School of Environmental Science and Engineering, Tianjin University, No. 135 Yaguan Road, Jinnan District, Tianjin, 300350, China.
Powerchina Northwest Engineering Corporation Limited, Xi'an, 710065, China.
Water Res. 2024 Nov 1;265:122250. doi: 10.1016/j.watres.2024.122250. Epub 2024 Aug 11.
The reducibility of iron oxides, depending on their properties, influences the kinetics of dissimilatory iron reduction (DIR) during vivianite recovery in sewage. This study elucidated the correlation between properties of iron oxides and kinetics of DIR during the long-term transformation into vivianite, mediated by Geobacter sulfurreducens PCA and sewage. The positive correlation between surface reactivity of iron oxides and reduction rate constant (k) influenced the terminal vivianite recovery efficiency. Akaganeite with the highest adhesion work and surface energy required the lowest reduction energy (Ea), obtained the highest k of 1.36 × 10 day and vivianite recovery efficiency of 43 %. The vivianite yield with akaganeite as iron source was 76-164 % higher than goethite, hematite, feroxyhyte, and ferrihydrite in sewage. The distribution of P with akaganeite during DIR in sewage further suggested a more efficient pathway of direct vivianite formation via bio-reduced Fe(II) rather than indirect reduction of ferric phosphate precipitates. Thus, akaganeite was screened out as superior iron source among various iron oxides for vivianite recovery, which provided insights into the fate of iron sources and the cycle of P in sewage.
铁氧化物的还原性取决于其性质，这会影响蓝铁矿回收过程中异化铁还原（DIR）的动力学。本研究阐明了在由 Geobacter sulfurreducens PCA 和污水介导的蓝铁矿长期转化过程中，铁氧化物的性质与 DIR 动力学之间的相关性。铁氧化物的表面反应性与还原速率常数（k）之间呈正相关，这影响了最终蓝铁矿的回收效率。纤铁矿具有最高的粘附功和表面能，需要的还原能（Ea）最低，获得了最高的 k 值为 1.36×10-2 day-1和 43%的蓝铁矿回收率。与针铁矿、赤铁矿、纤铁矿和水铁矿相比，以纤铁矿为铁源时污水中的蓝铁矿产量高 76-164%。污水中 DIR 期间纤铁矿中 P 的分布进一步表明，通过生物还原的 Fe(II) 直接形成蓝铁矿的途径比铁磷酸盐沉淀的间接还原更有效。因此，纤铁矿被筛选为蓝铁矿回收中各种铁氧化物的首选铁源，这为了解铁源的归宿和污水中 P 的循环提供了线索。
