The presence of various emerging contaminants and other recalcitrant halogenated organics in groundwater pose a serious threat to drinking water sources. The objective of the study is to investigate the degradation potential of such pollutants with zerovalent metals (Mg) and related bimetallic reductants (Pd-Mg and Cu-Mg) at bench-scale for the development of water treatment approaches. The degradation behavior and pathways of emerging organic contaminants and recalcitrant organic compounds, e.g., 1,3-dichloropropane (DCP) and 1,2,3-trichloropropane (TCP), dichloromethane (DCM), 1,2 dichloroethane (DCA), 1,1,2-trichloroethane (TCA), 1,1,1,2-tetrachloroethane (TeCA), is being investigated with granular forms of magnesium metal (zero valent magnesium or Mg) and bimetallic reductants (e.g., Pd-Mg, Cu-Mg) at bench-scale. In specific preparations, bimetallic reductants were freshly synthesized by solution deposition method. Batch reactors were set up in anaerobically sealed, 160 mL serum bottles with different preparations of metallic granular reductants in aqueous medium amended containing 96 mL acetate at various initial pH. Reactor headspace was analyzed by gas chromatography with flame ionization and electron capture detectors.  Preliminary results show that granular Pd-Mg can degrade carbon tetrachloride (CT), chloroform (CF), DCM, DCA, TCA, TeCA, DCP and TCP. The degradation rate constants of CT with Mg increased at lower initial pH, but the mass-fraction of CF produced from CT degradation was not significant (<10%). Compared to Mggranules, Pd-Mg and Cu-Mg bimetallic system showed potential in degrading other recalcitrant halogenated organics at neutral pH condition. Results also revealed that increase in Pd loading from 0.02 to 0.2% w/w in Pd-Mg did not influence DCM degradation rate constant; however, increase in loading of Pd-Mg granules accelerated the degradation kinetics, which suggests that surface area of the bimetallic Pd-Mg may play a key role in dechlorination reactions. The degradation of various emergent contaminants and recalcitrant halogenated organics, with Mg, Pd-Mg and Cu-Mg bimetallic reductants is under investigation.

Bench-scale degradation of emerging contaminants and recalcitrant organics by zerovalent magnesium and related bimetallic reductants

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.