Dehalogenation of Polychlorinated Biphenyls (PCBs) using chemical dechlorination

The objective of this study is concerned about the effects of ultrasound, KPEG/oil weight ratio and polyethylene glycol (PEG) molecular weight in the treatment of PCBs present in transformer oil using chemical dechlorination (KOH/PEG). The dechlorination performance was assessed in terms of the destruction and removal efficiency (DRE) of PCBs. DRE value was expressed as percentage. An Agilent 7890A Gas Chromatograph (GC) fitted with a flame ionization detector (FID) and a capillary column (HP-5) was used for the determination of PCBs. The best results (average DRE of 88.55 %) were obtained under the following conditions KPEG/oil ratio of 30 and PEG 600. PCBs dehalogenation in Sovtol-10 involves all congeners with high efficiency. In particular, congeners of high molecular mass disappear from the chromatogram in all runs. The removal of PCBs is strongly affected by KPEG/oil ratio, PEG and KPEG/oil ratio-PEG interaction, in this order

Chemical dechlorination for the treatment of PCBs present in transformer oil (Sovtol-10): parameter study

Different parameters for the treatment of PCBs present in transformer oil (Sovtol-10) using chemical dechlorination with polyethylene alkoxide (KPEG) were evaluated. The effect of the KPEG/oil weight ratio, KOH/PEG mole ratio and polyethylene glycol molecular weight (PEG) using KOH in pellets were determined first. With the optimal values obtained the influence of two other parameters: KOH in powder and ultrasound was investigated. The overall dechlorination performance was assessed in terms of the destruction and removal efficiency (DRE) of PCBs. Average DRE of 93.7 % was obtained under the following conditions: PEG 400, KPEG/oil weight ratio of 30 and KOH/PEG mole ratio 2 for 2 hours of reaction. The ultrasound initially increases DRE of PCBs by 8 % after 10 min of reaction time. After a reaction time of 120 min no difference in DRE was measured when using ultrasound