Direct-Read Fluorescence-Based Measurements of Bioaerosol Exposure in Home Healthcare.

Home healthcare workers (HHCWs) are subjected to variable working environments which increase their risk of being exposed to numerous occupational hazards. One of the potential occupational hazards within the industry includes exposure to bioaerosols. This study aimed to characterize concentrations of three types of bioaerosols utilizing a novel fluorescence-based direct-reading instrument during seven activities that HHCWs typically encounter in patients' homes.

Ventilation and posture effects on inhalation exposures to volatile cleaning ingredients in a simulated domestic worker cleaning environment.

Associations between cleaning chemical exposures and asthma have previously been identified in professional cleaners and healthcare workers. Domestic workers, including housecleaners and caregivers, may receive similar exposures but in residential environments with lower ventilation rates. Study objectives were to compare exposures to occupational exposure limits (OELs), to determine relative contributions from individual cleaning tasks to overall exposure, and to evaluate the effects of ventilation and posture on exposure.

Visible light activated TiO2/microcrystalline cellulose nanocatalyst to destroy organic contaminants in water.

Hybrid TiO(2)/microcrystalline cellulose (MC) nanophotocatalyst was prepared in situ by a facile and simple synthesis utilizing benign precursors such as MC and TiCl(4). The as-prepared nanocomposite was characterized by XRD, XPS, BET surface area analyzer, UV-vis DRS and TGA. Surface morphology was assessed by the means of SEM and HR-TEM.

Theoretical and practical aspects of chemical functionalization of carbon nanofibers (CNFs): DFT calculations and adsorption study.

The nitric acid-functionalized commercial carbon nanofibers (CNFs) were comprehensively studied by instrumental (XRD, BET, SEM, TGA) and theoretical (DFT calculations) methods. The detailed surface study revealed the variation in the characteristics of functionalized CNFs, such as a decreased (up to 34%) surface area and impacted structural, electronic and chemical properties. The effects of functional groups were studied by comparison with pristine nanofibers.

Combination of neural networks and DFT calculations for the comprehensive analysis of FDMPO radical adducts from fast isotropic electron spin resonance spectra.

The 4-hydroxy-5,5-dimethyl-2-trifluoromethylpyrroline-1-oxide (FDMPO) spin trap is very attractive for spin trapping studies due to its high stability and high reaction rates with various free radicals. However, the identification of FDMPO radical adducts is a challenging task since they have very comparable Electron Spin Resonance (ESR) spectra. Here we propose a new method for the analysis and interpretation of the ESR spectra of FDMPO radical adducts.

Efficiency of hydroxyl radical formation and phenol decomposition using UV light emitting diodes and H2O2.

A novel process combining hydrogen peroxide (H2O2) and radiation emitted by ultraviolet light emitting diodes (UV LEDs) has been investigated. The UV LEDs were used as UV-C light sources emitting radiation in the range 257-277 nm for decomposition of the model substance phenol in water. In addition, the effect of H2O2 to phenol molar ratio and initial phenol concentration was examined.

The effect of electrodialytic treatment and Na2H2EDTA addition on methanogenic activity of copper-amended anaerobic granular sludge: treatment costs and energy consumption.

The effect of electrodialytic treatment in terms of a current density, pH and Na(2)H(2)EDTA addition on the methanogenic activity of copper-amended anaerobic granular sludge taken from the UASB reactor from paper mill was evaluated. Moreover, the specific energy consumption and simplified operational and treatment costs were calculated. Addition of Na(2)H(2)EDTA (at pH7.

Free radical reaction pathway, thermochemistry of peracetic acid homolysis, and its application for phenol degradation: spectroscopic study and quantum chemistry calculations.

The homolysis of peracetic acid (PAA) as a relevant source of free radicals (e.g., *OH) was studied in detail.

Visible light induced photobleaching of methylene blue over melamine-doped TiO2 nanocatalyst.

TiO(2) doping with N-rich melamine produced a stable, active and visible light sensitized nanocatalyst that showed a remarkable efficiency towards the photobleaching of a model compound - methylene blue (MB) in aqueous solution. The photobleaching followed a mixed reaction order kinetics with the distinctive induction and acceleration periods.

Comparative kinetic analysis of silent and ultrasound-assisted catalytic wet peroxide oxidation of phenol.

The kinetic study of silent and ultrasound-assisted catalytic wet peroxide oxidation of phenol in water was performed to qualitatively assess the effect of ultrasound on the process kinetics. Various kinetic parameters such as the apparent kinetic rate constants, the surface utilization coefficient and activation energy of phenol oxidation over RuI(3) catalyst were investigated. Comparative analysis revealed that the use of ultrasound irradiation reduced the energy barrier of the reaction but had no impact on the reaction pathway.

Optimisation of electro-Fenton denitrification of a model wastewater using a response surface methodology.

Electro-Fenton denitrification of a model wastewater was studied using platinized titanium electrodes in a batch electrochemical reactor. The model wastewater was prepared from components based on the real aquaculture effluent with nitrate concentrations varying from 200 to 800 mg L(-1). The technical as well as scientific feasibility of the method was assessed by the relationship between the most significant process variables such as various Fenton's reagent to hydrogen peroxide ratios (1:5; 1:20 and 1:50) and current densities (0.

ESR ST study of hydroxyl radical generation in wet peroxide system catalyzed by heterogeneous ruthenium.

Ru-based catalysts gained popularity because of their applicability for a variety of processes, including carbon monoxide oxidation, wet air catalytic oxidation and wastewater treatment. The focus of a current study was generation of hydroxyl radicals in the wet peroxide system catalyzed by heterogeneous ruthenium, spin-trapped by DEPMPO and DIPPMPO by means of electron spin resonance spin-trapping technique (ESR ST). The mechanism of free radicals formation was proposed via direct cleavage of hydrogen peroxide over ruthenium active sites.

Low-frequency ultrasound in biotechnology: state of the art.

The use of low-frequency (10-60 kHz) ultrasound for enhancement of various biotechnological processes has received increased attention over the last decade as a rapid and reagentless method. Recent breakthroughs in sonochemistry have made the ultrasound irradiation procedure more feasible for a broader range of applications. By varying the sonication parameters, various physical, chemical and biological effects can be achieved that can enhance the target processes in accordance with the applied conditions.

Electro-Fenton, hydrogenotrophic and Fe2+ ions mediated TOC and nitrate removal from aquaculture system: different experimental strategies.

A number of methods for denitrification were studied including Electro-Fenton method, hydrogenotrophic as well as innovative Fe(2+) mediated denitrification and their technical feasibility in terms of changes in TOC and nitrate concentrations, effect of different Fenton's reagent dosage, current and the effect of the pH was investigated. This study was carried out using tailor made electrodialytic reactor. It was found that the highest TOC removal was achieved at pH 2.

Optimization of pulp mill effluent treatment with catalytic adsorbent using orthogonal second-order (Box-Behnken) experimental design.

Novel catalytic adsorbent (ruthenium on carbon) was employed for the treatment of pulp mill effluent in the presence of hydrogen peroxide. Mathematical model and optimization of the process regarding the most favorable COD (%), TOC (%) and color (%) removal rates was developed and performed with experimental design taking into account catalytic adsorption process kinetics. As the initial experimental design, 3(3-1) half-fractional factorial design (H-FFD) was accomplished at two levels to study the significance of the main effects, such as catalytic adsorbent (g l(-1)) and hydrogen peroxide (ppm) concentrations using the response surface methodology (RSM).

The hindering effect of experimental strategies on advancement of alkaline front and electroosmotic flow during electrokinetic lake sediment treatment.

The current study focused on the hindering of alkaline front during electrokinetic copper migration in artificially contaminated lake sediments and the effect of several experimental strategies on electroosmotic flow. Fourteen laboratory scale experiments in triplicates were performed using plastic container where the distance between electrodes was 30 cm at 40 mA, 60 mA and 120 mA electric currents (under density of 0.15 mA cm(-2), 0.

Chemical evaluation of potable water in Eastern Qinghai Province, China: human health aspects.

Electric conductivity, pH, COD(Mn), nutrient concentration, chloride and sulfate concentrations, total dissolved sodium, potassium, calcium, magnesium, manganese, iron, cadmium, copper, arsenic, nickel, zinc, chromium and lead were evaluated to clarify concerns about the quality and safety of water used for drinking purposes in Qinghai Province, China. For this purpose, 12 water samples were collected from different villages, Qinghai (Koko Nor) Lake and medicinal springs close to the Town of Pingang during a study visit to China in 2003. The results showed that National Chinese and WHO drinking water standards were exceeded for nutrient concentration (3.

Copper and trace element fractionation in electrokinetically treated methanogenic anaerobic granular sludge.

The effect of electrokinetic treatment (0.15 mA cm(-2)) on the metal fractionation in anaerobic granular sludge artificially contaminated with copper (initial copper concentration 1000 mg kg(-1) wet sludge) was studied. Acidification of the sludge (final pH 4.