Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
J Hazard Mater. 2020 Jan 15;382:121060. doi: 10.1016/j.jhazmat.2019.121060. Epub 2019 Aug 21.
Polymer hydrogel usually has limited catalytic activity and stability in Fenton catalysis. Here, we presented for the first time the preparation of a novel double-metal-crosslinked alginate hydrogel using graphene oxide to facilitate the Fe(II)/Fe(III) redox cycles. Five multivalent metal cations were used as crosslinkers to prepare different alginate-GO-M (Fe(III), Fe(II), La(III), Ce(III), and Co(II)), and the effects of assisted metal cations (La(III), Ce(III), and Co(II)) on different Fe(II) bimetallic alginate-GO-Fe-M(AG-Fe-M) complexes were investigated. Double-metal-crosslinked alginate-GO hydrogels can degrade tetracycline much faster during the initial 10 min than single-metal-crosslinked hydrogels. In addition, the release of iron from AG-Fe-Ce (10.59 ppm) was less than that from AG-Fe-Co (21.57 ppm) and AG-Fe-La (25.6 ppm) during the Fenton reaction. More importantly, the AG-Fe-Ce did not release TOC and maintained most of the catalytic activity after four reuse cycles, confirmed its excellent stability. For the treatment of raw water containing a high proportion of proteinaceous matter and tetracycline, the AG-Fe-Ce significantly reduced the molecular weight of the dissolved organic matter. We deduced that the humic acid and protein show good complexation ability to tetracycline, thereby reduced its bioavailability. This study provides new insights into the synthesis of polymer catalysts for water treatment.
水凝胶通常在芬顿催化中具有有限的催化活性和稳定性。在这里，我们首次制备了一种新型的双金属交联海藻酸钠水凝胶，使用氧化石墨烯来促进 Fe(II)/Fe(III) 氧化还原循环。使用五种多价金属阳离子作为交联剂来制备不同的海藻酸钠-GO-M（Fe(III)、Fe(II)、La(III)、Ce(III)和 Co(II)），并研究了辅助金属阳离子（La(III)、Ce(III)和 Co(II)）对不同 Fe(II)双金属海藻酸钠-GO-Fe-M（AG-Fe-M）配合物的影响。双金属交联海藻酸钠-GO 水凝胶在最初的 10 分钟内比单金属交联水凝胶更快地降解四环素。此外，在芬顿反应中，AG-Fe-Ce（10.59 ppm）释放的铁少于 AG-Fe-Co（21.57 ppm）和 AG-Fe-La（25.6 ppm）。更重要的是，AG-Fe-Ce 在四次重复使用循环后没有释放 TOC 并保持了大部分催化活性，证实了其优异的稳定性。对于处理含有高比例蛋白质和四环素的原水，AG-Fe-Ce 显著降低了溶解有机物的分子量。我们推断腐殖酸和蛋白质对四环素具有良好的络合能力，从而降低了其生物利用度。这项研究为水处理用聚合物催化剂的合成提供了新的思路。
