Song Langrun, Nan Jun, Liu Bohan, Wu Fangmin
State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
Chemosphere. 2023 Apr;319:138016. doi: 10.1016/j.chemosphere.2023.138016. Epub 2023 Jan 30.
Excessive phosphorus in water causes environmental security problems like eutrophication. Advanced two-dimensional material MXene has attracted raising attention in aquatic adsorption, while lack of selectivity and difficult recovery limit its application in phosphate removal. In this study, TiC-MXene embedded zirconium-crosslinked SA (MX-ZrSA) beads were synthesized and their phosphate adsorption performance under different conditions was assessed. Investigations using SEM/EDS, XRD, BET, TGA and contact angle meter reveal that the addition of TiC-MXene enhanced the thermal stability, mechanical strength, hydrophilicity, and formed loose network-like mesoporous inner structure with large surface area. The theoretical maximum adsorption capacity was 492.55 mg P/g and was well fitted by Freundlich and optimized Langmuir models. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis showed that chemisorption was involved, and the formation of Zr-O-P and Ti-O-P complexes accounted for high selectivity and affinity to phosphate. The adsorption experiments in real waters and lab-scale continuous flow Anaerobic-Anoxic-Oxic reactor further indicated the application potential of MX-ZrSA beads. Our study will provide insight into MXene and SA aerogel synergistic adsorption of aquatic contaminants and help with the removal and recovery of finite phosphorus resource.
水中过量的磷会引发诸如富营养化等环境安全问题。先进的二维材料MXene在水体吸附方面引起了越来越多的关注，然而缺乏选择性和回收困难限制了其在去除磷酸盐方面的应用。在本研究中，合成了嵌入锆交联海藻酸钠的TiC-MXene（MX-ZrSA）珠，并评估了它们在不同条件下的磷酸盐吸附性能。使用扫描电子显微镜/能谱仪（SEM/EDS）、X射线衍射仪（XRD）、比表面积分析仪（BET）、热重分析仪（TGA）和接触角测量仪进行的研究表明，TiC-MXene的添加提高了热稳定性、机械强度和亲水性，并形成了具有大表面积的疏松网络状介孔内部结构。理论最大吸附容量为492.55 mg P/g，Freundlich模型和优化的Langmuir模型对其拟合效果良好。傅里叶变换红外光谱和X射线光电子能谱分析表明存在化学吸附，Zr-O-P和Ti-O-P配合物的形成解释了对磷酸盐的高选择性和亲和力。在实际水体和实验室规模的连续流厌氧-缺氧-好氧反应器中的吸附实验进一步表明了MX-ZrSA珠的应用潜力。我们的研究将为MXene与海藻酸钠气凝胶协同吸附水体污染物提供见解，并有助于有限磷资源的去除和回收。
