Dissolved organic matter (DOM) is not only a vector for the migration of aquatic environmental pollutants, but is also key to the control of water pollution. Economic and effective DOM removal through coagulation is essential in water treatment processes. This work investigated the role of carboxylated magnetic metal organic frameworks (MMOFs) nanoparticles in polymeric iron-based coagulation for the removal of aquatic DOM using a MMOFs-doped polyferric iron-based coagulant (MMOF-PIC). Analytical methodologies and tools used in this research included scanning electron microscopy (SEM), zeta potential, molecular weight cut off (MWCO), vibrating sample magnetometer (VSM) measurement, excitation emission matrix spectroscopy (EEMs), and X-ray photoelectron spectroscopy (XPS). The results showed that MMOF-PIC had the potential to change the structure of the polyferric iron-based coagulant (PIC) and charge, as determined by a porous surface morphology, a higher medium polymeric species distribution, and a more positive zeta potential. The MMOFs consequently enhanced PIC action on the removal of UV254 exposed DOM species with molecular weight <30 kDa, including aromatic CC based compounds, org-N as primary amines and amide/peptide bound species, water containing microbial metabolites and protein-like materials. The coagulation of DOM was enhanced by improving charge neutralization, adsorption-bridging and sweep-flocculation in the presence of MMOFs nanoparticles. This was due to hydrogen bonds, π-π bonds and covalent bonds resulting from actions of nanoparticles and pollutants. These results indicate that magnetic MOF nanoparticles can improve PIC coagulation for DOM, enhancing future removal of target pollutants.

中文翻译：

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磁性MOF纳米颗粒在增强水溶有机物的铁凝结​​中的作用。

溶解有机物（DOM）不仅是水生环境污染物迁移的媒介，而且还是控制水污染的关键。通过凝结物经济有效地去除DOM在水处理过程中至关重要。这项工作研究了羧基化磁性金属有机骨架（MMOFs）纳米粒子在高分子铁基凝聚中的作用，该凝聚是使用MMOFs掺杂的多铁铁基凝聚剂（MMOF-PIC）去除水生DOM的。本研究中使用的分析方法和工具包括扫描电子显微镜（SEM），ζ电位，分子量截断（MWCO），振动样品磁力计（VSM）测量，激发发射矩阵光谱（EEM）和X射线光电子光谱（ XPS）。结果表明，MMOF-PIC具有改变聚铁基铁凝结剂（PIC）和电荷的结构的潜力，这是由多孔表面形态，较高的中等聚合物种类分布和更高的zeta电位确定的。因此，MMOF在去除分子量小于30 kDa的UV254暴露的DOM物种（包括基于芳族CC的化合物，作为伯胺和酰胺/肽结合的物种的org-N化合物，含有微生物代谢产物的水和蛋白质样物质）的过程中增强了PIC作用。在MMOFs纳米粒子的存在下，通过改善电荷中和，吸附桥联和吹扫絮凝来增强DOM的凝结。这是由于纳米粒子和污染物的作用导致的氢键，π-π键和共价键。