ABSTRACT

In this study, we constructed a three-chamber microbial fuel cell (TC-MFC) that avoided the adverse effects of H⁺ diffusion on anode microorganisms in the acidic catholyte and the precipitation of heavy metals in the soil near the cathode side (S4), while also achieving migration of copper from the soil and reduction of Cu²⁺ in the catholyte. The removal efficiency of acid-soluble Cu from the soil near the anode region reached 42.5% after 63 days of operation at an external resistance of 100 Ω and electrode spacing of 10 cm, and Cu²⁺ in the catholyte was completely removed within 21 days. Heavy metal mobility index (M_F) values indicated that the bioavailability and mobility of heavy metals were reduced by the TC-MFC. We found that changing the cathode potential and external circuit current in TC-MFC would affect the type (via XRD) and morphology (via SEM) of cathode deposits and the average removal rate of heavy metals. At the meantime, it should be noted that the interaction between the electric-field-dependent soil heavy metal migration and electron-dependent copper reduction in TC-MFC occurred, which was confirmed to have a relationship with the negative correlation between voltage and current during the test.

摘要

在本研究中，我们构建了一个三室微生物燃料电池（TC-MFC），避免了酸性阴极电解液中H ⁺扩散对阳极微生物的不利影响以及阴极侧附近土壤中重金属的沉淀（S4） ，同时还实现了铜从土壤中的迁移和阴极电解液中 Cu ^{2+ 的}还原。在外阻为100Ω、电极间距为10cm的条件下运行63天后，阳极区附近土壤中酸溶性Cu的去除效率达到42.5% ，阴极液中的Cu ²⁺在21天内完全去除. 重金属迁移指数（_MF) 值表明 TC-MFC 降低了重金属的生物利用度和迁移率。我们发现改变 TC-MFC 中的阴极电位和外电路电流会影响阴极沉积物的类型（通过 XRD）和形貌（通过 SEM）以及重金属的平均去除率。同时需要注意的是，TC-MFC 中电场依赖的土壤重金属迁移和电子依赖的铜还原之间发生了相互作用，这被证实与电压和电流之间的负相关关系有关。考试。