The presence of sewage-borne Organic Micro-Pollutants (OMP) in Wastewater Treatment Plants (WWTP) effluents represents an increasing concern when water is reclaimed for irrigation or even indirect ...potable reuse. During eighteen months, an innovative hybrid water reclamation scheme based on a Membrane Biological Reactor (MBR) enhanced with Powder Activated Carbon (PAC) was operated at pilot-scale (70 m3/d) in order to compare it with state-of-the art Wastewater Reclamation System (WWRS) also revamped with a final step of ozonation-UV. Removal of persistent OMP, water quality and treatment costs were evaluated and compared for the different treatment schemes. OMP removal efficiency results for the different schemes concluded that established technologies, such as physico-chemical and filtration systems as well as MBR, do not remove significantly (>15%) the most recalcitrant compounds. The upgrading of these two systems through the addition of ozonation-UV step and PAC dosing allowed improving average recalcitrant OMP removal to 85 ± 2 and 75 ± 5%, respectively. In term of costs, PAC-MBR represents an increase of 37% of costs regarding conventional systems but presents improvements of 50% reduction in space and water quality. On the other hand, ozonation requires up to a 15% increase of foot-print; nevertheless, represents lower costs and lower carbon footprint. Ozonation-UV seems to be the best option for upgrading existing facilities, while PAC-MBR should be considered when space represents a critical limitation and produced water is reused for high water quality purposes.
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•OMP Removal in advanced wastewater reclamation schemes was evaluated•Evaluation of a hybrid system based on PAC and membrane bioreactor for OMP removal•The operational benefits of PAC applied in MBR were estimated.•Technical and economic evaluation for PAC-MBR and tertiary ozonation-UV•OMP Removal over 80% and 75% for ozonation-UV and PAC-MBR, respectively were achieved
•First self-tunable compressed-sensing PIV algorithm.•Estimation of high-resolution ensemble particle modes.•Reconstruction of high-resolution maps from sparse-sampled fields.•Significant increase of ...the dynamic spatial range of particle-based velocimetry.
In this work, we present an approach to reconstruct high-resolution flow velocity or scalar fields from sparse particle-based measurements such as particle tracking velocimetry, thermographic phosphors or pressure-sensitive particles. The proposed approach can be applied to any of those fields; without leading its generality, it is hereby assessed for flow velocity measurements. Particles allow probing physical quantities at multiple time instants in randomly located points in the investigated region. In previous works, it has been shown that high-resolution time-averaged fields can be estimated by an ensemble average of the particles contained into spatial bins whose size can be reduced almost ad libitum. In this work, high-resolution ensemble particle modes are estimated from the ensemble average of particles, weighted with Proper Orthogonal Decomposition time coefficients which are estimated from low-resolution spatially-averaged fields. These modes represent a self-tunable compressed-sensing library for the reconstruction of high-resolution fields. High-resolution instantaneous fields are then obtained from a linear combination of these modes times their respective time coefficients. This data-enhanced particle approach is assessed employing two DNS datasets: the wake of a cylinder and a fluidic pinball. It is shown here that it is possible to reconstruct phenomena whose characteristic wavelength is smaller than the mean particle spacing whenever such events are correlated with any other flow phenomenon with a wavelength large enough to be sampled. The proposed approach is also applied to experimental wind-tunnel data, again showing excellent performances in presence of realistic measurement-noise conditions.
The knowledge of the anisotropic properties beneath the Iberian Peninsula and Northern Morocco has been dramatically improved since late 2007 with the analysis of the data provided by the dense ...TopoIberia broad-band seismic network, the increasing number of permanent stations operating in Morocco, Portugal and Spain, and the contribution of smaller scale/higher resolution experiments. Results from the two first TopoIberia deployments have evidenced a spectacular rotation of the fast polarization direction (FPD) along the Gibraltar Arc, interpreted as an evidence of mantle flow deflected around the high velocity slab beneath the Alboran Sea, and a rather uniform N100°E FPD beneath the central Iberian Variscan Massif, consistent with global mantle flow models taking into account contributions of surface plate motion, density variations and net lithosphere rotation. The results from the last Iberarray deployment presented here, covering the northern part of the Iberian Peninsula, also show a rather uniform FPD orientation close to N100°E, thus confirming the previous interpretation globally relating the anisotropic parameters to the LPO of mantle minerals generated by mantle flow at asthenospheric depths. However, the degree of anisotropy varies significantly, from delay time values of around 0.5s beneath NW Iberia to values reaching 2.0s in its NE corner. The anisotropic parameters retrieved from single events providing high quality data also show significant differences for stations located in the Variscan units of NW Iberia, suggesting that the region includes multiple anisotropic layers or complex anisotropy systems. These results allow to complete the map of the anisotropic properties of the westernmost Mediterranean region, which can now be considered as one of best constrained regions worldwide, with more than 300 sites investigated over an area extending from the Bay of Biscay to the Sahara platform.
•Completing the anisotropic map of the western Mediterranean region, with more than 300 sites investigated for anisotropy over an area covering N Morocco and the whole Iberian Peninsula.•Average fast velocity direction close to E–W beneath central and northern Iberia.•The origin of this anisotropy is globally related to the LPO of mantle minerals generated by mantle flow at asthenospheric depths•Significant regional variations are identified and related to major geodynamical processes.
Abstract
Imaging Atmospheric Cherenkov Telescopes (IACTs) currently in operation feature large mirrors and order of 1 ns time response to signals of a few photo-electrons produced by optical photons. ...This means that they are ideally suited for optical interferometry observations. Thanks to their sensitivity to visible wavelengths and long baselines optical intensity interferometry with IACTs allows reaching angular resolutions of tens to microarcsec. We have installed a simple optical setup on top of the cameras of the two 17 m diameter MAGIC IACTs and observed coherent fluctuations in the photon intensity measured at the two telescopes for three different stars. The sensitivity is roughly 10 times better than that achieved in the 1970’s with the Narrabri interferometer.
•An assessment of salinity gradient stability of an industrial solar pond was performed.•Two methodologies based on the stratification principle were adapted and used.•The boundaries of the salinity ...gradient appeared as the main source of instability.•The methodology based on coefficients of expansion is useful to control the solar pond.
In this study, an assessment of salinity gradient stability of an industrial solar pond during two operation seasons (2014 and 2105) is presented. An industrial solar pond was constructed to supply a low-temperature heat (up to 60 °C) to achieve the temperature requirements of the flotation stage in a mineral processing plant (Solvay Minerales in Granada (Spain)). Along the first season, the salinity gradient was considered technically destroyed in April 2015 as the height to the upper convective zone increases from 0.3 m in July 2014 to 0.8 m. Two different methodologies based on the stratification principle were adapted and used in order to evaluate the salinity gradient stability. The boundaries of the salinity gradient appeared as the main source of instability. In the upper zone it is associated with the environmental parameters (e.g., rain and wind) that affect the upper convective zone and the upper layers of the non-convective zone that subsequently transmit the instability to the lower layers. In the bottom zone it is caused by operation parameters, such as the heat extraction or the addition of salt. Both methodologies provided similar predictive capability of stability results. However, the results provided by the stability analysis using the thermal and salinity expansion coefficients are a more useful tool in the control of the salinity gradient for solar pond technology.
The downstream processing for the separation and purification of lactic acid is a hot research area in the bio-refinery field due to its continuous growing market in different sectors, such as the ...food, cosmetic and pharmaceutical sectors. In this work, the use of ion-exchange technology for lactic acid recovery is proposed. For that, four anion exchange resins with different polymer structures and functional groups were tested (A100, MN100, A200E and MP64). The sorption process was optimized by the Box–Behnken factorial design, and the experimental data obtained in the sorption process were analyzed by using the response surface methodology and fitted at different isotherms and kinetics models. Moreover, regenerant type, contact time and solid/liquid ratio were evaluated in the desorption process. Results showed that the best resin for lactic acid removal was A100, at pH = 4, with a resin/lactic acid solution ratio of 0.15 g/mL during a maximum of 1 h, achieving 85% of lactic acid removal. Moreover, equilibrium data sorption of lactic acid onto A100 resin was fitted by a Langmuir isotherm and by a kinetic model of a pseudo-second order. In addition, in the desorption process, it was stablished that a resin/regenerant ratio of 0.15 g/mL during 30 min with 0.1 M of NaOH solution provided the best results (4.45 ± 0.08 mg/g).
•A biotrickling filter was installed and operated at pilot-scale in a WWTP in Spain.•Operating conditions for biogas desulphurisation at acidic environment were determined.•An average elimination ...capacity of 169gH2Sm−3h−1 was obtained on the long-term.•Partial oxidation to elemental sulphur was envisaged to be the preferred mechanism.•Acidithiobacillus thiooxidans was dominant on the microbial consortium.
The most harmful biogas contaminant for energy conversion equipment such as fuel cells is hydrogen sulphide (H2S); thus efficient and cost-effective treatment systems for this compound should be designed and developed. A pilot-scale biotrickling filter (BTF) working in acidic media (pH=1.5–2) was operated for raw sewage biogas desulphurisation. Its operational performance as a function of two key important process parameters (temperature and retention time) was evaluated through short-term experimentation; showing that H2S removal efficiencies greater than 90% can be obtained at temperatures of 30°C, retention times of 80–85s and H2S Loading Rates of 210gH2S/(m3bedh). The system was afterwards operated for 924h and showed an average elimination capacity of 169gH2S/(m3bedh) at an average removal efficiency of 84%. The unit proved to be reversible to the effect of operation disruptions (lack of temperature control, limitations on oxygen supply), which were introduced to simulate possible system miss functioning or operational failures. Nevertheless, partial oxidation to elemental sulphur (S(s)) accounted for 70% of H2S removal progressively increasing the pressure drop over the column; reducing the availability of the treatment line and eventually leading to fuel cell shutdowns. More efficient systems for oxygen supply and solids removal are the key factors to be addressed for a sustainable deployment of BTF technology in waste water treatment plants (WWTP).
•An experimental solar pond integrating solar collectors is presented.•Heat extraction/supply experiments are performed using heat exchangers.•Solar collectors increases efficiency of solar pond ...during the cold season.•Large amount of heat extracted allows a greater storage capacity of the solar pond.
In this study, an experimental investigation of the performance of a salinity gradient solar pond (SGSP) integrating solar collectors is presented. The SGSP is located in Barcelona (Spain) and has a cylindrical tank 3 m in height and 8 m in diameter with a total area of 50 m2. For this purpose, four solar thermal collectors (10 m2) are integrated, as an external source of heat, with the solar pond pilot plant in order to increase the storage capacity and its overall efficiency. The aim of this study is to evaluate heat extraction and heat supply processes from and to the SGSP under different seasonal conditions. Two in-pond heat exchangers are used, a conventional one situated on the bottom of the pond and a second one covering the lateral wall area of the pond. Heat extraction and supply experiments are performed using both heat exchangers individually or both at the same time. The experiments are conducted under two different seasonal temperature conditions: winter (February and March) and summer (July). The variations of the temperature inside the pond during the heat extraction/supply tests are monitored and analyzed. The results have indicated that the use of solar collectors as an extra source of heat for the solar pond led to a 50% increase in the daily efficiency during the cold season tests, while heat extraction only appeared as the best option during the warm season tests. Higher daily efficiency and heat supply results can only be obtained if large amounts of heat are extracted, otherwise, the daily efficiency of the solar pond could decrease. Finally, the solar collectors can be considered a good alternative for avoiding a significant decrease in solar pond temperatures (especially during the cold season), which would not only result in a significant energy storage efficiency improvement but also increase the capacity of the solar pond to supply heat to an external application.
Abstract Background The Spanish “Registry of Pulmonary Arterial Hypertension” (REHAP), started in 2007, includes chronic thromboembolic hypertension (CTEPH) patients. Based on data provided by this ...registry and retrospective data from patients diagnosed during 2006 (≤ 12 months since the registry was created), clinical management and long-term outcomes of CTEPH patients are analyzed nationwide for the first time in a scenario of a decentralized organization model of CTEPH management. Methods and results A total of 391 patients (median Q1:Q3 age 63.7 48.0;73.3 years, 58% females) with CTEPH included during the period January 1, 2006–December 31, 2013 in the REHAP registry were analyzed. Rate of pulmonary endarterectomy (PEA) was 31.2%, and highly asymmetric among centers: rate was 47.9% at two centers designated as CTEPH expert centers, while it was 4.6% in other centers. Among patients not undergoing PEA, 82% were treated with therapies licensed for pulmonary arterial hypertension (PAH). Five-year survival rate was 86.3% for PEA patients, and 64.9% for non-PEA patients. Among non-PEA patients, presenting proximal lesions (42% of non-referred patients) was associated with a 3-fold increase in mortality. PEA patients achieved significantly better hemodynamic and clinical outcomes at one-year follow-up compared to non-PEA patients. Patients not being referred for PEA assessment were older and had a worse functional capacity. Older age was the most deterrent factor for non-operability. Conclusion Despite the increase in diagnosis and expertise in PEA-specialized centers, an important percentage of patients do not benefit of PEA in a decentralized organization model of CTEPH management.
The Cherenkov Telescope Array (CTA) represents the next generation of ground-based instruments for very-high-energy (VHE) gamma-ray astronomy, aimed at improving on the sensitivity of ...current-generation experiments by an order of magnitude and providing coverage over four decades of energy. The current CTA design consists of two arrays of tens of imaging atmospheric Cherenkov Telescopes, comprising Small, Medium and Large-Sized Telescopes, with one array located in each of the Northern and Southern Hemispheres. To study the effect of the site choice on the overall CTA performance and support the site evaluation process, detailed Monte Carlo simulations have been performed. These results show the impact of different site-related attributes such as altitude, night-sky background and local geomagnetic field on CTA performance for the observation of VHE gamma rays.
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