摘要
以甲醛(CH2O)为交联剂,聚乙二醇(PEG)为制孔剂,将腐殖酸(HA)交联到壳聚糖(CS)上成功制备了一种新型多孔吸附材料CS-HA凝胶球,研究其对Cr(Ⅵ)、Ni(Ⅱ)、Cu(Ⅱ)和Pb(Ⅱ)的吸附行为,以及在渗滤液环境下这四种重金属离子的动态吸附效果。结果表明:CS-HA凝胶球对Cr(Ⅵ)、Ni(Ⅱ)、Cu(Ⅱ)和Pb(Ⅱ)的最佳吸附pH分别为3、8、6和6;吸附均为自发进行的;吸附过程更符合拟二级动力学过程和Langmuir等温模型,其单层饱和吸附量分别为108.84 mg/g、170.40 mg/g、104.95 mg/g和92.80 mg/g。在动态吸附实验中,CS-HA凝胶球能同时吸附渗滤液中的Cr(Ⅵ)、Ni(Ⅱ)、Cu(Ⅱ)和Pb(Ⅱ),四种重金属离子的动态总吸附量相近;Ni(Ⅱ)达到耗竭点的时间最长,对吸附剂的利用率相对最高。FTIR红外光谱结果表明CS-HA凝胶球中的氨基、羟基和羧基等官能团与重金属离子的络合作用是主要的吸附机制。
Anovel porous composite adsorbent(CS-HA gel beads)was prepared by chitosan(CS)modified with humic acid(HA),using formaldehyde(CH2O)as the crosslinking agent and polyethylene glycol(PEG)as the pore-forming agent.The static adsorption performance of Cr(Ⅵ),Ni(Ⅱ),Cu(Ⅱ)and Pb(Ⅱ)by CS-HA gel beads and the dynamic adsorption capacity of the four heavy metal ions in the leachate environment were investigated.The results showed that the optimal adsorption pH of Cr(Ⅵ),Ni(Ⅱ),Cu(Ⅱ)and Pb(Ⅱ)were 3,8,6 and 6,respectively.The adsorption process of the four heavy metal ions conformed to the pseudo-second-order kinetics and Langmuir isothermal model,with the adsorption being spontaneous.The maximum adsorption capacity of Cr(Ⅵ),Ni(Ⅱ),Cu(Ⅱ)and Pb(Ⅱ)was 108.84 mg/g,170.40 mg/g,104.95 mg/g and 92.80 mg/g,respectively.The dynamic adsorption experiment results showed that CS-HA gel beads could simultaneously adsorb Cr(Ⅵ),Ni(Ⅱ),Cu(Ⅱ)and Pb(Ⅱ)from the leachate,and the adsorption capacity of the four heavy ions was similar.The depletion time of Ni(Ⅱ)was the longest,and the utilization efficiency of the adsorbent was the highest.The FTIR results indicated that the complexation of hydroxyl,amino and carboxyl groups with heavy metal ions was the main adsorption mechanism.
作者
刘珊
廖磊
魏莉
李炫妮
曹磊
王鑫
LIU Shan;LIAO Lei;WEI Li;LI Xuanni;CAO Lei;WANG Xin(School of Water and Environment,Chang an University,Xi’an 710054,China;Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region,Ministry of Education,Chang an University,Xi’an 710054,China;Fourth Institute of Geological and Mineral Exploration of Gansu Provincial Bureau of Geology and Mineral Resources,Jiuquan 735000,Gansu,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2023年第3期239-246,共8页
Materials Reports
基金
国家自然科学基金(51408041)。
关键词
壳聚糖
腐殖酸
渗滤液
重金属离子
吸附
chitosan
humic acid
leachate
heavy metal ion
adsorption
