Application of ZnO-Fe3O4 nanocomposite on the removal of azo dye from aqueous solutions: Kinetics and equilibrium studies

In this study, zinc oxide was immobilized on magnetite nanoparticles by chemical method and it was used as an adsorbent to remove reactive black 5 (RB5) dye from aqueous solution. The removal efficiency of RB5 was studied as the function of adsorbent dosage, pH, initial RB5 concentration, H2O 2, and ionic strength (sodium carbonate, sodium bicarbonate, sodium sulfate, and sodium chloride). Removal efficiency of RB5 by ZnO-Fe 3O4 was greater than that by ZnO and Fe3O 4 in similar conditions. Maximum adsorption of ZnO-Fe 3O4 was obtained at neutral pH, and adsorption capacity was estimated to be 22.1 mg/g. Adsorption kinetic study revealed that the pseudo-second-order model better described the removal rate than the pseudo-first-order model. Adsorption isotherm was analyzed by both Langmuir and Freundlich equations, and results showed that it was better described by the Langmuir equation. The removal efficiency of RB5 was increased with increasing initial H2O2 concentrations from 2 to 5 mM but was decreased above 5 mM. The adsorption capacities of RB5 was increased in the presence of NaCl but was greatly decreased in the presence of bicarbonate, carbonate, and sulfate ion. Adsorption activity of RB5 by ZnO-Fe 3O4 composite was maintained even after five successive cycles, suggesting a promising adsorbent for wastewater-contaminated organic dyes. © Springer International Publishing Switzerland 2014

Gold oxide films grown in the confined aqueous layer between gold and organic solvents

The properties of anodic passive films potentiostatically formed on polycrystalline gold in aqueous phosphate solutions were studied using voltammetry, electrochemical impedance spectroscopy, and contact angle measurements. The nature of the gold oxide layer was analyzed as a function of a potential holding in the aqueous double layer charge region at the interface between gold and the aqueous layer confined by insoluble organic solvents (hexane, chloroform, anisole, butyl acetate, xylene, and isopropyl ether). Different growth conditions change the homogeneity of the oxide layer leading to different passive properties. A synergetic effect on the gold oxidation of hydrogen dissolved in both the bulk metal and the confined aqueous layer is discussed.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasInstituto de Física de Líquidos y Sistemas Biológico

Optimization of dimethyl phthalate degradation parameters using zero-valent iron nanoparticles by response surface methodology: Determination of degradation intermediate products and process pathway

Background and purpose: Phthalic acid esters (PAEs) are a group of organic compounds that are used as additives in plastic industry. Among PAEs, dimethyl phthalate (DMP), the simplest compound in phthalates, is an aromatic pollutant that disturbs endocrine function. The aim of this study was to assess the effect of zero-valent iron nanoparticles (NZVI) on the DMP degradation. Materials and methods: NZVI were prepared by reduction of ferric chloride using sodium borohydride. Physical properties of nanoparticles were determined using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), and Vibrating Sample Magnetometer (VSM). Then, the effect of pH, DMP concentrations, the amount of NZVI, and contact time were investigated on DMP removal efficiency. Response surface methodology based on Box- Behnken was used to study the interaction between variables. Results: Maximum efficiency (99) of DMP removal by NZVI was achieved in optimum conditions (pH=3, NZVI dosage =0.6 g/l, DMP concentration = 2 mg/l, and contact time= 65 min). The Box-Behnken analysis confirmed that pH and NZVI dosage have had the highest and lowest effect in the process of DMP removal by NZVI, respectively. Conclusion: According to findings, NZVI in small amounts have a proper efficiency in DMP removal. Also, DMP degradation efficiency did not change much, after being used in five consecutive cycles of degradation reactions. This shows a potential application prospect of the synthesized NZVI in real water treatment. © 2015 Journal of Mazandaran University of Medical Sciences. All Rights Reserved

Unlocking the phylogenetic diversity, primary habitats, and abundances of free-living Symbiodiniaceae on a coral reef.

Dinoflagellates of the family Symbiodiniaceae form mutualistic symbioses with marine invertebrates such as reef-building corals, but also inhabit reef environments as free-living cells. Most coral species acquire Symbiodiniaceae horizontally from the surrounding environment during the larval and/or recruitment phase, however the phylogenetic diversity and ecology of free-living Symbiodiniaceae on coral reefs is largely unknown. We coupled environmental DNA sequencing and genus-specific qPCR to resolve the community structure and cell abundances of free-living Symbiodiniaceae in the water column, sediment, and macroalgae and compared these to coral symbionts. Sampling was conducted at two time points, one of which coincided with the annual coral spawning event when recombination between hosts and free-living Symbiodiniaceae is assumed to be critical. Amplicons of the internal transcribed spacer (ITS2) region were assigned to 12 of the 15 Symbiodiniaceae genera or genera-equivalent lineages. Community compositions were separated by habitat, with water samples containing a high proportion of sequences corresponding to coral symbionts of the genus Cladocopium, potentially as a result of cell expulsion from in hospite populations. Sediment-associated Symbiodiniaceae communities were distinct, potentially due to the presence of exclusively free-living species. Intriguingly, macroalgal surfaces displayed the highest cell abundances of Symbiodiniaceae, suggesting a key role for macroalgae in ensuring the ecological success of corals through maintenance of a continuum between environmental and symbiotic populations of Symbiodiniaceae

Optimization of dimethyl phthalate degradation parameters using zero-valent iron nanoparticles by response surface methodology: Determination of degradation intermediate products and process pathway

Background and purpose: Phthalic acid esters (PAEs) are a group of organic compounds that are used as additives in plastic industry. Among PAEs, dimethyl phthalate (DMP), the simplest compound in phthalates, is an aromatic pollutant that disturbs endocrine function. The aim of this study was to assess the effect of zero-valent iron nanoparticles (NZVI) on the DMP degradation. Materials and methods: NZVI were prepared by reduction of ferric chloride using sodium borohydride. Physical properties of nanoparticles were determined using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), and Vibrating Sample Magnetometer (VSM). Then, the effect of pH, DMP concentrations, the amount of NZVI, and contact time were investigated on DMP removal efficiency. Response surface methodology based on Box- Behnken was used to study the interaction between variables. Results: Maximum efficiency (99) of DMP removal by NZVI was achieved in optimum conditions (pH=3, NZVI dosage =0.6 g/l, DMP concentration = 2 mg/l, and contact time= 65 min). The Box-Behnken analysis confirmed that pH and NZVI dosage have had the highest and lowest effect in the process of DMP removal by NZVI, respectively. Conclusion: According to findings, NZVI in small amounts have a proper efficiency in DMP removal. Also, DMP degradation efficiency did not change much, after being used in five consecutive cycles of degradation reactions. This shows a potential application prospect of the synthesized NZVI in real water treatment. © 2015 Journal of Mazandaran University of Medical Sciences. All Rights Reserved

Salvage therapy with high dose Intravenous Immunoglobulins in acquired Von Willebrand Syndrome and unresponsive severe intestinal bleeding

A 91-year-old woman affected with acquired Von Willebrand (VW) syndrome and intestinal angiodysplasias presented with severe gastrointestinal bleeding (hemoglobin 5\ua0g/dl). Despite replacement therapy with VW factor/factor VIII concentrate qid, bleeding did not stop (eleven packed red blood cell units were transfused over three days). High circulating levels of anti-VW factor immunoglobulin M were documented immunoenzimatically. Heart ultrasound showed abnormalities of the mitral and aortic valves with severe flow alterations. When intravenous immunoglobulins were added to therapy, prompt clinical and laboratory responses occurred: complete cessation of bleeding, raise in hemoglobin, VW factor antigen, VW ristocetin cofactor and factor VIII levels as well as progressive reduction of the anti-VWF autoantibody levels

Prevalence of echinococcosis in humans, livestock and dogs in northern Italy

AbstractThe presence of Echinococcus sp. cysts was investigated in 822 sheep, 123 goats and 112,521 cattle from Lombardy region, North Italy. Faecal samples from 40 sheepdogs were also analyzed, with 9 samples containing taeniid eggs (22.5 %), 8 samples being coproantigen-positive (20 %), and one dog from a northern province (Lecco) positively confirmed by PCR. Cystic Echinococcosis (CE) was detected in 0.36 % of sheep and in 0.29 % of cattle in 2004. No goat resulted to be infected. Data from CE patients treated in Lombardy were collected by inspecting hospital discharge records. In 2004, 156 CE-related admissions (62 % male and 38 % female) were reported in Lombardy. Total hospital stay was 1,372 days (1,286 for inpatients, 86 for outpatients). Most patients (72.4 %) were residents in Lombardy and 1.9 % were from Piedmont; the remaining patients were from central and southern Italy. According to acquired data CE resulted hypoendemic in animals in Lombardy. Prevalence rates in humans were higher than expected in this region, usually considered as non-endemic. Assessment of the prevalence of CE in humans remains a difficult, costly, time-consuming and labourintensive task. The present study suggests establishing a National Registry of Cystic Echinococcosis with the aim to highlight regional risk factors and to benefit from its matching both clinical and epidemiological data

Electrochemical and optical study of the confined aqueous layer adsorbed on gold electrodes cycled in phosphate and dodecylsulphate solutions

The properties of the confined aqueous layer potentiodynamically formed on polycrystalline gold in aqueous phosphate and sodium dodecylsulphate solutions were studied using voltammetry, ellipsometry, and contact angle measurements. The nature of the incipient oxide layer was analyzed as a function of the cycling time in the double layer-oxide monolayer potential region. The replacement of the electrolyte by hexane allows the increase of the optical signal. Different potential cycling conditions change the homogeneity of the confined aqueous incipient oxide layer leading to different structural characteristics.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta