Environmental Research Institute ERI

Cork, Ireland

Environmental Research Institute ERI

Cork, Ireland
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McManamon C.,University College Cork | Holmes J.D.,University College Cork | Holmes J.D.,Environmental Research Institute ERI | Morris M.A.,University College Cork | Morris M.A.,Environmental Research Institute ERI
Journal of Hazardous Materials | Year: 2011

This paper studies the photocatalytic degradation of phenol using zirconia-doped TiO 2 nanoparticles. ZrO 2 was chosen due to its promising results during preliminary studies. Particles smaller than 10nm were synthesised and doped with quantities of ZrO 2 ranging from 0.5 to 4% (molar metal content). Particles were calcined at different temperatures to alter the TiO 2 structure, from anatase to rutile, in order to provide an ideal ratio of the two phases. Powder X-ray diffraction (PXRD) analysis was used to examine the transformation between anatase and rutile. Degradation of phenol was carried out using a 40W UV bulb at 365nm and results were measured by UV-vis spectrometry. TEM images were obtained and show the particles exhibit a highly ordered structure. TiO 2 doped with 1% ZrO 2 (molar metal content) calcined at 700°C proved to be the most efficient catalyst. This is due to an ideal anatase:rutlie ratio of 80:20, a large surface area and the existence of stable electron-hole pairs. ZrO 2 doping above the optimum loading acted as an electron-hole recombination centre for electron-hole pairs and reduced photocatalytic degradation. Synthesised photocatalysts compared favourably to the commercially available photocatalyst P25. The materials also demonstrated the ability to be recycled with similar results to those achieved on fresh material after 5 uses. © 2011 Elsevier B.V.

Delaney P.,University College Cork | Delaney P.,Environmental Research Institute ERI | McManamon C.,University College Cork | Hanrahan J.P.,Environmental Research Institute ERI | And 5 more authors.
Journal of Hazardous Materials | Year: 2011

In this study, the application of ordered mesoporous silica (OMS) doped with various metal oxides (Zr, Ti, Fe and Al) were studied for the removal of (ortho) phosphate ions from water by adsorption. The materials were characterized by means of N2 physisorption (BET), powder X-ray diffraction (PXRD) and transmission electron microscopy (TEM). The doped materials had surface areas between 600 and 700m2g-1 and exhibited pore sizes of 44-64Å. Phosphate adsorption was determined by measurement of the aqueous concentration of orthophosphate using ultraviolet-visible (UV-vis) spectroscopy before and after extraction. The effects of different metal oxide loading ratios, initial concentration of phosphate solution, temperature and pH effects on the efficiency of phosphate removal were investigated. The doped mesoporous materials were effective adsorbents of orthophosphate and up to 100% removal was observed under appropriate conditions. 'Back extracting' the phosphate from the doped silica (following water treatment) was also investigated and shown to have little adverse effect on the adsorbent. © 2010 Elsevier B.V.

McManamon C.,University College Cork | McManamon C.,Environmental Research Institute ERI | Delaney P.,University College Cork | Delaney P.,Environmental Research Institute ERI | And 2 more authors.
Journal of Colloid and Interface Science | Year: 2013

This study examines the addition of various dopants to TiO2 nanoparticles for the enhancement of photocatalytic activity. The materials were tested for efficiency on the degradation of methyl orange under UV light. The dopants were added at different molar ratios to find the ideal amount required for optimum results. BET analysis was used to determine surface areas while X-ray diffraction (XRD) analysis was used to study the effect of the dopant on the transformation of the TiO2 structure. The dopants used were Ag, S and Zr and displayed high levels of activity and show some ability to be reused. Decomposition of methyl orange was carried out using a 40W UV bulb at 365nm and results were measured by UV-vis spectrometry. It was determined that, overall, Ag doping displayed the best photocatalytic properties but was poor upon reuse. © 2013 Elsevier Inc.

McManamon C.,University College Cork | Burke A.M.,University College Cork | Holmes J.D.,University College Cork | Holmes J.D.,Environmental Research Institute ERI | And 2 more authors.
Journal of Colloid and Interface Science | Year: 2012

This study examines the synthesis of SBA-15 with tailored pore sizes through controlled thermal treatment for the adsorption of Pb and Cd ions. The aim is to produce a material that can adsorb heavy metals at both high and low concentrations. The materials were characterised by means of N 2 physisorption, powder X-ray diffraction (PXRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), microanalysis and transmission electron microscopy (TEM). The surface areas ranged from 410 to 871m 2g -1, and pore diameter was increased from 5.9 to 10.8nm. This method allows for maximum adsorption of metal ions at very low concentrations. Metal ion adsorption was determined using an Atomic Absorption Spectrophotometer. The effects of pH were found to play a major role in the precipitation and, therefore, adsorption of metal ions. This method proved to be efficient at adsorbing large quantities of both metals (39 and 41mgg -1 for Pb and Cd, respectively). © 2011 Elsevier Inc.

Millidine K.J.,Marine Scotland - Marine Laboratory | Malcolm I.A.,Marine Scotland - Marine Laboratory | Gibbins C.N.,University of Aberdeen | Fryer R.J.,Marine Scotland - Marine Laboratory | Youngson A.F.,Environmental Research Institute ERI
Ecological Indicators | Year: 2012

There have been few mechanistic studies linking local ecological characteristics of streams to morphological pressures. This paper reports the findings of an investigation of the impacts of canalisation on salmonid habitat. Habitat use by Atlantic salmon and brown trout, fry and parr was assessed using Generalised Additive Models (GAMs) based on seasonal electrofishing survey data and output from 2-dimensional hydraulic models. By overlaying the habitat models onto the physical characteristics of the canalised reach, it was possible to determine where and when environmental bottlenecks occurred, and for which species and life stages. The canalised reach was characterised by relatively uniform sedimentary and hydraulic characteristics compared to other reaches. Although it was generally well suited to fry, the lack of coarser substrate and low velocity areas during winter made the canalised reach unfavourable for salmon and trout parr respectively. Given the insights provided by this study, we suggest the approach of combining physical channel characterisation with locally derived seasonal habitat models is well suited to future research focussed on assessing the ecological impact of morphological pressures. © 2012 Elsevier Ltd. All rights reserved.

Andersen R.,Laval University | Andersen R.,James Hutton Institute | Andersen R.,Environmental Research Institute ERI | Pouliot R.,Laval University | Rochefort L.,Laval University
Wetlands | Year: 2013

The organic matter accumulation potential of a restored bog was estimated over 2 years as a balance between losses to decomposition and inputs through above-ground net primary productivity (AGNPP) in five micro-habitats of increasing complexity (relating to the moss carpet thickness and the number of vegetation functional groups). Decomposition and accumulation rates variations were hypothesized to lead to higher organic matter accumulation potential in the more complex micro-habitats. In general, for a given litter type, the mass losses and decomposition rates were rather homogeneous between micro-habitats, but, they were correlated to the cover of particular species: Eriophorum vaginatum with slower decomposition rates, and Ledum groendlandicum or Kalmia angustifolia with higher rates. Therefore, the abundance of some peatland species, rather than the habitat complexity itself, was a driver of decomposition rates. While the Sphagnum AGNPP did not compensate for decomposition losses, the organic matter accumulation potential was tipped towards a sink (positive) by the contribution of vascular species to the AGNPP. The organic matter accumulation potentials are much improved by the presence of Sphagnum, but from a restoration perspective, promoting the growth of vascular peatland species might also be a key to achieving a positive balance of organic matter accumulation. © 2013 Society of Wetland Scientists.

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