Effect of gamma radiation on destruction of toxic polychlorinated biphenyls (PCBs) in hydraulic oils

Polychlorinated biphenyls (PCBs) are synthetic organic chemicals and have been commercially used worldwide in many applications. PCBs have been used in oils because of their remarkable properties like flame resistance , thermal stability , dielectric constant , high break down voltage , low volatility etc . However , due to their adverse affects on human health and environment , the use of PCBs has now been banned . PCBs are today considered among widespread pollutants in the global system. Various remedial technologies have been developed in the world to detoxify PCBs. In the recent years, the radiation technology has emerged as an environment friendly technique for treatment of wide spread pollutants. The process involving gamma radiation is safe, reliable, energy efficient and environment- friendly. A study was undertaken to detoxify PCBs in hydraulic oils by gamma radiation using Cobalt 60 as radiation source. Analysis of PCBs in hydraulic oil before and after radiation was carried out by GC –MS instrument. The method used was found to be highly effective and destruction of PCBs was as high as 78.51 %. The degradation efficiency of PCBs destruction was found to be dependent on the applied radiation dose, source of hydraulic oil and also on the type of PCBs.