Nitrate reduction in bio-electrochemical systems (BESs) has attracted wide attention due to its low sludge yields and cost-efficiency advantages. However, the high resistance of traditional electrodes is considered to limit the denitrification performance of BESs. Herein, a new graphene/polypyrrole (rGO/PPy) modified electrode is fabricated via one-step electrodeposition and used as cathode in BES for improving nitrate removal from wastewater. The formation and morphological results support the successful formation of rGO/PPy nanohybrids and confirm the part covalent bonding of Py into GO honeycomb lattices to form a three-dimensional cross-linked spatial structure. The electrochemical tests indicate that the rGO/PPy electrode outperforms the unmodified electrode due to the 3.9-fold increase in electrochemical active surface area and 6.9-fold decrease in the charge transfer resistance (). Batch denitrification activity tests demonstrate that the BES equipped with modified rGO/PPy biocathode could not only achieve the full denitrification efficiency of 100% with energy recovery (15.9 10 ± 0.14 A/m), but also favor microbial attach and growth with improved biocompatible surface. This work provides a feasible electrochemical route to fabricate and design a high-performance bioelectrode to enhance denitrification in BESs.

中文翻译：

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新型石墨烯/聚吡咯（rGO/PPy）改性碳毡作为生物电化学系统（BES）中的生物阴极实现完全反硝化

生物电化学系统（BES）中的硝酸盐还原因其低污泥产量和成本效益优势而受到广泛关注。然而，传统电极的高电阻被认为限制了BES的反硝化性能。在此，通过一步电沉积制备了一种新型石墨烯/聚吡咯（rGO/PPy）修饰电极，并将其用作 BES 中的阴极，以改善废水中硝酸盐的去除。形成和形貌结果支持rGO/PPy纳米杂化物的成功形成，并证实Py部分共价键合到GO蜂窝晶格中，形成三维交联空间结构。电化学测试表明，rGO/PPy 电极的电化学活性表面积增加了 3.9 倍，电荷转移电阻降低了 6.9 倍，因此其性能优于未修饰的电极（）。批量反硝化活性测试表明，配备改性rGO/PPy生物阴极的BES不仅可以实现100%的完全反硝化效率并回收能量（15.9 10 ± 0.14 A/m），而且具有改善的生物相容性表面，有利于微生物的附着和生长。这项工作提供了一种可行的电化学途径来制造和设计高性能生物电极，以增强 BES 中的反硝化作用。