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This work reports the study of the adsorption of malachite green (MG) dye on Moroccan clay according to different parameters impacting the adsorption phenomenon, such as pH, the temperature of the medium and the MG dye concentration. The clay used as adsorbent was initially characterized by X-ray fluorescence spectrometry, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction, Brunauer-Emmett-Teller, and thermogravimetric analysis. The results indicate that the equilibrium of MG adsorption is reached in 90 min. The efficiency of dye removal on clay increases with the contact time, initial dye concentration, solution temperature and pH. The experimental data obtained were examined using isothermal and kinetic models based on the errors calculated values of R² (correlation coefficient) and χ² (chi-square). It was found that the nonlinear forms of the Langmuir isotherm and the pseudo-second-order kinetic model are the best-fitting with experimental data. The thermodynamic study showed that the adsorption was a spontaneous and exothermic process. However, FTIR analysis of the adsorbent, before and after MG adsorption, shows that the mechanism of MG adsorption occurs through the phenomenon of chemical interaction between the adsorbate and the adsorbent. [ABSTRACT FROM AUTHOR]

In Morocco, wastewater is continuously discharged without pretreatment downstream of urban centers and widely reused in agricultural irrigation, especially where water resources are limited and soils are deficient in organic matter. This constitutes a potential risk for the health of the population. Thus, this work has set as an objective to calculate the cost of damage caused by waterborne diseases in order to estimate how much they weigh (monetary burden) on one of the largest perimeters of Morocco where the reuse of raw wastewater is very responsive (Meknes, Khemisset, Tiflet and Sidi Allal El Bahraoui). For this purpose, we opted for a meso-economic analysis that would provide aid to public health policy decisions in a given region. To calculate the cost of damage caused by waterborne diseases in the provinces of Meknes and Khemisset, the same method used by the World Bank and the World Health Organization (WHO) in 2001 was used: Cost of damage caused by waterborne diseases = Cost of treatment (direct cost) + Cost of time spent caring for sick children (indirect cost). Then we compared the cost of damage caused by waterborne diseases with the cost of wastewater treatment in the two provinces. The results obtained clearly show that waterborne diseases are a real health problem, and weigh heavily on both provinces, particularly in the province of Meknes, despite the decrease in their incidence over time. The monetary quantification of the damage caused by waterborne diseases cannot be completely accurate because of the under-reporting of cases (the use of traditional medicine which escapes any reporting system. [ABSTRACT FROM AUTHOR]

In Algeria, Data and studies on the non-metal trace element selenium (Se) are presently lacking, therefore, the aim of this investigation is to provide new data on (Se) element via its determination for the first time from Mentha pulegium L. plant. The plant samples were collected in summer of 2012 from Ain-Oussera region, Djelfa province, Algeria; they were dried and powdered. After the neutron irradiation, the samples were digested using high oxidative reagents including H 2 SO 4 , HNO 3 , H 2 O 2 and HCl. The end of this process gave two phases, organic and aqueous discard phase. By using a separating funnel, the organic phase was transferred into a vial in order to measure their induce radionuclide 75Se using gamma-ray spectrometer. A non-chromatographic and sensitive analytical technique RNAA (Radiochemical Neutron Activation Analysis), was applied in this investigation due to its great significant minor systematic error. Results were determined using two distinguish calculation methods, relative-RNAA and k 0 -RNAA, the findings were quite significant, whereas, the average separation yield was about 85% for both calculation methodologies. Moreover, (Se) concentration obtained from M. pulegium L., is close to the minimal FAO (Food and Agriculture Organization of the United Nations) recommended consumption. • A non-chromatographic Radiochemical Neutron Activation Analysis was achieved for the separation of selenium. • The average separation yield was ranging between 84% and 87% for both calculation methods. • The trace element selenium has attracted attention because of its impact on human health. • The mean concentration obtained from M. pulegium L. leaves, is close to the minimal FAO recommendation. [ABSTRACT FROM AUTHOR]

This study aims at investigating the use of abundant materials such as clay and pomace olive in the preparation of tubular membranes. The use of olive pomace as a porosity agent produces a porous clay tubular membrane with controlled microstructure (porosity and pore size). The raw materials were characterized by physicochemical methods, namely X-ray fluorescence, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TGA/DTA) and scanning electron microscopy (SEM). These techniques show that the studied clay consists essentially of quartz; calcite and kaolinite. Tubular membranes made from a mixture of clay / X% (0, 4, 6, 8, 10 and 12 %) by weight of olive pomace were prepared by extrusion and sintered at different temperatures (700, 800, 900 and 1000 °C).The results obtained show that the sintered tubular membranes at 1000 °C are characterized by range value of shrinkage is 0.75–3.94 %, apparent porosity of 5.5–41 % and the reduced bending strength from 23.26 to 7 MPa depending on the olive pomace content. The pore structure was analyzed by SEM and the chemical resistance tests were performed in a sodium hydroxide solution and a nitric acid solution; they have better chemical resistance to alkalis but less resistance to acids. These results allow to conclude that the tubular membranes containing 8 % of olive pomace are promising porous ceramic structure for wastewaters filtration applications due to their excellent properties. [ABSTRACT FROM AUTHOR]

A versatile gamma ionization chamber (VGIC) has been designed, developed and characterized, in order to study experimentally its characteristics according to the geometry of the electrodes, the volume and pressure of the filler gas for the design of a gamma sealed chamber. The tests were conducted under the IEC (International Electro-technical Commission). The results obtained in various nuclear tests of the characterization and calibration of the ionization chamber gamma VGIC developed at our laboratory were presented in this paper. Three irradiators were operated, irradiator intensive gamma (60Co: 1.25 MeV), medium intensive gamma (137Cs: 0.662 MeV) and low-intensity gamma (60Co). Saturation curves and linearity were identified and the operating range and the sensitivity of the chamber have been deducted. The current, voltage (I,V) characteristics of the chamber filled, with argon gas at 0.4 M pa pressure, for gamma ray irradiator sources were studied, the chamber was irradiated with gamma rays using different gamma sources. The plateau region is reached above 200 V and the detector operating voltage is found to be 600V. It is observed that in the plateau region the slope is constant with an increase in the exposure rate. The (1/I, 1/V) and (I, l/V2) characteristic curves reveal the presence of the initial and volume recombination losses. The volume recombination losses are found to be smaller than the initial recombination losses. • A versatile gamma ionization chamber (VGIC) has been designed, developed and characterized. • The exprimantal tests were conducted under the IEC (International Electro-technical Commission). • The current, voltage (I,V) characteristics of a VGIC have been studied • Three irradiators were operated, irradiator intensive gamma (60Co: 1.25 MeV), medium intensive gamma (137Cs: 0.662 MeV) and low-intensity gamma (60Co) [ABSTRACT FROM AUTHOR]