Preparation of activated aluminum-coated basalt fiber mat for defluoridation from drinking water

Abstract

Alumina/basalt fiber mat composite (ABFMC) was fabricated by loading activated alumina (AA) on basalt fiber mat (BFM) via sol–gel method for fluoride removal. ABFMC and AA were characterized, and their performance for fluoride removal from aqueous solution was evaluated at different initial fluoride concentration and contact time. The loading capacity of AA on BFM increased with the increase in the sol viscosity, and the sol viscosity was optimized at 3.9 mPa s, whose corresponding loading percentage was 60.25 %. The results from the present study exhibit that ABFMC has shown good adsorption capacity for fluoride removal from aqueous solution. Experimental data revealed that the fluoride sorption on ABFMC was rapid, and 98.7 % fluoride removal was achieved within 30 min, whereas they were 96.8 % and 60 min in case of AA, respectively. The fluoride absorbed of ABFMC is well compared with that of most conventional materials and AA. The maximum of fluoride adsorbed on ABFMC was 1.872 mg/g. Adsorption isotherm analyses indicate that the adsorption of fluoride on ABFMC could be best described with the Langmuir isotherm, which suggested that the fluoride may create a monolayer layer on ABFMC. The adsorption kinetics was best described by the pseudo-second-order kinetic model followed by both intraparticle diffusion and film diffusion as the rate-controlling rate step.