Villaveza del Agua, Spain
Villaveza del Agua, Spain

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Casas S.,Polytechnic University of Catalonia | Bonet N.,Polytechnic University of Catalonia | Aladjem C.,Solvay Group | Cortina J.L.,Polytechnic University of Catalonia | And 2 more authors.
Solvent Extraction and Ion Exchange | Year: 2011

Electrodialysis (ED) was studied as a technology to concentrate NaCl from SWRO reject in order to be reused in the chlor-alkali industry. A mathematical model was developed based on Nernst-Planck equations to predict the performance of the Barcelona ED pilot plant. Several of the model parameters were obtained experimentally and others were taken from the literature. The model was able to accurately predict the NaCl concentration reached, the time required to reach maximum concentration, and production overflow as a function of the operation conditions. in this article, the mathematical model is fully described and validated with preliminary experimental results obtained. © Taylor & Francis Group, LLC.

Trulls E.,Polytechnic University of Catalonia | Corominas Murtra A.,Polytechnic University of Catalonia | Perez-Ibarz J.,Polytechnic University of Catalonia | Ferrer G.,Polytechnic University of Catalonia | And 3 more authors.
Journal of Field Robotics | Year: 2011

This paper presents a fully autonomous navigation solution for urban, pedestrian environments. The task at hand, undertaken within the context of the European project URUS, was to enable two urban service robots, based on Segway RMP200 platforms and using planar lasers as primary sensors, to navigate around a known, large (10,000 m2), pedestrian-only environment with poor global positioning system coverage. Special consideration is given to the nature of our robots, highly mobile but two-wheeled, self-balancing, and inherently unstable. Our approach allows us to tackle locations with large variations in height, featuring ramps and staircases, thanks to a three-dimensional, map-based particle filter for localization and to surface traversability inference for low-level navigation. This solution was tested in two different urban settings, the experimental zone devised for the project, a university campus, and a very crowded public avenue, both located in the city of Barcelona, Spain. Our results total more than 6 km of autonomous navigation, with a success rate on go-to requests of nearly 99%. The paper presents our system, examines its overall performance, and discusses the lessons learned throughout development. Copyright © 2011 Wiley Periodicals, Inc.

Casas S.,Polytechnic University of Catalonia | Aladjem C.,Solvay Group | Cortina J.L.,Polytechnic University of Catalonia | Larrotcha E.,CETAQUA | Cremades L.V.,Polytechnic University of Catalonia
Solvent Extraction and Ion Exchange | Year: 2012

Seawater RO brines have been identified as an alternative to common NaCl sources for the chlor-alkali industry. Electrodialysis (ED) has been evaluated as a preliminary step of NaCl concentration for these brines. Experimental results showed that ED was an effective concentration technology, where values up to 252 gNaCl L-1 were reached at 0.3-0.4 kA m -2 with a power consumption of approx. 0.20-0.30 kWh kg-1 NaCl. As the membranes used (Neosepta CIMS and ACS) were mainly selective for univalent ions, polyvalent ions were partially removed from the brine, benefiting its reuse. NaCl concentrated solutions are to be used as feed brine in the chlor-alkali industry after a purification step. © 2012 Copyright Taylor and Francis Group, LLC.

Lopez-Roldan R.,CETaqua | Kazlauskaite L.,CETaqua | Kazlauskaite L.,Wageningen University | Ribo J.,Polytechnic University of Catalonia | And 4 more authors.
Science of the Total Environment | Year: 2012

A new system for monitoring toxicity TOXcontrol® (MicroLAN BV, The Netherlands) has been used to assess the toxicity of a selection of priority or emergent compounds in the laboratory. In this study, inhibition curves and EC50 - Effective Concentration causing 50% inhibition - of selected compounds (including pesticides, pharmaceuticals, surfactants and metals commonly detected in surface or drinking waters) were determined. This new technology is based on the measurement of Vibrio fischeri bioluminescence inhibition (ISO 11348). The main advantage of this equipment, compared to other laboratory assays, is the fully automation of the procedure. The instrument can be operated online in a simple, rapid and reproducible way. The variability of the results obtained with the TOXcontrol® biomonitoring system has been studied. A comparison with standardised technology based in V. fischeri (Microtox®) and additional test with Daphnia magna for selected organic compounds is presented. The results show that the methodology based on the TOXcontrol® system being validated is accurate and reproducible enough enabling this system to be used as an on-line automatic alert system to detect abnormal concentrations of toxic compounds. © 2012 Elsevier B.V.

Reig M.,Polytechnic University of Catalonia | Casas S.,CETAQUA | Valderrama C.,Polytechnic University of Catalonia | Gibert O.,Polytechnic University of Catalonia | Cortina J.L.,Polytechnic University of Catalonia
Desalination | Year: 2016

Water scarcity in the Mediterranean basin has been solved by using seawater desalination reverse osmosis technology (SWD-RO). This technology produces brine which is discharged back into the sea resulting in an environmental impact on marine ecosystems. Under the circular economy approach, the aim of this work is to recover resources from NaCl-rich brine (˜ 60–70 g/L), e.g. in the form of NaOH and HCl, by integration of two ion exchange-based membrane technologies and quantify the electrical energy consumption. Electrodialysis (ED) incorporating monovalent selective cation exchange membranes as divalent ions purification and concentration of the NaCl present in the SWD-RO brine, was integrated with bipolar membrane ED (EDBM) to produce NaOH and HCl. Current densities of 0.30–0.40 kA/m2 at two temperature ranges simulating different seawater temperature regimes (15–18 °C and 22–28 °C) were tested and a pure NaCl solution was used as starting concentrate stream. NaCl-rich brines with 100 or 200 g NaCl/L were obtained by ED and then introduced in the EDBM stack producing HCl and NaOH up to 2 M, depending on the initial concentrations. A minimum energy consumption of 1.7 kWh/kg NaOH was calculated when working by EDBM with initial concentrations of 104 g NaCl/L and 0.24 M HCl and NaOH. © 2016 Elsevier B.V.

Reig M.,Polytechnic University of Catalonia | Casas S.,CETaqua | Gibert O.,Polytechnic University of Catalonia | Valderrama C.,Polytechnic University of Catalonia | Cortina J.L.,Polytechnic University of Catalonia
Desalination | Year: 2016

Nanofiltration (NF), as a selective Mg(II) and Ca(II) separation and concentration treatment, and electrodialysis with bipolar membranes (EDBM) were evaluated for the valorization of seawater desalination reverse osmosis brines (60. NaCl/L) to produce both rich Mg(II) and Ca(II) brines for phosphate recovery and HCl and NaOH as chemicals for desalination treatments. A NF pilot plant, using NF270 membranes at 20bar, provided a rich Mg(II) (8.3gMg(II)/L) and Ca(II) (2.1gCa(II)/L) brine on the concentrated stream with enrichment factors of 3.2 for Mg(II) and 2.5 for Ca(II). The NF permeate stream containing 50±2gNaCl/L was treated to remove residual Mg(II) (760mg/L) and Ca(II) (415mg/L) by chemical precipitation with Na2CO3 and NaOH before the EDBM unit. Divalent cations free brine containing NaCl (50gNaCl/L) were fed into the EDBM stack in order to produce NaOH and HCl under recirculation configuration. Constant voltage and acid and base concentrations at different initial conditions were evaluated to obtain the maximum acid and base concentration (approximately 1M NaOH/HCl) at 9V. No substantial effect of initial acid and base concentrations on the overall performance was observed. An energy consumption of 2.6kWh/kg NaOH and current efficiency of 77±3% were calculated. © 2015 Elsevier B.V.

Cefalo M.,Polytechnic University of Catalonia | Mirats Tur J.M.,Cetaqua
International Journal of Solids and Structures | Year: 2010

This work addresses the problem of real-time self-collision detection for a movable tensegrity structure. We show that it can be tackled as the collision detection between two generic cylinders moving in R3. It is a simplified version of the more general problem of dynamic collision detection between two general shaped rigid bodies in the space. Two algorithms are proposed. The first presented approach is based on the exact value of the distance between two cylinders, the second is based on a new theorem which allows to estimate the exact distance for a given maximum desired error. In some circumstances, the second approach can be preferred because faster. © 2010 Elsevier Ltd. All rights reserved.

Lopez-Roldan R.,CETaqua | Tusell P.,CETaqua | Cortina J.L.,CETaqua | Courtois S.,CIRSEE | Cortina J.L.,Polytechnic University of Catalonia
TrAC - Trends in Analytical Chemistry | Year: 2013

Microorganism contamination is a permanent concern in a wide range of fields, including the water-treatment, food and pharmaceutical industries, in which fast detection is critical to prevent microbial outbreaks.In water monitoring, current procedures for water-quality analysis are based on periodic sampling and detection by culture methods, which are slow, requiring 24-48. h for completion, so that, when first results reach the decision-takers and trigger an alarm, significant time has already passed and the population may have been exposed to a health hazard.There is a need for rapid, reliable detection of contaminants in a broad spectrum of water-management situations. For real-time detection, on-line monitoring seems to be the ideal approach, but the need to adjust the available techniques to autonomous operation and the optimization of response time are substantial challenges.This review presents the findings of an identification study about the state-of-the-art of technologies and commercial devices for on-line biomonitoring of water quality, specifically for the detection of fecal contamination. We also include studies dealing with verification or use of these devices. © 2012 Elsevier Ltd.

PubMed | Technological Center Foundation, Aigues de Barcelona, Polytechnic University of Catalonia and CETaqua
Type: | Journal: The Science of the total environment | Year: 2015

A methodology has been developed in order to evaluate the potential risk of drinking water for the health of the consumers. The methodology used for the assessment considered systemic and carcinogenic effects caused by oral ingestion of water based on the reference data developed by the World Health Organisation (WHO) and the Risk Assessment Information System (RAIS) for chemical contaminants. The exposure includes a hypothetical dose received by drinking this water according to the analysed contaminants. An assessment of the chemical quality improvement of produced water in the Drinking Water Treatment Plant (DWTP) after integration of membrane technologies was performed. Series of concentration values covering up to 261 chemical parameters over 5 years (2008-2012) of raw and treated water in the Sant Joan Desp DWTP, at the lower part of the Llobregat River basin (NE Spain), were used. After the application of the methodology, the resulting global indexes were located below the thresholds except for carcinogenic risk in the output of DWTP, where the index was slightly above the threshold during 2008 and 2009 before the upgrade of the treatment works including membrane technologies was executed. The annual evolution of global indexes showed a reduction in the global values for all situations: HQ systemic index based on RAIS dropped from 0.64 to 0.42 for surface water and from 0.61 to 0.31 for drinking water; the R carcinogenic index based on RAIS was negligible for input water and varied between 4.210(-05) and 7.410(-06) for drinking water; the W systemic index based on the WHO data varied between 0.41 and 0.16 for surface water and between 0.61 and 0.31 for drinking water. A specific analysis for the indexes associated with trihalomethanes (THMs) showed the same pattern.

Cefalo M.,Institute Of Robtica I Informtica Industrial | Mirats-Tur J.M.,Cetaqua
International Journal of Solids and Structures | Year: 2011

In this paper we propose a new dynamic model, based on quaternions, for tensegrity systems of class-1. Quaternions are used to represent orientations of a rigid body in the 3-dimensional space eliminating the problem of singularities. Moreover, the equations based on quaternions allow to perform more precise calculations and simulations because they do not use trigonometric functions for the representation of angles. We present a thorough introduction of tensegrities and the current state of research. We also introduce the quaternions and provide in the appendix some important details and useful properties. Applying the Euler-Lagrange approach we derive a comprehensive dynamic model, first for a simple rigid bar in the space and, at last, for a class-1 tensegrity system. We present two model forms: a matrix and a vectorial form. The first more compact and easier to write, the latter more suitable to apply the tools and the theory based on vector fields. © 2010 Elsevier Ltd. All rights reserved.

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