橄榄果渣活性炭负载层状双金属氧化物对Cr(Ⅵ)的吸附性能及机制  

The performance and mechanism of Cr(VI)adsorption by layered bimetallic oxide supported on activated carbon of olive pomace

作　　者：雷春妮 朱梦晨 王波 程修文[1] LEI Chunni;ZHU Mengchen;WANG Bo;CHENG Xiuwen(College of Resources and Environment,Lanzhou University,Lanzhou 730000,China;Lanzhou Customs Technology Center,Lanzhou 730030,China;School of Geography and Environmental Sciences,Northwest Normal University,Lanzhou 730070,China;Key Laboratory of Oasis Resources,Environment and Sustainable Development in Gansu Province,Lanzhou 730070,China)

机构地区：[1]兰州大学资源环境学院,兰州730000 [2]兰州海关技术中心,兰州730030 [3]西北师范大学地理与环境科学学院,兰州730070 [4]甘肃省绿洲资源环境与可持续发展重点实验室,兰州730070

出　　处：《环境工程学报》2024年第8期2155-2165,共11页Chinese Journal of Environmental Engineering

摘　　要：#利用橄榄果渣做原材料,通过碱性高温活化法制备橄榄果渣活性炭(OP-AC),采用化学共沉淀法将OP-AC制备为负载层状双金属氢氧化物(FeAl-LDH)的Fe Al-LDH@AC复合材料。制备优化结果表明:在Fe-Al摩尔比为2∶1,固液比为1∶15,共沉淀时间为24 h的条件下,制备的Fe Al-LDH@AC复合材料对Cr(Ⅵ)的去除效果达到最优。表征结果表明:Fe Al-LDH@AC含有丰富的含氧官能团;有大量的Fe元素、Al元素附着到OP-AC表面,使Fe元素、Al元素与OP-AC成功结合;Fe Al-LDH@AC复合材料中存在孔隙结构,以微孔为主,也存在少量的中孔和大孔。在p H=2、Cr(Ⅵ)初始质量浓度为20 mg·L^(-1)、吸附时间为24 h、Fe Al-LDH@AC投加量为20 g·L^(-1)的条件下,Fe AlLDH@AC对Cr(Ⅵ)的去除率达97.85%,吸附容量为0.9785 mg·g^(-1)。Fe Al-LDH@AC对Cr(Ⅵ)吸附过程较符合Freundlich模型和准二级吸附动力学模型,说明吸附过程更倾向于化学吸附并且是发生在非均匀表面的多分子层吸附;由Weber-Morris颗粒内扩散方程模型可以看出,整个吸附阶段可能是由膜扩散和内扩散同时控制的。以上研究结果表明Fe Al-LDH@AC可为有效去除Cr(Ⅵ)及橄榄果渣资源化利用提供参考。Olive pomace was taken as raw material to prepare olive pomace activated carbon(OP-AC)by the alkaline high-temperature activation method,then FeAl-LDH@AC composite was prepared by loading OP-AC with layered double metal hydroxide(FEAL-LDH)by the chemical coprecipitation method.The results showed that the FeAl-LDH@AC composite with the best removal effect on Cr(Ⅵ)was prepared under the conditions of Fe-Al molar ratio of 2∶1,solid-liquid ratio of 1∶15 and coprecipitation time of 24 h.XRD and FT-IR spectra showed that FeAl-LDH@AC composites contained rich oxygen-containing functional groups,and a large number of Fe elements and Al elements attached on the surface of OP-AC,and the successful combination between Fe elements/Al element and OP-AC occurred.The pore structure in FeAl-LDH@AC composites was mainly micropores,and there were also a few mesopores and macropores.Under the conditions of pH=2,initial concentration of Cr(Ⅵ)20mg·L^(-1),adsorption time 24h and FeAl-LDH@AC dosage of 20 g·L^(-1),the removal efficiency of Cr(Ⅵ)by FeAl-LDH@AC composite reached 97.85%,and the adsorption capacity was 0.9785 mg·g^(-1).The adsorption process of Cr(Ⅵ)by FeAl-LDH@AC composite conformed to Freundlich model and quasi-second-order adsorption kinetics model,indicating that the adsorption process was inclined to chemical adsorption and multi-molecular layer adsorption on heterogeneous surfaces.Based on Weber-Morris particle diffusion equation model fitting results,the whole adsorption stage could be dominated by both membrane diffusion and internal diffusion.The above results could provide a reference for effectively removing Cr(Ⅵ)by FeAl-LDH@AC composite and resource utilization of olive pomace.

关 键 词：LDHS 活性炭 重金属离子 复合材料 

分 类 号：X703[环境科学与工程—环境工程]