Real-time autonomous remote biogas monitoring: anaerobic digestion at Loughborough University

Rural Hybrid Energy Enterprise Systems (RHEES) is a research partnership between 6 UK and 7 Indian Universities. The aim of this project is to develop best practise at a smaller community scale which makes use of hybrid and combinations of biofuels. The idea is to improve rural energy availability, equity of cost and to generate an economic stimulus from the desire to provide greater energy security and reduced environmental impact. Our part of the project is AD deployment. Here, we summarise how a novel gas monitoring device for remotely controlled, autonomous monitoring of AD might avoid shock loadings from heterogeneous feedstocks

Real-time autonomous remote monitoring of biogas for rural communities in developing countries

Rural Hybrid Energy Enterprise Systems (RHEES) is a research partnership between 6 UK and 7 Indian Universities. The aim of this project is to develop best practise at a smaller community scale which makes use of hybrid and combinations of biofuels. The idea is to improve rural energy availability, equity of cost and to generate an economic stimulus from the desire to provide greater energy security and reduced environmental impact. Our part of the project is AD deployment. Here, we summarise how a novel gas monitoring device for remotely controlled, autonomous monitoring of AD might avoid shock loadings from heterogeneous feedstocks

Ion-selective electrodes in environmental analysis

An overview is given dealing with the application of ion-selective electrodes (ISEs) in environmental analysis. ISEs are placed into the context of the trend of development of sensors for extensive and frequent monitoring. Discussed are the issues such as sensing platforms and their mass-production, improvement of precision, diagnostic of sensor functionality, and development of reference electrodes. Several examples of real-life application of ISEs in environmental analysis are given. The main emphasis of this article is directed towards summarizing recent results of the authors during the past several years

Providing energy for rural Indian communities: anaerobic digestion at Loughborough University

Rural Hybrid Energy Enterprise Systems (RHEES) is a research partnership between 6 UK and 7 Indian Universities. The aim of this project is to develop best practise at a smaller community scale which makes use of hybrid and combinations of biofuels. The idea is to improve rural energy availability, equity of cost and to generate an economic stimulus from the desire to provide greater energy security and reduced environmental impact. Our part of the project is AD and here we describe the typical Assam design. We summarise how a novel gas monitoring device for remotely controlled, autonomous monitoring of AD might avoid shock loadings from heterogeneous feedstocks

Comparison of soil pollution concentrations determined using AAS and portable XRF techniques

Past mining activities in the area of Silvermines, Ireland, have resulted in heavily polluted soils. The possibility of spreading pollution to the surrounding areas through dust blow-offs poses a potential threat for the local communities. Conventional environmental soil and dust analysis techniques are very slow and laborious and consequently there is a need for fast and accurate analytical methods, which can provide real-time in situ pollution mapping. Laboratory-based aqua regia acid digestion of the soil samples collected in the area followed by the atomic absorption spectrophotometry (AAS) analysis confirmed very high pollution, especially by Pb, As, Cu, and Zn. In parallel, samples were analyzed using portable X-ray fluorescence radioisotope and miniature tube powered (XRF) NITON instruments and their performance was compared. Overall, the portable XRF instrument gave excellent correlation with the laboratory-based reference AAS method

Spiropyran Polymeric Microcapillary Coatings for Photodetection of Solvent Polarity

Fused silica microcapillaries were functionalized with spiropyran-polymer brushes using surface-initiated ring-opening metathesis polymerization. Based on the inherited spiropyran properties, the functionalized capillaries were successfully used to photoidentify solvents of different polarity when passing through the microcapillary in continuous flow. In the present study, six different solvents (toluene, tetrahydrofuran, acetone, acetonitrile, ethanol, and methanol) can be easily detected while passing through the modified microcapillary by simply irradiating a portion of it with UV light (365 nm). This converts the closed spiropyran moiety to the open merocyanine form, and as a consequence, the microcapillary gains a distinct color and spectral response depending on the polarity of the solvent. The rate of ring-opening of the spiropyran-polymer brushes coatings has been determined in situ in the presence of different solvents, showing that the coloration rate is also influenced by the solvent polarity and therefore can be used as an additional parameter for solvent sensing

An Electrochromic Ionic Liquid: Design, Characterization, and Performance in a Solid-State Platform

This work describes the synthesis and characteristics of a novel electrochromic ionic liquid (IL) based on a phosphonium core tethered to a viologen moiety. When integrated into a solid-state electrochromic platform, the viologen modified IL behaved as both the electrolyte and the electrochromic material. Platform fabrication was achieved through <i>in situ</i> photo-polymerization and encapsulation of this novel IL within a hybrid sol–gel. Important parameters of the platform performance, including its coloration efficiency, switching kinetics, and optical properties were characterised using UV–vis spectroscopy and cyclic voltammetry in tandem. The electrochromic platform exhibits a coloration efficiency of 10.72 cm² C^–1 and a varied optical output as a function of the incident current. Despite the rather viscous nature of the material, the platform exhibited approximately 2 orders of magnitude faster switching kinetics (221 s to reach 95 % absorbance) when compared to previously reported electrochromic ILs (18 000 s)

Fibers and fabrics for chemical and biological sensing

Wearable sensors can be used to monitor many interesting parameters about the wearer’s physiology and environment, with important applications in personal health and well-being, sports performance and personal safety. Wearable chemical sensors can monitor the status of the wearer by accessing body fluids, such as sweat, in an unobtrusive manner. They can also be used to protect the wearer from hazards in the environment by sampling potentially harmful gas emissions, such as carbon monoxide. Integrating chemical sensors into textile structures is a challenging and complex task. Issues which must be considered include sample collection, calibration, waste handling, fouling and reliability. Sensors must also be durable and comfortable to wear. Here, we present examples of wearable chemical sensors that monitor the person and also his/her environment. We also discuss the issues involved in developing wearable chemical sensors and strategies for sensor design and textile integration

Bayesian methods for ion-selective electrodes

With the increasing use of ion-selective electrodes in environmental and health applications, it is important to know the precision of estimated concentrations. A Bayesian model for non-linear calibration is introduced which provides estimates of measurement precision by incorporating uncertainty in calibration parameters and inherent random noise in emf response. The analysis of lead in 17 soil samples demonstrates that large gains in precision are possible when calibrations are extended to include multiple electrodes and standard addition data. The results highlight the need for improved calibration and routine use of standard addition as ion selective electrodes become increasingly popular for demanding, real world applications

Portable X-ray fluorescence as a rapid technique for surveying elemental distributions in soil

Case studies from two sites demonstrate how concentration distributions of hazardous contaminants can be rapidly measured and visualized using portable XRF (X-ray fluorescence) coupled with geostatistical interpolation tools. In this study, lead is used as an exemplar due to its well-known detrimental effect on human health through long-term exposure. A portable Thermo Scientific NITON X-ray fluorescence (XRF) instrument was used for real-time in-situ concentration measurements, which were linked to GPS coordinates of the sampling locations. A 52 point mixed sampling density survey was performed at a site near Maynooth, Co. Kildare, and a second 58 survey undertaken at Dublin City University (DCU). At Maynooth, high concentrations of Pb (above 110 mg/kg) were found close to the site where a local canal meets a road. At the DCU site, results indicate high Pb concentrations (above 160 mg/kg) near a busy main road. Geostatistical techniques were used to generate concentration prediction and critical threshold contour surfaces for both sites. Linked with GPS coordinates for each sampling location, this technology enables the distribution of multiple elements to be mapped over wide areas in a relatively short time. Supplemental materials are available for this article. Go to the publisher's online edition of Spectroscopy Letters to view the supplemental file