doi:10.16186/j.cnki.1673-9787.2021120070

Received:2021-12-21

Revised:2022-03-01

Online Date:2023-08-03

Remediation of insulating oil contaminated soil by pulsed discharge plasma（Online）

CHEN Chongming, GONG Yunqian, ZHOU Huibo, CHE Kai

State Grid Hebei Electric Power Research Institute，Shijiazhuang 050021，Hebei，China

Abstract:A needle-plate pulsed discharge plasma experimental system was set up to investigate the effects of main parameters such as peak voltage， moisture content and concentration of insulation oil on the degradation of insulation oil in soil.The results showed that the order of parameters affecting the degradation rate of insulation oil was peak voltage>water content>concentration of insulation oil>air flow rate>frequency> treatment time. The peak voltage should be higher than 10kV in order to degrade insulation oil，and high peak voltage could increase degradation rate and shorten processing time. The degradation rate and energy efficiency could reach 88.13% and 43.71 mg/kJ，respectively. The degradation rate decreased with the increase of insulation oil concentration.The degradation amount dropped off with higher concentration，because oil ingredient from inner layer soil could not contact with highly active substance. The increase of moisture content could promote oil degradation due to the increase of * OH amount.However， high moisture content inhibited soil degradation because the transportation of active ions was limited by the reduction of soil perme⁃ability and increase of soil aggregation.The insulation oil in soil is mainly saturated hydrocarbon before andafter treatment.The degradation effect of 4 cyclic aromatic hydrocarbons was better than that of 2-3 cyclicaromatic hydrocarbons. The content of aromatic hydrocarbons above 4 cyclic increased after treatment because of the condensation of small hydrocarbons with benzene rings under high temperature and the formation of polymer aromatic hydrocarbons.

Key words:pulsed discharge;plasma;soil remediation;insulation oil;degradation

CLC：O461;O539;X53