SEPARATION SCIENCE AND TECHNOLOGY, cilt.42, ss.2033-2047, 2007 (SCI İndekslerine Giren Dergi)
In this study, the ion exchange of metal ions (Al3+, La3+ and ZrO2+) on modified zeolites was carried out using batch method. Fluoride removal from water using Al3+-, La3+- and ZrO2+- exchanged zeolite was subsequently investigated to evaluate the fluoride sorption characteristics of the sorbents. Natural zeolite samples (<45 mu m) were pre-conditioned with HNO3 solution (ZEO-1), NaNO3 solution (ZEO-2), and deionized water (ZEO-3) before loading Al3+, La3+, and ZrO2+ on zeolite. ZEO-1 type zeolite had a higher capacity than ZEO-2 and ZEO-3 type zeolites. Metal exchange capacities are 0.233, 0.089, 0.090 mmol/g for ZrO2+-, La3+-, and Al3+- exchanged zeolite (ZEO-1), respectively. Equilibrium isotherms fitted well to Langmuir and Freundlich models. Percent removal of fluoride from aqueous solution containing 2.5 mg F/L was 94% using metal loaded zeolite (ZEO-1 type) at an adsorbent concentration of 6.00 g/L.