A significant loss of the treatment efficiency induced by Cl⁻ is a well-recognized drawback of the SO₄^·−-based AOPs and various mathematical model have been established to achieve quantitative prediction of the treatment efficiency of SO₄^·−-based AOPs at different levels of Cl⁻. However, the background water constituents (e.g., ammonia and dissolved organic matter (DOM)) complicate the chemistry of Cl⁻/SO₄^·− system and disable these models. This study shows that the degradation of sulfamethoxazole and bisphenol A by Co²⁺/PMS process decreased with dosing Cl⁻ at fresh water level, due to the shifted distribution of reactive species from SO₄^·− to Cl₂^·−, ClO^· and HOCl. Besides quenching radicals, HOCl also contributed to pollutant degradation. Though ammonia alone negligibly influence the Co²⁺/PMS process, ammonia reacts with the in situ formed HOCl in the Cl⁻/SO₄^·− process rapidly along with the generation of chloramine which mainly severed as radical scavenger rather than oxidant. Consequently, more severe efficiency loss of the SO₄^·−-based AOPs occur in the copresence of ammonia and Cl⁻. Unexpectedly, the efficiency loss was alleviated after dosing DOM, which was attributed to the suppressed formation of chloramine. The occurrence of chlorate and disinfection by-products are not concerns in the Co²⁺/PMS process when Cl⁻ coexists with ammonia and DOM, because of the decreased formation of HOCl. These results enhance our understanding of the complex chemistry of SO₄^·−-based AOPs in real water and promote the progress of SO₄^·−-based AOPs towards the niche applications in water treatment.

^{Cl -}引起的处理效率的显着损失是基于 SO _{4 ·- 的 AOPs 的一个公认的缺点，并且已经建立了各种数学模型来实现对 SO 4} ^· -基 AOPs 处理效率_的^定量预测不同水平的 Cl ^-。然而，背景水成分（例如氨和溶解的有机物（DOM））使Cl ^- /SO ₄ ^·-系统的化学性质复杂化，并使这些模型失效。该研究表明，Co ²⁺ /PMS 工艺对磺胺甲恶唑和双酚 A 的降解随 Cl ^-在淡水水位，由于活性物质从 SO ₄ ^·-到 Cl ₂ ^·-、ClO ^·和 HOCl 的移动分布。除了猝灭自由基外，次氯酸还有助于污染物降解。尽管氨单独对Co ²⁺ /PMS 过程的影响可以忽略不计，但氨与Cl ^- /SO ₄ ^·-过程中原位形成的HOCl反应迅速，同时生成主要作为自由基清除剂而不是氧化剂的氯胺。因此，在氨和 Cl - 的共存下，SO ₄ ^·-基 AOP的效率损失会更加严重^-. 出乎意料的是，投加 DOM 后效率损失得到缓解，这归因于氯胺的形成受到抑制。^{当 Cl -}与氨和 DOM 共存时，由于减少了 HOCl 的形成，因此在 Co ²⁺ /PMS 过程中不会出现氯酸盐和消毒副产物。这些结果加深了我们对真实水中SO 4 ·- 基AOPs 的复杂化学性质的理解，促进了SO ₄ ^· -_基^AOPs在水处理领域的应用。