Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
Northern Heavy Industries Group Co., Ltd, Shenyang, 110141, China.
J Hazard Mater. 2021 Jan 5;401:123360. doi: 10.1016/j.jhazmat.2020.123360. Epub 2020 Jul 1.
A combination process of Fenton-like and catalytic Mn(II) oxidation via molecular oxygen-induced abio-oxidation of As(III)-Mn(II)-rich acid mine drainage (AMD) is developed to rapidly and efficiently remove As and obtain low As-leaching solids in this study. The effect of pH, temperature, oxygen flow rate and neutralization reagent on As removal was investigated. The results showed that pH was important to As removal efficiency, which achieved maximum in 0.25-2 h, but decreased from ∼100 % to ∼92.6 % with the increase of pH 5-9. pH, temperature and oxygen flow rate played key roles in As(III) oxidation. The increase of As(III) oxidized from 16.8 to 67.1% to 98.6-99.0 % occurred as increasing the pH 5-9, 25-95 °C and oxygen flow rate of 0-2.4 L min. NaOH or Ca(OH) as base was less important to As removal. The mechanism involved Fenton-like reaction between Fe(II) and O for produced Fe(III) (oxy)hydroxide association with As(III + V) and Mn(II), catalytic Mn(II) oxidation for the formation of Mn(III, IV) oxides, and further As(III) oxidation by Mn(III, IV) oxides. As-bearing six-line ferrihydrite was the main solid product for low As-leaching fixation. pH 8, 95 °C and oxygen flow rate of 1.6 L min were optimal for As removal.
本研究开发了一种芬顿样和催化 Mn(II)氧化的组合工艺，通过分子氧诱导的贫 As(III)-Mn(II)酸性矿山排水（AMD）的生物氧化，以快速有效地去除 As，并获得低浸出率的 As 固体。考察了 pH、温度、氧气流速和中和剂对 As 去除的影响。结果表明，pH 对 As 去除效率很重要，在 0.25-2 h 内达到最大值，但随着 pH 从 5 增加到 9，从约 100%下降到约 92.6%。pH、温度和氧气流速对 As(III)氧化起关键作用。随着 pH 从 5 增加到 9、温度从 25 增加到 95°C 和氧气流速从 0 增加到 2.4 L min，As(III)的氧化从 16.8%增加到 67.1%，再增加到 98.6-99.0%。NaOH 或 Ca(OH)作为碱对 As 去除的影响较小。该机制涉及 Fe(II)和 O 之间的芬顿样反应，生成的 Fe(III)（氧）氢氧化物与 As(III+V)和 Mn(II)结合，催化 Mn(II)氧化形成 Mn(III,IV)氧化物，然后进一步通过 Mn(III,IV)氧化物氧化 As(III)。含六线水铁矿的含 As 固体是低浸出率固定的主要固体产物。pH 8、95°C 和氧气流速 1.6 L min 是最佳的 As 去除条件。
