Mihăilescu Maria, Negrea Adina, Ciopec Mihaela, Negrea Petru, Duțeanu Narcis, Grozav Ion, Svera Paula, Vancea Cosmin, Bărbulescu Alina, Dumitriu Cristian Ștefan
Research Institute for Renewable Energies, Politehnica University Timişoara, 2, P-ța Victoriei, 300006 Timişoara, Romania.
Faculty of Industrial Chemistry and Environmental Enginering, Politehnica University Timişoara, 2, P-ța Victoriei, 300006 Timişoara, Romania.
Toxics. 2021 May 20;9(5):111. doi: 10.3390/toxics9050111.
Gold is one of the precious metals with multiple uses, whose deposits are much smaller than the global production needs. Therefore, extracting maximum gold quantities from industrial diluted solutions is a must. Am-L-GA is a new material, obtained by an Amberlite XAD7-type commercial resin, functionalized through saturation with L-glutamic acid, whose adsorption capacity has been proved to be higher than those of other materials utilized for gold adsorption. In this context, this article presents the results of a factorial design experiment for optimizing the gold recovery from residual solutions resulting from the electronics industry using Am-L-GA. Firstly, the material was characterized using atomic force microscopy (AFM), to emphasize the material's characteristics, essential for the adsorption quality. Then, the study showed that among the parameters taken into account in the analysis (pH, temperature, initial gold concentration, and contact time), the initial gold concentration in the solution plays a determinant role in the removal process and the contact time has a slightly positive effect, whereas the pH and temperature do not influence the adsorption capacity. The maximum adsorption capacity of 29.27 mg/L was obtained by optimizing the adsorption process, with the control factors having the following values: contact time ~106 min, initial Au(III) concentration of ~164 mg/L, pH = 4, and temperature of 25 °C. It is highlighted that the factorial design method is an excellent instrument to determine the effects of different factors influencing the adsorption process. The method can be applied for any adsorption process if it is necessary to reduce the number of experiments, to diminish the resources or time consumption, or for expanding the investigation domain above the experimental limits.
黄金是用途广泛的贵金属之一，其储量远小于全球生产需求。因此，从工业稀释溶液中提取最大量的黄金势在必行。氨基-L-谷氨酸修饰的Amberlite XAD7型商业树脂（Am-L-GA）是一种新型材料，其吸附能力已被证明高于其他用于金吸附的材料。在此背景下，本文介绍了一项析因设计实验的结果，该实验旨在优化使用Am-L-GA从电子工业残留溶液中回收黄金的工艺。首先，使用原子力显微镜（AFM）对该材料进行表征，以突出对吸附质量至关重要的材料特性。然后，研究表明，在分析中考虑的参数（pH值、温度、初始金浓度和接触时间）中，溶液中的初始金浓度在去除过程中起决定性作用，接触时间有轻微的积极影响，而pH值和温度不影响吸附能力。通过优化吸附过程，得到了29.27 mg/L的最大吸附容量，控制因素的值如下：接触时间约106分钟，初始Au(III)浓度约164 mg/L，pH = 4，温度25°C。需要强调的是，析因设计方法是确定影响吸附过程的不同因素作用的极佳工具。如果需要减少实验次数、减少资源或时间消耗，或者扩大实验极限以上的研究范围，该方法可应用于任何吸附过程。
