ZSM-5分子筛表面酸碱性质及对Co^(2+)的吸附

采用XRD、FTIR和酸碱滴定等手段对ZSM-5分子筛性质进行研究。采用静态批实验方法研究pH值、离子强度、固液比、平衡时间和Co2+浓度等因素对Co2+在ZSM-5分子筛表面上吸附的影响。结果表明,ZSM-5分子筛对Co2+具有较好的吸附能力和吸附容量;在低pH值下ZSM-5分子筛表面吸附位是以XH、YOH、YO-、YOH2+和XNa形态为主;而在高pH值条件下以YO-和XNa两种形态为主。Co2+在ZSM-5分子筛上的吸附符合准二级动力学;吸附作用受离子强度和pH值影响比较明显。在低pH值下,Co2+主要与ZSM-5分子筛表面发生离子交换作用(X2Co);在高pH值下以表面络合吸附为主(主要形成YOHCo2+和YOCo+两种形态)。

高岭土和二氧化硅的表面酸碱性质定量模式计算

环境水化学研究中，水体颗粒物具有广义概念，研究的焦点之一就是表面络合原理及其定量计算模 式。通过对絮凝试验时常用到的物质高岭土、二氧化硅进行研究，根据表面络合原理，通过电位滴定及 ＦＩＴＥＱＬ程序，计算高岭土、二氧化硅的表面络合常数，并根据不同的表面络合理论进行比较、讨论，得到了 与实验数据相吻合的计算结果。

Surface Acidity of Amorphous Aluminum Hydroxide

The surface acidity of synthetic amorphous AI hydroxide was determined by acid/base titration with several complementary methods including solution analyses of the reacted solutions and XRD characterization of the reacted solids. The synthetic specimen was characterized to be the amorphous material showing four broad peaks in XRD pattern. XRD analyses of reacted solids after the titration experiments showed that amorphous AI hydroxide rapidly transformed to crystalline bayerite at the alkaline condition （pH〉10）. The solution analyses after and during the titration Ksp=^aAl^3＋/aH^＋^3 ,was 10^10.3. The amount of consumption of added acid or base during the titration experiment was attributed to both the protonation/deprotonation of dissolved AI species and surface hydroxyl group. The surface acidity constants, surface hydroxyl density and specific surface area were estimated by FITEQL 4.0.

表面络合理论中常用计算机模型软件

本文介绍了表面络合模式计算中用到的相关计算机软件 ,如MIRCQL、MINEQL、HYDKAQL和FITEQL等 。