Industrial wastewater often contains heavy metals, like lead, copper, nickel, cadmium, zinc, mercury, arsenic, and chromium. Overdoses of heavy metals will impose a severe threat to human health. Adsorption is the most efficient way of wastewater treatment for eliminating heavy metals. A novel material-reusable hydrogel-based adsorbent was developed in overcoming the regeneration issue. The polyethylene glycol diacrylate-3-sulfopropyl methacrylate potassium salt (PEGDA-SMP) hydrogel performed an ion-exchange rate to remove heavy metals from wastewater in 30–120 min. The adsorption capacity of PEGDA-SMP increases the increasing pH of a solution, in which pH 5 reaches the maximum. Pseudo-second-order adsorption and the Langmuir adsorption model can fully describe the adsorption properties of PEGDA-SMP for heavy metals. PEGDA-SMP prefers to exchange Pb²⁺ through K⁺, and its adsorption capacity can achieve 263.158 mg/g. Ag⁺, Zn²⁺, Ni²⁺, and Cu²⁺ were 227.27, 117.647, 102.041, and 99.010 mg/g, respectively. The hydrated ionic radius of the heavy metal might play an essential role to affect the adsorption preference. The removal efficiency of heavy metals can approach over 95% for each heavy metal. PEGDA-SMP performs rapid desorption and reaches desorption equilibrium in 15 min. After 10 consecutive adsorption–desorption cycles, the adsorption capacity remained over 90%. The hydrogel developed in this study showed reversible heavy metal absorption. Therefore, excellent adsorption–desorption properties of PEGDA-SMP can be potentially extended to industrial wastewater for removing heavy metals.

中文翻译：

---

用于去除重金属离子的可重复使用吸附剂的绿色合成

工业废水通常含有重金属，如铅、铜、镍、镉、锌、汞、砷和铬。过量摄入重金属会对人体健康造成严重威胁。吸附是去除重金属最有效的废水处理方式。为了克服再生问题，开发了一种新型材料可重复使用的水凝胶基吸附剂。聚乙二醇二丙烯酸酯-3-磺丙基甲基丙烯酸酯钾盐 (PEGDA-SMP) 水凝胶进行离子交换，可在 30-120 分钟内去除废水中的重金属。PEGDA-SMP 的吸附能力增加了溶液的 pH 值，其中 pH 值 5 达到最大值。伪二级吸附和Langmuir吸附模型可以充分描述PEGDA-SMP对重金属的吸附特性。²⁺通过 K ⁺，其吸附量可达 263.158 mg/g。Ag ⁺、Zn ²⁺、Ni ²⁺、Cu ²⁺分别为 227.27、117.647、102.041 和 99.010 毫克/克。重金属的水合离子半径可能对影响吸附偏好起重要作用。每种重金属的去除率可达95%以上。PEGDA-SMP 进行快速解吸并在 15 分钟内达到解吸平衡。经过10个连续的吸附-解吸循环后，吸附容量保持在90%以上。本研究中开发的水凝胶显示出可逆的重金属吸收。因此，PEGDA-SMP 优异的吸附-解吸特性可以潜在地扩展到工业废水中去除重金属。