Ultrasound assisted synthesis of guar gum-zero valent iron nanocomposites as a novel catalyst for the treatment of pollutants.

This study presents the synthesis of guar gum-zero valent iron nanocomposites (ZGNC) by a simple ultrasound co-precipitation method. The guar gum, one of the most cost effective due to ease of manufacture by extraction, abundant availability and high export value accounts almost 80% of total production in India. Guar gum, a natural polymer was used as binders in pharmaceutical formulations, and acts as a reducing and capping agent for the synthesis of zero valent iron nanoparticles (ZVI). The physicochemical properties of the ZGNC were characterized by TGA, FTIR, XRD, FESEM, EDS, HRTEM, DLS and XPS. The average particle size was ∼60-70 nm and the guar gum polymer on the ZVI were clearly visible from HRTEM. The XPS of ZGNC clearly confirms the elemental composition of the ZVI, guar gum and FeO. The 0.5 g/L ZGNC when used for the pollutants treatment, 15 ppm ciprofloxacin was adsorbed with a removal efficiency of 94% in 60 min at pH 4.0 whereas it had exhibited catalytic oxidation for 100 ppm methyl orange with an efficiency of 99% in 60 min at pH 7.0.