论文部分内容阅读
用3-巯丙基三甲氧基硅烷(MPTMS)对13X分子筛表面进行修饰,采用XRD和FT-IR测试方法对功能化前后的分子筛结构进行表征,结果表明,功能化后分子筛在保持原有结构同时表面还接枝了对Pb2+离子有吸附能力的巯基基团。吸附实验表明,巯基功能化分子筛对水中Pb2+离子比原分子筛具有更强的吸附去除效果,饱和吸附容量和去除率提高近一倍。SH-13X对Pb2+离子的等温吸附符合Langmuir模型,最大吸附容量为47.01 mg/g,吸附强度b为2.26。动力学分析表明SH-13X对Pb2+离子的吸附过程更符合准二级动力学模型,而且粒内扩散不是该吸附过程的主要吸附机制。溶液中的Pb2+与嫁接在分子筛表面及孔口位置的-SH功能团形成配位络合物而去除。
The surface of 13X molecular sieve was modified by 3-mercaptopropyltrimethoxysilane (MPTMS). The molecular sieve structure before and after functionalization was characterized by XRD and FT-IR. The results showed that the functionalized molecular sieve retained the original structure At the same time also grafted on the surface of Pb2 + ion adsorption capacity of thiol group. Adsorption experiments show that the sulfhydryl-functionalized molecular sieve has a stronger adsorption and removal effect on Pb2 + ions in the water than the original molecular sieve, and the saturated adsorption capacity and removal rate nearly doubled. The isothermal adsorption of Pb2 + ions by SH-13X conformed to the Langmuir model with the maximum adsorption capacity of 47.01 mg / g and the adsorption strength b of 2.26. Kinetic analysis shows that the adsorption of Pb2 + by SH-13X is more in accordance with quasi-second-order kinetic model, and intragranular diffusion is not the main adsorption mechanism of this adsorption process. The Pb2 + in the solution forms a coordination complex with the -SH functional group grafted on the surface of the molecular sieve and the position of the orifice.