Russo Eleonora, Sgarbossa Paolo, Gelosa Simone, Copelli Sabrina, Sieni Elisabetta, Barozzi Marco
Department of Industrial Engineering, University of Padova, Via F. Marzolo 9, 35131 Padova, Italy.
Department of Chemistry Materials and Chemical Engineering, Politecnico of Milan, Via Luigi Mancinelli 7, 20131 Milan, Italy.
Materials (Basel). 2024 Apr 23;17(9):1942. doi: 10.3390/ma17091942.
Graphene oxide and its magnetic nanoparticle-based composites are a well-known tool to remove heavy metals from wastewater. Unfortunately, one of the major issues in handling such small particles consists of their difficult removal from treated wastewater (even when their magnetic properties are exploited), due to their very small diameter. One possible way to overcome this problem is to embed them in a macroscopic biopolymer matrix, such as alginate or chitosan beads. In this way, the adsorbent becomes easier to handle and can be used to build, for example, a packed column, as in a traditional industrial adsorber. In this work, the removal performances of two different embedded magnetic nanocomposite adsorbents (MNAs) are discussed. The first type of MNA is based on ferrite magnetic nanoparticles (MNPs) generated by coprecipitation using iron(II/III) salts and ammonium hydroxide, while the second is based on a 2D material composed of MNP-decorated graphene oxide. Both MNAs were embedded in cross-linked alginate beads and used to treat artificial water contaminated with chromium(III), nickel(II), and copper(II) in different concentrations. The yield of removal and differences between MNAs and non-embedded magnetic nanomaterials are also discussed. From the results, it was found that the time to reach the adsorption equilibrium is higher when compared to that of the nanomaterials only, due to the lower surface/volume ratio of the beads, but the adsorption capacity is higher, due to the additional interaction with alginate.
氧化石墨烯及其基于磁性纳米颗粒的复合材料是从废水中去除重金属的一种知名工具。不幸的是，处理此类小颗粒的主要问题之一在于，由于其直径非常小，很难从处理后的废水中去除它们（即使利用了它们的磁性）。克服这个问题的一种可能方法是将它们嵌入宏观生物聚合物基质中，例如藻酸盐或壳聚糖珠粒。通过这种方式，吸附剂变得更易于处理，并且可用于构建例如填充柱，就像传统工业吸附器那样。在这项工作中，讨论了两种不同的嵌入式磁性纳米复合吸附剂（MNAs）的去除性能。第一种类型的MNA基于使用铁（II/III）盐和氢氧化铵通过共沉淀生成的铁氧体磁性纳米颗粒（MNPs），而第二种基于由MNP修饰的氧化石墨烯组成的二维材料。两种MNA都被嵌入交联藻酸盐珠粒中，并用于处理被不同浓度的铬（III）、镍（II）和铜（II）污染的人工水。还讨论了去除率以及MNA与未嵌入的磁性纳米材料之间的差异。从结果中发现，与仅使用纳米材料相比，由于珠粒的表面/体积比更低，达到吸附平衡的时间更长，但由于与藻酸盐的额外相互作用，吸附容量更高。
