Plant-based Biopolymers for Entrapping Metal Nanoparticles for Arsenic removal: Biodegradation and Treatability Studies


Researchers: Harjyoti Kalita, Achintya N. Bezbaruah, Bret Chisholm

Project sponsors: USGS/NDWRRI (03/2010-02/2012)


Nanoscale zero-valent iron (nZVI) particles have been attractive for remediation of various contaminants including arsenic. However, because of the smaller particle size and relatively higher dispersibility, nZVI becomes mobile in aquifers. Moreover, in higher concentration, nZVI tend to agglomerate due to magnetic and Van der Waals forces. This allows them to form large particle and settle into aquifer media pores. Agglomerated particle has decreased specific surface and hence lose the reactivity that individual nZVI has. Polymers are used to coat or entrap nZVI to overcome the problem of agglomeration or uncontrolled dispersion, Such entrapped nZVI have shown higher reactivity towards contaminants. However, polymers synthesized in previous research are not biodegradable or shows limited biodegradation. Lack of biodegradation may limit the use of these polymers in groundwater where polymers may themselves become 'pollutants'. It is imperative to development and use polymers which are easily biodegradable to benign end product in the aquifer. This project proposes to use plant-based (bio) polymers to entrap nZVI and study microbial biodegradation of the polymers used. A soybean-based biopolymer will be the primary focus of this study for removal of Arsenic.