The heterogeneous catalytic ozonation process is a promising treatment option for high salinity reverse osmosis concentrate (ROC) however the influence of salts on the catalyst performance is not well understood. In this work, we investigate the effect of salts on the performance of the catalytic ozonation process for treatment of synthetic ROC using a commercially available Fe-loaded Al₂O₃ catalyst. Our results show that the presence of salts influences the rate and extent of degradation of organic compounds present in the synthetic ROC when subjected to the heterogeneous catalytic ozonation process. Scavenging of aqueous O₃ by chloride ions and/or transformation of organics (particularly humics) to more hydrophobic form as a result of charge shielding between adjacent functional groups and/or intramolecular binding by cations inhibits the bulk oxidation of organics to a measurable extent. While the scavenging of aqueous hydroxyl radicals at the salt concentrations investigated here was minimal, the accumulation of chloride ions in the electric double layer near the catalyst surface, particularly when pH< pH_pzc, results in more significant scavenging of surface associated hydroxyl radicals. Overall, the presence of salts (particularly chloride ions) has a significant influence on the performance of both conventional and catalytic ozonation processes with some scope to mitigate this effect through appropriate choice of catalyst.

多相催化臭氧化过程是高盐度反渗透浓缩物 (ROC) 的一种很有前途的处理选择，但盐对催化剂性能的影响尚不清楚。在这项工作中，我们研究了盐对使用市售的负载铁的 Al ₂ O ₃催化剂处理合成 ROC 的催化臭氧化工艺性能的影响。我们的结果表明，盐的存在会影响合成 ROC 中存在的有机化合物在进行非均相催化臭氧化过程时的降解速率和程度。_{O 3}水溶液的清除通过氯离子和/或由于相邻官能团之间的电荷屏蔽和/或阳离子的分子内结合而将有机物（特别是腐殖质）转化为更疏水的形式，在可测量的程度上抑制了有机物的整体氧化。虽然在此处研究的盐浓度下对水性羟基自由基的清除是最小的，但氯离子在催化剂表面附近的双电层中的积累，特别是当 pH < pH _pzc时，会导致更显着的表面相关羟基自由基清除。Overall, the presence of salts (particularly chloride ions) has a significant influence on the performance of both conventional and catalytic ozonation processes with some scope to mitigate this effect through appropriate choice of catalyst.