Disinfection by-products (DBPs) play a significant role in human health. Identification of the precursor of DBPs, which constitutes dissolved organic matter (DOM), can help optimize the processes in a drinking water treatment plant (DWTP). This is very important for obtaining more safe water.
View Article and Find Full Text PDFMany studies have focused on the use of BiVO as a photocatalyst, but few have investigated the production of free radicals during the photocatalytic process. Following synthesis of flowerlike BiVO and characterization by X-ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM) Scanning electron microscopy (EDX), UV-Vis and XPS, we successfully prepared BiVO. Then we used electron spin resonance (ESR) to determine the production and degradation of individual active free radicals, including the superoxide radical (·[Formula: see text]) and the hydroxyl radical (·OH).
View Article and Find Full Text PDFIn this paper a novel visible light-driven ternary compound photocatalyst (β-NaYF:Ho@TiO-rGO) was synthesized using a three-step approach. This photocatalyst was characterized using X-ray diffraction, Raman scattering spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Transmission electron microscopy, X-ray photoelectron spectroscopy, fluorescence spectrometries, ultraviolet-visible diffuse reflectance spectroscopy, Brunauer-Emmett-Teller surface area measurement, electron spin resonance, three-dimensional fluorescence spectroscopy, and photoelectrochemical properties. Such proposed photocatalyst can absorb 450 nm visible light while emit 290 nm ultraviolet light, so as to realize the visible light-driven photocatalysis of TiO.
View Article and Find Full Text PDFIn this paper, YF₃:Ho@TiO₂ core-shell nanomaterials were prepared by hydrolysis of tetra--butyl titanate (TBOT) using polyvinylpyrrolidone K-30 (PVP) as the coupling agent. Characterization methods including X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) under TEM, X-ray photoelectron spectroscopy (XPS), fluorescence spectrometry, ultraviolet-visible diffuse reflectance spectroscopy, and electron spin resonance (ESR) were used to characterize the properties and working mechanism of the prepared photocatalyst material. They indicated that the core phase YF₃ nanoparticles were successfully coated with a TiO₂ shell and the length of the composite was roughly 100 nm.
View Article and Find Full Text PDFA novel Ag-reduced graphene oxide (rGO)-bismuth vanadate (BiVO₄) (AgGB) ternary composite was successfully synthesized via a one-step method. The prepared composite was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Brunauer-Emmett-Teller (BET) surface area measurement, Raman scattering spectroscopy, and ultraviolet-visible diffuse-reflection spectroscopy (UV-vis DRS). The results showed that bulk monoclinic needle-like BiVO₄ and Ag nanoparticles with a diameter of approximately 40 nm formed microspheres (diameter, 5-8 μm) with a uniform size distribution that could be loaded on rGO sheets to facilitate the transport of electrons photogenerated in BiVO₄, thereby reducing the rate of recombination of photogenerated charge carriers in the coupled AgGB composite system.
View Article and Find Full Text PDFObjective: To estimate the prevalence of asthma in workers by occupation in Washington State.
Methods: Data from the 2006-2009 Behavioral Risk Factor Surveillance System (BRFSS) and the BRFSS Asthma Call-Back Survey (ACBS) in Washington State (WA) were analyzed. Using state-added and coded Industry and Occupation questions, we calculated prevalence ratios (PRs) for 19 occupational groups.
Int J Hyg Environ Health
March 2014
Dissolved organic matters (DOM) are critical in the formation of the mutagenic disinfection byproducts (DBPs). In this study, five DOM fractions were isolated and investigated from a contaminated river and a clean reservoir source waters using resin adsorption. The DOM fractions were characterized with excitation-emission matrix, and several typical DBPs formation potentials and the mutagenicity of each DOM fraction were measured.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
February 2014
Membrane biofouling, resulting from biofilm formation on the membrane, has become the main obstacle hindering wider application of membrane technology. Initial biofouling proves to be crucial which involves early stages of microbial adhesion and biofilm formation. Biological control of microbial attachment seems to be a promising strategy due to its high efficiency and eco-friendliness.
View Article and Find Full Text PDFInt J Environ Res Public Health
April 2011
In this study, Fe(3)O(4)/SiO(2)/TiO(2) photocatalyst was prepared via a sol-gel method, and Fe(3)O(4) particles were used as the core of the colloid. Diffraction peaks of Fe(3)O(4) crystals are not found by XRD characterization, indicating that Fe(3)O(4) particles are well encapsulated by SiO(2). FTIR characterization shows that diffraction peaks of Ti-O-Si chemical bonds become obvious when the Fe(3)O(4) loading is more than 0.
View Article and Find Full Text PDFWe evaluated 52 renal grafts transplanted into 41 patients with a pretransplantation diagnosis of Alport's syndrome. Overall 1-, 5-, and 10-year patient and graft survival rates were 95.1%, 90.
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