Fluoride Adsorption By Chlorine Doped Polyaniline In Continuous Column Mode Operation

Abstract

This study focuses on optimisation of pH for fluoride uptake by adsorbent polymer polyaniline doped with chloride and synthesised on surface of jute fiber (PANI-Cl-Jute) in continuous column mode operation. At reactor bed depth of 1.5 m, flowrate of 1.2 mL/min and initial fluoride concentration of 5 mg/L, the breakthrough time at pH 1, 2, 4 and 6 were 11, 7, 5 and 1 hour respectively suggesting favourable adsorption at acidic pH. On characterized with Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Measurements (EDAX), F- uptake by PANI-Cl-jute was confirmed. Total amount of ions adsorbed at different bed depth of 1.5, 2 and 3 m yields and F- uptake of 11.87, 15.85 and 26.53 mg respectively thus amounting an average uptake of 0.07 mg F-/g PANI-Cl-jute against a higher uptake of 12.99 mg/g in batch mode studies. The formation of mass transfer zone in continuous mode unlike adsorption equilibrium in batch mode is the main reason for lower uptake in continuous column mode operation. However a throughput volume of 620 mL was able to achieve under the study condition with F- below the permissible limit suggesting the effective adsorption of F- by PANI-Cl-jute.