This research article published by Scientific Research Publishing Inc., 2016
The levels of fluoride in various ground water sources in East Africa are above the
World Health Organization upper limit of 1.5 mg/L. Research on diverse defluoridation technologies has proven that adsorption stands out as an affordable, efficient,
and facile technology. Fish swim bladder-derived porous carbon (FBPC) activated by
KOH and surface oxidized by nitric acid was successfully investigated as an adsorbent for defluoridation at portable water pH. The FBPC was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-raydiffraction (XRD) and energy dispersive spectroscopy (EDS). Batch methods were
used to study physiochemical parameters viz., initial fluoride concentration, temperature, adsorbate dosage, contact time and pH. Freundlich, Temkin, Langmuir and
Dubinin-Radushkevich isotherms were plotted and analyzed to understand the adsorption process. Bangham, Weber Morris, pseudo first and second-order models
were used to elucidate the kinetics of adsorption. Optimal conditions for fluoride
removal were found to be: pH of 6, FBPC adsorbent dose of 5.0 g/L and contact time
of 50 min. Flouride adsorption followed pseudo second-order kinetic model and
Langmuir isotherm best describes the adsorption process.