Papers by Gillian Greenway
SiO2/RuO2 modified high surface area titania dioxide nanoparticles prepared by hydrogen reduction... more SiO2/RuO2 modified high surface area titania dioxide nanoparticles prepared by hydrogen reduction were examined for their catalytic properties towards the photodegradation of methyl orange (MO), a common water pollutant in the textile industry. The modified materials present enhanced photocatalytic activity and can decompose the MO faster than the unmodified TiO2. Results showed that doping with RuO2 only offered a marginal benefit over TiO2 alone. On the other hand, modification of TiO2with RuO2 and SiO2 resulted in a marked increase in the rate constant and the photodegradation efficiency. These results are consistent with the unique structural, morphologoical and surface characteristics of the composite titania dioxide/ruthenium dioxide/silicon dioxide materials. The lower the average particle size and roughness of the materials, the higher the percentage of photodecomposition and the rate constant. The surface doping and modification effects thus appears synergetic to the charge separation process and the photocatalytic results are explained on the basis of the mechanism that involves efficient separation of electron–hole pairs induced by the silicon dioxide particles. This enhances the ability of the modified TiO2 particles to effectively capture protons. Results also show that the modified nanoparticles can be used repeatedly over a long time without loss of efficiency.
Chromated copper arsenate (CCA) is a common wood preservative that has been used worldwide. Studi... more Chromated copper arsenate (CCA) is a common wood preservative that has been used worldwide. Studies have shown that there are leaching risks of the preservative components arsenic, chromium and copper. These risks include contamination of soil and water, resulting in toxic effects to humans, animals, plants and ecosystems. This study investigates leaching of the preservative components following exposure of the wood waste as mulch to soil and water. Diffusive gradient in thin films (DGTs) were used to quantify leaching of potentially bioavailable/dissolved forms of the elements along the soil profile. Speciation of chromium was also carried out. All elements were found to leach out of the wood. The containers that included CCA-treated wood waste as a mulch leached higher levels of arsenic, chromium and copper than the controls. The distribution was highest in the top 5 cm of the soil profile and decreased with depth. DGTs proved to be a useful, novel technique for measuring in situ leaching and speciation from waste materials into the environment.
Process Biochemistry, 2010
RSC Advances
We studied the nanotoxicity of titania nanoparticles (TiO2NPs) of various hydrodynamic diameters ... more We studied the nanotoxicity of titania nanoparticles (TiO2NPs) of various hydrodynamic diameters and crystallite sizes towards C. reinhardtii microalgae and S. cerevisiae (yeast) upon illumination with UV and visible light. The cell viability was assessed for a range of nanoparticle concentrations and incubation times. We found that bare TiO2NPs affect the C. reinhardtii cell viability at much lower particle concentrations than for yeast. We observed an increase of the TiO2NPs toxicity upon illumination with UV light compared with that in dark conditions due to the oxidative stress of the produced reactive oxygen species. We also found an increased TiO2NPs nanotoxicity upon illumination with visible light which indicates that they may also interfere with the microalgae's photosynthetic system leading to decreased chlorophyll content upon exposure to TiO2NPs. The results indicate that the larger the hydrodynamic diameter of the TiO2NPs the lower is their nanotoxicity, with anatas...
Determination of amitriptyline using electrogenerated chemiluminescence
Analytical Communications, 1996
ABSTRACT
Electrogenerated chemiluminescence determination of some local anaesthetics
Analytical Communications, 1996
Page 1. Analytical Communications, May 1996, Vol33 ( I 71-1 74) 171 Elect rogenerated Chem il urn... more Page 1. Analytical Communications, May 1996, Vol33 ( I 71-1 74) 171 Elect rogenerated Chem il urn inescence Determination of Some Local Anaesthetics Andrew W. Knight and Gillian M. Greenway School of Chemistry, University of Hull, Hull, North Humberside, UK HU6 7RX ...
Microreactor Technology for Biological Applications
Microreaction Technology: Industrial Prospects, 2000
Luminol Chemiluminescence Systems for Metal Analysis by μTAS
Micro Total Analysis Systems 2000, 2000
Hydrology and Earth System Sciences Discussions, 2012
This paper introduces new insights into the hydrochemical functioning of lowland river-systems us... more This paper introduces new insights into the hydrochemical functioning of lowland river-systems using field-based spectrophotometric and electrode technologies. The streamwater concentrations of nitrogen species and phosphorus fractions were measured at hourly intervals on a continuous basis at two contrasting sites on tributaries of 5 the River Thames, one draining a rural catchment, the River Enborne, and one draining a more urban system, The Cut. The measurements complement those from an existing network of multi-parameter water quality sondes maintained across the Thames catchment and weekly monitoring based on grab samples. The results of the sub-daily monitoring show that streamwater phosphorus concentrations display highly complex, 10 seemingly chaotic, dynamics under storm conditions dependent on the antecedent catchment wetness, and that diurnal phosphorus and nitrogen cycles occur under low flow conditions. The diurnal patterns highlight the dominance of sewage inputs in controlling the streamwater phosphorus and nitrogen concentrations at low flows, even at a distance of 7 km from the nearest sewage works in the rural, River Enborne, and that 15 the time of sample collection is important when judging water quality against ecological thresholds or standards. An exhaustion of the supply of phosphorus from diffuse and septic tank sources during storm events was evident and load estimation was not improved by sub-daily monitoring beyond that achieved by daily sampling because of the eventual reduction in the phosphorus mass entering the stream during events. The 20 dominance of respiration over photosynthesis in The Cut indicated a prevalence of heterotrophic algae, and the seasonal patterns in respiration and photosynthesis corresponded with those of temperature and light in this nutrient over-enriched stream. These results highlight the utility of sub-daily water quality measurements but the deployment of modified wet-chemistry technologies into the field was limited by mains 25 electricity availability. A new approach is therefore needed to allow measurement of a wide range of analytes at a broader range of locations for the development of water 6459 quality web-sensor networks. The development and field deployment of a miniaturised "lab-on-a-chip" ion chromatograph is proposed and justified.
Interfacing Microchip CE with ICPMS for Element Speciation
Micro Total Analysis Systems 2002, 2002
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Papers by Gillian Greenway