氢氧化铝胶体对2,2′,4,4′-四溴联苯醚的吸附

溴代阻燃剂多溴联苯醚（polybrominated diphenyl ethers, PBDEs）是一种被广泛使用的阻燃剂，其对神经、甲状腺、肝脏等具有潜在毒性。其中，2,2′,4,4′-四溴联苯醚（BDE-47）作为一种重要单体，在环境介质中被广泛检出。胶体是环境中污染物迁移过程中的重要载体，它对有机污染物在土壤-地下水系统中的迁移有不可忽略的影响。开展典型无机胶体氢氧化铝胶体对BDE-47的吸附动力学和吸附热力学研究，以期为BDE-47在土壤-地下水中的迁移提供理论依据。结果表明：Sips等温吸附方程对该吸附过程拟合效果最佳（R2adj=0.943 94），计算得出氢氧化铝胶体对BDE-47的饱和吸附量为609.37 mg·g-1；吸附动力学实验结果显示，准二级反应动力学方程拟合氢氧化铝胶体对BDE-47吸附反应过程最佳（R2adj>0.95），同时该吸附反应速率随BDE-47浓度的升高逐渐减小；Van’t Hoff方程拟合表明，吸附热力学参数标准反应焓变△H0 =40.506 kJ·mol-1、标准反应熵变△S0 =0.075 7 kJ·（mol·K）-1，标准反应吉布斯自由能△G0 （298 K）=17.98 kJ·mol-1。此外，反应体系的pH和阳离子种类及浓度均会影响氢氧化铝胶体对BDE-47的吸附过程。

Adsorption of BDE-47 on aluminium hydroxide colloid

Polybrominated diphenyl ethers (PBDEs), which are a kind of widely used brominated flame retardants, are found potentially threatening nervous system, thyroid, and liver etc. As an important congener, 2,2′,4,4′-tetrabrominated biphenyl ether(BDE-47) is widely detected in environmental medium. Colloid is a key carrier during migration process of pollutants in the environment, especially for the migration of organic compounds in soil-groundwater system. This paper focused on the adsorption kinetics and thermodynamics of BDE-47 on aluminium hydroxide colloid of typical inorganic colloid, in order to provide theoretical basis for migration of BDE-47 in the environment. The results show that the Sips equation can describe adsorption process of BDE-47 on aluminium hydroxide colloid best (R2adj=0.943 94), and saturated adsorption capability is 609.37 mg·g-1 under the situation. Adsorption kinetics study indicates that pseudo-second-order equation gives the best fitting result with adsorption process (R2adj>0.95). The reaction rate of adsorption process decreased with the increasing concentration of BDE-47. Thermodynamic parameters calculated by Van’t Hoff equation are △H0 =40.506 kJ·mol-1, △S0 =0.075 7 kJ·(mol·K)-1，△G0 (298 K)=17.98 kJ·mol-1. Besides, pH, species and concentration of cations definitely affect the adsorption process of BDE-47 on aluminium hydroxide colloid.