Dechlorination and Decomposition Behavior of PCBs by the Sodium Dispersion Process.

Metal-Mediated Reductive Hydrodehalogenation of Organic Halides

“…38 A metallic sodium dispersion based process was developed by several groups to study the dechlorination and decomposition behavior of PCBs. 39,40 Sodium metal in conjunction with a poly(methylhydrosiloxane) (PMHS), 19, proved to be a very efficient system to achieve the complete dechlorination of a series of PCBs 18 at ambient conditions (Scheme 8). 41 Dechlorination proceeded via the formation of a polychorobiphenyl radical anion, which underwent carbon-chlorine bond cleavage with a regioselectivity similar to that normally observed in nucleophilic substitution of polyarenes.…”

“…The reaction of sodium atoms with PTFE under ultra-high-vacuum conditions, which was followed by photoelectron spectroscopy (XPS), also showed surface defluorination together with the formation of sodium fluoride . A metallic sodium dispersion based process was developed by several groups to study the dechlorination and decomposition behavior of PCBs. , …”

Production and characterization of KOH-activated carbon derived from polychlorinated biphenyl residue generated by the sodium dispersion process

“…1 The dechlorination reaction proceeds by the biphenyl generation reaction at low temperatures (333-393 K) and by the polymerization reaction at high temperatures (423-443 K). 1 In the process, a barely soluble polymer, biphenyl, and sodium chloride are generated, and hence PCB detoxifi cation is accomplished under safe conditions (333-443 K and atmospheric pressure).…”

“…1 The dechlorination reaction proceeds by the biphenyl generation reaction at low temperatures (333-393 K) and by the polymerization reaction at high temperatures (423-443 K). 1 In the process, a barely soluble polymer, biphenyl, and sodium chloride are generated, and hence PCB detoxifi cation is accomplished under safe conditions (333-443 K and atmospheric pressure). The barely soluble polymer and the biphenyl (hereinafter referred to as PCB residue) are easily separated from insulation oil by solvent extrution process; this solution can then be disposed of as combustible industry waste, provided the PCB concentration is less than 0.5 mg/kg, the suggested environmental quality standard in Japan.…”

Efecto de los hidrocarburos en suelos arenosos de la mesa de Guanipa-Venezuela y propuesta de tratamientos alternativos para la recuperación de suelos contaminados con gasoil y aceites dieléctricos con BPC

“…Tiene fuerte afinidad por ciertos elementos, incluido el cloro, por esta razón el sodio reacciona con los átomos de cloro de las moléculas de BPC dando cloruro sodio, que puede extraerse de la fracción orgánica por filtración o centrifugación. Normalmente, el proceso tiene lugar a presión atmosférica y a temperaturas de entre 60 °C y 180 °C (Ariizumi et al, 1997).…”