Fluoride removal from water using ceramic based adsorbent prepared from spent mosquito repellent liquid vaporiser rods

Abstract

ABSTRACT A new adsorbent has been tested which is prepared from the recycled material for the fluoride removal from water. The spent mosquito repellent liquid vaporiser rod/wick has been collected and carbonised to cleanse from any other substance already present on it. The need for low cost, easy maintenance and capacity to remove impurities even at low concentration inspired to use these recyclable ceramic rods. Fluoride adsorption characteristics were studied in the batch system. Effects of parameters like potential of H+, stirring speed, adsorbent dose, contact time and also initial F¯ ions concentration were tested. Optimum conditions for experimental data revealed that the adsorbent showed maximum F¯ ions removal of 80% at 5 mg/L F¯ concentration at pH 7. At stirring speed of 300 rpm, 8 g/L adsorbent dose and 180 minutes maximum F¯ ions removal was observed and remained constant even after increment in parameters. Langmuir and Freundlich isotherms were interpreted from the data for fluoride removal and maximum adsorption capacity of 16.69 mg/g was obtained from Langmuir isotherm. The adsorbent prepared has obeyed the Freundlich isotherm more than Langmuir. In addition to this, in kinetic studies it has been found that adsorption reaction followed pseudo-second order reaction kinetics. Several advantages of ceramics enhance adsorbent as effective medium i.e. granular structure, more surface area along with cost effective preparation from rods.