基于羟胺的零价铁/过硫酸盐体系降解水中PAEs的强化作用和反应机制

以邻苯二甲酸酯（PAEs）为代表的环境激素因在水环境中分布广泛、具有较大毒性和持久性而引起关注。本项目针对均相类芬顿体系因氧化剂利用率低、铁泥量大、pH适用范围窄而应用受限的问题，基于硫酸根自由基（SO4•-）的选择性氧化能力和羟胺（HA）的还原特性，提出HA/零价铁/过硫酸盐非均相体系（HA/Fe0/S2O82-）。以邻苯二甲酸二丁酯（DBP）为目标物，通过DBP降解动力学、降解途径、及活性物种定性与定量分析，揭示活性物种生成与转化基本规律；通过HA转化及其产物生成的规律，明确HA强化作用机制；通过Fe2+浓度变化规律，阐明活性物种生成的均相机制；通过对Fe0表面腐蚀产物的特性表征，探究活性物种生成的非均相机制；解析操作条件和水质参数影响，考察实际水体背景中DBP降解效能，从而构建基于SO4•-的HA/Fe0/S2O82-体系，为高效降解PAEs等难降解有机污染物提供理论依据与技术参考

The phthalate esters (PAEs) in aqueous environment have gained increasing attention for their characteristics of wide distribution, high toxicity and persistence. The intrinsic drawbacks of low oxidants utilization rate, high production of iron sediment and narrow pH range limit the application of homogeneous Fenton and Fenton-like systems to degrade PAEs. Due to the selectivity and high reactivity of sulfate radicals (SO4•-), and the reducing capacity of hydroxylamine (HA), HA was introduced to accelerate the generation of SO4•- via the activation of persulfate (S2O82-) with zero-valent iron (Fe0). Using dibutyl phthalate (DBP) as the target compound, this study intended to (I) uncover the basic rule of formation and transformation of major reactive species by the qualitative and quantitative analysis of reactive species, and the study of degradation kinetics and degradation pathways of DBP, (II) verify the role of HA according to the transformation of HA and the formation of by-products, (III) elucidate the homogeneous generation mechanism of SO4•- according to the changes of Fe2+ concentration during the reaction, (IV) explore the heterogeneous generation mechanism of SO4•- on the basis of identifying the corrosion products on the surface of Fe0, and (V) clarify the influences of operation conditions, water quality parameters and water background on DBP degradation. This study can provide a feasible and promising approach (HA/Fe0/S2O82- system based on SO4•-) for the efficient degradation of PAEs and other refractory organic pollutants.