Radiation-induced degradation of water pollutants—state of the art☆

Removal of persistent organic pollutants (POPs) from waters and wastewaters by the use of ionizing radiation.

Radiation induced decomposition of chlorinated phenols in water

Polychlorinated biphenyls (PCBs) appear as environmental pollutants in various phases. Aqueous media polluted with such compounds may potentially be detoxified by electron beam irradiation. In the present study, we discuss the possible mechanisms of radiolytic detoxification under various conditions, and we study 2,6-dichlorobiphenyl (DCB) as a model compound for PCBs. Electron beam and γ-irradiation of DCB in aqueous methanol solutions lead to degradation of this compound and formation of Cl- ions, but high doses are required. Solutions of 1 mmol L-1 DCB require a dose of 30 kGy to produce 1 equiv of Cl- (G = 0.03 μmol J-1) to form the less toxic monochlorobiphenyl (MCB), but 600 kGy is required to achieve full dechlorination. This low yield is due to the concomitant formation of acid, which competes with DCB for the solvated electrons, the main reducing species in this system. The radiolytic yields are improved dramatically by the addition of carbonate; only 20 kGy are required for practically quantitat...

Mechanisms of Ionizing Radiation-Induced Destruction of 2,6-Dichlorobiphenyl in Aqueous Solutions

Present-day applications of ionizing radiation to environmental protection are surveyed. This part of the review summarizes new data on the radiation-chemical purification of municipal, industrial, and agricultural wastewater; liquid radioactive wastes; oils; etc.

Philip Smalley

Papers

Radiolytic dechlorination of polychlorinated biphenyls