Enhanced bioelectrochemical nitrogen removal in flow through electrodes
Enhanced bioelectrochemical nitrogen removal in flow through electrodes
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DOI：
10.1016/j.seta.2021.101507
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发表时间：
2021-10
影响因子：
8
通讯作者：
Secil Tutar Oksuz;H. Beyenal
中科院分区：
文献类型：
--
作者：
Secil Tutar Oksuz;H. Beyenal
在过去的十年中，生物电化学系统（BES）已经被广泛研究，用于发电和最大化功率密度。近年来，人们注意到BES的应用可以显著改善废水处理。以前的大多数BES工作都使用了不同的反应器几何形状和配置，废水成分，电解质溶液和恒定的电极尺寸，以最大限度地发电。然而，有有限的研究调查增加电极尺寸对废水处理过程的影响。考察了电极表面积的增加对废水处理效率的影响，并对脱氮机理进行了研究。在这项研究中，我们开发了一种流通电极在3电极生物电化学反应器。阳极生物膜在电极上富集一周。在阳极富集期之后，反应器以半连续模式用原始生活废水操作。为了研究废水处理效率，测定了化学需氧量（COD）、总氮（TN）、氨氮（NH3-N）、亚硝酸盐（NO2--N）和硝酸盐（NO3--N）的浓度。我们发现，增加阳极的表面积并没有显着有助于COD去除率，最有可能表明BES的限制。在另一方面，TN去除率增加成比例的表面积的阳极在BES。实验还发现，出口NO_3 ~--N和NO_2 ~--N浓度分别为1.2 ± 0.2和3.2 ± 0.9 mg/L。研究结果表明，该工艺可以同时去除COD和TN。微生物群落结构分析表明，系统中的微生物除氮过程主要由产硫、阳极氨氧化、自养和异养反硝化以及将NO3--N还原为NO2--N等过程组成。
In the past decade, bioelectrochemical systems (BESs) have been studied extensively for the generation of power and maximizing power densities. In recent years, it was noticed that BESs applications can critically improve wastewater treatment. Most of the previous BESs work has used varied reactor geometry and configuration, wastewater composition, electrolyte solution, and constant electrode size to maximize power generation. However, there is limited research investigating the influence of increased electrode size on the wastewater treatment process. We investigated the effect of increased electrode surface area on wastewater treatment efficiency and studied the mechanism of nitrogen removal. In this study, we developed a flow-through electrode in a 3-electrode bioelectrochemical reactor. The anodic biofilms were enriched on electrodes for one week. Following the anodic enrichment period, the reactor was operated in a semi-continuous mode with raw domestic wastewater. To investigate the wastewater treatment efficiency, the chemical oxygen demand (COD), total nitrogen (TN), ammonia (NH3-N), nitrite (NO2–-N), and nitrate (NO3–-N) concentrations were measured. We found that increased surface area of anode did not significantly contribute to COD removal rate, most likely indicating the limits of BES. On the other hand, the TN removal rate increased proportionally to the surface area of the anode in the BES. We also found that outlet NO3–-N and NO2–-N concentrations were 1.2 ± 0.2 and 3.2 ± 0.9 mg/L, respectively. Our results indicated that it is possible to remove COD and TN simultaneously. Analysis of the microbial community structure showed that nitrogen removal was dominated by sulfidogenesis, anodic ammonia oxidation, autotrophic and heterotrophic denitrification as well as reducing NO3–-N to NO2–-N usingGeobacterspecies in our system.