doi:10.1038/nindia.2017.39 Published online 3 March 2017
Researchers have synthesized a nanocomposite-based hydrogel that can help discolouration of organic dyes, remove pollutants and kill pathogenic bacteria, making it potentially useful for treating industrial wastewater and contaminated groundwater1.
Soluble toxic pollutants and water-borne microbes render water unsafe to drink and make the disposal of wastewater difficult. Existing pollutant-removing techniques that use pure metal nanoparticles are ineffective and release potentially harmful nanoparticles into the environment.
To develop an eco-friendly pollutant-removing material, scientists from Indian Institute of Technology (Indian School of Mines), Jharkhand and CSIR-Central Salt and Marine Chemicals Research Institute, Gujarat prepared a nanocomposite-based hydrogel using modified maize amylopectin, titanate nanosheet and silver nanoparticles.
Functioning as a catalyst, the nanocomposite reduced para-nitro phenol, an organic pollutant within 16 seconds. This reaction shows that the catalyst can be reused by taking it out of the solution and drying.
It also rapidly catalysed the discolouration of organic dyes such as methyl orange and methylene blue, retaining its catalytic efficiency through five cycles. When exposed to two colony-forming bacteria such as Escherichia coli and Bacillus subtilis, the nanocomposite killed these bacteria by releasing silver nanoparticles.
“The nanocomposite efficiently reduced the microbial load in a sample of pond water and discoloured organic dyes present in a sample of textile wastewater, indicating its potential for large-scale applications,” says Sagar Pal, one of the researchers from the IIT (ISM), Jharkhand.