond the reach of those poorest communities in urgent need of drinking water and sanitation improvements. Situations like these demonstrate that rapid science and engineering-based indicators of safe drinking water are essential to reduce poverty and develop sustainable livelihoods. Such indicators are likely to be most widely adopted when delivered as part of a community- based drinking water solution. In more developed nations, the challenge to ensure microbial quality is addressed by water utilities through disinfection during treatment processes. Using chlorine, ozone, or chlorine dioxide as a disinfectant in water rich in organic matter, which also acts as a microbial food source, can generate potentially carcinogenic disinfection byproducts. Consequently, utilities must manage the competing needs of biological and chemical compliance. It is, therefore, vital that companies monitor the microbial and chemical quality of drinking water at various stages of treated water supply systems, including trunk mains, service reservoirs and the distribution network. Measurement of both organic and microbial matter currently relies on collection and transportation of discrete samples that then take days to analyse. Such approaches provide retrospective confirmation of water quality. In-situ real time measurement is, therefore, highly desirable, as it would enable rapid assurance of water quality. For developed countries, this would facilitate optimisation of process control and overall proactive and preventative operation of water supply systems. In less developed nations it would provide first-level screening and safety assessment of an area's water supply arrangements. There is a pressing need for novel technologies that enable real time, in-situ, low powered and, ideally, continuous analysis of drinking water quality. Focusing on these global challenges, researchers from the Department of Civil Engineering T he issues associated with limited access to safe, reliable water supplies are well- documented, and yet microbiological waterborne disease remains a significant concern for the global community. Pathogens in drinking water sources cause ill health, hindering sustainable settlement development and disproportionately affecting the poor. Despite the efforts of those responding to the UN Millennium Development Goals, there are still 663 million people without access to safe drinking water supplies and 2.4 billion have no access to improved sanitation services. A primary concern for water utilities worldwide is to ensure that drinking water does not pose an unacceptable health risk to consumers. The number and type of different pathogens present in waters is extensive, varied and dependent on a range of environmental factors. It is, therefore, not feasible to regularly isolate and identify each specific pathogen. Reliance has traditionally been placed on the measurement of total plate counts, as an overall indicator of microbial load and detection of faecal indicator bacteria and other coliform bacteria for contamination. Although precise, these tests can take more than 30 hours to produce results. In the natural environment, oŽen only 1% or less of microbes can be cultured in this way, leading to what has become commonly known as the "great plate count anomaly". The duo fluor (top, with Professor Bridgeman, and middle) could help developing world communities