摘要
以果胶为原料,利用溶胶-凝胶法,Ca2+为交联剂制备出果胶-Ca微球,使用多巴胺修饰果胶-Ca微球生成功能化的吸附剂果胶-聚多巴胺(PDA)微球。探讨了该吸附剂去除Th4+的吸附性能,并利用SEM、FTIR和XPS分析了其功能化制备和吸附的机理。结果表明,果胶-PDA微球在pH=3.5时吸附效果最好,在25℃、pH=3.5、初始Th4+质量浓度为24mg/L、吸附剂质量为0.03g的条件下,接触时间为1200min时,吸附容量可达到37.172mg/g;共存离子Cs+、Sr2+、Mn2+和Mg2+对Th4+的吸附影响较小,说明该吸附剂对Th4+的吸附选择性较好;热力学和动力学研究结果表明,吸附过程符合线性Langmuir等温吸附模型和准二级动力学模型,最大吸附量为99.010 mg/g;热力学数据表明,果胶-PDA吸附Th4+是一个自发吸热的过程;TG分析可知,果胶-PDA的热稳定性较改性前果胶-Ca有所提高;果胶-PDA上的N、O与溶液中Th4+发生的螯合作用是果胶-PDA微球对Th4+的主要吸附机理。
Pectin-Ca microspheres were prepared by sol-gel method with Ca2+ as cross-linking agent, and then dopamine was used to modify the pectin-Ca microspheres to prepare functional pectin-PDA microspheres as adsorbent. The adsorption performance of this adsorbent for removing Th4+ was discussed.SEM, FTIR and XPS techniques were used to analyze the preparation of pectin-PDA microspheres and its adsorption mechanism. The results showed that pectin-PDA microspheres had the best adsorption effect for Th4+ at pH=3.5. The adsorption capacity of adsorbent reached 37.172 mg/g under the conditions of 25 ℃,initial mass concentration of Th4+ 24 mg/L, adsorbent dosage 0.03 g, and contact time 1200 min.Co-existing ions Cs+, Sr2+, Mn2+ and Mg2+ had little effect on the adsorption of Th4+, indicating that the adsorbent had better adsorption selectivity for Th4+. The thermodynamics and kinetics showed that the adsorption was described well by the Langmuir linear isotherm model and the kinetic data conformed to the pseudo-second-order kinetics model. The maximum adsorption capacity was 99.010 mg/g. The thermodynamic data showed that the adsorption of Th4+ by pectin-PDA was a spontaneous absorption. TG analysis revealed that the thermal stability of pectin-PDA microspheres was better than that of pectin-Ca microspheres. Coordination of N and O from pectin-PDA microspheres with Th4+ in solution was the main adsorption mechanism of pectin-PDA microspheres for Th4+.
作者
张永德
张思月
易发成
乔丹
贾岷明
ZHANG Yong-de;ZHANG Si-yue;YI Fa-cheng;QIAO Dan;JIA Min-ming(National Defense Key Discipline Laboratory of Nuclear Waste and Environmental Safety,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;Research Center of Biomass Materials,Ministry of Education,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;School of MaterialsScience and Engineering,Mianyang 621010,Sichuan,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2019年第6期1217-1227,1248,共12页
Fine Chemicals
基金
国家核设施退役及放射性废物治理科研重点项目(14ZG6101)
西南科技大学平台基金项目(14tdsc01)
西南科技大学龙山学术人才科研支持计划(17LZX202,18LZX207)~~
关键词
果胶
多巴胺
Th4+
吸附性
热稳定性
水处理技术与环境保护
pectin
dopamine
Th4+
adsorption
thermal stability
water treatment technology and environmental protection
