Advanced Water Management Centre (AWMC), The University of Queensland , St Lucia, Queensland QLD 4072, Australia.
Center for Microbial Ecology and Technology (CMET), Ghent University , Coupure Links 653, 9000 Ghent, Belgium.
Environ Sci Technol. 2017 Nov 7;51(21):12229-12234. doi: 10.1021/acs.est.7b01748. Epub 2017 Oct 24.
Recently, naturally occurring magnetite (FeO) has emerged as a new material for sulfide control in sewers. However, unrefined magnetite could have high heavy metal contents (e.g., Cr, Zn, Ni, Sn, etc.) and the capacity to remove dissolved sulfide is reasonably limited due to relatively large particle sizes. To overcome the drawbacks of unrefined magnetite we used an electrochemical system with mild steel as sacrificial electrodes to in-situ generate high strength solutions of plate-like magnetite nanoparticles (MNP). MNP with a size range between 120 and 160 nm were electrochemically generated at 9.35 ± 0.28 g FeO-Fe/L, resulting in a Coulombic efficiency (CE) for iron oxidation of 93.5 ± 2.8%. The produced MNP were found to effectively reduce sulfide levels in sewage from 12.7 ± 0.3 to 0.2 ± 0.0 mg S/L at a sulfide-to-MNP ratio of 0.26 g S/g FeO-Fe. Subsequently, MNP were continuously generated with polarity switching at stable cell voltage for 31 days at 4.53 ± 0.35 g FeO-Fe/L with a CE for iron oxidation of 92.4 ± 7.2%. The continuously produced MNP reduced sulfide at similar levels to around 0.2 mg S/L at a ratio of 0.28 g S/g FeO-Fe.
最近，天然磁铁矿 (FeO) 作为一种新型的下水道硫化物控制材料而出现。然而，未经精制的磁铁矿可能含有高重金属含量（例如 Cr、Zn、Ni、Sn 等），并且由于粒径较大，其去除溶解态硫化物的能力相当有限。为了克服未精制磁铁矿的缺点，我们使用了一个带有低碳钢作为牺牲电极的电化学系统，在原地生成高强度的板状磁铁矿纳米颗粒（MNP）溶液。在 9.35 ± 0.28 g FeO-Fe/L 的条件下，电化学生成的 MNP 粒径在 120 至 160nm 之间，铁氧化的库仑效率（CE）为 93.5 ± 2.8%。结果表明，在硫化物与 MNP 的比例为 0.26 g S/g FeO-Fe 时，所产生的 MNP 可有效将污水中的硫化物水平从 12.7 ± 0.3 降至 0.2 ± 0.0 mg S/L。随后，通过极性切换，在 4.53 ± 0.35 g FeO-Fe/L 的稳定电池电压下连续 31 天持续生成 MNP，铁氧化的 CE 为 92.4 ± 7.2%。连续生成的 MNP 在硫化物与 MNP 的比例为 0.28 g S/g FeO-Fe 时，也可将硫化物降低到类似的 0.2 mg S/L 左右。
