石油类污染场地的自然衰减作用

Natural Attenuation of A Petroleum Contaminated Site

在野外石油类污染场地地质、水文地质调查的基础上,对场地地下水中总石油烃的吸附、生物降解等自然衰减作用进行研究。开展了砂质粉土、粉砂、细砂等场地包气带、含水层介质对总石油烃的吸附动力学实验、等温吸附实验、不同矿化度吸附实验、生物降解实验和挥发实验等。实验结果显示,砂质粉土、粉砂、细砂的吸附平衡时间分别为4、7和10 h;通过计算确定了每种介质对总石油烃的等温吸附模型。矿化度对介质吸附总石油烃能力的影响表现为,矿化度越高吸附量越高。生物降解实验结果表明,在场地水土条件下,降解能力最强,且降解符合一级衰减动力学方程。研究表明,地下水受到污染后,吸附、降解、挥发等自然衰减作用对地下水石油类污染物的去除具有非常重要的作用。

Based on the geological and hydrogeological investigation,natural attenuation of a petroleum contaminated site was studied.Different experiments to study total petroleum hydrocarbon(TPH) adsorption kine-tics,isotherm adsorption,TDS influence,biodegradation and volatilization were conducted on different vodase zones and aquifer materials(sandy silt,fine sand and silt sand).The results showed that the adsorption equilibrium time of sandy silt,fine sand and silt sand are 4 h,7 h and 10 h respectively.The adsorption isotherm models were obtained through calculation.The sorption of TPH on different materials increased with higher TDS content.The biodegradation experiments implied that the highest degradation rate could be achieved when the experiments conditions were the same as the site.Also,the biodegradation could be described by first-order kinetics.The results demonstrated that natural attenuation plays a very important role in contaminated ground-water remediation.