摘要
为探索制备绿色、低碳的甲醛吸附材料,通过碱溶(1 mol/L的Na_(2)SiO_(3)和2 mol/L的NaOH)-水热反应改性硅藻土,制备出可吸附甲醛的硅藻土基材料,其对甲醛去除率达82.6%,且符合伪-二级吸附模型。红外光谱(FT-IR)结果表明硅藻土中的≡Si—O—Si≡结构发生了“解聚-重组”过程,并与硅藻土中的铝反应形成具有Al—O—Si结构物质;X-射线衍射(XRD)结果表明硅藻土中的硅铝化合物可原位合成少量ZSM-5沸石分子筛及大量的无定形物质;^(29)Si核磁共振(^(29)Si NMR MAS)结果进一步证实Al和Si的结合方式主要为2个Al取代三维≡Si—O骨架结构Q_(0)^(4),并形成具有Q_(2)^(4)的结构单元;扫描电镜(SEM)结果表明碱溶-水热处理可促使具有规则孔洞结构的硅藻土形成更多无定型、结构更复杂的孔网结构,进而提高其对甲醛的吸附性能。
A novel modified diatomite was prepared through alkaline dissolution(1 mol/L Na_(2)SiO_(3) and 2 mol/L NaOH)hydrothermal reaction to seek green and low carbon formaldehyde-adsorption materials,with a strong adsorption capacity to formaldehyde,its removal rate for formaldehyde reached 82.6%,fitting pseudo-secondary adsorption model.The results of FT-IR demonstrated that the process of"depolymerization-reorganization"occurred for the ≡Si—O—Si≡structure involved in diatomite,and it reacted with activated aluminum of diatomite to form Al—O—Si structures.XRD results showed that the ZSM-5 zeolite molecular sieve could be in situ synthesized by silicon and aluminum of diatomite,as well as the amorphous material.It confirmed further that the three dimensional ≡Si—O skeletal structure Q_(0)^(4) mainly transformed into Q_(2)^(4) with two[Al(OH)4]replacement of Si(OH)_(4) from ^(29)Si MAS—NMR results.SEM results revealed that the alkaline dissolution hydrothermal reaction prompted the diatomite with regular hole structure transform into more amorphous,more complex inter-penetrating network structure,leading to an increase in the adsorption ability to formaldehyde.
作者
刘小丽
LIU Xiaoli(School of Architecture and Engineering,Guangdong Polytechnic of Science and Technology,Zhuhai Guangdong 519090,China)
出处
《工业安全与环保》
2023年第9期74-79,共6页
Industrial Safety and Environmental Protection
基金
智能绿色建筑技术与海绵城市建设工程中心科研资助项目(K01057058)。
关键词
硅藻土
微观结构
核磁共振
吸附机理
甲醛
diatomite
microstructure
nuclear magnetic resonance
adsorption mechanism
formaldehyde
