中文摘要：

为开发一种表征土壤中有机污染物流动性和生物有效性的新型方法,建立了一套热解吸装置,并对甲苯和芘在3种土壤中的水解吸和热解吸进行了比较研究.2种解吸行为均呈现二元模式,表明吸附态芳烃化合物在土壤中处于不同的结合状态.用两室一级动力学模型和指数衰减平衡方程对甲苯和芘的水、热解吸行为进行分析,分别得到水解吸易解吸部分所占百分数Frap和水、热解吸速率常数bw、bt等参数.甲苯在1、2、3号土中的Frap分别是27.9%、12.5%、16.0%;芘的分别是2.4%、22.0%、19.1%;甲苯3种土中的bw的值分别是0.241、0.018、0.038;芘的分别是0.008、0.013、0.012.Frap与bw呈正相关（甲苯：R^2=0.982;芘：R^2=0.991）.250℃时,甲苯在3种土中的bt的值分别是0.167、0.064、0.141;芘的分别是0.036、0.062、0.047;400℃时,甲苯的bt值分别是0.429、0.084、0.398;芘的分别是0.066、0.162、0.153.bw与bt有一定的相关性（250℃：R^2=0.985;400℃：R^2=1.848）,且Frap与.bt有正相关关系.由于水解吸所得的Frap可被用于表征生物可利用性,因此可以通过热解吸技术预测污染物在土壤中的生物可利用性.

英文摘要：

In order to develop a new method to study the mobility and bioavailability of organic contaminants in soils,a set of thermal desorption device was established.Water desorption and thermal desorption of toluene and pyrene in three types of soils were investigated.The two desorption occurred as bi-phase,which indicates that the combination states of the aromatic hydrocarbons in soils are different.The desorption was described by the first-order two compartment model and an exponential decay equation.Parameters,such as fast desorption fraction Frap,water and thermal desorption rate constants,bw and bt were derived.For toluene,values of Frap in three soils were 27.9%,12.5%,16.0%,respectively,and 2.4%,22.0%,and 19.1% for pyrene.Values of bw were 0.241,0.018,0.038 for toluene and 0.008,0.013,0.012 for pyrene.There is a significantly positive correlation relationship between Frapand bw（toluene： R^2= 0.982;pyrene： R^2= 0.991）.At 250℃,values of bt in three soils were 0.167,0.064,0.141 for. toluene,and 0.036,0.062,0.047 for pyrene.At 400℃,the corresponding values were 0.429,0.084,0.398 for toluene and 0.066,0.162,0.153 for pyrene.Meanwhile,the water bw shows a good correlation with bt at selected temperatures（250℃： R^2= 0.985;400℃： R^2= 0.848）.Moreover,Frapis positively correlated with bt.As Frap has been used to predict bioavailability,thermal desorption can therefore be used to predict bioavailability.