Membranes are used to remove viruses from treated wastewater to make it safe for discharge or recycling. It is important to monitor the integrity of membranes and check that viruses cannot break through. This creates a need for surrogates that are cheaper, safer and easier to use than the non-hazardous indicator virus currently applied to test membrane integrity. This research synthesised a series of fluorescent nanoparticles with similar dimensions to viruses, with the idea that the fluorescence would support continuous in situ monitoring in real time, but unfortunately the nanoparticles did not emit enough fluorescence and could not be detected in the product water.

Fish, frogs, and other aquatic animals sometimes show signs of ‘endocrine disruption’; aberrant changes to their hormone or reproductive systems that are thought to be caused by chemicals in the water they inhabit. Very few of these chemicals have been identified, and this prevents the use of classical chemistry-based analytical methods. The other problem is that the levels of hormone-like chemicals which have endocrine-disrupting biological effects tend to be so low that standard chemical methods cannot detect them. This research developed a suite of biological tests sensitive enough to detect very low levels of chemicals associated with certain types of endocrine disruption. These tests were used to examine wastewater, surface water and drinking water collected from Australia, South Africa and four European countries. The water samples were also subjected to standard chemical analysis, and the datasets compared. It was concluded that some wastewater and surface water samples contained compounds that interacted with components of the estrogen, progesterone, androgen and mineralocorticoid hormone systems, but none of the biological tests detected endocrine disrupting activity in drinking water.

Chlorine removes harmful pathogens from water but has the disadvantage of forming disinfection by-products (DBPs) by reacting with organic matter sometimes found in water. Chloramine also disinfects, is less likely to form DBPs and is more stable, so remains active in for longer in the pipelines which distribute drinking water from the plant to the tap. The problem is that it is difficult to predict exactly how much chloramine to add; it needs to be enough to maintain disinfecting activity in the pipeline distribution system, but not so much that customers find the smell of chlorine in tap water unpleasant. Traditionally, the chemical reaction rate has been used to predict the gradual ‘decay’ of chloramine in pipelines, but this is inaccurate. This research developed a computer software statistical programme that uses ‘artificial neural network’ concepts and operations to predict the longevity of chloramine residuals in water distribution systems. This is more accurate than traditional methods.

The aim of this project was to examine the utility of ultra-violet (UV) spectroscopy as a real-time water quality monitoring system. Two case studies were conducted. One assessed stormwater and showed that the UV system could detect that the first flush contained chemicals used as surrogates for water quality whereas later flows contained bacterial and biological markers. From this it was concluded that the sources of bacteria and chemicals were probably physically separated until they were mixed during surface runoff. In the second case study, the UV measurement equipment was set up in a groundwater filtration plant. It proved possible to accurately characterise water quality changes and assist operational decision-making.