MECHANOCHEMICAL DECHLORINATION OF MONO-CHLORO-BIPHENYL BY ITS CO-GRINDING WITH OXIDE POWDER

摘要

A monochloro-biphenyl (BP-Cl_2, C_6H_4CI-C_6H_5) sample, as a model sample of polychlorinated biphenyl (PCB), was ground with one of oxides such as La_2O_3 and MgO to investigate mechanochemical dechlorination of BP-C1 According to the GC/MS analysis for the ground products with La_2O_3, several intermediates with biphenyl are formed by 2-hours in grinding, but any organic phases are not observed when the grinding is continued for 6-hours or more, besides amorphous carbon. The complete decomposition of BP-C1 is achieved when La_2O_3 is added. On the other hand, some organic phases are formed when MgO is used as an additive. It is confirmed that other rare earth oxides are also effective additives for the decomposition of BP-C1. This suggests the use of similar effective additives for the decomposition of BP-C1 in the practical operation by heating a mineral sample containing rare earth.