Balslevcross2881

In the PCA, the first principal component showed that REE resources were commonly associated with the distribution of granitic rocks and REE-bearing minerals. Anthropogenic contaminations from mining, urban, and anthropogenic areas played important roles as the origin of some toxic elements (e.g. Ni, Pb, Sb). Comparisons between these GBs effectively elucidated the enrichment of certain toxic elements (e.g., Hg, Sb) in ore deposit areas. This data-driven study not only clarified the origins of toxic elements, but also revealed the location of potential REE mineral resources in the Tohoku region.Chrysene, a four-ring polycyclic aromatic hydrocarbon (PAH), is recalcitrant to biodegradation and persistent in the environment due to its low water solubility. Here, we investigated the atmospheric degradation process of chrysene initiated by OH radical in the presence of O2 and NOX using quantum chemical calculations. The reaction mechanisms were elucidated by density functional theory (DFT) at M06-2X/6-311++G(3df,2p)//M06-2X/6-311+G(d,p) level, and the kinetics calculations were conducted with Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The results show that the oxidation products of atmospheric chrysene are oxygenated PAHs (OPAHs) and nitro-PAHs (NPAHs), including nitro-chrysene, hydroxychrysene, hydroxychrysenone, 11-benzo[a]fluorenone and dialdehydes. Most of the products have deleterious effects on the environment and human beings due to their acute toxicity, carcinogenicity and mutagenicity. The overall rate constant for the reaction of chrysene with OH radical is 4.48 × 10-11 cm3 molecule-1 s-1 and the atmospheric lifetime of chrysene determined by OH radical is 6.4 h. The present work provided a comprehensive understanding on the degradation mechanisms and kinetics of chrysene, which could help to clarify its atmospheric fate and environmental risks.In current work, Prussian blue (PB)- and hydroxyapatite (HAp)-embedded micro-adsorbents (PB-HAp-MAs) were rationally fabricated through an easy and flexible custom-made micronozzle system as a novel bifunctional adsorbent. The adsorption performance of the as-prepared samples was conducted based on the removal of cesium (Cs+) and strontium (Sr2+) ions. Adsorption behaviors of the PB-HAp-MAs were also evaluated as function extrusion dimensions and adsorbate concentration. The adsorption isotherm was well fitted by the Langmuir model with adsorption capacities of 24.688 mg g-1 and 29.254 mg g-1 for Cs+ and Sr2+, respectively. Specially, the enhanced adsorption activity can be synergistically attributed to the porous nature of the developed alginate backbone with a high surface area of encapsulated functional nanoparticles, thus leading to rapid saturation within 1 min. In addition, the as-synthesized PB-HAp-MAs were successfully separated from the aqueous solution within 10 s by applying a magnetic field. We expect that our findings will provide valuable guidelines towards developing highly efficient adsorbents for environmental remediation.The low-quality of automotive fuels may lead to the generation of pollutants harmful to both environmental and human health. The quality evaluation of automotive fuels requires a multiparameter conformity assessment, which may lead to an increased total risk of false conformity decisions even if all parameters comply with the acceptance limits. Thus, the aim of this work was to propose the establishment of multivariate acceptance limits in order to ensure a reduced total risk of false conformity decisions applied to automotive fuels analysis. Particular and total (consumers' and/or producers') risks were estimated using frequentist (specific) and Bayesian (global) approaches. Multivariate acceptance limits were estimated using Monte Carlo method, adopting an appropriate multivariate coverage factor (k') defined using MS Excel Solver function. The definition of multivariate acceptance limits ensures a total risk below the maximum admissible risk (typically 5%) and was successfully employed in the conformity assessment of automotive fuels (diesel and gasoline). The employment of the multivariate acceptance limits may be useful in the conformity assessment of several multiparameter products.Microbial extracellular polymeric substances (EPS) represent an important source of labile component in natural organic matter (NOM) pool. However, the sorption behavior of EPS to mineral surfaces and associated effects on sorption of hydrophobic organic contaminants (HOCs) are not well understood. Here, we systematically investigated the fractionation of EPS extracted from two different microbial sources (Gram-positive B. subtilis and Gram-negative E. coli) during sorption to montmorillonite, kaolinite, and goethite using collective characterization methods (SEM, electrophoretic mobility, FTIR, 1H NMR, UV-vis, fluorescence, and size exclusion chromatography). The peptide-like substances and acidic components with high aromaticity in B. subtilis EPS were more preferentially sorbed than those fractions in E. coli EPS by the three minerals, especially by goethite. Additionally, goethite sorbed more negatively charged and lower molecular weight fractions compared to montmorillonite. The presorption of EPS (1.68-3.79% organic carbon) on the three minerals increased the sorption distribution coefficient (Kd) of phenanthrene (a model apolar HOC) by 2.83-5.29 times, depending on the EPS-mineral complex. All the six examined EPS-mineral complexes exhibited approximately one order of magnitude larger organic carbon (OC)-normalized sorption coefficient (KOC) than the two pristine EPS, indicating that the sorptive interactions were pronouncedly facilitated by the sorbed EPS on mineral surfaces. Thus, the type and surface property of minerals as well as the biological source of EPS are key determinants of sorption fractionation of EPS on minerals and in turn affect sorption affinity of apolar HOCs to EPS-mineral complexes.Polychlorinated dibenzo-p-dioxins and -furans (PCDD/PCDFs) are highly toxic organic pollutants in soils and sediments which persist over timescales that extend from decades to centuries. There is a growing need to develop effective technologies for remediating PCDD/Fs-contaminated soils and sediments to protect human and ecosystem health. The use of sorbent amendments to sequester PCDD/Fs has emerged as one promising technology. selleck kinase inhibitor A synthesis method is described here to create a magnetic activated carbon composite (AC-Fe3O4) for dioxin removal and sampling that could be recovered from soils using magnetic separation. Six AC-Fe3O4 composites were evaluated (five granular ACs (GACs) and one fine-textured powder AC(PAC)) for their magnetization and ability to sequester dibenzo-p-dioxin (DD). Both GAC/PAC and GAC/PAC-Fe3O4 composites effectively removed DD from aqueous solution. The sorption affinity of DD for GAC-Fe3O4 was slightly reduced compared to GAC alone, which is attributed to the blocking of sorption sites.