doi:10.1038/nindia.2013.88 Published online 28 June 2013
Researchers have synthesised a new nano-composite that can remove dye and pathogenic bacteria from contaminated water. They synthesised the composite with silver nanoparticles and nano-silica as a novel antifouling adsorbent for cost-effective and ecofriendly water purification.
Currently used means for synthesis of metal nanoparticles on solid support require chemical agents, which often raises environmental and safety issues. To address this problem, the researchers fabricated well-dispersed silver nanoparticles on a nano-silica surface (NSAgNP) through protein mediated reduction of silver ions at ambient temperature. The composite exhibited excellent dye adsorption capacity both in single and multi-component systems, and demonstrated satisfactory tolerance against variations in pH and dye concentration.
Moreover, the NSAgNP killed both planktonic cells and biofilms of gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. The antibacterial activity of AgNPs retarded the initial attachment of bacteria on NSAgNP and thus significantly improved the antifouling properties of the nanomaterial, which further inhibited biofilm formation.
"High adsorption capacity, reusability, removal of dyes and bacteria from contaminated water along with the composite's antifouling properties will provide new opportunities to develop cost-effective and ecofriendly water purification processes," says one of the researchers Sujoy Das.