నైరూప్య

Bio synthesis of silver nanoparticles and its application in microbial treatment of drinking water

P.S.Harikumar, Litty Joseph, C.M.Manjusha

The microbial contamination of water is a world-wide environmental problem. Nanotechnology is one of the efficient tools which can be applied to solve this problem. Silver nanoparticles are known to be highly toxic to microorganisms, showing strong biocidal effect and are nontoxic to the human body at low concentration. The aim of this work was to determine the antimicrobial potential of bio synthesized Ag nanoparticles for the treatment of water. Silver nanoparticles were synthesized using the microorganisms; Escherichia coli and Klebsiella sp. and the Carica papaya plant extract. The presence was confirmed by UV-Visible spectroscopy, Scanning Electron Microscopy (SEM) and Energy dispersive X-ray analysis (EDS). The silver nanoparticles were adsorbed on granular activated carbon and were used as a bacterial filter for treating contaminated water.Antibacterial action of Ag nanomaterials was studied using Colony Forming Unit (CFU) and Most Probable Number (MPN). The effects of Ag nanoparticles on microbial strains were calculated. Time and dose dependent study of Ag nanoparticles showed that the effectiveness of particles increases with increasing particle dose and treatment time. Also the effect of Ocimum tenuiflorum (Tulasi) and Caesalpinia sappan (Pathimugam) extract on the antimicrobial activity of silver nanoparticles in water treatment was studied. The obtained results showed that the Ocimum tenuiflorum was more efficient compared to Caesalpinia sappan in the treatment of water. Our work suggests that silver-adsorbed granular activated carbon can be used as an excellent antibacterial media and would have several applications in water treatment system. Biosynthetic method is an economical, efficient, ecofriendly simple process and can be used as an alternative to chemical and physical one