摘要: |
【目的】研究铝锰复合氧化物负载锯末对F-的吸附效果,为促进农业废弃物的资源化利用提供参考。【方法】通过氧化还原 共沉淀法制备铝锰复合氧化物负载锯末(AMOCS),采用静态吸附试验和动态吸附试验批处理法,探究AMOCS去除F-的吸附动力学和吸附等温线特征,并讨论pH(3~10)和共存阴离子(Cl-,CO2-3,SO2-4,SiO2-3,PO3-4)对F-吸附效果的影响。【结果】当AMOCS投加量为0.3~3 g/L时,F-去除率随着AMOCS投加量的增加而升高;当AMOCS投加量高于3 g/L后,继续增大AMOCS投加量,F-去除率增加幅度不明显。AMOCS对F-的吸附过程可用Langmuir等温线方程拟合,且拟合结果显示,AMOCS对F-的最大吸附量可达35.698 mg/g。AMOCS吸附F-的适宜pH为5~8,pH<5和pH>8时,F-吸附均会受到明显抑制。CO2-3、Cl-对AMOCS吸附F-没有明显的抑制作用,而SO2-4、PO3-4、SiO2-3对AMOCS吸附F-的抑制作用较强,且抑制作用随阴离子浓度的升高而加剧。动态吸附试验中,吸附柱的穿透时间和吸附剂饱和时穿透时间均随着空床接触时间的增加而增大。【结论】与锯末相比,AMOCS对F-的吸附作用有明显提高。 |
关键词: 铝锰氧化物负载锯末 氟 吸附作用 |
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基金项目:国家自然科学基金项目(51208415/51578440);陕西省教育厅重点实验室项目(14JS042) |
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Performance of aluminum-manganese bimetal oxide coated sawdust for fluorine adsorption |
LEI Hang,LEI Chao,LIU Ting,et al
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Abstract: |
【Objective】This study investigated the adsorption of F- on alumina-manganese bimetal oxide coated sawdust (AMOCS) to provide reference for comprehensive utilization of agricultural wastes resource.【Method】This study focused on the adsorption kinetics and adsorption isotherm characteristics of F- adsorption by AMOCS with the static and dynamic adsorption test batch with redox co-precipitation method.The influences of pH (3-10) and coexisting ions (Cl-,CO2-3,SO2-4,SiO2-3,and PO3-4) on F- adsorption were also investigated.【Result】The F- removal rate increased with the increase of AMOCS dosage in 0.3-3 g/L,but the increase was not significant when AMOCS dosage was higher than 3 g/L.The kinetic data followed the pseudo-second-order model and the equilibrium data could be satisfactorily described by the Langmuir isotherm model.The saturated adsorption capacity of the modified sawdust was 35.698 mg/g.The optimal pH for F- adsorption was 5-8,while F- adsorption was inhibited with pH<5 and pH>8.The presence of CO2-3 and Cl- had no negative effect on F- adsorption,while SO2-4,PO3-4,and SiO2-3 inhibited the adsorption becaues of the competitive adsorption.Higher ion concentrations resulted in stronger inhibition.In dynamic experiments,the breakthrough time for F- removal decreased with the increase of inlet water velocity.【Conclusion】Compared with sawdust, AMOCS showed better adsorption of F-. |
Key words: aluminum-manganese bimetal oxide coated sawdust (AMOCS) fluorine adsorption |