Synthesis of some novel adsorbents for antimicrobial activity and removal of arsenic from drinking water

Arsenic contamination in drinking water is alarming for human beings; especially for those people who use ground water directly for drinking purposes. Attempts were made to design adsorbents for the removal of arsenic. Silica gel has been tested as adsorbent for such removal. After optimizing concentration, time and amount of adsorbent, Langmuir, Freundlich and D-R isotherms are drawn to determine different parameters for the evaluation of arsenic adsorption. Kinetics of adsorption is also calculated by using pseudo first order and pseudo second order rate equations. Zerovalent iron and manganese nanoparticles have been coated on silica gel and efficiency of removal of arsenic have been determined. Iron and manganese particles have been stabilized with polyvinyl alcohol (PVA). Similarly mixtures of iron-silver and manganese-silver nanoparticles have been synthesized by stabilizing with PVA, which show better efficiency than individual nanoparticles of iron and manganese coated silica gel. The newly synthesized adsorbents are very much effective for not only arsenic but also for antimicrobial activity. Concentration of arsenic in water has been determined spectrophotometrically using variamine blue as indicator.