Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Environ Sci Pollut Res Int. 2021 Nov;28(44):63319-63329. doi: 10.1007/s11356-021-15157-x. Epub 2021 Jul 5.
Phenylarsonic acid compounds, which were widely used in poultry and swine production, are often introduced to agricultural soils with animal wastes. Fenton coagulation process is thought as an efficient method to remove them. However, the substituted amino group could apparently influence the removal efficiency in Fenton coagulation process. Herein, we investigated the optimal conditions to treat typical organoarsenic contaminants (p-arsanilic acid (p-ASA) and phenylarsonic acid (PAA)) in aqueous solution based on Fenton coagulation process for oxidizing them and capturing the released inorganic arsenic, and elucidated the influence mechanism of substituted amino group on removal. Results showed that the pH value and the dosage of HO and Fe significantly influenced the performance of the oxidation and coagulation processes. The optimal conditions for removing 20 mg L-As in this research were 40mg L Fe and 60mg L HO (the mass ratio of Fe/HO = 1.5), initial solution pH of 3.0, and final solution pH of 5.0 adjusting after 30-min Fenton oxidation reaction. Meanwhile, the substituted amino group made p-ASA much more easily be attacked by ·OH than PAA and supply one more binding sites for forming complexes with Fe hydrolysates, resulting in 36% higher oxidation rate and 7% better coagulation performance at the optimal conditions.
苯胂酸化合物在禽类和猪类养殖中被广泛应用，常随动物粪便进入农业土壤。芬顿凝聚法被认为是去除这些化合物的有效方法。然而，取代的氨基会明显影响芬顿凝聚法的去除效率。在此，我们研究了基于芬顿凝聚法处理典型有机胂污染物（对氨基苯胂酸（p-ASA）和苯胂酸（PAA））的最佳条件，以将其氧化并捕获释放的无机砷，并阐明了取代的氨基对去除的影响机制。结果表明，pH 值和 HO 和 Fe 的剂量显著影响氧化和凝聚过程的性能。在本研究中，去除 20mg/L 砷的最佳条件为 Fe 浓度为 40mg/L，HO 浓度为 60mg/L（Fe/HO 的质量比为 1.5），初始溶液 pH 值为 3.0，30min 芬顿氧化反应后调节最终溶液 pH 值为 5.0。同时，取代的氨基使 p-ASA 比 PAA更容易受到·OH 的攻击，并为与 Fe 水解产物形成配合物提供了一个额外的结合位点，从而在最佳条件下氧化速率提高了 36%，凝聚性能提高了 7%。
