23 DOI: https://doi.org/10.1016/j.emcon.2016.03.002 English eng A. Elhalil Contributor <p><span style="margin: 0px; padding: 0px; color: rgb(31, 31, 31); font-family: ElsevierGulliver, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif, sans-serif; font-size: 16px;"><span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px;">The present study evaluated calcined Mg/Al <a href="https://www.sciencedirect.com/topics/materials-science/layered-double-hydroxides" class="topic-link" style="margin: 0px; padding: 0px; color: rgb(31, 31, 31); --sd-arp-topic-annotations-text-colour: #1f1f1f; --sd-arp-topic-annotations-hover-text-decoration-colour: #eb6500; --sd-arp-topic-annotations-focus-outline-colour: #eb6500; text-decoration: underline 1px rgb(31, 31, 31); text-underline-offset: 1px;">layered double hydroxide</a> (CLDH) availability for the removal of fluoride from local groundwaters. The Mg/Al layered double hydroxide (LDH) was synthesized by co-precipitation method and characterized by </span><a href="https://www.sciencedirect.com/topics/materials-science/x-ray-powder-diffraction" class="topic-link" style="margin: 0px; padding: 0px; color: rgb(31, 31, 31); --sd-arp-topic-annotations-text-colour: #1f1f1f; --sd-arp-topic-annotations-hover-text-decoration-colour: #eb6500; --sd-arp-topic-annotations-focus-outline-colour: #eb6500; text-decoration: underline 1px rgb(31, 31, 31); text-underline-offset: 1px;">XRD</a>, FT-IR and TGA-TDA analyses. Batch defluoridation experiments were performed under various conditions such as </span><a href="https://www.sciencedirect.com/topics/materials-science/calcination" class="topic-link" style="margin: 0px; padding: 0px; color: rgb(31, 31, 31); --sd-arp-topic-annotations-text-colour: #1f1f1f; --sd-arp-topic-annotations-hover-text-decoration-colour: #eb6500; --sd-arp-topic-annotations-focus-outline-colour: #eb6500; text-decoration: underline 1px rgb(31, 31, 31); text-underline-offset: 1px;">calcination</a><span style="margin: 0px; padding: 0px;">, solution pH, contact time, temperature, material dosage and reuse. Experimental results indicate that fluoride removal strongly increased after <a href="https://www.sciencedirect.com/topics/chemical-engineering/calcination" class="topic-link" style="margin: 0px; padding: 0px; color: rgb(31, 31, 31); --sd-arp-topic-annotations-text-colour: #1f1f1f; --sd-arp-topic-annotations-hover-text-decoration-colour: #eb6500; --sd-arp-topic-annotations-focus-outline-colour: #eb6500; text-decoration: underline 1px rgb(31, 31, 31); text-underline-offset: 1px;">calcination</a> of the LDH up to 600 °C. The maximum fluoride removal was obtained at solution pH of 6.85. Kinetics of fluoride removal followed the pseudo-second order </span></span><a href="https://www.sciencedirect.com/topics/engineering/kinetic-model" class="topic-link" style="margin: 0px; padding: 0px; color: rgb(31, 31, 31); --sd-arp-topic-annotations-text-colour: #1f1f1f; --sd-arp-topic-annotations-hover-text-decoration-colour: #eb6500; --sd-arp-topic-annotations-focus-outline-colour: #eb6500; text-decoration: underline 1px rgb(31, 31, 31); text-underline-offset: 1px;">kinetic model</a><span style="margin: 0px; padding: 0px;">. The rise in solution temperature strongly enhances the removal efficiency. The adsorption mechanism involved surface adsorption, ion exchange interaction and original LDH structure reconstruction by rehydration of mixed <a href="https://www.sciencedirect.com/topics/materials-science/metal-oxide" class="topic-link" style="margin: 0px; padding: 0px; color: rgb(31, 31, 31); --sd-arp-topic-annotations-text-colour: #1f1f1f; --sd-arp-topic-annotations-hover-text-decoration-colour: #eb6500; --sd-arp-topic-annotations-focus-outline-colour: #eb6500; text-decoration: underline 1px rgb(31, 31, 31); text-underline-offset: 1px;">metal oxides</a> and concomitant intercalation of fluoride ions into the interlayer region. The optimum dosages required to meet the national standard for </span></span><a href="https://www.sciencedirect.com/topics/materials-science/potable-water" class="topic-link" style="margin: 0px; padding: 0px; color: rgb(31, 31, 31); --sd-arp-topic-annotations-text-colour: #1f1f1f; --sd-arp-topic-annotations-hover-text-decoration-colour: #eb6500; --sd-arp-topic-annotations-focus-outline-colour: #eb6500; text-decoration: underline 1px rgb(31, 31, 31); text-underline-offset: 1px; font-family: ElsevierGulliver, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif, sans-serif; font-size: 16px;">drinking water</a><span style="color: rgb(31, 31, 31); font-family: ElsevierGulliver, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif, sans-serif; font-size: 16px;"> quality were found to be 0.29 and 0.8 g/L, respectively, for Bejaad and Settat goundwaters. A decrease in the fluoride uptake with increasing the number of regeneration cycles was observed.</span></p> Elsevier March 2016 pdf Emerging Contaminants Defluoridation of groundwater by calcined Mg/Al layered double hydroxide mixed material Elsevier