Tǎmaş Andra, Cozma Ioana, Cocheci Laura, Lupa Lavinia, Rusu Gerlinde
Faculty of Industrial Chemistry and Environmental Engineering, University Politehnica Timisoara, Timisoara, Romania.
"Coriolan Dragulescu" Institute of Chemistry, Timisoara, Romania.
Front Chem. 2020 Nov 30;8:573535. doi: 10.3389/fchem.2020.573535. eCollection 2020.
The dye industry is one of the largest water consuming industries, and at the same time generates large quantities of wastewaters. The resulting wastewaters require proper treatment before discharge, because the dye contents have a negative effect on the water body and organisms present in it. The most efficient treatment method for water containing dyes is represented by adsorption processes. The challenge with these adsorption processes is to develop new, efficient, viable, and economic adsorbent materials. Therefore, in the present paper, the performance of ZnAl-layered double hydroxide, prepared from an industrial waste (zinc ash) as a zinc source, was investigated in the Orange II dye adsorption process. The ZnAl-layered double hydroxide prepared from secondary sources presents similar morphological and structural characteristics as those prepared from analytical grade reagents. The influence of initial dye concentration, adsorption time, solid:liquid ratio, pH, and temperature was evaluated in order to confirm the benefit of this waste valorization. A comparison with the reference ZnAl-layered double hydroxide prepared from analytical grade reagents was performed and the results show that due to the small presence of impurities, the material prepared from zinc ash shows better adsorption capacities (q = 42.5 mg/g at 293 K) than the material prepared from reagents (q = 36.9 mg/g at 293 K), justifying the utilization of secondary sources for layered double hydroxides preparation. The proposed treatment process presents advantages from both economic and environmental protection point of view.
染料工业是最大的耗水工业之一，同时会产生大量废水。这些产生的废水在排放前需要进行适当处理，因为染料成分会对水体及其中的生物产生负面影响。对于含染料的水，最有效的处理方法是吸附法。这些吸附法面临的挑战是开发新型、高效、可行且经济的吸附剂材料。因此，在本文中，研究了以工业废料（锌灰）作为锌源制备的ZnAl层状双氢氧化物在橙黄II染料吸附过程中的性能。由二次资源制备的ZnAl层状双氢氧化物呈现出与由分析纯试剂制备的类似的形态和结构特征。评估了初始染料浓度、吸附时间、固液比、pH值和温度的影响，以确认这种废料资源化利用的益处。与由分析纯试剂制备的参比ZnAl层状双氢氧化物进行了比较，结果表明，由于杂质含量少，由锌灰制备的材料比由试剂制备的材料表现出更好的吸附容量（293K时q = 42.5mg/g）（293K时q = 36.9mg/g），证明了利用二次资源制备层状双氢氧化物的合理性。所提出的处理工艺从经济和环境保护角度来看都具有优势。
