Departamento de Ingeniería Hidráulica y Ambiental, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile.
Departamento de Química Inorgánica, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile.
Int J Environ Res Public Health. 2020 Sep 21;17(18):6911. doi: 10.3390/ijerph17186911.
Adsorption technologies are a focus of interest for the removal of pollutants in water treatment systems. These removal methods offer several design, operation and efficiency advantages over other wastewater remediation technologies. Particularly, graphene oxide (GO) has attracted great attention due to its high surface area and its effectiveness in removing heavy metals. In this work, we study the functionalization of GO with zinc oxide nanoparticles (ZnO) to improve the removal capacity of aluminum (Al) and copper (Cu) in acidic waters. Experiments were performed at different pH conditions (with and without pH adjustment). In both cases, decorated GO (GO/ZnO) nanocomposites showed an improvement in the removal capacity compared with non-functionalized GO, even when the pH of zero charge (pH) was higher for GO/ZnO (5.57) than for GO (3.98). In adsorption experiments without pH adjustment, the maximum removal capacities for Al and Cu were 29.1 mg/g and 45.5 mg/g, respectively. The maximum removal percentages of the studied cations (Al and Cu) were higher than 88%. Further, under more acidic conditions (pH 4), the maximum sorption capacities using GO/ZnO as adsorbent were 19.9 mg/g and 33.5 mg/g for Al and Cu, respectively. Moreover, the removal percentages reach 95.6% for Al and 92.9% for Cu. This shows that decoration with ZnO nanoparticles is a good option for improving the sorption capacity of GO for Cu removal and to a lesser extent for Al, even when the pH was not favorable in terms of electrostatic affinity for cations. These findings contribute to a better understanding of the potential and effectiveness of GO functionalization with ZnO nanoparticles to treat acidic waters contaminated with heavy metals and its applicability for wastewater remediation.
吸附技术是水处理系统中去除污染物的研究热点。与其他废水修复技术相比，这些去除方法在设计、操作和效率方面具有优势。特别地，氧化石墨烯 (GO) 因其高比表面积和去除重金属的有效性而受到极大关注。在这项工作中，我们研究了氧化锌纳米粒子 (ZnO) 对 GO 的功能化，以提高其在酸性水中对铝 (Al) 和铜 (Cu) 的去除能力。实验在不同的 pH 条件下进行（有和没有 pH 调节）。在这两种情况下，与未功能化的 GO 相比，修饰后的 GO (GO/ZnO) 纳米复合材料显示出对 Al 和 Cu 的去除能力的提高，即使 GO/ZnO 的零电荷 pH (pH) 比 GO 的更高（分别为 5.57 和 3.98）。在没有 pH 调节的吸附实验中，Al 和 Cu 的最大去除容量分别为 29.1 mg/g 和 45.5 mg/g。所研究的阳离子（Al 和 Cu）的最大去除百分比均高于 88%。此外，在更酸性的条件下 (pH 4)，使用 GO/ZnO 作为吸附剂时，Al 和 Cu 的最大吸附容量分别为 19.9 mg/g 和 33.5 mg/g。此外，Al 的去除百分比达到 95.6%，Cu 的去除百分比达到 92.9%。这表明，用 ZnO 纳米粒子对 GO 进行修饰是提高 GO 对 Cu 去除的吸附能力的一种有效方法，对 Al 的吸附能力也有一定程度的提高，即使在 pH 不利于阳离子静电亲和力的情况下也是如此。这些发现有助于更好地理解 GO 与 ZnO 纳米粒子的功能化在处理受重金属污染的酸性水方面的潜力和有效性，以及其在废水修复方面的应用。
