This study evaluates the applicability of nano-sized calcium peroxide (CaO₂) as a source of H₂O₂ to remediate 2,4-dichlorophenol (2,4-DCP) contaminated groundwater via the advanced oxidation process (AOP). First, the effect and mechanism of 2,4-DCP degradation by CaO₂ at different Fe concentrations were studied (Fenton reaction). We found that at high Fe concentrations, 2,4-DCP almost completely degrades via primarily the oxidation of ·OH within 5 h. At low Fe concentrations, the degradation rate of 2,4-DCP decreased rapidly. The main mechanism was the combined action of ·OH and O₂^·−. Without Fe, the 2,4-DCP degradation reached 13.6% in 213 h, primarily via the heterogeneous reaction on the surface of CaO₂. Besides, 2,4-DCP degradation was significantly affected by solution pH. When the solution pH was>10, the degradation was almost completely inhibited. Thus, we adopted a two-dimensional water tank experiment to study the remediation efficiency CaO₂ on the water sample. We noticed that the degradation took place mainly in regions of pH < 10 (i.e., CaO₂ distribution area), both upstream and downstream of the tank. After 28 days of treatment, the average 2,4-DCP degradation level was ≈36.5%. Given the inadequacy of the results, we recommend that groundwater remediation using nano CaO₂: (1) a buffer solution should be added to retard the rapid increase in pH, and (2) the nano CaO₂ should be injected copiously in batches to reduce CaO₂ deposition.

这项研究评估了纳米级过氧化钙（CaO ₂）作为H ₂ O ₂的来源，通过高级氧化过程（AOP）修复2，4-二氯苯酚（2,4-DCP）污染的地下水的适用性。首先，研究了在不同的铁浓度下CaO ₂降解2,4-DCP的作用和机理（芬顿反应）。我们发现，在高铁浓度下，2,4-DCP在5小时内主要通过·OH的氧化几乎完全降解。在低铁浓度下，2,4-DCP的降解速率迅速降低。主要机理是·OH和O ₂ ^·-的联合作用。在没有Fe的情况下，主要通过CaO ₂表面的异质反应，在₂小时内2,4-DCP的降解达到了13.6％。此外，溶液pH显着影响2,4-DCP的降解。当溶液的pH＞ 10时，降解几乎完全被抑制。因此，我们采用二维水箱实验研究了水样对CaO ₂的修复效率。我们注意到降解主要发生在pH值小于10的区域（即CaO ₂分布区域），在储罐的上游和下游。经过28天的治疗，平均2,4-DCP降解水平约为36.5％。鉴于结果不足，我们建议使用纳米CaO ₂修复地下水：（1）应该添加缓冲溶液以阻止pH值的快速增加，（2）应当分批大量注入纳米CaO ₂以减少CaO _2的沉积。