Fuel, Vol.215, 499-505, 2018
Zeolite-hydroxyapatite-activated oil palm ash composite for antibiotic tetracycline adsorption
Mesoporous zeolite-hydroxyapatite-activated palm ash (Z-HAP-AA) composites were synthesized through hydrothermal method using different ratios of oil palm ash and electric arc furnace (EAF) steel slag under alkaline conditions. Structural properties of the synthesized materials were studied by various characterization techniques. Ca/P = 1.667 and SiO2/Al2O3 = 3, characteristic to hydroxyapatite and zeolite-X respectively were obtained. Increase in activated oil palm ash ratio during synthesis resulted in increased surface area of Z-HAP-AA composite due to increase in carbon component. Among various synthesized composites Z-HAP-AA-1:3 was selected as best adsorbent for tetracycline. Adsorption performance of Z-HAP-AA-1: 3 was examined for tetracycline removal in batch process with respect to initial tetracycline concentration (50-400 mg/L), temperature (30-50 degrees C) and pH (3-1 3). Best representation of data was obtained by the Freundlich model. Maximum monolayer adsorption capacity of Z-HAP-AA for tetracycline at 30 degrees C, 40 degrees C and 50 degrees C was 186.09 mg/g, 212.56 mg/g, and 244.63 mg/g respectively.