Electro-coagulation coupled Electro-floatation process: Feasible choice in Doxycycline removal from Pharmaceutical effluents

Article CC-BYInternational audienceElectrochemical treatment involving a coupled coagulation and floatation was performed in the removal of Doxycycline Hyclate (DCH) from aqueous solutions. All the experiments were carried out in an electrochemical reactor of 1.5 L which contained aluminium electrodes as cathode and anode. The removal of doxycycline hyclate (DCH) species by EC/EF was determined as a function of electrolysis time, pH, current intensity, flow rate and DCH concentration. From the observed results, it was corroborated that the DCH removal through the EC/EF process was excellent. The effective contribution from initial pH (7.03) and current intensity (5.39 mA cm-2) was very much remarkable and well apparent from flocs of good buoyancy. The removal of DCH was inversely proportional to spacing between electrodes (SBE) and circulating flow rate in the presence of the supporting NaCl electrolyte of 1 g L-1. It was also highly promoted by the addition of NaCl in comparison to NaNO3 and KCl to the electrolytic system. The compliance of four kinetic models was verified with DCH removal system. The free energy values from DKR model suggested the nature of bonding by chemical forces. Characterization by FTIR, SEM and XRD interpreted the assignments of various functional groups, surface morphology and crystalline incorporated amorphous nature, respectively of electro – generated flocs. The current efficiency and specific electrical energy consumption at optimized conditions of the EC/EF system were calculate

Moisture sorption isotherms and heat of sorption of Algerian bay leaves (Laurus nobilis)

The moisture sorption isotherms of Algerian bay leaves (Laurus nobilis) were determined experimentally in this work. The equilibrium moisture contents of the leaves were measured at 40, 50, and 60 °C using static gravimetric method. Six mathematical models were tested to fit the experimental data of sorption isotherms and predict the hygroscopic behavior during storage or drying. Peleg model was found to be the best fitting model for describing the sorption curves. The net isosteric heat of sorption was computed from the equilibrium data at different temperatures by applying the integrated form of the Clausius-Clapeyron equation. The net isosteric heat of sorption is inversely proportional to the equilibrium moisture content and is found to be an exponential function of moisture content

Moisture sorption isotherms and heat of sorption of Algerian bay leaves (Laurus nobilis)

ABSTRACT: The moisture sorption isotherms of Algerian bay leaves (Laurus nobilis) were determined experimentally in this work. The equilibrium moisture contents of the leaves were measured at 40, 50, and 60 °C using static gravimetric method. Six mathematical models were tested to fit the experimental data of sorption isotherms and predict the hygroscopic behavior during storage or drying. Peleg model was found to be the best fitting model for describing the sorption curves. The net isosteric heat of sorption was computed from the equilibrium data at different temperatures by applying the integrated form of the Clausius-Clapeyron equation. The net isosteric heat of sorption is inversely proportional to the equilibrium moisture content and is found to be an exponential function of moisture content

Individual differences in causal learning and decision making

This is an accepted author manuscript of an article subsequently published by Elsevier. The final published version can be found here: http://dx.doi.org/10.1016/j.actpsy.2005.04.003In judgment and decision making tasks, people tend to neglect the overall frequency of base-rates when they estimate the probability of an event; this is known as the base-rate fallacy. In causal learning, despite people s accuracy at judging causal strength according to one or other normative model (i.e., Power PC, DP), they tend to misperceive base-rate information (e.g., the cause density effect). The present study investigates the relationship between causal learning and decision making by asking whether people weight base-rate information in the same way when estimating causal strength and when making judgments or inferences about the likelihood of an event. The results suggest that people differ according to the weight they place on base-rate information, but the way individuals do this is consistent across causal and decision making tasks. We interpret the results as reflecting a tendency to differentially weight base-rate information which generalizes to a variety of tasks. Additionally, this study provides evidence that causal learning and decision making share some component processes

Photocatalytic reduction of Cr(VI) on the new hetero-system CuAl2O4/TiO2.

International audienceVisible light driven HCrO(4)(-) reduction was successfully achieved over the new hetero-system CuAl(2)O(4)/TiO(2). The spinel, elaborated by nitrate route, was characterized photo electrochemically. The optical gap was found to be 1.70 eV and the transition is directly allowed. The conduction band (-1.05 V(SCE)) is located below that of TiO(2), more negative than the HCrO(4)(-)/Cr(3+) level (+0.58 V(SCE)) yielding a thermodynamically feasible chromate reduction upon visible illumination. CuAl(2)O(4) is stable against photo corrosion by holes consumption reaction involving salicylic acid which favors the charges separation. There is a direct correlation between the dark adsorption and the photo activity. A reduction of more than 95% of chromate was achieved after 3 h irradiation at pH 2 with an optimal mass ratio (CuAl(2)O(4)/TiO(2)) equal to 1/3. The reduction follows a first order kinetic with a half life of ∼1 h and a quantum yield of 0.11% under polychromatic light. Prolonged illumination was accompanied by a deceleration of the Cr(VI) reduction thanks to the competitive water discharge. The hydrogen evolution, an issue of energetic concern, took place with a rate of 3.75 cm(3) (g catalyst)(-1) h(-1)

Anti-inflammatory activity of essential oil of an endemic Thymus fontanesii Boiss. & Reut. with chemotype carvacrol, and its healing capacity on gastric lesions

International audienceThe aim of the current study is to evaluate the anti-inflammatory effect of Thymus fontanesii with chemotype carvacrol and its gastroprotective effect against ethanol-induced gastric ulcer model by using the image analysis method by means of the ImageJ® software. The chemical composition of the essential oil was analyzed by gas chromatography/mass spectrometry and the acute toxicity was evaluated. The anti-inflammatory activity was assessed by two methods such the Carrageenan-induced paw edema in mouse at dose of 500 mg/kg and topical inflammation induced by 12-O-tetradecanoylphorbol-13-acetate at dose of 03 and 10 mg/ear. The antiulcer activity of the essential oil of the studied plant was assayed at dose of 250 and 500 mg/kg, by ethanol-induced gastric ulcer model in rats, showed a significant decrease of gastric lesion areas. The obtained results confirm the anti-inflammatory and the gastroprotective activity probably attributed to its main compound, carvacrol which support the traditionally uses of the studied plant. Practical applications: The Thymus fontanesii, which is an endemic plant to Algeria and Tunisia, is traditionally used in the treatment of inflammation and fever. This study revealed that the T. fontanesii essential oil with chemotype carvacrol possesses significant anti-inflammatory activity, side by side with the antiulcer activity as the Ethanol-induced gastric ulcer model showed a significant decrease of gastric lesion areas. Thus, it stands as a promising candidate for further investigations in this area. © 2017 Wiley Periodicals, Inc

Valorization of Inula viscosa waste extraction, modeling of isotherm, and kinetic for the tartrazine dye adsorption

International audienceThe aim of this study was the tartrazine dye removal from aqueous solutions using a solid waste from the essential oil extraction of Inula viscosa. Experiments carried out in batch mode showed that the adsorption depended on physical parameters such as pH, adsorbent dose, initial pollutant concentration, and temperature. The results of scanning electron microscopy and energy dispersion X-ray indicated that the potential to adsorb tartrazine dye onto I. viscosa was related to the adsorbent structure. The nature of the surface groups on the adsorbent was determined from the Fourier transform infrared spectroscopy and specific surface area. The dye retention was found to be pH-dependent and the tartrazine adsorption decreased with increasing pH over the pH range (1-6). The Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models were used to analyze the adsorption behavior. The maximum adsorption capacity was found to be ~43.1 mg g−1 at pH 2 and 298 K. Dye adsorption kinetic was well described by a pseudo-second-order model. The thermodynamic parameters indicated that the adsorption of tartrazine was spontaneous and endothermic, and the process was governed by physisorption owing to the low enthalpy. Therefore, I. viscosa is promising as a low-cost adsorbent for the dye removal from aqueous solutions

Richness of drilling sludge taken from an oil field quagmire: potentiality and environmental interest

International audienceThe drilling sludge represents a complex environment, containing several types of pollutants that can be even used as nutrients by indigenous microorganisms, like hydrocarbon-degrading bacteria, having good potentialities for the biodegradation of petroleum products. In this study, a drilling sludge was collected from drilling quagmire. Physicochemical characterization of the drilling sludge was done. Its mineralogy was obtained by diffractometry. The indigenous aerobic sludge hydrocarbon-degrading bacteria were checked by counting on Bushnell–Haas medium, and their isolation and purification were performed by the selective microbial enrichment technique in a batch-enriched Bushnell–Haas culture, with crude oil as the sole carbon source. Isolates were characterized, and their power to emulsify crude oil was determined by emulsification index and oil spreading tests. Environmental conditions in the quagmire, like temperature, pH and moisture, were suitable for bacterial development. Physicochemical characteristics of the drilling sludge showed richness in chemical elements and promote microbial life. Fifteen different colonies of hydrocarbon-degrading bacteria were isolated and purified; they have diversified morphological and microscopic aspects. Most isolates had a good emulsification index (between 31 and 76 %). Oil spreading test gave clear zone diameters >28 mm, with a maximum of 60 mm. The results of these investigations prove the elementary, mineralogy and microbiology richness of drilling sludge and reveal the high diversity of its indigenous hydrocarbon-degrading bacterial flora. These properties can be exploited for the own restoration of petroleum quagmires in oil fields, by means of bioremediation applications and by integrating indigenous microorganisms. © 2016, Islamic Azad University (IAU)