微波和催化剂联合作用对污染土壤中石油烃去除的影响

Microwave radiation and catalyst integrated effect on the removal of petroleum hydrocarbon in contaminated soils

采用微波加热技术,微波频率2 450 MHz、额定微波输出功率400 W、压力0.2 MPa条件下,分别添加催化剂活性炭C、Fe_3O_4和TiO_2,去除污染土壤中的石油烃。结果表明,添加3种催化剂后,微波作用下土壤中石油烃的去除效果显著提高。Fe_3O_4和C加入量为0.2%时,石油烃去除效果最好;TiO_2加入量为0.5%时,石油烃具有最佳去除效果。TiO_2作催化剂时的最佳微波辐射时间为5 min,C和Fe_3O_4为7 min。土壤含水量是影响石油烃去除的重要因子,土壤含水量为16%～20%时,石油烃去除效果最好。TiO_2作催化剂、微波辐射7min、土壤含水量16%时,石油烃的去除率最高,可达84.5%。微波加热和催化剂联合作用可增强污染土壤中石油烃的去除,对石油污染土壤有一定修复作用,具有一定应用前景。

This paper intends to present its authors＇ research results over the integrated effect of microwave radiation and catalyst on the removing of hydrocarbon contaminants from the soil, including the activated carbon （C）, Fe304 and TiO2.The operational conditions we have adopted can be described as follows： the microwave frequency is 2 450 MHz; the rated microwave output power is 400 W at the pressure of 0.2 MPa. The influence of the quantity of catalyst, the irradiation length of time of the microwave used and the soil water content on the actual removing results have also been investigated in turn. The actual results gained from our experimental study can be shown as follows： the removal efficiency of petroleum hydrocarbons in the contaminated soil has been remarkably increased due to the addition of 3 different kinds of catalyst, including activated carbon （C）, Fe3O4 and TiO2. We have also found that the optimum removal efficiency of petroleum hydrocarbon contaminants can be obtained when the dosage of Fe3O4 and C contents was adopted at 0.2 % , while that of TiO2 was 0.5%, respectively. In addition, the optimum irradiation time should be 5 min for TiO2 and 7 min for C and Fe3O4 respectively. The other important influential factor that may affect the removal effect is the the soil water content. The optimum water content is 16% - 20 % . With the optimal dosage of the 3 catalysts and irradiation time for 7 minutes, the ideal removal efficiency of petroleum hydrocarbon contaminants can be gained is 84.5% when TiO2 is used as the catalyst.