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► A peer-review literature on the analysis of organics in sludge is presented. ► Both priority and emerging pollutants were detected in sludge samples. ► Current state-of-the-art is ...discussed involving extraction, clean-up and analysis. ► Classical techniques represent high percentages of the papers of organics in sludge. ► PLE represents more than a half of the total manuscripts using novel techniques.
Priority pollutants constitute only a part of the large chemical pollution puzzle where the number of potentially hazardous chemicals that reaches the environment is very wide and new substances are constantly being developed and released. Among them, a diverse group of unregulated pollutants, many times called “emerging” contaminants, including pharmaceuticals and personal care products (PPCPs), is found. This group of emerging contaminants constitutes a broad class of chemicals widely used in daily life, such as synthetic fragrances, UV filters, antiseptics, antioxidants and insect repellents. The large amount of them and other emerging contaminants consumed in modern society contribute as well to a wide range of contamination in the aquatic environment, introduced mainly through wastewater treatment plants (WWTPs). The agricultural application of sewage sludge has become the most widespread method for its disposal, since it is the most economical outlet for sludge and offers the opportunity to recycle plant nutrients and organic matter to soil for crop production. However, due to the presence of metals, organic contaminants and pathogenic bacteria in sewage sludge, concern has increased about the human exposure to priority and emerging pollutants via crops cultivated in sewage/compost-amended soils. Because of the potentially dangerous consequences of the presence of those contaminants in the environment, data concerning the concentration, fate and behavior of those pollutants is urgently necessary. With this purpose in mind, sensitive and robust analytical methods for complex matrices such as sewage sludge are necessary in order to obtain reliable data that help us to understand the risk of agricultural use of sewage sludge. The present manuscript reviews the different approaches present in the literature for determining organic pollutants (priority and emerging) in sewage sludge. A review of the last ten years has been performed and the three main steps of an analytical procedure (extraction, clean-up and analysis) have been reviewed.
Key Points
The modelization of gates as internal boundary conditions
2D finite volume hydraulic model to simulate flooding scenarios
regulation by gates
This work presents a two‐dimensional hydraulic ...model that includes gates as internal structures. The flow is modeled using the two‐dimensional shallow water equations and the gates are formulated as internal boundary conditions to provide a simulation tool for water flood management. When open channel flow in a river passes through a gate, the shallow water equations are no longer valid and energy conservation laws are required. The change in the set of equations is avoided by modeling gates as a spatial discontinuity or internal boundary condition, providing an alternative algorithm to the one used in the rest of the flooded computational domain. In the first part of this work, the requirements of an adequate discretization for gate modeling are provided in the context of a finite volume numerical scheme able to handle all kind of flow regimes over complex bed topography. In the second part of this work, the formulation of the internal boundary conditions is verified by means of a test case with exact solution. A benchmark test case is then proposed as a synthetic river reach with lateral storage areas controlled by gates. Dimensional analysis is used to establish the regulation parameters influencing the attenuation of the outlet peak discharge. It is also shown that the peak outflow discharge can be reduced by coupling the present simulator with a proportional‐integral‐derivative regulation algorithm. Finally, a river reach of the Ebro River is simulated with a real flooding scenario.
Transient phenomena such as abrupt changes in wind direction occur frequently during the operation of wind farms. The wakes produced behind wind turbines are affected by these situations, modifying ...the impact on nearby turbines, both in power output and life expectancy of the blades. In this work, a group of 4 turbines in a wind farm is analysed via Computational Fluid Dynamic (CFD) simulations during wind shifts. Large Eddy Simulations (LES) are carried out by means of the open-source software OpenFOAM, including the SOWFA libraries. Once the wakes reach a time average stationary solution the wind direction is modified by means of a pressure gradient forcing, imposing different change rates. An actuator disk with the ability to correct yaw misalignment is used to represent turbines. Besides, neutral Atmospheric Boundary Layer (ABL) flows are considered. Results show that for higher change rates the greatest impact on the downwind turbine is produced when turbines are no longer collinear with wind direction due to the wake curvature. Also, higher change rates produce a higher curvature modifying the impact on power output of downwind turbines. This study provides a deeper understanding of the cause of greater deficits in wind farm output.
In this work, a dynamic internal boundary condition is used as subgrid model in a two-dimensional (2D) model based on the shallow water equations in order to model narrow regions in the domain. In ...this way, computational savings are sought, since it is not necessary to discretize these regions with cells of reduced size. The new internal boundary condition simplifies other works where 1D–2D coupled models were presented, since the 1D model is a subgrid for the 2D mesh, so the coupling between both models is simple and direct. The coupling is performed using mass conservation, simplifying the calculation in the transfer between both models. Test cases are studied to validate the implemented boundary condition, and a mountain catchment as a realistic case. The results obtained with a fully 2D mesh and a 2D mesh with rills in narrow regions are very similar, with a large reduction in computational cost when using rills, both in test cases and in the realistic case. Thus, the use of the implemented internal boundary condition is an effective tool to study regions with narrow regions by reducing the computational cost with little loss of accuracy in the results.
•A dynamic IBC for narrow regions in 2D hydrological problems is developed.•The 1D internal boundary condition (rill) is a subgrid for the 2D mesh.•The use of rills avoids excessive refinement of the 2D mesh.•The computational cost is greatly reduced by using rills with no loss of accuracy.
A
bstract
RADES (Relic Axion Detector Exploratory Setup) is a project with the goal of directly searching for axion dark matter above the 30
μ
eV scale employing custom-made microwave filters in ...magnetic dipole fields. Currently RADES is taking data at the LHC dipole of the CAST experiment. In the long term, the RADES cavities are envisioned to take data in the BabyIAXO magnet. In this article we report on the modelling, building and characterisation of an optimised microwave-filter design with alternating irises that exploits maximal coupling to axions while being scalable in length without suffering from mode-mixing. We develop the mathematical formalism and theoretical study which justifies the performance of the chosen design. We also point towards the applicability of this formalism to optimise the MADMAX dielectric haloscopes.
The design of a wet cooling tower involves a number of trade-offs including the efficiency of the device to remove waste heat (thermal performance) and environmental aspects (emissions level). This ...paper deals with the experimental characterisation of a new cooling tower prototype. The novelty of the work relies on the study of a cooling tower designed to avoid the emission of airborne particles to the atmosphere. The experiments were conducted in a pilot plant built ad hoc for this purpose. The sensitive paper method was used in the environmental impact assessment (emissions level). The comparison between the obtained results and those found in the literature for similar cooling towers indicates that performance of the inverted cooling tower in terms of emissions is remarkable: D=1.47⋅10−6 (0.00015% of the circulating water). This value is up to 300 times lower than the limits imposed by several international standards and involves a reduction in terms of emissions ranging from 40.21% to 82.54% compared to commercial towers. The maximum size of the measured escaping droplets is dd = 50 μm, and the Sauter Mean Diameter of the ensemble of droplets is 31.42μm. Concerning thermal performance, the observed results are more modest. Operating at nominal conditions, the inverted cooling tower cools the water up to 33.5 °C. The efficiency of the tower is similar to that of a commercial tower equipped with a film-flow distribution system (up to 6.98% better). The difference is larger (41.16% lower) when compared to the same tower equipped with a splash distribution system.
•This paper addresses the experimental evaluation of a new cooling tower prototype.•The measured rate of drift emissions is 0.00015% of the circulated water.•The emissions are reduced 40.21–82.54% compared to commercial towers.•The cooling tower cools the water up to 33.5 °C operating at design conditions.•The thermal performance is similar to a commercial tower with a film-flow system.
•A fully conservative 1D–2D coupled model for solving the SWE is presented.•The boundary conditions in each model play an important role within the modelization.•Two different strategies to couple ...1D–2D models are proposed.•The use of the adequate strategy is justified, according to the flow regime.•The coupled model is tested in academic and real scenarios proving accurate results.
A 1D–2D coupled numerical model is presented in this work. 1D and 2D models are formulated using a conservative upwind cell-centred finite volume scheme. The discretization is based on cross-sections for the 1D model and with triangular unstructured grid for the 2D model. The resulting element of discretization for the coupled model is analysed and two different coupling techniques based on mass conservation and mass and momentum conservation respectively are explored, considering both frontal and lateral configurations. The interaction with the boundaries in each model is highlighted and the necessity of using the appropriate strategy according to the flow regime is also justified. The coupled model is tested through academic test cases where the numerical results are compared with a fully 2D model as well as with experimental measurements in steady and unsteady scenarios. It is also applied to a real world configuration, where the flood wave propagation in the river bed is simulated by means of a 1D model and the inundation of the riverside is dealt with a 2D model. The computational gain is also analysed.
Lymphatic vessels are critical for the maintenance of tissue fluid homeostasis and their dysfunction contributes to several human diseases. The activin receptor-like kinase 1 (ALK1) is a transforming ...growth factor-β family type 1 receptor that is expressed on both blood and lymphatic endothelial cells (LECs). Its high-affinity ligand, bone morphogenetic protein 9 (BMP9), has been shown to be critical for retinal angiogenesis. The aim of this work was to investigate whether BMP9 could play a role in lymphatic development. We found that Bmp9 deficiency in mice causes abnormal lymphatic development. Bmp9-knockout (KO) pups presented hyperplastic mesenteric collecting vessels that maintained LYVE-1 expression. In accordance with this result, we found that BMP9 inhibited LYVE-1 expression in LECs in an ALK1-dependent manner. Bmp9-KO pups also presented a significant reduction in the number and in the maturation of mesenteric lymphatic valves at embryonic day 18.5 and at postnatal days 0 and 4. Interestingly, the expression of several genes known to be involved in valve formation (Foxc2, Connexin37, EphrinB2, and Neuropilin1) was upregulated by BMP9 in LECS. Finally, we demonstrated that Bmp9-KO neonates and adult mice had decreased lymphatic draining efficiency. These data identify BMP9 as an important extracellular regulator in the maturation of the lymphatic vascular network affecting valve development and lymphatic vessel function.
•BMP9 is required for lymphatic valve formation.•Mice deficient in Bmp9 exhibit reduction in lymphatic draining efficiency.
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•Degreening strongly affected consumers’ expectations of maturity and quality.•Degreening increased consumers’ purchase intentions.•The effect of degreening on physico-chemical ...properties depended on cultivar.•Degreening did not affect the internal sensory properties that consumers perceived.
Degreening treatment is normally applied to early-season citrus varieties grown in the Mediterranean area in order to enhance the external colour when fruits have already reached internal maturity. Despite profound knowledge about the effect of ethylene on the physico-chemical quality of citrus fruit, less is known about its effect on consumers’ expectations in the supermarket or consumer quality perceptions when they eat such fruit. In this study, three mandarin cultivars (‘Owari’, ‘Clemenules’ and ‘Oronules’) with two initial colours at harvest, and one orange cultivar, ‘Navelina’, were submitted to the degreening treatment under commercial conditions. The effect of treatment on both external and internal qualities perceived by consumers was evaluated. The main physico-chemical parameters were also determined. The degreening treatment slightly affected firmness, total soluble solids or acidity level in ‘Owari’ and ‘Navelina’. However, sensory triangle tests, in which 100–122 consumers compared the internal quality of degreened fruit and control fruit, did not show significant differences between treatments for any of the studied cultivars. A survey based on images of citrus fruit was responded by 340 consumers; it showed that the degreening treatment strongly affected consumers’ maturity expectations, which resulted in improved fruit liking expectations and increased the number of consumers willing to buy. The extent of this effect depended on the initial colour of the fruit submitted to degreening. In order to improve liking expectations, fruit should arrive on the market with an external colour index (CI = 1000a/Lb) between +10 and +20. We conclude that the ethylene degreening treatment, which did not have any effect on the internal quality that consumers perceive, is a potent postharvest tool to increase citrus fruit sales at the beginning of the season.
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