Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, PR China.
Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, PR China.
Water Res. 2019 Oct 15;163:114861. doi: 10.1016/j.watres.2019.114861. Epub 2019 Jul 15.
Hydrogen peroxide (HO) is used widely as Fenton's reagent for organic wastewater treatment. However, the application range of the optimum Fenton reaction is narrow, needing to adjust pH before and after treatment. Besides, the disproportionation of HO and generated iron precipitation also confine the normal operation of Fenton method. To overcome the drawbacks of the traditional Fenton process, a Fe(II) catalyzed calcium peroxide (CaO) Fenton-like process assisted by oxalic acid (OA) for aqueous organic pollutants degradation was proposed (Fe/OA/CaO). The methyl orange (MO) as a typical organic pollutant, its removal performances by this Fe/OA/CaO system were evaluated. In the optimized conditions, 99% of MO was degraded within 15 min, and 38% mineralized after 180 min when the molar ratio of Fe: OA: CaO was 1: 2: 2 (Fe = 1.5 mM). Radicals detection indicated that hydroxyl radical (HO) was the main reactive species for the MO elimination. Furthermore, density functional theory calculation was in good agreement with the experimental results, which proved that the Fe/OA/CaO could improve the circulation between Fe and Fe, promoting the oxygen reactive species generation and pollutant removal. The main intermediates were identified and the degradation pathways were proposed based on the results of the mass spectrum analysis, and the attack of HO was suggested as the main function for the MO decomposition. The matrix effects of water constituents on the performance of Fe/OA/CaO were investigated, and the results showed that a certain amount of Cl, NO, HCO, and HA affected the elimination than SO. Finally, the attempt of actual wastewater disposal indicated the synergistic system possessed good potential for future practical application.
过氧化氢（HO）广泛用作芬顿试剂来处理有机废水。然而，最佳芬顿反应的应用范围较窄，需要在处理前后调节 pH 值。此外，HO 的歧化和生成的铁沉淀也限制了芬顿法的正常运行。为了克服传统芬顿工艺的缺点，提出了一种 Fe(II)催化过碳酸钠（CaO）芬顿样过程，并辅以草酸（OA）用于降解水中有机污染物（Fe/OA/CaO）。以甲基橙（MO）作为典型的有机污染物，评价了该 Fe/OA/CaO 体系对其的去除性能。在优化条件下，MO 在 15 min 内降解 99%，180 min 时矿化 38%，当 Fe:OA:CaO 的摩尔比为 1:2:2（Fe=1.5 mM）时。自由基检测表明，羟基自由基（HO）是 MO 消除的主要反应性物质。此外，密度泛函理论计算与实验结果吻合较好，证明 Fe/OA/CaO 可以改善 Fe 和 Fe 之间的循环，促进氧反应性物质的生成和污染物的去除。根据质谱分析的结果，确定了主要的中间产物，并提出了降解途径，HO 的攻击被认为是 MO 分解的主要功能。研究了水成分对 Fe/OA/CaO 性能的基质效应，结果表明，一定量的 Cl、NO、HCO 和 HA 比 SO 更能影响其去除效果。最后，实际废水处理的尝试表明，协同体系具有很好的实际应用潜力。
