Distributed sensing devices for monitoring marine environment

The lack of affordable, self-sustaining platforms for monitoring marine water quality means that measurements are done primarily through grab sampling at a limited number of locations and time, followed by analysis back at a centralised facility. This has resulted in huge gaps in our knowledge of water quality. This project aims to develop platforms capable of remote sampling and analysis over extended periods of time. This would provide the building blocks for establishing an 'environmental nervous system' comprised of many distributed sensing devices that share their data in near real-time on the web. The envisaged 'environmental nervous system’ allows marine environment to be closely monitored, enabling the early detection of pollution events to minimise the danger to people and contamination of distribution systems

Occurrence of PAHs in wastewater treatment plant effluent

Polycyclic aromatic hydrocarbons (PAHs) are a group of both naturally occurring and man-made chemicals which exist in over 100 different forms. They are most commonly considered a group of 16 which have been chosen as priority pollutants according to the Water Framework Directive (WFD) 2000/60/EC. The main sources of PAHs in the environment are anthropogenic as they are by-products of incomplete combustion, coal gasification and liquification processes, waste incineration, petroleum cracking, and in the production of coke, coal tar pitch, carbon black, and asphalt. PAHs may also be released into marine environments via sewage, industrial wastewater, road runoff, street dust, and through oil spills and ship traffic due to their presence in un-combusted petroleum. While an efficient wastewater treatment process is said to remove 90 – 95 % of pollutants, it is important to ensure that waste water treatment plant (WWTP) outflow is not contaminating receiving water bodies, making the monitoring of WWTP effluent very important. Effluent samples have been collected from both a secondary and a tertiary waste water treatment plant over a period of 3 months, and 6 months, respectively, including several weeks of high intensive sampling. Solid phase extraction, (SPE), is used in the sample preparation process with subsequent analysis by gas chromatography (GC) with mass spectrometric detection (MS)

Review of methods used in priority pollutant analysis

The Water Framework Directive (WFD), Directive 2000/60/EC, was introduced in 2000 with the aim of member countries attaining ‘good status’ in water bodies that are below good status at present, as well as retaining good or better status where it already exists by 2015. According to WFD [1] 41 priority substances and a further 25 priority hazardous substances were identified to be included in water monitoring programmes. These substances can be divided into four main groups: pesticides, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and metals and trace elements. A standardised, reliable and efficient method, incorporating both sample preconcentration and analysis steps, is required to facilitate these monitoring programmes. As popular techniques currently in use involve solid-phase extraction (SPE), or liquid chromatography (LC), a critical evaluation has been carried out on their applications, with regard to priority pollutants and hazardous substances. SPE is used for sample pre-concentration and cleanup, for removal of specific substances from aqueous solutions, and for the purification of various chemicals, while LC is used for the separation and subsequent detection of analytes

Monitoring and modelling the occurrence of priority substances in wastewater

In 2000 the Water Framework Directive (WFD), 2000/60/EC, was introduced and a group of 66 chemicals, including pesticides, polycyclic aromatic hydrocarbons, and metals were listed as chosen priority pollutants. The levels of these priority pollutants in the environment are regulated by set environmental quality standards (EQSs) and are affected by a number of emission factors including anthropogenic activities, population equivalents, and weather. In order for these EQSs to be enforced, regular monitoring of all water bodies must be carried out, a process which is both costly and time consuming. We have developed a model defining emission levels relating to priority pollutants occurrence in the environment. This is based on information collected from local authorities, Met Eireann and pollutant levels in waste water treatment plant (WWTP) effluents

Investigation into the use of satellite remote sensing data products as part of a multi-modal marine environmental monitoring network

In this paper it is investigated how conventional in-situ sensor networks can be complemented by the satellite data streams available through numerous platforms orbiting the earth and the combined analyses products available through services such as MyOcean. Despite the numerous benefits associated with the use of satellite remote sensing data products, there are a number of limitations with their use in coastal zones. Here the ability of these data sources to provide contextual awareness, redundancy and increased efficiency to an in-situ sensor network is investigated. The potential use of a variety of chlorophyll and SST data products as additional data sources in the SmartBay monitoring network in Galway Bay, Ireland is analysed. The ultimate goal is to investigate the ability of these products to create a smarter marine monitoring network with increased efficiency. Overall it was found that while care needs to be taken in choosing these products, there was extremely promising performance from a number of these products that would be suitable in the context of a number of applications especially in relation to SST. It was more difficult to come to conclusive results for the chlorophyll analysis

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

Passive sampling for emerging compounds: An Irish perspective

A collaborative project investigating the potential of passive sampling technologies and integrative sampling to meet chemical monitoring requirements of the Water Framework Directive (2000/60/EC) in Ireland began in February 2013. Polar (POCIS) and non-­‐polar (silicon rubber) passive sampling, grab samples and biota samples are being collected at ten sites across Ireland over two years. The first five sites (Fig. 1) are taking a catchment approach. All samples will be tested for emerging and priority compounds listed in the Environmental Quality Standard (EQS) Directive (2008/105/EC) and its 2012 amendment

Determination of priority substances in wastewater using SPE, LCMS and GCMS

In 2000 the Water Framework Directive (WFD), 2000/60/EC, was introduced and a group of 66 chemicals, including pesticides, polycyclic aromatic hydrocarbons, and metals were listed as chosen priority pollutants. The levels of these priority pollutants in the environment are regulated by set environmental quality standards (EQSs) and are affected by a number of emission factors including anthropogenic activities, population equivalents, and weather. In order for these EQSs to be enforced, regular monitoring of all water bodies must be carried out, a process which is both costly and time consuming

Development of bio-inspired antifouling coatings

Biofouling is the accumulation of micro and macro organisms on a solid surface exposed to a marine environment. It cause a reduction of operational effectiveness of marine structures[1]. The process begins with the settlement of microorganisms on the surface demonstrated in figure 1, the microorganisms then produce Extracellular Polymeric Substances (EPS) forming a biofilm. Hydrophobic surfaces have been shown to inhibit biofouling and it has been noted that some strains of macroalgae use surface topography and leaching of antimicrobials to minimise biofouling

Optically clear superhydrophobic coatings

The overall performance of optical equipment and devices is ultimately dependent on their transparency. This is especially evident when such devices are constantly exposed to varying environmental conditions. Thus the development of a robust, transparent and self-cleaning coating is highly desirable. This work discusses the inherent difficulties in the design of transparent self-cleaning coatings. Describing hydrophobicity and the potential challenges the achievement of transparency can introduce. Before detailing the various established methods of characterisation of super hydrophobic surfaces and outlining some of the group’s preliminary results