Dechlorination of Polychlorinated biphenyls in real waste transformer oil using a modified household microwave oven at the present sodium hydroxide and polyethylene glycol

This research was carried out to assess the dechlorination and decomposition of Polychlorinated biphenyls (PCBs) in the real waste transformer oil using PEG1000/NaOH through a modified household microwave oven. To do so, the influence of polyethylene glycol (PEG) (1.5-7.5 g) and NaOH (0.3-1.5 g) under MW power of 500w on the dechlorination efficiency of PCBs, existed in real waste transformer oil, was investigated. The results show that by increasing the PEG 1000 (1.5- 7.5g) and NaOH (0.3-1.5g) amounts, the dechlorination efficiency of PCBs increased from 35 to 99.99% under microwave power of 500 w at the reaction time of 6 min. The optimum amounts of PEG and NaOH were 5 g and 1 g, respectively. The PCBs dechlorination rate was investigated in the optimum amounts of variables in the various reaction times. The results indicated that the PCBs dechlorination rate was fitted with the one-order kinetic (k = 0.019, R2 = 0.91), and more than 90% of total PCBs were dechlorinated at the first 90 seconds of the reaction time. After 90 seconds, the dechlorination rate decreased. Accordingly, results showed that MW has extraordinary influence on PCBs decomposition from waste transformer oil, and the reaction time decreased more 10 times in comparison to conventional heating.