摘要
用酰胺基团溴化后碘化镉-淀粉显色分光光度法测定了在0~50mg/L低浓度范围内聚丙烯酰胺(PAM)在高岭土和蒙脱土上的吸附等温线,并考察了电解质浓度和类型对吸附的影响.结果表明,PAM在黏土矿物上有很强的吸附亲合力,吸附等温线为Langmuir型.电解质能大大增强PAM在黏土矿物上的吸附,其中二价离子比一价阳离子更有效.电解质浓度较低时,PAM分子主要以链序态吸附,电解质浓度较高时,以链环态、链端态吸附的数量逐渐增多.PAM的吸附只限制在层状黏土矿物的外表面上.在Na+介质中,PAM在两种黏土矿物上的吸附量差别不大;而在Ca2+介质中,蒙脱土悬浮颗粒产生分裂,为PAM的吸附提供新的外表面积,PAM的吸附量大大高于在高岭土上的吸附量,前者约是后者的2~3倍.
In this paper, the adsorption isotherms of polyacrylamide (PAM) on kaolinite and montmorillonite were measured in low concentration of 0 [similar to] 50 mg/L and the effect of type and concentration of electrolyte on PAM adsorption were examined. Results show that PAM has a high adsorptive affinity on clay minerals and the isotherms display a Langmuir type. The amount of anionic PAM adsorbed on clay minerals increases greatly by electrolyte in which divalent cation is more effective than monovalent cation. In lower electrolyte concentration, adsorbed PAM molecules are mainly in trains; while in higher electrolyte concentration, their adsorption amount increases gradually as loops and tails. In Na+ medium, there are no significant difference between the adsorption amounts of PAM on kaolinite and on montmorillonite, while in Ca2+ medium, the amounts of PAM adsorbed on montmorillonite is 2 [similar to] 3 times higher than on kaolinite, which is due to the discerption of suspended montmorillonite particles thus providing new outer-surface for PAM adsorption.
出处
《中国环境科学》
EI
CAS
CSSCI
CSCD
北大核心
2001年第5期476-480,共5页
China Environmental Science
