The aim of the present work is the removal of phenol by adsorption on a raw and activated crude or hard coal (C) with NaOH, ZnCl2 and H3PO4 in the region of Bechar (south-western Algeria). The development of adsorbent...The aim of the present work is the removal of phenol by adsorption on a raw and activated crude or hard coal (C) with NaOH, ZnCl2 and H3PO4 in the region of Bechar (south-western Algeria). The development of adsorbents from precursors is inexpensive, requiring innovative techniques using concepts developed relevant to the physical handling, processing physical and chemical activation of coal into an activated coal, with the ability of fixing aromatic organic pollutants, namely phenol. The maximum surface area obtained from the activation with ZnCl2, H3PO4 and NaOH were 1000, 850 and 3000 m2 / g, respectively. The results clearly showed that hard coal activation greatly improved phenol fixing. The rate of phenol adsorption by activated hard coal is much higher than those obtained from raw coal through its holding capacity. Activated carbon porosity with NaOH is much higher than those obtained from coal activated by ZnCl2 and H3PO4. Activated coal can be an effective means of confinement in industrial disposal sites, avoiding migration of organic pollutants contained in these wastes to groundwater via the adsorption phenomenon. The development of such effective barriers, based on local resources can help solve the problem of water contamination.展开更多
Recently, lanthanum oxide doped by group IIA elements may strongly influence solid state reaction. A series of samples, noted LaSrX (where X = % atomic of strontium) have been prepared by hydrolysis, in neutral medium...Recently, lanthanum oxide doped by group IIA elements may strongly influence solid state reaction. A series of samples, noted LaSrX (where X = % atomic of strontium) have been prepared by hydrolysis, in neutral medium from La2O3 and SrCO3. These samples were calcined under air at 450?C and 1150?C then characterized by specific surface area (BET), X-ray diffraction, scanning electron microscopy (SEM), thermogravimetry (TG) and differential thermal analysis (DTA). Obtained results show that after calcinations at: 1) 450?C, the addition of strontium is without effect on surface of La2O3 and the XRD analysis revealed no interaction between lanthanum oxide and strontium carbonate;2) 1150?C, the sintering of the samples is very important, reduction of 70% of surfaces compared to the samples calcined at 450?C;XRD results show that LaSrX are formed principally by two oxides: SrLa2O4 and La2O3, which is confirmed by SEM method. The reaction between La2O3 and SrCO3 showed three endothermic weight losses;elimination of water, a partial dehydroxylation of La(OH)3 and formation of La2O2CO3 and La2(CO3)3.展开更多
文摘The aim of the present work is the removal of phenol by adsorption on a raw and activated crude or hard coal (C) with NaOH, ZnCl2 and H3PO4 in the region of Bechar (south-western Algeria). The development of adsorbents from precursors is inexpensive, requiring innovative techniques using concepts developed relevant to the physical handling, processing physical and chemical activation of coal into an activated coal, with the ability of fixing aromatic organic pollutants, namely phenol. The maximum surface area obtained from the activation with ZnCl2, H3PO4 and NaOH were 1000, 850 and 3000 m2 / g, respectively. The results clearly showed that hard coal activation greatly improved phenol fixing. The rate of phenol adsorption by activated hard coal is much higher than those obtained from raw coal through its holding capacity. Activated carbon porosity with NaOH is much higher than those obtained from coal activated by ZnCl2 and H3PO4. Activated coal can be an effective means of confinement in industrial disposal sites, avoiding migration of organic pollutants contained in these wastes to groundwater via the adsorption phenomenon. The development of such effective barriers, based on local resources can help solve the problem of water contamination.
文摘Recently, lanthanum oxide doped by group IIA elements may strongly influence solid state reaction. A series of samples, noted LaSrX (where X = % atomic of strontium) have been prepared by hydrolysis, in neutral medium from La2O3 and SrCO3. These samples were calcined under air at 450?C and 1150?C then characterized by specific surface area (BET), X-ray diffraction, scanning electron microscopy (SEM), thermogravimetry (TG) and differential thermal analysis (DTA). Obtained results show that after calcinations at: 1) 450?C, the addition of strontium is without effect on surface of La2O3 and the XRD analysis revealed no interaction between lanthanum oxide and strontium carbonate;2) 1150?C, the sintering of the samples is very important, reduction of 70% of surfaces compared to the samples calcined at 450?C;XRD results show that LaSrX are formed principally by two oxides: SrLa2O4 and La2O3, which is confirmed by SEM method. The reaction between La2O3 and SrCO3 showed three endothermic weight losses;elimination of water, a partial dehydroxylation of La(OH)3 and formation of La2O2CO3 and La2(CO3)3.
