Operating parameters adjustment and effects evaluation of electrical resistance heating for soil remediation
Operating parameters adjustment electrical resistance heating(ERH)are important factors affecting soil remediation effectiveness and energy consumption.A sandbox platform was used to study ERH operating parameters and evaluate the corresponding effects.The results showed that soil voltage increased with decreasing of distance to electrode and increasing of soil depth.Soil temperature of the heating zone rose synchronously with a similar rate.An uniform gradient thermal field with the temperature range of 91.8-95.8 ℃ was formed after heating the soil at a high power density of 1 440 W/m3 for 24 h.Compared to the low power density(720 W/m3),the high power density mode increased the heating rate 1.9 times and shortened heating time by 65.5％.Concurrently,it improved the electric-heat conversion coefficient by 70.6％and decreased energy consumption by 30.2％.The current and heating power density during ERH process varied greatly,so combination control methods were needed in order to ensure the pre-set heating target achieved.After 60 d operation with a pre-set heating target of 80 ℃,the concentrations of vinyl chloride,chloroform and carbon tetrachloride in the soil significantly decreased and met the remediation targets.
万方数据
维普
