Landfill gas monitoring network - development of wireless sensor network platforms

A wireless sensor network has been developed for the application of landfill gas monitoring, specifically sensing methane, carbon dioxide and extraction pressure. This collaborative work with the Irish Environmental Protection Agency has been motivated by the need to reduce greenhouse gas emissions as well as aiming to improve landfill gas management and utilisation. This paper describes the preliminary findings of an ongoing trial deployment of multiple sensing platforms on an active landfill facility; data has been acquired for nine months to date. The platforms have operated successfully despite adverse on-site conditions, with validity demonstrated by reasonably strong correlation with independent on-site measurements. The increased temporal and spatial resolution provided by distributed sensor platforms is discussed with regard to improving landfill gas management practice

Screen printed electrochemical sensors for real-time sodium monitoring in sweat

We report on the preparation of disposable potentiometric sensor strips for monitoring sodium in sweat. We also present their integration in a microfluidic chip used to harvest sweat in-situ during exercise. The sensor-chip is integrated with a miniaturized electronic platform able to transmit data wirelessly in real time during a stationary cycling session in a controlled environment

Sensors for in-situ monitoring of eutrophication in marine environments

Accelerated eutrophication of marine ecosystems as a result of nutrient enrichment is a widespread problem within European marine margins. Eutrophication has several adverse effects on the marine ecosystem such as the formation of harmful algae blooms reduced water clarity and reduced oxygen levels. The reliable quantification of the causative nutrients is challenging due to the matrix within which they are held. Here we propose methods for the identification and optimisation of appropriate detection chemistries for phosphate, ammonia, nitrate and nitrite in marine matrices. The work presented is carried out as part of the COMMON SENSE FP7 European project. COMMON SENSE aims to provide a reliable sensing platform for in-situ measurements on key parameters relating to eutrophication. The nutrient sensor is based on a combination of microfluidic analytical systems, colorimetric reagent chemistry, low-cost LED-based optical detection, and wireless communications

Development of cost effective sensors for the in-situ monitoring of eutrophication

This work is carried out as part of the COMMON SENSE European FP7 project. The COMMON SENSE project aims to provide a reliable sensing platform for in-situ measurements on key marine water quality parameters relating to eutrophication, heavy metal contaminants, marine litter and underwater noise. The COMMON SENSE nutrient sensor is based on a combination of microfluidic analytical systems, colorimetric reagent chemistry, low-cost LED-based optical detection, and wireless communications. The reliable quantification of nutrients in marine environments is challenging due to the low concentration of these solutes in the ocean and the nature of the matrix in which they are held. Initial studies are focussed on validating a method for the sequential determination of nitrite and nitrate in marine environments. Coupled with the traditional well established Griess–Ilosvay reaction for the determination of nitrite, a vanadium chloride (VCl3) solution is used as the reducing agent. The method shows potential as an alternative to the toxic cadmium column for the reduction of NO3- to NO2- in marine water as results indicate that there are no apparent interferences from variances in salinity. The method was tested on a series of samples with varying salinities and sample matrices (costal, estuarine and freshwater), the method is low cost, reproducible and requires low volumes of sample and reagents

Non invasive detection of biological fluids: a new perspective in monitoring pH in saliva and sodium in sweat

The chemical composition of body fluids contains crucial information about the state of health of an individual. While many efforts have been already directed toward real time analysis of blood and urine, there is still a pressing need for new solutions to non-invasively monitor other fluids like saliva and sweat1. Towards this aim, the main technological challenge is the development of devices that are at the same time low-cost, minimally invasive and wearable, so that they could be used for in situ and real-time monitoring of physiological conditions2. For example, continuous recording of sodium levels in sweat could be an informative tool to assist clinicians in prescribing a more personalised treatment of diseases such as Cystic Fibrosis3 and in assessing athletes’ performances4. Similarly, the monitoring of pH levels in saliva provides valuable information for the treatment of pathologies where physiological mouth conditions are compromised, like in Gastroesophageal Reflux Disease (GERD)5. Ion Selective Electrodes (ISEs) are potentiometric sensors designed to detect specific ions in blood and saliva. Using dual-screen printed electrodes as substrates, we were able to reduce their production cost, improve reproducibility, and combine pH5 and sodium ISEs with solid contact reference electrodes. In our design, the sensors will be interfaced to two miniaturized potentiometric platforms (WIXEL for pH and Tyndall Mote for sodium detection) that were wirelessly connected to a base station. For pH measurements, the device will be accommodated into a gum shield. For sodium detection instead, we will use a microfluidic channel to convey sweat to the electrodes. The mote communication platform was adapted so that it could be worn on the upper shoulder through a fiber strip

Textile sensor glove for health monitoring – Application in home assessment of Rheumatoid Arthritis

Background: Wearable sensors and smart garments can be used for continual monitoring of a person’s physiology or physical activities. These garments may be used to assess chronic conditions in the home setting and for rehabilitation by providing feedback and motivation to users and to identify effectiveness and adherence to therapists. This work focusses on the use of a sensor glove for home assessment of rheumatoid arthritis in assessing joint stiffness through range and velocity of movement. Material & Methods: A sensor glove has been developed using fabric stretch sensors integrated into an oedema glove. The stretch sensors are made of a knit fabric coated with conducting polymer, giving them piezoresistive properties. This means that when the fabric is stretched the resistance changes, which can be measured using straightforward circuitry and captured using a microprocessor platform. An arduino fio with integrated Xbee radio is used to collect and wirelessly transfer the data to a laptop. Results: Wooden blocks cut at various angles are used to calibrate the glove. To do this the user rests their hand on the block which maintains the joint position at a particular angle. A neural network is then used to calculate the joint position during dynamic movements. An animated hand on the computer gives immediate visual feedback to the user. The next stage will be to compare the glove performance to a motion capture system such as Vicon. Conclusions: The advantage of the glove is in the fit and comfort for the wearer, the sensors and the glove itself are made from a lycra spandex material. Conventional bend sensors and fibre optics are more rigid and while suitable for computer gaming and motion capture applications are not ideal for use in people with impaired dexterity and mobility. This work presents a low-cost solution for home assessment of conditions such as rheumatoid arthritis and a means user feedback to assist and motivate users with prescribed therapeutic exercises

Digital pulse actuated flow control on a centrifugal disc towards multiparameter water quality monitoring

In this paper we present a novel dissolvable film (DF) based valving architecture for use on the centrifugal microfluidic platform. We seal fluidic reservoirs on a disc substrate with a series of these valves such that, by pulsing the spin rate, the next valve in the series is opened. Thus centrifugal flow control advances from ‘analogue’ scheme, where valves are successively opened by incremental steps of the rotational frequency, to a ‘digital pulse’ based method. The performance of these valves is demonstrates through a disc designed towards multi-parameter water quality monitoring

Life cycle assessment of waste water treatment plants in Ireland

The European Water Act 91/271/EEC introduced a series of measures for the purpose of protecting the environment from the adverse effects of effluent discharge from Waste Water Treatment Plants (WWTP). There are environmental costs associated with attaining the required level of water quality set out in the act such as, emissions from energy production, ecotoxicity from sludge application to land. The goal of this study is to assess these costs. Life Cycle Assessment (LCA) has been the analytical tool used to evaluate the environmental loadings. The CML 2001 Life Cycle Impact Assessment (LCIA) methodology has been adopted and implemented using GaBi 6.0 LCA software. Two plants of varying size and location were chosen for the study. The study found that energy consumption and sludge application to land are the largest contributors to the environmental impact associated with waste water treatment

The evaluation of technologies for small, new design wastewater treatment systems

Life cycle costing of small wastewater treatment systems can often be generic and lack a degree of detail that could affect the choice of system. Critical factors such as variations in loading, location and discharge limits are sometimes not given the required weight of importance, and as a result the most suitable, most economical system may not always be implemented. A decision support tool for small, new design wastewater treatment plants has been developed that accounts for variations in several parameters such as scale, discharge limits and sludge disposal. Capital and operational costs have been combined to produce life cycle models for six treatment systems. Each system was assessed in a number of scenarios with variations in scale, discharge limits and sludge disposal route. The results show that in most scenarios, constructed wetlands represent the most economical option where surface area is not restricted. For each system, the percentage contribution of labour to the total operational cost increases as agglomeration size is reduced