Chemical functionalization and thermal destruction of persistent organic pollutants: polychlorinated biphenyls

Utilization of persistent organic pollutants (POP) is an urgent problem all over the world. POP cause great harm to human health and the environment. For more than 20 years, scientists offer different methods and approaches to dispose of POP, but still there is no safe and economically advantageous method of utilization these pollutants. This paper proposes an environmentally friendly two-step approach (chemical functionalization and thermal destruction) to disposal of POP. We have selected the commercial mixtures of polychlorinated biphenyls "Sovol," "Trichlorbiphenyl" and individual trichlorobiphenyl congeners (PCB 29), pentachlorobiphenyl (PCB 101) as the objects of our study. From these initial components, we synthesized mixtures of hydroxy derivative polychlorinated biphenyls. It has been established for the first time that the best pre-prepared mixtures for burning are hydroxy derivatives. We have found that the thermal destruction of all hydroxy derivatives to the simplest volatile substances (CO2, H2O, HCl, etc.) takes place without the evaporation process. In our studies, we analyzed the thermal destruction of the initial mixtures "Sovol," "Trichlorbiphenyl" and their respective hydroxy and methoxy (hydroxy) derivatives. We have shown that the thermal destruction of hydroxy derivatives of PCB is a more environmentally friendly process in comparison with the thermolysis of unsubstituted commercial mixtures and methoxy (hydroxy) derivatives. The obtained results might be useful for the development of an integrated approach of PCB destruction through two stages: The first is the chemical, and the second is the thermal.