D301和MIEX两种阴离子交换树脂对水中BrO_(3)^(-)的吸附性能

Adsorption Properties of BrO_(3)^(-) from Water on D301 and MIEX Anion Exchange Resins

研究了D301和MIEX两种阴离子交换树脂对水中BrO_(3)^(-)的吸附性能。结果表明:pH值对两种树脂吸附BrO_(3)^(-)的影响相似,两种树脂均在pH为4~9范围时对BrO_(3)^(-)的吸附量最大。共存Cl^(-)、SO42-和NO_(3)^(-)明显削弱两种树脂对BrO_(3)^(-)的吸附,其影响大小顺序为NO_(3)^(-)>SO_(4)^(2-)>Cl^(-)。MIEX树脂吸附BrO_(3)^(-)仅需4 min达到平衡,D301树脂吸附BrO_(3)^(-)需180 min达到平衡,MIEX树脂具有比D301树脂更大的准二级速率常数K_(2)和颗粒内扩散速率常数K_(id)。BrO_(3)^(-)在D301和MIEX两种树脂上的吸附等温线符合Freundlich方程,MIEX树脂对BrO_(3)^(-)的吸附量大于D301树脂对BrO_(3)^(-)的吸附量。D301和MIEX两种树脂对BrO_(3)^(-)的吸附机理为阴离子交换。

The adsorption properties of BrO_(3)^(-)from water on D301 and MIEX anion exchange resins were investigated.The results showed that the effects of pH on the adsorption of BrO_(3)^(-)on the two resins were similar.The two resins exhibited the largest adsorption capacities of BrO_(3)^(-)at pH 4~9.The adsorption capacities of BrO_(3)^(-)were significantly weakened by the coexistence anions of Cl^(-),SO_(4)^(2-)and NO_(3)^(-).The influence of the coexistence anions followed the order NO_(3)^(-)>SO42->Cl^(-).It took only 4 min for MIEX to reach adsorption equilibrium of BrO_(3)^(-),and 180 min for D301 to reach adsorption equilibrium of BrO_(3)^(-).MIEX exhibited a larger pseudo-second-order rate constant k_(2) and a larger intraparticle diffusion rate constant k_(id)than that of D301.The adsorption isotherms of BrO_(3)^(-)on D301 and MIEX were in accordance with Freundlich equation.Adsorption isotherms and adsorption thermodynamics indicated that the adsorption capacities of BrO_(3)^(-)on MIEX were higher than those of D301.The adsorption mechanism of BrO_(3)^(-)on D301 and MIEX was anion exchange.