苯并[a]芘污染土壤的臭氧氧化研究

Removal of Benzo[a]pyrene in Contaminated Soil by Ozonation

在土壤污染中,多环芳烃(PAHs)类污染土壤受到了广泛的关注。针对臭氧氧化修复污染土壤臭氧利用率不高的缺点,该研究采用机械搅拌提高臭氧修复苯并[a]芘(BaP)污染土壤效率。以模拟100 mg/kg BaP污染土壤为研究对象,研究了搅拌速度、含水率及臭氧浓度对BaP的降解率、土壤p H、电导率、土壤溶解性有机碳(DOC)和CO2产量的影响。结果表明,机械搅拌提高了污染土壤修复效率,并能在30 min内快速降解BaP。最佳条件下(100 r/min搅拌速度、3%含水率、73.7 mg/L臭氧浓度)氧化120 min后BaP降解率达93.67%,p H下降了2.01,电导率升高到154 mS/cm,DOC升高到1.74 g/kg,共有14.43 g/kg CO2积累。该研究首次采用了机械搅拌提高PAHs污染土壤的氧化效率以及可生物降解性,该方法可为臭氧氧化修复低含水率的有机物污染土壤提供理论依据。

Polycyclic aromatic hydrocarbons(PAHs)contaminated soil has been widely concerned.In view of the low utilization rate of ozone in remediation of PAHs contaminated soil,the physical method of agitation was used to improve the efficiency of ozone in remediation of contaminated soil with benzo[a]pyrene(BaP).The simulated 100 mg/kg BaP polluted soil was taken as the research object,the effects of agitation speed,moisture content and ozone concentration on the degradation rate of BaP,soil pH,electrical conductivity,soil dissolved organic carbon(DOC)and the cumulative amount of carbon dioxide were studied.The results showed that the agitation could improve the remediation efficiency of polluted soil and degrade BaP rapidly within 30 min.Under the optimal conditions(100 r/min agitation speed,3%soil moisture content and73.7 mg/L ozone concentration),the degradation rate of BaP was 93.67%after 120 min oxidation,the soil pH decreased by 2.01,electrical conductivity increased to 154 mS/cm,DOC increased to 1.74 g/kg,and a total of 14.43 g/kg CO2 was accumulated.In this study,agitation was first used to improve the oxidation efficiency and biodegradability of PAHs contaminated soil,which provides a theoretical basis for remediation of organic pollutants contaminated soil with low water content by ozonation.