Nanoscale zerovalent iron supported on uniform carbon microspheres for the in situ remediation of chlorinated hydrocarbons

Nanoscale zerovalent iron particles (NZVI) are a preferred option for reductive dehalogenation of dense nonaqueous phase chlorinated hydrocarbons such as trichloroethylene (TCE) because of their environmentally benign nature, high efficiency, and low cost. This study describes an approach to engineered particles containing NZVI that are effective targeted delivery agents for the remediation of these compounds. The particles contain highly uniform carbon microspheres embedded with NZVI (Fe0/C composite particles). The highly adsorptive carbon keeps the TCE in the proximity of the reactive sites and serves as a sorptive sink for TCE removal. The Fe0/C composite particles are in the optimal size range for transport through soil and the polyelectrolyte (Carboxymethyl cellulose, CMC) is used to stabilize the composite microspheres in aqueous solution. The multiple functionalities associated with these particles can be designed at low cost and the materials are environmentally benign.