阿特拉津及其代谢物在砂质壤土中的吸附

采用批量平衡法研究了阿特拉津（AT）及其主要代谢物脱乙基阿特拉津（DEA）和脱异丙基阿特拉津（DIA）在砂质壤土中的吸附行为，讨论了离子强度和温度对吸附的影响.结果表明，3种化合物的吸附24h基本达到平衡，吸附量大小顺序为AT > DIA > DEA；二级动力学模型可以很好地预估平衡吸附容量和初始吸附速率常数，颗粒内扩散方程表明颗粒扩散不是唯一的控速手段，Elovich方程拟合所得AT、DEA和DIA的瞬时吸附占各自吸附总量的53%、85%和80%；Freundlich方程能很好地描述3种化合物在供试土壤中的吸附特性，吸附系数（K_f）范围为0.7992~1.3201mg^1-1/n·mL^1/n/kg，经验常数1/n范围为0.7440~0.7530.溶液的离子强度和温度影响土壤对化合物的吸附，温度升高，K_f值降低；CaCl₂从0~0.01mol/L，K_f值增大，再继续增加，吸附系数有降低的趋势.

Sorption of atrazine and its metabolites on a sandy loam soil

The sorption ability of atrazine and its metabolites deethylatrazine and deisopropylatrazine onto a sandy loam soil were studied, and its influencing factors, such as the ionic strength of aqueous solution, and temperature, were also investigated. The results showed the sorption process was controlled by instantaneous equilibrium followed by a time-dependent phase until 24h, and the equilibrium sorption capacity decreased in the order of AT > DIA > DEA. The equilibrium sorption capacity and initial sorption rate constant were well described by the second order equation, and the predicted values agreed well with the experimental ones. Intraparticle diffusion model indicated that the rate of sorption was not only controlled by intraparticle diffusion for the entire sorption period. The percentage of instantaneous sorption of AT, DEA and DIA achieved from Elovich equation was 53%, 85% and 80%, respectively. The sorption isotherms of the AT, DEA and DIA were well described by the Freundlich equation and the K_f values were 1.2574, 0.7992 and 1.3201 for AT, DEA and DIA, respectively. The solution ionic strength and temperature have a significant effect on the sorption of AT, DEA and DIA for test soil. The K_f values were all decreased with the temperature and have positive correlation of ionic strength.