Abstract:
Effective elimination of heavy metals from complex wastewater is of great significance for industrial wastewater treatment. Herein, bimetallic adsorbent Fe3O4-CeO2 was prepared, and H2O2 was added to enhance Sb(V) adsorption by Fe3O4-CeO2 in complex wastewater of Sb(V) and aniline aerofloat (AAF) for the first time. Fe3O4-CeO2 showed good adsorption performance and could be rapidly separated by external magnetic field. After five adsorption/desorption cycles, Fe3O4-CeO2 still maintained good stability. The maximum adsorption capacities of Fe3O4-CeO2 in single Sb(V), AAF + Sb(V), and H2O2+AAF + Sb(V) systems were 77.33, 70.14, and 80.59 mg/g, respectively. Coexisting AAF inhibited Sb(V) adsorption. Conversely, additional H2O2 promoted Sb(V) removal in AAF + Sb(V) binary system, and made the adsorption capacity of Fe3O4-CeO2 increase by 14.90%. H2O2 could not only accelerate the reaction rate, but also reduce the optimal amount of adsorbent from 2.0 g/L to 1.2 g/L. Meanwhile, coexisting anions had little effect on Sb(V) removal by Fe3O4-CeO2+H2O2 process. The adsorption behaviors of Sb(V) in three systems were better depicted by pseudo-second-order kinetics, implying that the chemisorption was dominant. The complexation of AAF with Sb(V) hindered the adsorption of Sb(V) by Fe3O4-CeO2. The complex Sb(V) was oxidized and decomposed into free state by hydroxyl radicals produced in Fe3O4-CeO2+H2O2 process. Then the free Sb(V) was adsorbed by Fe3O4-CeO2 mostly through outer-sphere complexation. This work provides a new tactic for the treatment of heavy metal-organics complex wastewater.
摘要:
有效消除复杂废水中的重金属对工业废水处理具有重要意义。在这里,制备了Fe3O4-CeO2双金属吸附剂,首次添加H2O2以增强Fe3O4-CeO2对Sb(V)和苯胺气浮法(AAF)复合废水中Sb(V)的吸附。Fe3O4-CeO2具有良好的吸附性能,能在外加磁场下快速分离。在五个吸附/解吸循环后,Fe3O4-CeO2仍保持较好的稳定性。Fe3O4-CeO2在单一Sb(V)中的最大吸附容量,AAF+Sb(V),H2O2+AAF+Sb(V)系统分别为77.33、70.14和80.59mg/g,分别。共存AAF抑制Sb(V)吸附。相反,在AAF+Sb(V)二元体系中,添加H2O2促进Sb(V)的去除,并使Fe3O4-CeO2的吸附量提高了14.90%。H2O2不仅能加快反应速率,而且还将吸附剂的最佳用量从2.0g/L降低到1.2g/L。同时,共存阴离子对Fe3O4-CeO2+H2O2工艺去除Sb(V)影响不大。通过拟二级动力学较好地描述了Sb(V)在三种体系中的吸附行为,暗示化学吸附占主导地位。AAF与Sb(V)的络合阻碍了Fe3O4-CeO2对Sb(V)的吸附。配合物Sb(V)被Fe3O4-CeO2H2O2过程中产生的羟基自由基氧化并分解为游离态。然后游离的Sb(V)主要通过外球络合被Fe3O4-CeO2吸附。本研究为重金属有机物复合废水的处理提供了一种新的策略。