Zerovalent iron encapsulated chitosan nanospheres – A novel adsorbent for the removal of total inorganic Arsenic from aqueous systems

Evaluation of Chitosan zerovalent Iron Nanoparticle (CIN) towards arsenic removal is presented. Addition of chitosan enhances the stability of Fe(0) nano particle. Prepared adsorbent was characterized by FT-IR, SEM EDX, BET and XRD. It was found that, with an initial dose rate of 0.5 g L−1, concentrations of As (III) and As (V) were reduced from 2 mg L−1 to <5 μg L−1 in less than 180 min and the adsorbent was found to be applicable in wide range of pH. Langmuir monolayer adsorption capacity was found to be 94 ± 1.5 mg g−1 and 119 ± 2.6 mg g−1 at pH 7 for As (III) and As (V) respectively. Major anions including sulfate, phosphate and silicate did not cause significant interference in the adsorption behavior of both arsenite and arsenate. The adsorbent was successfully recycled five times and applied to the removal of total inorganic arsenic from real life groundwater samples.

► CIN removed As (III) and As (V) at wide range of pH.
► Chitosan acts as a stabilizer of Fe(0) nanoparticle.
► High surface area, hence a very high adsorption capacity.
► Anions like Silicate, phosphate and sulfate does not interfere in the adsorption.
► Removed total inorganic arsenic from contaminated ground water.