College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China.
Departments of Materials and Chemical Engineering, Hunan Institute of Technology, Hengyang, 421008, China.
Environ Sci Pollut Res Int. 2020 May;27(13):15198-15210. doi: 10.1007/s11356-020-07804-6. Epub 2020 Feb 18.
The present study employs a novel technique combining Fenton reaction with sinusoidal alternating current electrocoagulation (FSACEC), which is used to remove chemical oxygen demand (COD) in the simulated electroplating wastewater with the advantages of low energy consumption and small sludge. Fe, produced from the dissolution of Fe anodes in the FSACEC process, reacts with HO to generate more ·OH and forms the iron hydroxide precipitates. The higher efficiency of COD removal is achieved through both effects of the oxidation reaction and the physical adsorption. The scanning electron microscopy (SEM) analysis shows that the particle size of FSACEC products is between 30 and 40 nm, which is less than the Fenton-direct current electrocoagulation products. The effect of the current concentration (I), initial pH (pH), and the addition of hydrogen peroxide (30% HO) was discussed on the optimal process parameters. In pH 2.0 wastewater, applying current concentration of 1 A dm, the addition 20 cm dm 30% HO, the removal efficiency of COD reached 94.21% and the residual COD in wastewater was only 60 mg dm after 90 min of operation. In order to investigate the maximum removal efficiency in a certain period of operation, the larger current concentration is applied to remove COD. The FSACEC process exhibits the higher removal COD efficiency and wider operation range of pH than the single Fenton technique. The FSACEC process is in accordance with the kinetic law of the pseudo-second-order kinetic adsorption model.
本研究采用了一种新颖的联合芬顿反应与正弦交流电混凝（FSACEC）的技术，用于去除模拟电镀废水中的化学需氧量（COD），具有能耗低、污泥少的优点。FSACEC 过程中，Fe 阳极的溶解产生的 Fe 与 HO 反应生成更多的·OH，并形成铁氢氧化物沉淀。这种 COD 去除效率的提高是氧化反应和物理吸附两种作用的结果。扫描电子显微镜（SEM）分析表明，FSACEC 产物的粒径在 30 到 40nm 之间，小于芬顿直接电流电混凝产物。研究了电流浓度（I）、初始 pH 值（pH）和添加过氧化氢（30%HO）对最佳工艺参数的影响。在 pH 值为 2.0 的废水中，施加 1A dm 的电流浓度，添加 20cm dm 30%HO，经过 90min 的运行，COD 的去除率达到 94.21%，废水中的残留 COD 仅为 60mg dm。为了考察在一定运行时间内的最大去除效率，采用较大的电流浓度去除 COD。FSACEC 工艺比单一的芬顿技术具有更高的 COD 去除效率和更宽的 pH 操作范围。FSACEC 过程符合准二级动力学吸附模型的动力学规律。
