Mcgrathadams2146

However, larger studies may be required if differences close to the clinically meaningful threshold are to be detected.The present study elaborates uranium sequestration by bacteria from alkaline wastewaters. In the investigation, a few bacterial strains were isolated from alkaline uranium mine water and were tested for uranium sequestration properties 16S rRNA analysis assigned the 10 bacterial isolates to 4 genera of Actinobacteria and Firmicutes. Among all the isolates tested, the strain Bacillus aryabhattai (TP03) has shown superior sequestration capacity at 5 and 10 mg/L U in 1 mM carbonate-bicarbonate buffer at pH 9.2. At low uranium concentrations (5 mg/L as uranyl carbonate), the strain could sequester ~70% of the uranium in 6 h with a loading capacity of 4.3 mg U/g dry bacterial biomass. Increase in carbonate-bicarbonate buffer concentrations and pH reduced the sequestration capacity. Scanning electron microscopy and energy dispersive X-ray fluorescence spectroscopy studies indicated the presence of uranium with the bacterial biomass. Fourier transform infra-red spectroscopy results confirmed the uranium sequestration by cell membrane phosphate, amide, and carboxyl functional groups. Transmission electron microscopy study showed uranium presence within the cell cytoplasm, thus supporting the hypothesis on active metabolism-dependent bioaccumulation of uranium. The kinetics study of uranium sequestration was well fitted to the pseudo-second-order model. Overall, this study infers that the isolated alkaliphilic bacteria from the mine waters have significant sequestration property for treating uranium-containing alkaline wastewaters.Oil mist emitted during cooking is one of the major sources of atmospheric particulate matter in urban areas. A conventional electrostatic precipitator (ESP) is used in some large restaurants; it requires regular electrode cleaning to maintain particle collection performance. However, oil mist generated during cooking is viscous and difficult to clean with water. Herein, we introduce a methodology and a device for cleaning collected oil mist using surface dielectric barrier discharge (surface-DBD) plasma. Our device uses corona discharge for the collection of oil mist. Subsequently, the oil mist collected is decomposed to gas-phase species by surface-DBD plasma. A maximum collection efficiency of 93.25% (for 230 nm di-ethyl hexyl sebacate (DEHS) particle) is obtained at a flow velocity of 1.5 m/s. The maximum oil mist decomposition efficiency is 96.4%. More than 80% of the decomposed oil mist is converted to CO2 and CO under all test conditions. Some of the byproducts other than CO and CO2 are released as particles. Higher frequency results in higher oil mist decomposition efficiency, but also higher byproduct formation of particles. The mechanism of oil mist decomposition by surface-DBD plasma is discussed using optical emission spectroscopy data.The adsorption and desorption behavior of the refrigerant HFC-134a on pitch-based activated carbon fibers (ACFs) with various Brunauer-Emmett-Teller surface areas was investigated by the flow method. Fixed-bed adsorption experiments performed at 20, 5, -15, -20, and -25 °C showed that the use of lower temperatures resulted in an increase in the adsorption capacity of the ACF. In particular, the complete adsorption time was dramatically increased at -25 °C. Crucially, even after five cycles of adsorption at -20 °C and desorption at 30 °C of HFC-134a in a electrothermal swing adsorption apparatus, significant decreases in the adsorption capability were not observed. The desorption of HFC-134a from saturated ACF was carried out using electric power directly applied to the ACF itself. The electric heating increased the ACF temperature, causing desorption within several minutes. The results of this study show that the regenerative adsorption of HFC-134a by ACF coupled with electric power is possible.Hydrogels have extensively studied as adsorbents, raw materials for the preparation of adsorbent hydrogels have low strength, while high strength hydrogels have weak adsorption capacity. In this study, PVA hydrogel was crosslinked via trihydroxy melamine and epichlorohydrin, and β-cyclodextrin with strong adsorption capacity was added to remove the heavy metal ions. Results showed that the addition of trihydroxy melamine with 8%, the compressive strength of the hydrogel was increased by approximately 20%. The Langmuir isotherm model showed that the adsorption capacity of the hydrogel for Pb(II) and Ni(II) reached 505.9 mg/g and 286.7 mg/g, respectively, and the efficiency of removing the low-concentration heavy metal ions in water more than 99%. The hydrogel is low cost, and maintained highly removal efficiency under low pH. The removal efficiency of the hydrogel remained above 90% after five repeated adsorption-desorption experiments. The hydrogels have a potential to be used in wastewater treatment as adsorbents.A novel CeO2 doped high silica ZSM-5(CeO2@HSZSM-5) composite was originally fabricated via ammonia precipitation for the catalytic ozonation of sulfamethoxazole (SMX). Physicochemical properties have been investigated through electron microscope, Raman spectroscopy, X-ray photoelectron spectroscopy, etc. The prepared nanometer CeO2@HSZSM-5 had a much higher specific surface (348-395 m2/g), a finer crystallite size (8.2-33.5 nm) and superior stability. Temperature-programmed desorption and reduction analysis revealed that the formed CeO2 nanoparticles on the surface of CeO2@HSZSM-5 could improve the reducibility of surface-capping oxygen, induce more oxygen vacancies and promote oxygen migration. CeO2@HSZSM-5 exhibited excellent catalytic performance for SMX mineralization in the pH range of environmental waters. The great enhancement of CeO2@HSZSM-5 catalytic activity was ascribed to the conversion of O3 into active oxygen involved in SMX mineralization, including .OH, O2.- and 1O2. This work provides a reference for the removal of pollutants by zeolite supported Ce catalytic ozonation process in water.The convenient and effective detection of toxins is urgently demanded for food security and human health. Herein, based on the catalytic activity of mimetic peroxidase from the Cu2O@Fe(OH)3 yolk-shell nanocages, a dual-modal multi-colorimetric and ratiometric fluorescence immunosensor for the sensitive detection of ochratoxin A (OTA) was successfully developed. For the multi-colorimetric detection, H2O2 can be effectively decomposed by Cu2O@Fe(OH)3 to form ·OH groups, thus Au nanorods (Au NRs) can be etched to exhibit vivid color variations and localized surface plasmon resonance (LSPR) shifts. For the ratiometric fluorescence detection, o-phenylenediamine was oxidized by Cu2O@Fe(OH)3 to form 2,3-diaminophenazine (DAP) in the presence of H2O2. Interestingly, the exogenous fluorescence signal source of carbon dots can be quenched by DAP via inner filter effect, while a new emission peak at 563 nm can be discovered, forming a ratiometric fluorescence signal. Due to the independent signals and mutual confirmation, the performance of the dual-modal immunosensor for the detection of OTA was significantly improved, where a broad linear range from 1 ng/L to 10 μg/L with a detection limit of 0.56 ng/L (S/N = 3) was achieved. The sensing strategy was also used to monitor OTA in millet and lake water samples with a satisfied performance.Knowledge on distribution of per- and poly-fluoroalkyl substances (PFASs) in open oceans is limited. By taking part in the 32nd Chinese Antarctic Research Expedition, 41 surface seawater samples were collected in the northwestern Pacific Ocean (NW-PO), eastern Indian Ocean (E-IO) and Southern Ocean (SO), and 23 PFASs comprised of legacy perfluoroalkyl carboxylic acids, perfluoroalkyl sulfonate acids and some new emerging homologs such as 62 chlorinated polyfluorinated ether sulfonate (62 Cl-PFESA) were measured. The concentrations of the total PFASs decreased in the order of NW-PO>E-IO>SO. Perfluorooctanoic acid (PFOA) was the most dominant, followed by perfluorooctane sulfonate (PFOS). The PFOA concentration declined exponentially with the offshore distance, while such trend was not obvious for PFOS and other legacy PFASs, suggesting that PFOA was mainly derived from the ongoing land-based emissions, while PFOS was mainly from historical residues. 62 Cl-PFESA was identified ( less then 11.1-170 pg/L) in the oceanic waters with relatively high level at the sites near Australia. Multiple receptor models indicated that PFASs in the SO were mainly contributed by atmosphere input, while those in the NW-PO and E-IO were originated from land sources. Isomeric profiles of PFOA showed that telomere-based source became more outstanding than electrochemical fluorinated production in recent years.Na+2Eu3+2Ca6(PO4)6F2 is explored as a potential host for radioactive waste immobilization. Since Eu3+ ion is a surrogate of highly radioactive Am3+ ion, the photoluminescence (PL) characteristics of Eu3+ ion helped to investigate the possible distribution of hazardous and radioactive Am3+ ion among the two lattice sites in the matrix. It was observed that Am3+ will prefer to occupy the Ca2-site lattice which has a direct linkage to F atom. From DFT calculation we have found that both Eu3+ and Am3+ ions are following similar trend of distribution into the Ca2-site compared to Ca1-site which has no F atom linkage. The radiation stability of the compound was also investigated by PL study after irradiating it with a 60Co gamma source with different doses starting from 2 kGy to as high as 1000 kGy. It was observed that radiation induced changes were more surrounding the Ca1-site than in Ca2-site.Considering all the experimental and theoretical observations it is concluded that from radioactive waste immobilization point of view it is more preferable to dope the Am3+ ion into the Ca2 site. selleck chemicals The Eu3+ doped compound was also found to be red color emitting phosphor materials with color purity of 95.24%.The goal of this study was to incorporate community data into the effect assessment of environmental and regulatory relevant metal mixtures. In this experiment three fixed mixture ratios (Canadian soil quality guideline ratio - CSQG; Agricultural, residential and Loamy ratio - ARL; and Sudbury ratio - SUD) were tested in a natural community microcosm with 11 doses for each mixture ratio. The effect of metal mixtures on the community was measured using the community effect concentration (EC) concept which assumes that as contamination increases, the community similarity between test and control treatments decreases producing a dose response curve allowing the calculation of community effect concentrations. In regulatory mixture ratios (CSQG and ARL) community EC10s were four times higher than regulatory thresholds and current regulation might be overprotective of the microarthropod communities in some soils. For the contaminated site ratio (SUD), the field dose in the contaminated site corresponded to a community EC20 and if metal concentrations were reduced by 1TU, (from 3.1TU to 2.1TU) effects would be below a community EC10. Overall, the community EC concept was successfully applied and has the potential for inclusion in risk assessment schemes as a measure of community response.