For the prevention of freshwater reservoirs from contamination through industrial effluents, eco-friendly adsorbents with minimal aging impact are required. Here, redox-sensitive nanoscale zero-valent iron(nZVI) particles were supported on four different surfaces with varying bentonite(B)/charcoal(C) ratio to mimic layered and porous surfaces. Different dyes, i.e. rhodamine-B(RB) and methylene blue(MB) were reacted with redox-sensitive supported nZVI composites, and degradation mechanisms were delineated using FT-IR spectroscopic analysis of reaction precipitates. A 300-day exposure to open-air was provided to the composites to comparatively evaluate the impact of aging on their reactivity for dyes in wastewater.

Results interpret that dyes removal was a combination of different interfacial chemical processes, i.e., reduction or organic degradation probably through Fenton like processes, along with sorption. These mechanisms were found to be surface dependent, i.e., nZVI on charcoal enriched porous surfaces, degrade dyes through organic degradation while on layered clay surfaces, MB gets removed through reduction with limited and slower RB removal. Nanocomposites show a minimal impact of aging with removal capacities >100 mg/g for BC-1/3-nZVI and C-nZVI for MB and 50−75 mg/g for RB with significant removal in wastewater. Overall, the study concludes C-nZVI and novel BC-1/3-nZVI as two efficient dye adsorbents with minimal aging impact.

为了防止淡水水库受到工业废水的污染，需要具有最小老化影响的环保型吸附剂。在这里，氧化还原敏感的纳米级零价铁（nZVI）颗粒被负载在具有不同膨润土（B）/木炭（C）比的四个不同表面上，以模拟层状和多孔表面。使不同的染料，如若丹明-B（RB）和亚甲基蓝（MB）与氧化还原敏感的负载型nZVI复合材料反应，并使用FT-IR光谱分析反应沉淀物描述了降解机理。向复合材料提供了300天的露天暴露，以比较评估老化对其对废水中染料的反应性的影响。

结果表明，染料的去除是不同界面化学过程的结合，即可能通过Fenton样过程的还原或有机降解以及吸附。发现这些机制是表面依赖性的，即，在富含木炭的多孔表面上，nZVI通过有机降解来降解染料，而在层状粘土表面上，通过有限且较慢的RB去除通过还原去除MB。纳米复合材料显示出对老化的影响最小，对BC-1 / 3-nZVI和C-nZVI的MB去除能力> 100 mg / g，对RB的去除能力> 50-75 mg / g，其中废水的去除率很高。总体而言，研究得出结论，C-nZVI和新型BC-1 / 3-nZVI是两种有效的染料吸附剂，对老化的影响最小。