2,4,6-三氯酚在盐城湿地土壤中的吸附行为

Adsorption behaviors of 2,4,6-TCP in Yancheng wetland soil

2,4,6-三氯酚（2,4,6-TCP）是造纸废水中的有机污染物之一,具有毒性强、难生物降解等特点。为了解盐城湿地土壤对2,4,6-TCP的吸附行为,采用批平衡实验研究了2,4,6-TCP在该土壤中的动力学和热力学吸附特征,并考察了不同溶液pH及离子强度对土壤吸附2,4,6-TCP的影响。结果表明,在水土比为10∶1的条件下,当溶液pH为3~9时,吸附系数Kd随pH的升高由8.01 L/g降到1.57 L/g;当Ca Cl2溶液浓度为0、0.01和0.1 mol/L时,该土壤对10 mg/L 2,4,6-TCP的吸附量则分别为20.64、26.62和39.57 mg/kg。与拟一级动力学模型和拟二级动力学模型相比,双室一级动力学模型能较好地描述湿地土壤对2,4,6-TCP的动态吸附过程。在288、298和308 K温度下Freundlich方程能较好地拟合2,4,6-TCP的吸附等温线,吸附系数Kf随温度的升高依次为5.91、7.35和11.14（mg/kg）/（mg/L）n,该吸附过程为自发的吸热反应。

The 2,4,6-trichlorophenol（2,4,6-TCP） is one of the organic pollutants of papermaking wastewater and has high toxicity and nonbiodegradable properties.In order to understand the adsorption behaviors of 2,4,6-TCP in Yancheng wetland soil,batch equilibrium experiments were conducted to study the kinetic and thermodynamics of 2,4,6-TCP adsorption in the soil,and the effects of different solution pH value and ion strength on adsorption of the 2,4,6-TCP were also investigated.Results showed that the adsorption coefficient（Kd） decreased from 8.01 L/g to 1.57 L/g with increasing solution pH ranging from 3 to 9; the adsorption capacity of 10 mg/L2,4,6-TCP dissolved in 0,0.01 and 0.1 mol/LCa Cl2 solution in the soil were 20.64,26.62 and39.57 mg/kg,respectively under the condition of the solution-to-solid of 10 ∶ 1.Two-compartment first-order model perform better than Pseudo-first-order model and Pseudo-second-order model in description of 2,4,6-TCP kinetic adsorption.The Freundlich equation can well fit 2,4,6-TCP adsorption isotherm in wetland soil at 288,298 and 308 K,and the adsorption coefficient（Kf） were 5.91,7.35 and 11.14（mg /kg） /（mg /L）nin turn with increased temperature,the adsorption process is spontaneous endothermic reaction.