摘要
采用直接法和后嫁接法成功制备出骨架掺杂Al原子,孔道表面接枝大位阻含胺基基团的双功能介孔硅基吸附材料.采用SAXRD、TEM、FTIR、NH3-TPD等手段对合成材料进行表征,结果表明合成的双功能AN-SBA-15具有有序的二维六方介孔结构,孔道表面的Al-OH与胺基不会发生自发复合反应.对模拟废水中Cd^(2+)和Cr_2O_7^(2-)的同时吸附去除实验研究表明AN-SBA-15具备同时吸附废水中Cd^(2+)和Cr_2O_7^(2-)离子的能力,吸附最佳pH值为5.0,吸附在40 min就达到平衡.AN-SBA-15对Cd^(2+)和Cr_2O_7^(2-)离子的吸附符合Langmuir模型,属于单层吸附.由Langmuir模型拟合出的AN-SBA-15对Cd^(2+)和Cr_2O_7^(2-)离子的最大吸附容量分别为125.9 mg·g^(-1)和156.5 mg·g^(-1).此外AN-SBA-15具备良好的脱附再生能力.
A bifunctional mesoporous silica adsorbent（ AN-SBA-15） was synthesized with a two-step process. Aluminum atoms were firstly incorporated into the framework of SBA-15 and then sterically hindered groups were anchored onto the Al-substituted SBA-15. The results of SAXRD,TEM,FTIR and NH3-TPD showed that the AN-SBA-15 kept an ordered hexagonal mesostructure after the functionalization processes. The aluminum hydroxyl groups and sterically hindered groups maintained the optimal synergy,avoiding the occurrence of spontaneous neutralization reactions. AN-SBA-15 had an excellent performance for simultaneous removal of Cd^（2＋）and Cr2O2-7from wastewater and the optimized p H value was 5.0. The adsorption rate was extremely fast,and the equilibrium reached within 40 min. The adsorption of Cd^（2＋）and Cr2O2-7by AN-SBA-15 fitted better to Langmuir than Freundlich,indicating that Cd^（2＋）and Cr2O2-7adsorption onto AN-SBA-15 followed the mechanism of monolayer adsorption. The maximum adsorption capacities toward Cd^（2＋）and Cr2O2-7of AN-SBA-15 were 125.9 mg·g^（-1） and 156.5 mg·g-1,respectively. Furthermore,AN-SBA-15 could be easily regenerated and repeatedly utilized in the wastewater treatment.
出处
《环境科学学报》
CAS
CSCD
北大核心
2016年第7期2483-2490,共8页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.512102047
51472050)~~
