Nanofilter for wastewater
doi:10.1038/nindia.2010.75 Published online 9 June 2010
New research has shown that nanoparticles modified with protein may selectively bind to toxic metal ions, looking set to help treat metal-contaminated wastewater.
Mining, electroplating and electronic industries discharge metal-contaminated wastewater, which poses a threat to health and the environment. To address this problem, researchers turned their attention to protein-modified nanoparticles. Proteins are good for such an application because they strongly bind to metal ions.
The researchers modified malachite nanoparticles (made from copper mineral) with bovine serum albumin (BSA), a type of protein. BSA molecules were adsorbed onto malachite nanoparticles and stabilised using an organic solution. Both bare and BSA-modified malachite nanoparticles were then exposed to synthetic wastewater containing metal ions.
The bare malachite nanoparticles were able to bind to chromium, nickel, zinc and copper ions, whereas the BSA-modified nanoparticles could bind to gold, palladium, silver and mercury ions.
BSA was found to be a good candidate as an adsorbent for the metal ions. The adsorption of specific metal ions by BSA can be attributed to several amino acid groups present in the protein molecule.
"Studies with synthetic wastewater also reflect the potential of this system in selective adsorption of toxic metal ions in wastewater treatment," says lead researcher Gopal Das. "BSA can be a good eco-friendly candidate as an adsorbent of metal ions," he adds.
The authors of this work are from: Centre for the Environment, Department of Civil Engineering, and Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India.
- Saha, B. et al. A rational approach for controlled adsorption of metal ions on bovine serum albumin-malachite bionanocomposite. J. Phys. Chem. C 114, 9817-9825 (2010) | Article |