磺胺类抗生素的活性炭吸附过程研究

采用煤质活性炭对3种磺胺类抗生素(浓度在1～2 mg/L之间)的吸附处理过程做了深入研究。结果表明,3种磺胺类抗生素在2～3 h之内可以达到吸附平衡;准一级动力学对其吸附动力学的模拟结果良好,且SMZ、SM1和SM2的一级吸附动力学常数k1分别为0.029、0.024和0.017 min-1,3种抗生素的平衡吸附容量分别为3.75、3.23和2.95 mg/g,SMZ的平衡吸附容量最大,最先达到吸附平衡,且平衡浓度也最低。3种磺胺类抗生素的吸附过程中,吸附前期的阻力主要是内扩散,而吸附后期较低浓度的抗生素吸附过程的阻力主要来自于膜扩散;采用Freundlich等温线方程描述3种磺胺类抗生素的吸附过程更为合理。

Research on adsorption process of sulfonamide antibiotics with activated carbon

The adsorption removal of three sulfanilamide antibiotics with coal-based activated carbon at intermediate concentrations(1~2 mg/L) was studied in depth.The results showed that equilibrium can be achieved within 2~3 h for the three sulfonamide antibiotics.The adsorption kinetic can be well described with Lagergren kinetic model,and the first-order rate constant k1 were 0.029,0.024 and 0.017 min-1,respectively for SMZ,SM1and SM2.The adsorption capacities were 3.75,3.23 and 2.95 mg/g,respectively.SMZ firstly reached equilibrium,and equilibrium concentration was the lowest.The adsorption process of sulfonamide antibiotics with activated carbon was controlled by intra-particle diffusion at the early adsorption stage,then at the later stage liquid membrane diffusion resistance was do minant.It was more reasonable for Freundlich isotherm to describe the adsorption process of the three sulfanilamide antibiotics.