naa a22 4500 51075175X CHVBK 20180411083107.0 cr unu---uuuuu 180411e20130501xx s 000 0 eng 10.1007/s11270-013-1552-y doi (NATIONALLICENCE)springer-10.1007/s11270-013-1552-y Defluoridation of Groundwater Using Termite Mound [Elektronische Daten] [Fekadu Fufa, Esayas Alemayehu, Bernd Lennartz] High concentration of fluoride in groundwater is a longstanding health problem. Fluoride adsorption capacity of termite mound (TM), containing mainly silicon, aluminum, iron, and titanium oxides, was investigated under a batch adsorption system. The influence of parameters such as contact time, solution pH, adsorbent dose, initial fluoride concentration, and the presence of competing anions was investigated. Equilibrium was achieved within 10min of agitation time. A high percentage (~90%) of fluoride removal was obtained in a wide pH range 3-8, which is important in the practical application. Kinetics data followed the pseudo-second-order model (R 2 > 0.99). The Dubinin-Radushkevich isotherm described most satisfactorily (R 2 = 0.968, χ 2 = 0.09) the equilibrium adsorption, giving a sorption capacity of 2.70mg/g. The obtained mean free energy (E DR = 11.62kJ/mol) suggested that chemisorption should be mainly responsible for fluoride adsorption. Fluoride removal was significantly decreased in the presence of carbonate and phosphate ions, whereas slightly increased in the presence of chloride, nitrate, and sulfate. The adsorbent reduced 7.56mg/L fluoride content of groundwater to below 1.5mg/L. The fluoride-loaded TM was successfully regenerated using calcined eggshell or NaOH solution with insignificant loss of metals. The adsorption efficiency of the regenerated TM was comparable to the fresh TM. The results obtained from this study could provide important information for evaluating the application of TM for defluoridation. Springer Science+Business Media Dordrecht, 2013 Calcined eggshell nationallicence Equilibrium nationallicence Kinetics nationallicence Regenerable adsorbent nationallicence Fufa Fekadu Faculty of Agricultural and Environmental Sciences, Rostock University, Justus-Von-Liebig-Weg 6, 18059, Rostock, Germany aut Alemayehu Esayas Jimma Institute of Technology, Jimma University, Jimma, Oromia, Ethiopia aut Lennartz Bernd Faculty of Agricultural and Environmental Sciences, Rostock University, Justus-Von-Liebig-Weg 6, 18059, Rostock, Germany aut Water, Air, & Soil Pollution Springer Netherlands 224/5(2013-05-01), 1-15 0049-6979 224:5<1 2013 224 11270 https://doi.org/10.1007/s11270-013-1552-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11270-013-1552-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fufa Fekadu Faculty of Agricultural and Environmental Sciences, Rostock University, Justus-Von-Liebig-Weg 6, 18059, Rostock, Germany aut NATIONALLICENCE 700 1- Alemayehu Esayas Jimma Institute of Technology, Jimma University, Jimma, Oromia, Ethiopia aut NATIONALLICENCE 700 1- Lennartz Bernd Faculty of Agricultural and Environmental Sciences, Rostock University, Justus-Von-Liebig-Weg 6, 18059, Rostock, Germany aut NATIONALLICENCE 773 0- Water, Air, & Soil Pollution Springer Netherlands 224/5(2013-05-01), 1-15 0049-6979 224:5<1 2013 224 11270 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer