Biosorptive removal of inorganic arsenic species and fluoride from aqueous medium by the stem of Tecomella undulate

- Simultaneously removal of fluoride and arsenic from water by green technology.
- SEM and FTIR studies indicated the sorption of fluoride and inorganic arsenic species.
- Kinetic and isotherm sorption study were used to design large scale removal method.
- Thermodynamic study stated the process of sorption was exothermic and spontaneous.

Simultaneous removal of fluoride (F−), inorganic arsenic species, AsIII and AsV, from aqueous samples has been performed using an economic indigenous biosorbent (Stem of Tecomella undulata). The inorganic As species in water samples before and after biosorption were determined by cloud point and solid phase extraction methods, while F− was determined by ion chromatography. Batch experiments were carried out to evaluate the equilibrium adsorption isotherm studies for AsIII, AsV and F− in aqueous solutions. Several parameters of biosorption were optimized such as pH, biomass dosage, analytes concentration, time and temperature. The surface of biosorbent was characterized by SEM and FTIR. The FTIR study indicated the presence of carbonyl and amine functional groups which may have important role in the sorption/removal of these ions. Thermodynamic and kinetic study indicated that the biosorption of AsIII, AsV and F− were spontaneous, exothermic and followed by pseudo-second-order. Meanwhile, the interference study revealed that there was no significant effect of co-existing ions for the removal of inorganic As species and F− from aqueous samples (p > 0.05). It was observed that the indigenous biosorbent material simultaneously adsorbed AsIII (108 μg g−1), AsV (159 μg g−1) and F− (6.16 mg g−1) from water at optimized conditions. The proposed biosorbent was effectively regenerated and efficiently used for several experiments, to remove the AsIII, AsV and F− from real water sample collected from endemic area of Pakistan.

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