Abstract
The effect of electrostatic fields on the bioelectrochemical removal of ammonium and nitrite from nitrogen-rich wastewater was investigated at strengths ranging from 0.2 to 0.67 V/cm in bioelectrochemical anaerobic batch reactors. The electrostatic field enriched the bulk solution with electroactive bacteria, including ammonium oxidizing exoelectrogens (AOE) and denitritating electrotrophs (DNE). The electroactive bacteria removed ammonium and nitrite simultaneously with alkalinity consumption through biological direct interspecies electron transfer (DIET) in the bulk solution. However, the total nitrogen (ammonium and nitrite) removal rate increased from 106.1 to 166.3 mg N/g volatile suspended solids (VSS).d as the electrostatic field strength increased from 0.2 to 0.67 V/cm. In the cyclic voltammogram, the redox peaks corresponding to the activities of AOE and DNE increased as the strength of the electrostatic field increased. Based on the microbial taxonomic profiling, the dominant genera involved in the bioelectrochemical nitrogen removal were identified as Pseudomonas, Petrimonas, DQ677001_g, Thiopseudomonas, Lentimicrobium, and Porphyromonadaceae_uc. This suggests that the electrostatic field of 0.67 V/cm significantly improves the bioelectrochemical nitrogen removal by enriching the bulk solution with AOE and DNE and promoting the biological DIET between them.
Highlights
Nitrogen compounds in the water environment can over-stimulate the growth of aquatic life, significantly reducing the value of water use [1,2]
It seems that the biological direct interspecies electron transfer (DIET) involved in the ammonium oxidation and nitrite reduction to form nitrogen gas was quickly activated in BENRs by electrostatic fields
The electrostatic field enriched the bulk solution with electroactive bacteria, including ammonium oxidizing exoelectrogens (AOE) and denitritating electrotrophs (DNE), and simultaneously removed ammonium and nitrite through the biological DIET
Summary
Nitrogen compounds in the water environment can over-stimulate the growth of aquatic life, significantly reducing the value of water use [1,2]. Treatment of nitrogen-rich wastewater has been a concern in the management of the water environment. Nitrogen in wastewater is usually removed by a conventional biological nitrogen removal (BNR) process consisting of aerobic autotrophic nitrification and anoxic heterotrophic denitrification [1,4]. Conventional BNR is an expensive process for the treatment of nitrogen-rich wastewater. Partial nitritation and denitritation technologies have been studied to improve the economics of the conventional BNR process [5,6,7]. Several stringent operational conditions including a high temperature, a short retention time, and a low level of dissolved oxygen required for partial nitritation and denitritation have limited their field applications [1,5,6]. Anammox microorganisms grow slowly, and the Anammox process requires strict partial nitritation and produces nitrate as a by-product [4,5,6,7]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
