| Abstrakt: |
Lithium extraction from geothermal brines has recently become a strong interest due to the large volume of lithium resources in over 2000 geothermal wells and hot springs worldwide. This article discusses the adsorption behavior of lithium contained in local geothermal brine water originating from the Ciseeng geothermal field in Bogor Regency, West Java Province of Indonesia, by Amberlite IR-120 Na resin. The lithium uptake and the selectivity of lithium adsorption by Amberlite IR 120 Na resin towards alkaline and alkaline earth elements contained in the geothermal brine samples, the equilibrium behavior, and adsorption kinetics were studied. The experimental results show that lithium adsorption increased by the increase in contact time of brine water and Amberlite IR 120 in 4-day continuous adsorption and reached a maximum level at day-3 to 0.0356 mmol/g Li. Li adsorption decreased after day-3, indicating that the Li adsorption had reached an equilibrium state at day-3. The highest adsorption recovery during 4-day continuous adsorption is exhibited by K, followed by Li, Na, Ca, and Mg. Considering a low adsorption percentage of Li (maximum 36.6%) but still higher than that of Ca, Mg, and Na, the adsorption parameters are still to be improved. Linear fitting of the experimental data on the four different isotherm adsorption models indicated that the lithium adsorption from Ciseeng brine fit mostly with Freundlich and Temkin model with an adsorption capacity of the Amberlite IR 120 of 0.051 mg/g. Based on the linear fitting procedure of the experimental data to four different kinetics models, the lithium adsorption from Ciseeng brine onto Amberlite resin follows the Elovich kinetic model (R2 = 0.986), which indicates the dominant chemisorption mechanism in the lithium adsorption process. [ABSTRACT FROM AUTHOR] |
