凹凸棒石铁/铝氢氧化物纳米复合材料对磷的吸附动力学研究  

Kinetics of phosphate adsorption from aqueous solution onto iron/aluminium hydroxide modified palygorskite nanocomposite

作　　者：潘敏[1] 黄晓鸣[1] 陈天虎[2] 谢晶晶[2] 吴光学[3] 

机构地区：[1]厦门理工学院环境科学与工程学院,福建厦门361024 [2]合肥工业大学资源与环境工程学院,安徽合肥230009 [3]清华大学深圳研究生院,广东深圳518055

出　　处：《矿物学报》2015年第1期29-34,共6页Acta Mineralogica Sinica

基　　金：国家自然科学基金(批准号:41102023);福建省自然科学基金(编号:2013J01210);厦门市科技计划项目(编号:3502Z20130039)

摘　　要：用铁/铝盐水解法制备了凹凸棒石/铝氢氧化物(PNCMⅠ)、凹凸棒石/铁氢氧化物(PNCMⅡ)和凹凸棒石/铁铝氢氧化物(PNCMⅢ)3种凹凸棒石纳米复合材料。对比了这3种纳米复合材料对水中磷的吸附净化能力,并利用吸附动力学实验探讨了3种材料对磷的吸附机理。结果发现:负载了铝/铁氢氧化物后凹凸棒石的晶体结构没有改变;温度对于3种吸附剂吸附磷的动力学参数影响不显著;3种吸附剂对磷的实际吸附量、理论吸附量和初始吸附速率均随着磷的初始浓度增大而增大。PNCMⅠ对磷的理论吸附量为18.18 mg/g,较其他2种吸附剂大。当磷的初始浓度从5 mg/L增加到50 mg/L,PNCM I对磷的初始吸附速率从0.125 mg/(g·min)增加到1.425 mg/(g·min)。3种凹凸棒石黏土纳米复合材料对磷的吸附符合准二级动力学方程,表明其吸附均为化学吸附。In this study,three kinds of nano-adsorbents were prepared by supporting aluminum hydroxide,iron hydroxide,and aluminum/iron hydroxide onto palygorskite in hydrolysis processes(named PNCMⅠ,PNCMⅡ and PNCMⅢ) to remove phosphate from aqueous solution.They were characterized by using X-ray diffraction(XRD) and X-ray fluorescence(XRF).The adsorption behaviour and adsorption capabilities of phosphate were investigated in batch experiments.Results show that the preparation processes do not change palygorskite's crystal structure.Temperature has no obvious effects on thethree kinds of nano-adsorbents adsorbing phosphate,while the adsorption capacities and initial adsorption rates increase with increasing initial phosphate concentrations.Compared with PNCMⅡ and PNCMⅢ,PNCMⅠ shows the highest phosphate adsorption capacity of 18.18 mg/g.The initial adsorption rate of PNCMⅠ increases from 0.125 mg/g·min to 1.425 mg/g·min with increasing initial phosphate concentrations from 5 mg/L to 50 mg/L.The adsorption rates of phosphate on the three kinds of nano-adsorbents fit pseudo-second-order kinetic models,indicating that chemisorption mechanism plays an important role and that the initial adsorption rate may be controlled by a chemical reaction between Al(OH)3 and Fe(OH)3 on adsorbents and phosphate.

关 键 词：凹凸棒石 吸附 磷 动力学 

分 类 号：X703[环境科学与工程—环境工程] TQ424[化学工程]