Fellow: Umma Salma Rashid
Advisor: Achintya Bezbaruah, Associate Professor, Department of Civil and Environmental Engineering, North Dakota State University.
Degree Progress: M.S. in Civil and Environmental Engineering (Graduation in Fall 2015).

Within this research, novel bio-based polymer for coating nanoscale zero-valent iron (NZVI) is being developed such that NZVI can be used in permeable reactive barriers (PRBs). NZVI will act as the reactive media to remove contaminants from groundwater. The use of NZVI in PRBs is an emerging technology. Because of low cost and high contaminant removal efficiency, NZVI has drawn the attention of researchers. However, NZVI particles agglomerate very quickly and surface modification of NZVI is necessary to improve their colloidal stability (i.e., increase their dispersibility). The current project will use a food starch based surface modifier for coating NZVI in such a way that it will increase the sticking coefficient of NZVI to the aquifer materials (e.g., sand) while not letting the nanoparticles agglomerate. Nitrate is selected as the contaminant of interest for this project. 

Project Objectives:

The specific objectives of this research are:

• Prepare novel bio-based polymers which will not only be cost effective but also environmentally friendly.
• Use of the new polymer to coat nanoscale zero-valent iron (NZVI) to improve their dispersibility in aqueous media and sticking coefficient to aquifer materials.
• To conduct two dimensional transport study to determine if coated NZVI particles could be the potential candidates for creating permeable reactive barriers (PRBs) in the subsurface at different flow velocities and different porosity.
• To evaluate contaminant degradation by coated NZVI particles.
• To evaluate the efficiency of coated NZVI as the reactive material in PRBs.

Progress:

Nanoscale zero-valent iron (NZVI) was coated with OSA modified tapioca starch to improve colloidal stability of NZVI. Two dimensional transport and contaminant degradation studies were conducted both with the bare NZVI and coated NZVI.

Significance:

This research is aimed at preparing novel bio-based polymers for coating NZVI for using in PRBs to remove toxic contaminants from groundwater. The technology can also be applied for surface water remediation. Once optimized, the technology can be applied to various North Dakota contaminated sites and other sites across the globe.

Research Outcomes:

     Rashid, U.S., Simsek, S., Bezbaruah, A.N. Injectable Nanoparticle-based Permeable Reactive Barriers for Groundwater Contaminant Remediation, ND EPSCoR State Conference, Fargo, North Dakota, April 2015. (Poster)