The water pollution caused by the heavy metal ions have raised potent damages to the water ecosystem and human health. It is thus important to develop materials that can capture the heavy metal ions effectively and efficiently in the wastewater to resolve this issue. Herein, a highly porous functional hydrogel from the egg white (EW) integrated with polyethyleneimine (PEI) was prepared and examined for the adsorptive removal of the Cu²⁺, Pb²⁺ and Cd²⁺ ions in aqueous solutions. A systematic study was performed to illustrate the EW/PEI hydrogel's excellent affinity to the metallic ions in both the mono- and competitive adsorption systems. The maximum adsorption capacities for the Cu²⁺, Pb²⁺ and Cd²⁺ ions in the mono-adsorption system were determined to be 7.494, 2.194 and 3.705 mmol g⁻¹, respectively with the adsorption rates and isotherms complying with the pseudo-second order kinetics and Langmuir isotherm model, respectively. Furthermore, in situ reduction turned the adsorbed Cu²⁺ ions into uniformly distributed Cu nanoparticles (NPs) in the EW/PEI hydrogel. This material can serve as an excellent catalyst as confirmed by a ~98% conversion of 4-nitrophenol (20 mmol) to 4-aminophenol in 10 min at the ambient temperature. The EW/PEI hydrogel and the Cu NPs-decorated EW/PEI hydrogel catalyst can be regenerated easily as proved by the consecutive adsorption/desorption and catalysis experiments for several repetitions, respectively. Therefore, the current study highlights the application of the EW/PEI hydrogel as an effective and practical approach for capturing and recycling/utilizing the toxic metal ions in the wastewater.

重金属离子造成的水污染已经严重破坏了水生态系统和人类健康。因此，重要的是开发能够有效和高效地捕获废水中重金属离子的材料来解决此问题。在此，从与聚乙烯亚胺（PEI）结合的蛋清（EW）中制备了高度多孔的功能性水凝胶，并研究了其在水溶液中对Cu 2 ⁺，Pb ²⁺和Cd ²⁺离子的吸附去除。进行了系统的研究，以说明EW / PEI水凝胶在单吸附和竞争吸附系统中对金属离子均具有出色的亲和力。Cu 2 ⁺，Pb ²⁺和Cd的最大吸附量确定单吸附系统中的²⁺离子分别为7.494、2.194和3.705 mmol g ^-1，其吸附速率和等温线分别符合拟二级动力学和Langmuir等温线模型。此外，原位还原使吸附的Cu ²⁺离子进入EW / PEI水凝胶中的均匀分布的Cu纳米颗粒（NPs）。该材料可以用作出色的催化剂，在环境温度下，在10分钟内将4-硝基苯酚（20 mmol）转化为4-氨基苯酚的转化率约为98％，这证实了该材料。EW / PEI水凝胶和用Cu NPs修饰的EW / PEI水凝胶催化剂可以轻松地再生，这分别通过连续几次吸附/解吸和催化实验证明。因此，当前的研究强调了EW / PEI水凝胶的应用作为一种有效和实用的方法，用于捕获和回收/利用废水中的有毒金属离子。