Small particle size magnesium in one-pot Grignard-Zerewitinoff reactions: Kinetics of and practical application to reductive dechlorination of persistent organic pollutants

I&EC 18

Volker Birke, birke@uni-lueneburg.de, Koordinierung BMBF-Forschungsverbund RUBIN, Leuphana Universität Lüneburg, Projektbüro: Steinweg 4, D-30989 Gehrde, Lüneburg, Germany
Ball mills can be utilized as mechanochemical (MC) reactors for producing micro- and/or nano-sized base metals which accomplish simultaneously, i.e., during permanently milling, rapid reductive dechlorinations of added various hazardous polychlorinated compounds to their parent hydrocarbons in high yields at room temperature in a one-pot reaction. For instance, polychlorinated biphenyls (PCBs) are dechlorinated to harmless chloride and biphenyl by applying alkali or alkaline-earth metals, aluminum, or iron, plus a low acidic hydrogen source.

Regarding magnesium and amines, resp., a kinetic study, employing dichloro- or monochlorbenzene as the model pollutant, reveals that one-pot Grignard-Zerewitinoff reactions most likely occur. A specific, coupled system of ordinary differential equations (ODE), i.e., rate equations representing single steps of the entire mechanism, could successfully be fitted simultaneously to various data sets gathered through different degradation experiments.