Jahan Kousar, Thankachan Darieo, Shakya Kaushal, Mehrotra Nitisha, C S Nimish, Verma Vivek
Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India; Cochin University of Science and Technology, Kochi 682022, India.
Int J Biol Macromol. 2024 Dec;282(Pt 2):136784. doi: 10.1016/j.ijbiomac.2024.136784. Epub 2024 Oct 22.
In this study, we have developed agar, a seaweed derived polysaccharide based green adsorbent for the removal of heavy metal ions (Pb, Cu, Cr and Cd) from multimetal solution. Porous cryogels of agar grafted with 3-aminopropyl triethoxysilane (APTES) were prepared by freeze-drying. The adsorption capacity and selectivity of the optimized APTES-agar cryogel for heavy metal ions (Cu, Cr, Pb, Cd) were investigated in multimetal solutions. >95 % of all the cationic metal ions were removed from 400 mg/L multimetal metal solutions having equal concentrations of each metal at pH 5.5. The experimental adsorption capacities of Cr, Cu, Pb, and, Cd were changed from 39.14, 39.0, 39.20, 37.93 mg/g, to 52.58, 52.70, 45.53, 31.10 mg/g, respectively, for the 400 mg/L and 800 mg/L multimetal solutions suggesting competitive adsorption of the metal ions for active sites. The competitive adsorption studies showed that Cd ions had lower affinity than other metal ions for active sites on APTES grafted agar surface, and adsorption followed in the order of Cu ≈ Cr > Pb > Cd. The developed seaweed-derived agar-based porous adsorbent exhibits promise in the removal of several heavy metal ions from wastewater, and this approach would increase the use of natural polysaccharides that are sustainable.
在本研究中，我们开发了琼脂，一种基于海藻衍生多糖的绿色吸附剂，用于从多金属溶液中去除重金属离子（铅、铜、铬和镉）。通过冷冻干燥制备了接枝3-氨丙基三乙氧基硅烷（APTES）的琼脂多孔冷冻凝胶。研究了优化后的APTES-琼脂冷冻凝胶对多金属溶液中重金属离子（铜、铬、铅、镉）的吸附容量和选择性。在pH值为5.5的情况下，从每种金属浓度相等的400mg/L多金属溶液中去除了>95%的所有阳离子金属离子。对于400mg/L和800mg/L的多金属溶液，铬、铜、铅和镉的实验吸附容量分别从39.14、39.0、39.20、37.93mg/g变为52.58、52.70、45.53、31.10mg/g，这表明金属离子对活性位点存在竞争性吸附。竞争性吸附研究表明，镉离子对APTES接枝琼脂表面活性位点的亲和力低于其他金属离子，吸附顺序为铜≈铬>铅>镉。所开发的基于海藻衍生琼脂的多孔吸附剂在去除废水中的几种重金属离子方面显示出前景，并且这种方法将增加可持续天然多糖的使用。
