Selenium Removal from Surface and Groundwater using Iron Nanoparticles


Researchers: Achintya N. Bezbaruah, Michael Quamme

Project sponsors: USGS/NDWRRI (03/2012-02/2013)


Bare nanoscale zero-valent iron (NZVI) particles and NZVI entrapped in calcium (Ca) alginate beads were tested for the remediation of selenium (Se) species in aqueous solution. The study has demonstrated that NZVI is a very effective medium for the remediation of Se. In batch studies, bare NZVI reduced Se from 34 μg/L to < 1μg/L (> 97% removal) in 3 h. The Ca-alginate entrapped NZVI achieved a slower yet effective removal (> 85% in 12 h). While the collection and disposal of spent bare NZVI were very difficult, the Ca-alginate entrapped particles were easier to be collected and disposed off. Ca-alginate entrapment appears to be a promising method for application in aqueous Se removal. Permeable reactive barriers with entrapped NZVI can be installed for groundwater remediation, and batch application method can be practiced for surface water. Experiments are underway to find out the interferences of various ions (e.g., phosphate, nitrate, ammonium) and environmental parameters (e.g., ionic strength, temperature, pH) on Se removal by NZVI.


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