改性花生壳对酸性橙Ⅱ的吸附影响因素及动力学研究

摘要

分别采用草酸、乙酸、盐酸对花生壳进行酸化改性,制备得到3种生物吸附剂:草酸改性花生壳(OPS)、乙酸改性花生壳(APS)、盐酸改性花生壳(HPS);将其用于吸附酸性橙Ⅱ,考察了改性剂、改性花生壳粒度、吸附时间、酸性橙Ⅱ溶液pH值、改性花生壳投加量及酸性橙Ⅱ溶液初始浓度等因素对吸附率的影响,初步探讨了吸附动力学.结果表明,改性花生壳对酸性橙Ⅱ的吸附能力较未改性花生壳显著提高,其中HPS的吸附效果最好.在改性花生壳粒度为120目、吸附时间为100 min、酸性橙Ⅱ溶液pH值为2.3、改性花生壳投加量为10g·L-1、酸性橙Ⅱ溶液初始浓度为50mg·L-1时,OPS、APS和HPS对酸性橙Ⅱ的吸附率分别为88.6％、92.0％和95.4％.吸附动力学研究表明,改性花生壳对酸性橙Ⅱ的吸附行为符合Lagergren准二级动力学模型,吸附过程主要为化学吸附,且吸附速率常数与改性剂酸度有关.%We prepared three biosorbents OPS,APS,and HPS,which were modified with peanut shell by oxalic acid,acetic acid,and hydrochloric,respectively.Three biosorbents were applied to adsorb acid orange Ⅱ.We investigated the effects of modifier,particle size of modified peanut shell,adsorption time,pH value of acid orange Ⅱ solution,dosage of modified peanut shell,and initial concentration of acid orange Ⅱ solution on the adsorption rate.Meanwhile,we preliminarily discussed the adsorption kinetics.The results showed that the adsorption capacity of modified peanut shell was superior to that of unmodified peanut shell,and HPS was the best one.When particle size of modified peanut shell was 120 mesh,adsorption time was 100 min,pH value of acid orangeⅡ solution was 2.3,dosage of modified peanut shell was 10 g · L-1,and initial concentration of acid orangel] solution was 50 mg · L-1,the adsorption rates of OPS,APS,and HPS were 88.6％,92.0％,and 95.4％,respectively.The adsorption kinetics indicated that the adsorption behavior of modified peanut shell to acid orange Ⅱ followed the Lagergren pseudo-second order kinetics model,the adsorption process was mainly chemical adsorption,and the adsorption rate constant was associated with the acidity of modifier.