School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430074, China.
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China.
Chemosphere. 2021 Apr;269:128695. doi: 10.1016/j.chemosphere.2020.128695. Epub 2020 Oct 24.
Manganese oxides (MnO), important environmental oxides, have drawn significant attention in areas such as detoxification of micro-hazardous organic contaminants with electron-donating functional groups such as -OH. However, studies on whether these oxidized processes might further impact the fate of some esters like organophosphorus pesticide (OPPs) remain poorly understood. Herein, we propose a new mechanism involved in the enhanced removal of methyl parathion in mixtures of MnO and phenol. Specifically, the removal of methyl parathion (up to 73.7%) was significantly higher for a binary system than for MnO alone (approximately 9.3%) and was primarily due to adsorption rather than degradation. The extent of methyl parathion adsorption was dependent significantly on pH, reactant loading and metal ion co-solutes (such as Ca, Mg, Fe and Mn). Both spectroscopic (FT-IR, SEM-EDX and XPS) and chromatographic (LC/HRMS) analyses showed that the remarkable increase in the number of organics (e.g., polymers) onto the MnO surface dominated methyl parathion adsorption via hydrogen bonding, n-π and π-π interactions, van der Waals forces and pore-diffusion. The results from this study provided evidence for the role of manganese oxides in adsorption of methyl parathion in soil-aquatic environments involving phenolic compounds.
锰氧化物（MnO）作为重要的环境氧化物，在解毒具有供电子官能团（如-OH）的微毒害有机污染物等领域引起了广泛关注。然而，关于这些氧化过程是否可能进一步影响某些酯类（如有机磷农药（OPPs））命运的研究仍知之甚少。在此，我们提出了一种 MnO 和苯酚混合物中增强甲基对硫磷去除的新机制。具体来说，二元体系中甲基对硫磷的去除率（高达 73.7%）明显高于 MnO 单独存在时（约 9.3%），这主要是由于吸附而不是降解。甲基对硫磷的吸附程度显著依赖于 pH 值、反应物负载和金属离子共溶质（如 Ca、Mg、Fe 和 Mn）。光谱（FT-IR、SEM-EDX 和 XPS）和色谱（LC/HRMS）分析表明，MnO 表面上有机物质（例如聚合物）数量的显著增加通过氢键、n-π 和 π-π 相互作用、范德华力和孔扩散主导了甲基对硫磷的吸附。本研究结果为锰氧化物在涉及酚类化合物的土壤-水环境中吸附甲基对硫磷的作用提供了证据。
