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Frijns J.,KWR Watercycle Research Institute | Smith H.M.,Cranfield University | Brouwer S.,KWR Watercycle Research Institute | Garnett K.,Cranfield University | And 2 more authors.
Water (Switzerland) | Year: 2016

The governance dimensions of water reuse scheme development and operation, such as policies and regulatory frameworks, and public involvement and stakeholder collaboration, can serve to both facilitate and constrain wider adoption of water reuse practices. This paper explores the significance and underlying structure of the key governance challenges facing the water reuse sector in Europe. It presents empirical evidence from interviews and focus group sessions conducted at four water reuse schemes: an indirect potable reuse scheme at Torreele (Belgium), the urban reuse of treated municipal wastewater at the London Olympic Park (United Kingdom) and at Sabadell (Spain), and the reuse of agro-industrial effluent for irrigation at Capitanata (Italy). The findings underscore the importance of clarity in policy arrangements around water reuse, as well as of the financial competitiveness of reuse projects compared to alternative water supply options. Operators of water reuse schemes expressed a preference for water quality standards, which focus on appropriateness for use rather than over-emphasise the waters' origin so that unnecessary treatment and costs can be avoided. Positive public support was widely acknowledged as an important factor in the success or failure of water reuse schemes. We conclude that constructive institutional relationships underpin many of the challenges faced by reuse scheme operators and that greater emphasis should be given to building confidence and gaining trust in water service providers through early identification of how governance regimes shape the viability of new schemes. © 2016 by the authors.


Gibert O.,Polytechnic University of Catalonia | Gibert O.,Water Technology Center | de Pablo J.,Polytechnic University of Catalonia | de Pablo J.,Center Tecnologic Of Manresa | And 3 more authors.
Environmental Geochemistry and Health | Year: 2010

In this study, two mixtures of municipal compost, limestone and, optionally, zero-valent iron were assessed in two column experiments on acid mine treatment. The effluent solution was systematically analysed throughout the experiment and precipitates from both columns were withdrawn for scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry analysis and, from the column containing zero-valent iron, solid digestion and sequential extraction analysis. The results showed that waters were cleaned of arsenic, metals and acidity, but chemical and morphological analysis suggested that metal removal was not due predominantly to biogenic sulphide generation but to pH increase, i.e. metal (oxy)hydroxide and carbonate precipitation. Retained arsenic and metal removal were clearly associated to co-precipitation with and/or sorption on iron and aluminum (oxy)hydroxides. An improvement on the arsenic removal efficiency was achieved when the filling mixture contained zero-valent iron. Values of arsenic concentrations were then always below 10 μg/L. © 2010 Springer Science+Business Media B.V.


Benito J.A.,Polytechnic University of Catalonia | Benito J.A.,Center Tecnologic Of Manresa | Tejedor R.,Polytechnic University of Catalonia | Rodriguez-Baracaldo R.,National University of Colombia | And 4 more authors.
Materials Science Forum | Year: 2010

This paper reviews the ductility of nanostructured and ultrafine iron obtained using a variety of methods. Mechanical milling of powder and subsequent hot consolidation, one of the most popular methods offer high mechanical strength but poor ductility. Improvements made in the consolidation processes and the introduction of final heat treatments, in addition to new approaches such as spark plasma sintering and high pressure torsion, have increased the total plastic strain of nanostructured iron. The development of bimodal structures enables the existence of strain hardening and more uniform deformation. The paper also includes a steel study, which finds that the hardness of milled powder and the role of carbon atoms inside ferrite grains make it more difficult to improve the ductility of nanostructured samples. © (2010) Trans Tech Publications.


Gibert O.,Water Technology Center | Gibert O.,Polytechnic University of Catalonia | Lefevre B.,Water Technology Center | Fernandez M.,Water Technology Center | And 4 more authors.
Water Research | Year: 2013

Under normal operation conditions, granular activated carbon (GAC) employed in drinking water treatment plants (DWTPs) for natural organic matter (NOM) removal can be colonised by microorganisms which can eventually establish active biofilms. The formation of such biofilms can contribute to NOM removal by biodegradation, but also in clogging phenomena that can make necessary more frequent backwashes. Biofilm occurrence and evolution under full-scale-like conditions (i.e. including periodic backwashing) are still uncertain, and GAC filtration is usually operated with a strong empirical component. The aim of the present study was to assess the formation and growth, if any, of biofilm in a periodically backwashed GAC filter. For this purpose, an on-site pilot plant was assembled and operated to closely mimic the GAC filters installed in the DWTP in Sant Joan Despí (Barcelona, Spain). The study comprised a monitoring of both water and GAC cores withdrawn at various depths and times throughout 1 year operation. The biomass parameters assessed were total cell count by confocal laser scanning microscopy (CLSM), DNA and adenosine triphosphate (ATP). Visual examination of GAC particles was also conducted by high-resolution field emission scanning electron microscopy (FESEM). Additionally, water quality and GAC surface properties were monitored. Results provided insight into the extent and spatial distribution of biofilm within the GAC bed. To sum up, it was found that backwashing could physically detach bacteria from the biofilm, which could however build back up to its pre-backwashing concentration before next backwashing cycle. © 2012 Elsevier Ltd.


Vila M.,Institute Geologic Of Catalonia | Martinez-Llado X.,Center Tecnologic Of Manresa
Journal of Geochemical Exploration | Year: 2015

Geochemical reference levels are necessary preliminary steps for appropriate environmental legislation, especially in the assessment of management of soil pollution and protection measures. The problem of establishing reference levels in areas with variable basic geology and anthropogenic pressure is addressed by characterising the geochemistry of 82 representative samples of the geologic materials of the Congost River basin (NE Iberia). The samples have been grouped in a system of 12 operative geochemical units comprising the entire area of the basin. The 'total' and 'partial' concentrations of 54 chemical elements have been determined. The geochemical variability has been discussed by means of statistical methodologies, diagrams and GIS techniques.The analysed samples reveal that the composition of the Congost catchment is highly varied. The differences between the 'total' and 'partial' concentrations define complex patterns reflecting the mineralogy of samples. The results indicate that bedrock geology is the most important factor influencing the major and trace element distributions in the basin. Pb and Zn were observed to be enriched in units more exposed to pollution than their parent materials. In general, the defined operative geologic units are characterised by different major and trace element compositional ranges as a consequence of their lithological diversity. The fact that the samples have been linked to a system of regional geological units allows the geochemical comparison of materials from the Congost River basin with other reference materials from neighbouring areas, or worldwide. For such an approach, we have focused on the geochemistry of the Pleistocene detritic sediments. We close the study by proposing that a good way of expressing the geographic distribution of the geochemical variability of a region could be to apply geologic extrapolation of three representative statistics, an average value (the 50th percentile), a low value (the 25th percentile) and a high value (the 75th percentile). As an example, we present the Th maps, which permit the clear discussion of the Th distribution in the basin. © 2014 Elsevier B.V.


Heras I.,Abengoa | Guillen E.,Abengoa | Krause M.,Helmholtz Center Dresden | Pardo A.,Center Tecnologic Of Manresa | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

The design of an efficient and stable solar selective coating for Concentrating Solar Power central receivers requires a complex study of the materials candidates that compose the coating. Carbon-transition metal nanocomposites were studied in this work as absorber materials because they show appropriate optical properties with high absorption in the solar region and low thermal emittance in the infrared. Furthermore metal carbides are thermal and mechanical stable in air at high temperatures. In this work a solar selective coating was grown by a dual source filtered cathodic vacuum arc. The complete stack consists on an infrared reflection layer, an absorber layer of carbon-zirconium carbide nanocomposites and an antireflection layer. The aim of this research is optimize the absorber layer and for that, the metal content was controlled by adjusting the pulse ratio between the two arc sources. The elemental composition was determined by Ion Beam Analysis, X-Ray diffraction measurements show the crystal structure and the optical properties were characterized by spectroscopic ellipsometry measurements. The reflectance spectra of the complete selective coating were simulated with the optical software CODE. Bruggeman effective medium approximation was employed to average the dielectric functions of the two components which constitute the nanocomposite in the absorber layer. The optimized coating exhibited a solar absorptance of 95.41% and thermal emittance of 3.5% for 400°C. The simulated results were validated with a deposited multilayer selective coating. © 2015 SPIE.

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