摘要
将氧化石墨烯(GO)、致孔剂与海藻酸钠共混后与CaCl2交联制备的GO/海藻酸钙(CA)水凝胶复合膜作为含重金属废水的吸附材料。采用SEM和TEM表征了复合膜的表面形貌及透射性能,且分析了GO的加入对复合膜的力学性能、平均孔径、水通量及表面官能团的影响。为探究GO/CA水凝胶复合膜的吸附性能,考察了其吸附Cd(Ⅱ)的影响因素:pH(6~7)值、初始离子浓度、接触时间、温度(三者均正相关)。用FTIR、XPS在吸附前后对复合膜进行了表征;引入了吸附动力学和等温线模型分析其吸附机制。探究结果表明GO的加入提高了复合膜的力学性能、平均孔径及水通量;吸附过程遵循Langmuir等温线,属于单层吸附,拟合得到的最大吸附量为173.61 mg/g;伪一级和伪二级吸附动力学分别在低浓度和高浓度时能较好地描述吸附过程的动力学行为;吸附机制主要为物理作用力吸附和离子交换。经过5个连续的吸附-解吸循环证明了GO/CA水凝胶复合膜的可重复利用性。
The crosslinked graphene oxide(GO)/calcium alginate(CA)hydrogel composite membranes,prepared by blending GO,porogenas as well as Na alginate hydrogel(SA),cross-linking with CaCl2,were used as adsorbent for wastewater containing heavy metal ions.SEM and TEM were used to characterize the composite membranes.The influences of GO on the mechanical properties,average pore diameter,water flux and surface functional groups of the composite membrane were analyzed.To explore the adsorption performance of GO/CA hydrogel composite membrane,the influencing factors of Cd(Ⅱ)adsorption including pH(6-7),initial ion concentration,contact time and temperature(all positively correlated)were investigated.The composite membranes before and after adsorption of Cd(Ⅱ)were characterized by FTIR and XPS;The adsorption kinetics and adsorption isotherm model were introduced to analyze the adsorption mechanism.The results show that the introduction of GO improves the mechanical properties,average pore diameter and water flux of the composite membrane.The adsorption process follows the Langmuir isotherm,belonging to the monolayer adsorption.The maximum adsorption capacity is 173.61 mg/g.The pseudo-first and pseudo-second adsorption kinetics could describe the adsorption process at low and high concentration,respectively.The adsorption mechanism is mainly physical force adsorption and ion exchange.The recyclability of the GO/CA hydrogel composite membranes was demonstrated by five successive adsorption-desorption cycles.
作者
白成玲
王磊
朱振亚
王旭东
BAI Chengling;WANG Lei;ZHU Zhenya;WANG Xudong(Key Laboratory of Membrane Separation of Shaanxi Province,Shaanxi Key Laboratory of Environment Engineering,School of Environmental and Municipal Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Province Key Laboratory of Sustained Utilization and Development of Water Resources,School of Water Resources and Environment,Hebei GEO University,Shijiazhuang 050031,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2020年第6期1458-1465,共8页
Acta Materiae Compositae Sinica
基金
陕西省重点科技创新团队计划(2017KCT-19-01)
陕西省重点产业链(群)项目(2017ZDCXL-GY-07-03)
西安市科技计划项目(201805033YD11CG17(3))
陕西省技术创新引导专项(2018HJCG-18)
陕西省自然科学基础研究计划课题(2017JM5110)。
