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Prince Johnsen posted an update 5 days, 13 hours ago
Air quality data from Bogotá, Colombia, show high levels of particulate matter (PM), which often generate respiratory problems to the population and a high economic cost to the government. Since 2016, air quality in the city of Bogotá has been measured through the Bogota Air Quality Index (IBOCA) which works as an indicator of environmental risk due to air pollution. However, available technological tools in Bogotá are not enough to generate early alerts due to PM10 and PM2.5. Currently, alerts are only announced once the measured PM values exceed a certain standard (e.g., 37 μ g/m3), but not with enough anticipation to efficiently protect the population. It is necessary to develop an early air quality alert in Bogotá, in order to provide information that improves risk management protocols in the capital district. The purpose of this investigation is to validate the correctivealert presented on the 14th and 15th of February of 2019, through the WRF-Chem model under different weather conditions, using three different setups of the model to simulate PM10 and PM2.5 concentrations during two different climatic seasons and different resolutions. The results of this article generate a validation of two configurations of the model that can be used for the Environmental Secretary of the District (SDA) forecasts in Bogotá, Colombia, in order to contribute to the prediction of pollution events produced by PM10 and PM2.5 as a tool for an early alert system (EAS) at least 24 h in advance.The aim of this study is to evaluate the polyphenolic and flavonoid contents in the leaves extracts of Ruscus hypophyllum. Antioxidant activity was estimated by α,α-diphenyl-β-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) assays. The anticoagulant activity of Ruscus extracts was evaluated in vitro, using the prothrombin time (PT) and a PTT-activated partial thromboplastin time tests. The antibacterial activity was tested against large number of important medically and resistant bacteria by the broth dilution method. In this study, ethyl acetate and chloroform extracts displayed the highest total phenols contents (74.76 mg EAG/g and 73.89 mg EAG/g, respectively) and flavonoid content 40 and 32.43 mg EC/g, respectively. The GC-MS analysis of ethyl acetate extract confirmed the presence of oxygenated sesquiterpenes and hydrocarbon diterpenes with percentages of 16.41% and 10.72%, respectively, but chloroform extract was rich with, oxygenated monoterpenes, and oxygenated diterpenes, with percentages of 6.19 and 3.27%, respectively. Among tested extracts, ethyl acetate exhibited the best antioxidant and anticoagulant activities. Furthermore, ethyl acetate and chloroform extracts showed important antibacterial activity against resistant bacteria methicillin-resistant Staphylococcus aureus (SARM), Acinetobacter imipenem-resistant (IMP/R), P. aeruginosa imipenem-resistant (IMP/R) and extended-spectrum beta-lactamase producing E. cloacae (BLSE) with minimal inhibitory concentration (MIC) values varying between 0.125 and 0.5 mg/mL.Marine diesel engines produce a lot of exhaust gas (NO, SO2). Based on the situation that wet scrubbing methods have been already applied to ship desulfurization and seawater is easily accessible around the ships, this paper proposed a novel AOP (advanced oxidation process) of NaClO2 (sodium chlorite) with Cl- (abundant Cl- exist in seawater) to remove NO from the flue gases of marine engines. The buffer capacity of NaAC (sodium acetate), the effect of Cl- concentration, and Cl- promotion mechanism on NO removal were investigated. The result showed that the existence of NaAC in solution could inhibit the rapid decline of the solution pH. The addition of Cl- achieved a remarkable promotion to NO removal at lower NaClO2 concentration, which was due to the fast generation of ClO2 from the promotion decomposition of NaClO2 by Cl- in acidic condition. Then, the thermodynamic and dynamic mechanism of the generation of ClO2 was intensively analyzed. And the mechanism of NO removal was discussed finally.In this study, the experimental and kinetic modeling investigations were performed to evaluate the ability of mesoporous and microporous canola stalk-derived activated carbon (CSAC) on 2,4-dichlorophenoxyacetic acid (2,4-D) removal from synthetic and natural water in both batch and continuous systems. Three empirical models (pseudo-first-order equation (PFOE), pseudo-second-order equation (PSOE), and the Elovich equation (EE)) and three theoretical models (film diffusion model (FDM), particle diffusion model (PDM), and second-order chemical reaction rate model (SOCRRM)) were compared in terms of diffusion coefficients, maximum 2,4-D adsorption, and rate constants at various operating conditions. CSAC was prepared at 600 °C and activated with water steam under a controlled flow and subsequently characterized by various analytical methods. The results showed that the maximum 2,4-D uptake by CSAC was achieved as 135.8 mg g-1 under a pH of 2 and an initial 2,4-D concentration of 150 mg L-1. The CSAC removed 38.3% of Na+, 43.49% of K+, 8.96% of Mg2+, 45.14% of Ca2+, 17.2% of Cl-1, 39.48% of HCO3-, 63.74% of SO42-, and 100% of the herbicide from agricultural subsurface drainage water and also retained its usability after regenerated by acetone for five cycles. It was concluded that the 2,4-D was adsorbed on the surface of the CSAC through its aromatic ring interaction with the reactive functional groups of the adsorbent. The model result indicated that the PDM is the best-fitting kinetic model for the adsorption of 2,4-D by CSAC, followed by FDM, SOCRRM, PSOE, PFOE, and EE. The mass balance equation based on PDM describes the dynamic behavior of the column satisfactorily. Graphical abstract.The wetland plants are very sensitive to hydrological regimes. PIK-III price In this study, the individual sizes of a widely distributed species (i.e., Deyeuxia angustifolia) at three typical marshes with different water table depths (i.e., wet meadow (WM) marsh; seasonal inundated (SI) marsh; perennial inundated (PI) marsh) were investigated in the Sanjiang Plain of Northeast China. Concurrently, three primary point pattern processes (homogeneous Poisson (HP) process, homogeneous Thomas (HT) process, and inhomogeneous Thomas (IT) process) were used to model spatial patterns in the distribution at 0-50 cm scale for this tillering-cloning species. The plant height, diameter at breast height (d.b.h), internode number, branches number, and individual aboveground biomass of D. angustifolia decreased sharply with rising water level; however, its density and coverage increased first and then decreased as water level increases. The distribution of D. angustifolia totally diverged from the complete spatial randomness (CSR) model (i.