丙烯酸接枝改性丙纶非织造布的吸附与解吸研究

Adsorption and desorption of acrylic acid-grafted polypropylene nonwovens

采用丙烯酸接枝改性聚丙烯非织造布(PP-g-AA)对阳离子红X-GRL染料进行吸附与解吸,探讨了PP-g-AA对染料的吸附动力学机理、解吸过程和解吸动力学机理,以及基于动态吸附的过滤分离操作,分析了PP-g-AA对染料吸附-解吸再生循环利用的可行性。结果表明:不同初始染料浓度下,PP-g-AA的吸附动力学符合Lagergren's准二级动力学模型和双指数模型;解吸液的最佳配比为表面活性剂质量分数5%,乙醇与水的体积比3∶7,解吸率随吸附量的增大呈现先增大后减小的趋势,解吸符合Lagergren's准二级动力学模型;动态吸附-解吸再生循环10次后,染料的去除率达96%以上,再生循环8次时,PP-g-AA的跨膜压力为37.1 k Pa,水通量最大达38.6 L/(m2·h)。

The adsorption and desorption of acrylic acid grafted polypropylene （PP-g-AA） nonwovens to cationic red X-GRL dye were studied. The adsorption and desorption process and kinetics of PP-g-AA to cationic dyes were discussed. The feasibility of adsorption-desorption recycling of cationic dyes on PP-g-AA was analyzed based on dynamic adsorptive filtration and separation operation. The results showed that both Lagergren＇s pseudo-second order and double-exponential models were applicable for the fitting of the adsorption kinetic data of PP-g-AA at different dye initial concentration; the optimal ingredient of desorption solution was 5% anionic surfaetant by mass fraction and 3 ： 7 ethanol-to-water volume ratio; the desorption rate was increased and then decreased with the increase of adsorption capacity; the desorption kinetics also followed Lagergren＇s pseudo-second order model; the removal rate of dyes was above 96% after 10-time dynamic adsorption-desorption cycles; and the transmembrane pressure of PP-g-AA was 37.1 kPa and the water flux reached the maximal value of 38.6 L/（ m^2 · h） after 8-time recycling cycles.