新疆不同质地土壤对石油类污染物的吸附作用

ADSORPTION OF PETROLEUM POLLUTANTS ON DIFFERENT TEXTURE SOILS IN XINJIANG

石油类污染物的迁移转化研究对环境保护及人体健康均有重要意义。由于石油类污染物在不同质地土壤中的吸附行为不同,采用静态吸附实验方法,研究了新疆甘泉堡工业区3种质地土壤(粉土、粉砂、粉质黏土)对石油烃的吸附动力学及吸附热力学行为,进行了吸附动力学和等温吸附拟合,并分析了土壤粒径、有机质含量、pH值及以含盐量对石油烃吸附量的影响。结果表明:粉土、粉砂、粉质黏土对石油烃的吸附均能在240 min达到吸附平衡,平衡吸附量分别为0.7765,0.6763,0.7173 mg/g;吸附能力顺序为粉土>粉质黏土>粉砂,准二级动力学模型(R^(2)=0.9967~0.9989)能够更加准确地描述石油烃在土壤中的吸附过程;等温线为Langmuir型,其吸附平衡常数(K_(a))分别为0.6126(粉土)、3.1310(粉砂)和0.1180(粉质黏土),表明石油烃在不同质地土壤中的吸附为单分子层吸附;土壤对石油烃的吸附量随土壤粒径和pH值的减小、有机质含量和含盐量的增加而逐渐增大。

The study on the migration and transformation of petroleum pollutants is of great significance to environmental protection and human health.Because of their different adsorption behaviors in soils with different textures,the static adsorption test method was adopted,and the adsorption kinetics and adsorption thermodynamics of petroleum hydrocarbons on three kinds of soils(silty soil,silty sand and silty clay)in Ganquanbao industrial area of Xinjiang were studied.The effects of soil particle size,organic matter content,pH value and salt content on the adsorption of petroleum hydrocarbons were analyzed.The results showed that the adsorption of petroleum hydrocarbons by silty soil,silty sand and silty clay reached adsorption equilibrium in 240 minutes.The adsorption capacity from large to small was silty soil,silty clay,and then silty sand,and the equilibrium adsorption capacity was 0.7765 mg/g,0.6763 mg/g and 0.7173 mg/g respectively.The quasi-second-order kinetic model(R^(2)=0.9967~0.9989)could more accurately describe the process of soil adsorption of petroleum hydrocarbons.The isotherm was of Langmuir type,and their adsorption equilibrium constants(K_(a))were 0.6126(silty soil),3.1310(silty sand)and 0.1180(silty clay),indicating that the adsorption of petroleum hydrocarbons in different texture soils was monolayer adsorption.The amount of soil adsorbed to petroleum hydrocarbons gradually increased with the decrease of soil particle size and pH,and the increase of organic matter content and salt content.