摘要
采用浸渍沉淀法,制备了La(OH)_(3)/SiO_(2)气凝胶吸附材料,并利用XRD、SEM、FT-IR、XPS、BET对吸附剂结构、表面形貌等进行表征。研究了吸附剂投加量、初始pH和共存离子对磷酸根吸附效果的影响,探究了吸附过程的吸附动力学、等温吸附过程及吸附热力学模型。实验结果表明:AER-La0.2(质量比为0.2∶1时)的磷酸根吸附量可达294.1 mg/g(La);且对磷酸根具有较好的吸附选择性;吸附剂添加量为0.4 g/L时获得最好的吸附能力;在较宽的pH范围内保持了较好的吸附能力。准二级动力学模型和Langmuir等温吸附模型的结果更准确,说明吸附过程主要受化学吸附控制且主要为单层吸附。吸附热力学的结果表明,吸附过程为吸热过程,温度越高对吸附越有利。结合表征手段,推断AER-La0.2的主要吸附作用可能为静电吸引及配体交换。
La(OH)_(3)/SiO_(2)aerogel adsorption materials were prepared via immersion precipitation technique and the adsorbent structure and surface morphology were characterized by XRD,SEM,FT-IR,XPS,and BET.The effects of adsorbent dosage,initial pH values,and coexisting ions on the adsorption effect of phosphate were investigated.Meanwhile,the adsorption kinetics,isothermal adsorption processes,and adsorption thermodynamic models were studied.Experimental results showed that the phosphate adsorption capacity of AER-La0.2(at a mass ratio of 0.2∶1)was up to 294.1 mg/g(La)with good adsorption selectivity.The best adsorption capacity was obtained at an adsorbent addition of 0.4 g/L,and very good adsorption capacity can be maintained in a wide pH range.As a fact the quasi-second-order kinetic model and the Langmuir isothermal adsorption model fit better with the actual data,it was indicated that the adsorption process was mainly controlled by chemisorption and monolayer adsorption.The results of adsorption thermodynamics showed that the adsorption process is heat-absorbing,and higher temperature is more favorable for adsorption.Combined with the characterization methods,it is inferred that the main adsorption of AER-La0.2 may be through electrostatic attraction and ligand exchange.
作者
林晓燕
练钊华
林璟
左建良
刘自力
LIN Xiao-yan;LIAN Zhao-hua;LIN Jing;ZUO Jian-liang;LIU Zi-li(School of Chemistry and Chemical Engineering,Guangzhou University,Guangzhou 510006,China)
出处
《化学试剂》
CAS
2024年第3期39-48,共10页
Chemical Reagents
基金
Pd基催化剂化学环境调控及其对甲酸分解制氢性能的影响(2021A1515010078)。
