717型阴离子交换树脂吸附水溶性芳香族有机污染物研究

研究了717型阴离子交换树脂对苯酚、苯甲酸和十二烷基苯磺酸钠(SDBS)等水溶性芳香族污染物吸附过程的基本化学问题.研究结果表明:717型树脂对苯酚、苯甲酸和SDBS的吸附过程均符合Lagergren二级吸附动力学方程,吸附速率均随着温度的升高而加快,吸附表观活化能Ea分别为13.2kJ/mol、59.5kJ/mol和48.1kJ/mol,吸附过程△H0和△S0均为正值,△G0均为负值,吸附能够自发进行；吸附等温模型符合Langmuir等温式；318K时,717型树脂在pH=9.1对SDBS的饱和吸附容量为360mg/g;在pH=10.2,对苯酚和苯甲酸的饱和吸附容量分别为194mg/g和286mg/g.用浓度均为0.5mol/L,体积比为5∶1的NaCl-NaOH混合溶液可快速洗脱树脂上吸附的污染物,洗脱率达98％以上.该树脂对水溶性芳香族污染物吸附容量大,易于再生和循环利用,可用于环境水体中水溶性芳香族有机污染物的吸附治理.

REMOVAL OF SOLUBLE ORGANIC CONTAMINANTS BY 717-TYPE STRONGLY BASIC ANION EXCHANGE RESIN

The adsorption of the water soluble aromatic contaminations,such as phenol,benzoic acid and sodium dodecylbenzene sulfonate(SDBS),by 717-type strongly basic anion exchange resin was investigated.The adsorption process was studied under different experimental conditions including pH,contact time,initial concentration of contamination solution and temperature.Results showed that the kinetic experimental data correlated well with the pseudo-second-order model;the rate constant of the adsorption increased with the temperature increasing.The apparent activation energy for the adsorption of different substances was calculated as follows: 13.2kJ/mol for phenol,59.5kJ/mol for benzoic acid and 48.1kJ/mol for SDBS,respectively.The values of ΔHo and ΔSo were all positive,which indicated a spontaneous and endothermic adsorption procedure.Adsorption pattern on the 717-type resin fitted Langmuir isotherms and maximum adsorption capacity were 194mg/g for phenol,286mg/g for benzoic acid and 360mg/g for SDBS,respectively.Moreover,under the room temperature,0.5mol/L NaCl and NaOH mixture solution(v/v=5:1) can be used as a desorption solution whose desorption ratio can reach up to 97%.The advantages of 717-type resin,such as higher removal efficiency of aromatic pollutants,easier regeneration;lower cost and better recyclability,can make it useful in the treatment of soluble organic contaminants containing hydroxyl,carboxyl and sulfonic acid group in environmental water.