Rahman Md Musfiqur, Hafez Islam, Tajvidi Mehdi, Amirbahman Aria
Laboratory of Renewable Nanomaterials, School of Forest Resources, University of Maine, 5755 Nutting Hall, Orono, ME 04469, USA.
Department of Civil, Environmental and Sustainable Engineering, Santa Clara University, 500 El Camino Real, Santa Clara, CA 95053, USA.
Nanomaterials (Basel). 2021 Oct 23;11(11):2818. doi: 10.3390/nano11112818.
The application and optimal operation of nanoparticle adsorbents in fixed-bed columns or industrial-scale water treatment applications are limited. This limitation is generally due to the tendency of nanoparticles to aggregate, the use of non-sustainable and inefficient polymeric resins as supporting materials in fixed-bed columns, or low adsorption capacity. In this study, magnesium-doped amorphous iron oxide nanoparticles (IONPs) were synthesized and immobilized on the surface of cellulose nanofibrils (CNFs) within a lightweight porous aerogel for arsenic removal from water. The IONPs had a specific surface area of 165 m g. The IONP-containing CNF aerogels were stable in water and under constant agitation due to the induced crosslinking using an epichlorohydrin crosslinker. The adsorption kinetics showed that both As(III) and As(V) adsorption followed a pseudo second-order kinetic model, and the equilibrium adsorption isotherm was best fitted using the Langmuir model. The maximum adsorption capacities of CNF-IONP aerogel for As(III) and As(V) were 48 and 91 mg As g-IONP, respectively. The optimum IONP concentration in the aerogel was 12.5 wt.%, which resulted in a maximum arsenic removal, minimal mass loss, and negligible leaching of iron into water.
纳米颗粒吸附剂在固定床柱或工业规模水处理应用中的应用和优化运行受到限制。这种限制通常是由于纳米颗粒的聚集倾向、在固定床柱中使用不可持续且效率低下的聚合物树脂作为支撑材料，或者吸附容量较低。在本研究中，合成了镁掺杂的非晶态氧化铁纳米颗粒（IONPs），并将其固定在轻质多孔气凝胶内的纤维素纳米纤维（CNFs）表面，用于从水中去除砷。IONPs的比表面积为165 m²/g。由于使用环氧氯丙烷交联剂诱导交联，含IONP的CNF气凝胶在水中和持续搅拌下均保持稳定。吸附动力学表明，As(III)和As(V)的吸附均遵循准二级动力学模型，平衡吸附等温线用Langmuir模型拟合效果最佳。CNF-IONP气凝胶对As(III)和As(V)的最大吸附容量分别为48和91 mg As/g-IONP。气凝胶中IONP的最佳浓度为12.5 wt.%，此时砷去除率最高，质量损失最小，铁向水中的浸出可忽略不计。
