改性锯末生物炭对水中As(Ⅲ)和Cd(Ⅱ)吸附机制的研究  

Removal characteristics of As(Ⅲ) and Cd(Ⅱ) from aqueous solution by modified sawdust-ash biochar

作　　者：解攀 张言 王雪梅 张萌 季宏兵 XIE Pan;ZHANG Yan;WANG Xue-mei;ZHANG Meng;JI Hong-bing(School of Energy and Environmental Engineering,University of Science&Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学能源与环境工程学院,北京100083

出　　处：《应用化工》2020年第2期296-301,307,共7页Applied Chemical Industry

基　　金：国家自然科学基金(41173113)。

摘　　要：以农业废弃物锯末为材料制备生物炭,用铁锰氧化物对锯末生物炭改性,探究某吸附As和Cd的能力与机制。结果表明,改性生物炭增大了孔径和比表面积,增加了更多的吸附点位,尤其是铁、锰、生物炭的质量比为1∶3∶15的吸附剂吸附效果最好,对于砷和镉的平衡吸附量分别增大了35倍和5倍,最大吸附量分别为7.452,17.053 mg/g。低pH环境下,Cd^2+的吸附受到抑制,而As^3+受pH影响较小。Cd和As吸附符合准二级吸附动力学模型,As和Cd的吸附热力学符合Langmuir模型,这表明吸附过程为单层吸附。The biochar was prepared by sawdust-ash,and modified by the iron-manganese oxide.The batch adsorption experiments were carried out to investigate the adsorption capacity of adsorbents for As and Cd.The results show that the modified biochar increases the pore size and specific surface area,and increases the adsorption point.The mass ratio of iron,manganese and biochar was 1∶3∶15 which was the best,the equilibrium adsorption capacity of arsenic and cadmium increased by 35 times and 5 times,respectively,the maximum adsorption amounts for As and Cd were 7.452 and 17.053,respectively.The effect of solution pH showed that the adsorption of Cd^2+ was inhibited in low pH environment,while As^3+ was less affected by pH,the adsorption of Cd and As is in accordance with the quasi second order adsorption kinetic model and the adsorption thermodynamics of As and Cd is in accordance with the Langmuir model,which indicates that the adsorption process is monolayer adsorption.

关 键 词：复合污染 改性生物炭 铁锰氧化物 竞争吸附 

分 类 号：TQ424[化学工程]