This work studied the influence of several parameters on free cyanide (CN⁻) degradation (50 mg L⁻¹) by the UVC-activated persulfate (PS) at alkaline conditions (UVC/PS). Firstly, photolysis and alkaline activation of PS were evaluated. Then, the effect of initial PS concentration (0.2, 0.4, and 0.6 g L⁻¹) and dissolved oxygen in solution (absence/presence) were studied. Lastly, the influence of phosphate, carbonate, and nitrate presence at different concentrations (50, 150, 350, and 500 mg L⁻¹) on CN⁻ elimination was tested. Additionally, the electric energy per order (E_EO), a measure of the energy consumption in the process was determined, and a mechanistic view of CN⁻ degradation was proposed. The results show that photolysis and alkaline activation of PS degraded 8 and 11% of CN⁻, respectively, whereas their combination presented a synergistic effect on CN⁻ pollutant elimination. While oxygen had a vital role in photolysis due to the formation of ¹O₂ to oxidize CN⁻ to CNO⁻, HO^• and SO₄^•− were primarily responsible for CN⁻ degradation by UVC/PS. It was also found that cyanide removal followed a pseudo-first-order kinetics whose apparent reaction rate constant (k) increased from 0.0104 to 0.0297 min⁻¹ as the initial concentration of PS increased from 0.2 to 0.6 g L⁻¹, indicating a strong dependency of the removal efficiency on the PS amount. Remarkably, cyanide degradation by the combined UVC/PS showed a high CN⁻ conversion and selectivity even in the presence of high concentrations of phosphate, carbonate, and nitrate ions (500 mg L⁻¹), which resulted in CN⁻ removals higher than 80% after 60 min of degradation treatment. Furthermore, the E_EO values were similar in the presence and absence of phosphate or carbonate; however, they decreased slightly with nitrate presence. All these results suggest the feasibility of the combined UVC/PS process for the elimination of cyanide such as that found in mining wastewater.

这项工作研究了几个参数对碱性条件 (UVC/PS) 下 UVC 活化的过硫酸盐 (PS)对游离氰化物 (CN ^- ) 降解 (50 mg L ^-1 ) 的影响。首先，评价PS的光解和碱活化。然后，研究了初始 PS 浓度（0.2、0.4 和 0.6 g L ^-1）和溶液中的溶解氧（不存在/存在）的影响。最后，测试了不同浓度（50、150、350 和 500 mg L ^-1）存在的磷酸盐、碳酸盐和硝酸盐对 CN ^-消除的影响。此外，还确定了每个订单的电能 (E _EO )、过程中能源消耗的度量以及 CN ^-的机械视图。提出了降级。结果表明，PS 的光解和碱活化分别降解了 8% 和 11% 的 CN ^-，而它们的组合对 CN ^-污染物的消除具有协同作用。由于形成¹ O ₂以将 CN ^-氧化为 CNO ^-，氧气在光解中起着至关重要的作用，而H2O ^•和 SO ₄ ^•-则是UVC/PS 降解CN ^{- 的}主要原因。还发现氰化物去除遵循准一级动力学，其表观反应速率常数 (k) 从 0.0104 增加到 0.0297 min ^-1随着 PS 的初始浓度从 0.2 增加到 0.6 g L ^-1，表明去除效率对 PS 量有很强的依赖性。值得注意的是，即使在高浓度磷酸盐、碳酸盐和硝酸根离子 (500 mg L ^-1 )存在的情况下，UVC/PS 联合降解氰化物也显示出高 CN ^-转化率和选择性，这导致 CN ^-去除率高于 80降解处理 60 分钟后的百分比。此外，E _EO存在和不存在磷酸盐或碳酸盐时的值相似；然而，随着硝酸盐的存在，它们略有下降。所有这些结果表明，UVC/PS 联合工艺消除氰化物的可行性，例如在采矿废水中发现的氰化物。