This study focused on two woody leafy vegetables Leptadenia hastata Decne and Senna obtusifolia Link, commonly consumed in Senegal. Leaves were col-lected from three regions. Then, proximate analyses and micronutrient...This study focused on two woody leafy vegetables Leptadenia hastata Decne and Senna obtusifolia Link, commonly consumed in Senegal. Leaves were col-lected from three regions. Then, proximate analyses and micronutrients were carried out to evaluate their nutritional values. Results revealed that protein level of S. obtusifolia (SO) is richer (21.75%) than Leptadenia hastata (LH) (18.16%). The cellulose and carbohydrate contents of the two vegetable’s leaves are in the same order except those of LH from Widou which are less rich in cellulose (8.31%) and richest in carbohydrate (6.35%). These leaves are also good sources of various mineral elements and especially iron. Leaves of LH appear to be richer in iron and magnesium, while SO appears to be richer in calcium. Vitamin C intakes of SO leaves are better than those of LH and respectively range from 142 to 196.5 and 22.5 to 159.5 mg/100 g. According to the use of this leafy vegetable by the populations, a domestication opportunity is thus justified to ensure availability and accessibility of these significant sources of micronutrients.展开更多
In this work, an inexpensive and environmentally friendly natural adsorbent obtained from shelled (GD) and unshelled (GND) </span><span style="font-family:""><i></span><i>&...In this work, an inexpensive and environmentally friendly natural adsorbent obtained from shelled (GD) and unshelled (GND) </span><span style="font-family:""><i></span><i><span style="font-family:"">Moringa oleifera</span></i><i><span style="font-family:""></i></span></i><i><span style="font-family:""> </span></i><span style="font-family:"">seeds was used for copper adsorption from aqueous solutions. A series of experiments were performed to assess the parameters influencing the adsorption pheno<span>menon such as pH, adsorbent mass, adsorption equilibrium time and</span> temper<span>ature. The kinetic results of adsorption described a pseudo-second order</span> mod<span>el. The adsorption isotherms are satisfactorily described by the Langmuir</span> mathematical model. The thermodynamic data revealed a spontaneous and endothermic adsorption phenomenon. The level of copper in surface water be<span>fore and after addition of moringa powders was carried out to verify the effectiveness of the adsorbent. A maximum adsorption rate of 51.28% and </span>61.96% was obtained with GD and GND powders respectively. </span><span style="font-family:""><i></span><i><span style="font-family:"">Moringa oleifera</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> seed powders are an effective alternative for the removal of copper from surface water.展开更多
<i><span style="font-family:;" "=""><i></i></span><i><span style="font-family:;" "="">Moringa oleifera</span></i>...<i><span style="font-family:;" "=""><i></i></span><i><span style="font-family:;" "="">Moringa oleifera</span></i><i><span style="font-family:;" "=""></span></i></i><span style="font-family:;" "=""> is an edible plant cultivated throughout the tropical belt. It belongs to the family Moringaceae and is one of its 14 known species. This paper presents a synthesis of the main factors responsible for the retention of trace metal elements (TMEs) by </span><span style="font-family:;" "=""><i></i></span><i><i><span style="font-family:;" "="">Moringa oleifera</span></i><i><span style="font-family:;" "=""></span></i></i><span style="font-family:;" "=""> seed powder, a natural adsorbent. The five main factors studied are metal concentration, solution pH, adsorbent particle size, adsorbent dose and adsorbent/adsorbate contact time. Through these factors, we present the optimal conditions for removal of these TMEs, as well as adsorption isotherm models appropriate for the conditions of retention of these metal cations by the adsorbent. The times of 20 min (GD) and 50 min (GND) are the equilibrium times obtained in our study. An optimal adsorbent mass (GD and GND powders) of 4.5 g was found. 20</span><span style="font-family:;" "="">%</span><span style="font-family:;" "=""> to 97% abatement is observed for average pH values between 6 and 8. The coefficients of determination (R2) obtained (0.972</span><span style="font-family:;" "="">,</span><span style="font-family:;" "=""> 0.963</span><span style="font-family:;" "="">,</span><span style="font-family:;" "=""> 0.991 and 0.799) during the isotherm experiments carried out at 20</span><span style="font-family:;" "="">°</span><span style="font-family:;" "="">C, 30</span><span style="font-family:;" "="">°</span><span style="font-family:;" "="">C, 40</span><span style="font-family:;" "="">°</span><span style="font-family:;" "="">C and 50</span><span style="font-family:;" "="">°</span><span style="font-family:;" "="">C are close to 1. Also, the separation factor (R<sub>L</sub>), an essential characteristic of the Langmuir isotherm whose values are between 0 and 1, attest to the applicability of the Langmuir isotherm model to fit the experimental data of copper adsorption by Moringa powders.</span><span style="font-family:;" "=""> In this paper, we are particularly interested in the following TMEs (Mn, Ni, Cr, Cu, Cd, Co, Pb, Fe, Zn, Ag).</span>展开更多
Iodization of dietary salt is recommended to prevent and control iodine deficiency disorders. The kinetic study of dietary iodized salt proves to be of interest not only for the determination of the conditions of prod...Iodization of dietary salt is recommended to prevent and control iodine deficiency disorders. The kinetic study of dietary iodized salt proves to be of interest not only for the determination of the conditions of production of iodine, but also for a good knowledge of the kinetic and thermodynamic parameters of the reaction. In this work, two salt brands were studied and one of them was used for the kinetic study. The kinetic study showed that the reaction proceeded slowly at a medium rate. Since the reaction admits a global order equal to 1, potassium iodide has no influence on this reaction rate. The concentration of iodate ions introduced in the dietary salt is a kinetic parameter that affects the reaction rate. Calculated rate constant was inversely proportional to time. The study has therefore determined experimentally kinetic parameters of the reaction between iodate and iodide ions.展开更多
文摘This study focused on two woody leafy vegetables Leptadenia hastata Decne and Senna obtusifolia Link, commonly consumed in Senegal. Leaves were col-lected from three regions. Then, proximate analyses and micronutrients were carried out to evaluate their nutritional values. Results revealed that protein level of S. obtusifolia (SO) is richer (21.75%) than Leptadenia hastata (LH) (18.16%). The cellulose and carbohydrate contents of the two vegetable’s leaves are in the same order except those of LH from Widou which are less rich in cellulose (8.31%) and richest in carbohydrate (6.35%). These leaves are also good sources of various mineral elements and especially iron. Leaves of LH appear to be richer in iron and magnesium, while SO appears to be richer in calcium. Vitamin C intakes of SO leaves are better than those of LH and respectively range from 142 to 196.5 and 22.5 to 159.5 mg/100 g. According to the use of this leafy vegetable by the populations, a domestication opportunity is thus justified to ensure availability and accessibility of these significant sources of micronutrients.
文摘In this work, an inexpensive and environmentally friendly natural adsorbent obtained from shelled (GD) and unshelled (GND) </span><span style="font-family:""><i></span><i><span style="font-family:"">Moringa oleifera</span></i><i><span style="font-family:""></i></span></i><i><span style="font-family:""> </span></i><span style="font-family:"">seeds was used for copper adsorption from aqueous solutions. A series of experiments were performed to assess the parameters influencing the adsorption pheno<span>menon such as pH, adsorbent mass, adsorption equilibrium time and</span> temper<span>ature. The kinetic results of adsorption described a pseudo-second order</span> mod<span>el. The adsorption isotherms are satisfactorily described by the Langmuir</span> mathematical model. The thermodynamic data revealed a spontaneous and endothermic adsorption phenomenon. The level of copper in surface water be<span>fore and after addition of moringa powders was carried out to verify the effectiveness of the adsorbent. A maximum adsorption rate of 51.28% and </span>61.96% was obtained with GD and GND powders respectively. </span><span style="font-family:""><i></span><i><span style="font-family:"">Moringa oleifera</span></i><i><span style="font-family:""></i></span></i><span style="font-family:""> seed powders are an effective alternative for the removal of copper from surface water.
文摘<i><span style="font-family:;" "=""><i></i></span><i><span style="font-family:;" "="">Moringa oleifera</span></i><i><span style="font-family:;" "=""></span></i></i><span style="font-family:;" "=""> is an edible plant cultivated throughout the tropical belt. It belongs to the family Moringaceae and is one of its 14 known species. This paper presents a synthesis of the main factors responsible for the retention of trace metal elements (TMEs) by </span><span style="font-family:;" "=""><i></i></span><i><i><span style="font-family:;" "="">Moringa oleifera</span></i><i><span style="font-family:;" "=""></span></i></i><span style="font-family:;" "=""> seed powder, a natural adsorbent. The five main factors studied are metal concentration, solution pH, adsorbent particle size, adsorbent dose and adsorbent/adsorbate contact time. Through these factors, we present the optimal conditions for removal of these TMEs, as well as adsorption isotherm models appropriate for the conditions of retention of these metal cations by the adsorbent. The times of 20 min (GD) and 50 min (GND) are the equilibrium times obtained in our study. An optimal adsorbent mass (GD and GND powders) of 4.5 g was found. 20</span><span style="font-family:;" "="">%</span><span style="font-family:;" "=""> to 97% abatement is observed for average pH values between 6 and 8. The coefficients of determination (R2) obtained (0.972</span><span style="font-family:;" "="">,</span><span style="font-family:;" "=""> 0.963</span><span style="font-family:;" "="">,</span><span style="font-family:;" "=""> 0.991 and 0.799) during the isotherm experiments carried out at 20</span><span style="font-family:;" "="">°</span><span style="font-family:;" "="">C, 30</span><span style="font-family:;" "="">°</span><span style="font-family:;" "="">C, 40</span><span style="font-family:;" "="">°</span><span style="font-family:;" "="">C and 50</span><span style="font-family:;" "="">°</span><span style="font-family:;" "="">C are close to 1. Also, the separation factor (R<sub>L</sub>), an essential characteristic of the Langmuir isotherm whose values are between 0 and 1, attest to the applicability of the Langmuir isotherm model to fit the experimental data of copper adsorption by Moringa powders.</span><span style="font-family:;" "=""> In this paper, we are particularly interested in the following TMEs (Mn, Ni, Cr, Cu, Cd, Co, Pb, Fe, Zn, Ag).</span>
文摘Iodization of dietary salt is recommended to prevent and control iodine deficiency disorders. The kinetic study of dietary iodized salt proves to be of interest not only for the determination of the conditions of production of iodine, but also for a good knowledge of the kinetic and thermodynamic parameters of the reaction. In this work, two salt brands were studied and one of them was used for the kinetic study. The kinetic study showed that the reaction proceeded slowly at a medium rate. Since the reaction admits a global order equal to 1, potassium iodide has no influence on this reaction rate. The concentration of iodate ions introduced in the dietary salt is a kinetic parameter that affects the reaction rate. Calculated rate constant was inversely proportional to time. The study has therefore determined experimentally kinetic parameters of the reaction between iodate and iodide ions.