Towards the development and design of in-situ faecal matter sensing platforms for aquatic environments.

Standard methods for the assessment of faecal contamination of water rely on laboratory-based techniques, which are time-consuming,labour-intensive and unable to be employed for continuous monitoring. Currently, 18 hours are required after sampling for the analysis to be performed. Our focus is to develop a remotesensing platform able to continuously monitor and provide near real-time measurements of Escherichia Coli(E.Coli)in environmental waters. The detection and quantification of E.Coli is studied using the activity of β-D-glucuronidase(GUD) marker enzyme

Comparison of fluorogenic substrates for the detection of faecal indicator bacteria in water samples using a continuous fluorometric assay.

At present standard methods employed for the microbiological monitoring of bathing waters require at least 18 hours to perform and are based on culturing techniques. This is a huge drawback when immediate action is required. Real-time and on-line monitoring are key factors for consideration in current method development for continuous indicator organism detection in order to meet early warning requirements and water safety plans. Methods utilising β-D-Glucuronidase (GUD) activity as an indicator of Escherichia Coli presence use labelled glucuronides to produce optical signals. Fluorometric assays for the measurement of Escherichia Coli GUD activity are traditionally performed using the fluorogenic substrate 4-methyl-umbelliferone-β-D-glucuronide (4-MUG) which upon hydrolysis releases the fluorophore 4-methyl-umbelliferone (4-MU). The major drawback of 4-MU is its high pKa (7.8), which causes only partial dissociation at pHs around the optimum pH for GUD activity (6.5-7.0). To overcome this issue researchers have employed discontinuous enzyme assays which require the addition of alkali. In this context we explore the spectrophotometric properties of three fluorogenic substrates and their respective aglycons (Fig.1 ) for the continuous measurement of GUD activity and we apply the developed method for the rapid detection of Escherichia Coli in environmental water samples

Improving data driven decision making through integration of environmental sensing technologies

Coastal and estuarine zones contain vital and increasingly exploited resources. Traditional uses in these areas (transport, fishing, tourism) now sit alongside more recent activities (mineral extraction, wind farms). However, protecting the resource base upon which these marine-related economic and social activities depend requires access to reliable and timely data. This requires both acquisition of background (baseline) data and monitoring impacts of resource exploitation on aquatic processes and the environment. Management decisions must be based on analysis of collected data to reduce negative impacts while supporting resource-efficient, environmentally sustainable uses. Multi-modal sensing and data fusion offer attractive possibilities for providing such data in a resource efficient and robust manner. In this paper, we report the results of integrating multiple sensing technologies, including autonomous multi-parameter aquatic sensors with visual sensing systems. By focussing on salinity measurements, water level and freshwater influx into an estuarine system; we demonstrate the potential of modelling and data mining techniques in allowing deployment of fewer sensors, with greater network robustness. Using the estuary of the River Liffey in Dublin, Ireland, as an example, we present the outputs and benefits resulting from fusion of multi-modal sensing technologies to predict and understand freshwater input into estuarine systems and discuss the potential of multi-modal datasets for informed management decisions

A study of the SOURCE-TO-SEA occurrence of poly- and perfluoroalkyl substances (PFASs) of emerging concern in Ireland

Perfluorinated compounds are ubiquitous. Approximately 4,700 PFAS have been identified to date. Some examples of these products include carpets, glass, paper, clothing, and other textiles, cookware, food packaging, electronics, and personal care products. PFAS have been used in industrial and consumer products since the 1950s due to their physical and chemical properties. PFAS molecules can include oxygen, hydrogen, sulphur, and/or nitrogen atoms, whereas perfluorocarbon molecules contain only carbon and fluorine atoms. Perfluorinated compounds (PFAS) contain a fully fluorinated hydrophobic linear carbon chain attached to one or more hydrophilic head groups. The carbon-fluorine bond is so strong that these chemicals do not degrade in the environment. They are often referred to as ‘forever chemicals’. Some PFAS have been linked to an increased risk of cancer, high cholesterol, reproductive disorders, hormonal disruption or endocrine disruption, and weakening of the immune system. Currently, two PFAS are restricted under the international Stockholm Convention on POPs and the EU POPs Regulation. PFOS (perfluoroctanesulfonic acid) and its derivatives have been restricted since 2009/2010. PFOA (perfluorooctanoic acid), its salts, and related compounds are also regulated as of 4th July 2020. Over the past decades, global manufacturers have started to substitute long-chain PFAS with shorter-chain PFAS or with non-fluorinated substances. This trend has been driven by the fact that the undesired effects of long-chain PFAS on human health and the environment were assessed and recognised first by scientists and authorities around the globe. However short-chain PFAS are now thought to have similar or other properties of concern such as fluorinated compounds like Gen X and ADONA. The combined effects of PFAS are not widely studied and relatively unknown. There is also little biological assessment currently done for drinking water and especially marine water. These are both research gaps, by using biological assessment one can study the cumulative and combined effect of various PFAS on marine species which is what we aim to do in this stud

A novel dynamic passive sampling approach for the marine monitoring of emerging contaminants

Anthropogenic contaminants enter the marine environment directly from land-based sources, however they can also be emitted or re-mobilised in the marine environment. The EU Marine Strategy Framework Directive (MSFD) is responsible for providing provisions against the pollution of marine waters by chemical substances. These contaminants are of great concern due to their known toxicological effects (i.e., endocrine disruption, immunotoxicity), with some known to accumulative in organisms and food webs. However, it is impossible to capture all contaminants that may be present in this dynamic marine environment. As a result, many of these chemicals and chemical mixtures have been characterised as ‘contaminants of emerging concern’ (CECs). Passive samplers can accumulate pollutants and concentrate sufficient amounts of pollutants from water for chemical analysis where spot sampling methods often fail. This study evaluates the use of a novel dynamic passive sampling approach for the determination of CECs in seawater

A smart city-smart bay project - establishing an integrated water monitoring system for decision support in Dublin Bay

Environmental and water quality monitoring is key to measuring and understanding the chemical and biological quality of water and for taking reactive remedial action. Over the coming years, monitoring of water bodies will increase within Europe, in order to comply with the requirements of the Water Framework Directive (WFD, Council Directive 2000/60/EC), and globally owing to pressure from climate change. The establishment of high quality long-term monitoring programmes is regarded as essential if the implementation of the WFD is to be effective. However, the traditional spot/grab sampling using conventional sampling and laboratory based techniques can introduce a significant financial burden, and is unlikely to provide a reasonable estimate of the true maximum and/or mean concentration for a particular physico-chemical variable in a water body with marked temporal variability. When persistent fluctuations occur, it is likely only to be detected through continuous measurements, which have the capability of detecting sporadic peaks of concentration. The aim of this work is to demonstrate the potential for continuous monitoring data in decision support as part of a smart city project. The multi-modal data system shows potential for low-cost sensing in complex aquatic environments around the city. Continuous monitoring data from both visual and water quality sensors is collected and data from grab samples collected support the observations of trends in water quality