Superfund Research Program
Chloro-Organic Degradation by Polymer Membrane Immobilized Iron-Based Particle Systems
Project Leader: Dibakar Bhattacharyya
Grant Number: P42ES007380
Funding Period: 2000-2019
This work is focused on advancing water remediation membrane-based technologies for the degradation of chlorinated organic compounds to non-toxic products. A variety of membrane platforms were explored. Specifically, flat-sheet spongy (FS) and hollow fiber (HF) polyvinyl diflouride (PVDF) membranes, metallic thin films, and graphene-based membranes. These membranes were functionalized with responsive polymers and in-situ synthesized reactive iron/palladium nanoparticles. Polymerization parameters were optimized for iron loading capacity and remediation. The nanoparticles were characterized using novel focused ion beam (FIB, purchased through NSF funding) technology at various depths inside membrane pores, enabling maximization of particle reactivity (Wan et al., 2016). Trichloroethylene (TCE) and polychlorinated biphenyls (PCBs) were effectively degraded using various platforms to non-toxic products through reductive and oxidative pathways. FS membranes exhibited significantly higher TCE treatment efficiency. PCB 126, considered more difficult to degrade because of the multiple chlorines per molecule, was degraded using functionalized commercial membranes and iron/palladium particles involving multiple treatment cycles. Another advancement was in the area of creating thin nanoporous bimetallic films directly on commercial membrane surfaces. These films demonstrated over 99% dechlorination of chloro-biphenyl. Also, nanocomposite system of graphene oxide membrane and iron was investigated for the more efficient oxidative treatment of chlorinated organics. The research team’s membrane technology from the NIEHS work has found other applications in industrial water reuse sector (Colburn, Meeks (Southern Company) et al., 2016). A review was completed and published as a book chapter (Hernandez, Saad et al., 2016) on pH responsive, temperature responsive, and nanocomposite membranes for water treatment applications.