Tertiary denitrification and organic matter variations of secondary effluent from wastewater treatment plant by the 3D-BER system

Simultaneous removal of nitrate and sulfate using an up-flow three-dimensional biofilm electrode reactor: Performance and microbial response

“…Granular activated carbon (4-8 mm) was selected as the third electrode, which was filled between the anode and cathode after pretreated according to previous methods (Hao et al, 2013). Under the action of electric field, activated carbon could not only generate CO 2 to stabilize pH in the solution and provide inorganic carbon source for autotrophic microbes, but also be induced into complex bipolar microelectrodes to promote current efficiency (Huang et al, 2020). Furthermore, it would provide large surface area for microorganism attachment.…”

“…In contrast, the single-chamber BERs eliminate the internal resistance caused by exchange membrane and improve current density, thereby it is conducive to reducing construction and operating cost (Miller et al, 2019). Moreover, to enhance the performance of single-chamber BERs, a three-dimensional biofilm electrode reactor (3D-BER) is designed by inserting conductive particles such as anthracite, granular activated carbon, sulfur and iron between anode and cathode, and these particles are usually called third bipolar electrodes (Feng et al, 2018;Huang et al, 2020). 3D-BER can not only improve surface area for biomass attachment but also enhance current efficiency by forming numerous charged microelectrodes (Wu et al, 2019).…”

Nano α-Fe2O3 Self-Assembled Hybrid Biofilm Boosts Hydrogen Autotrophic Denitrification in a Three-Dimensional Biofilm Electrode Reactor

“…Recently, the electrode-biofilm denitrification technology has been proposed, which utilizes the hydrogen gas generated by the electrode as electron donors in situ to efficiently reduce nitrate. To improve mass transfer and current efficiency, three-dimensional biofilm electrode reactors (3D-BERs) are being developed based on the electrode-biofilm technology by filling conductive particles such as activated carbon and graphite between the anode and the cathode, − By applying an external electric field, these particles are polarized, forming a large number of microelectrodes and providing spaces for microbial growth . In particular, CO 2 produced by activated carbon creates anoxic and anaerobic environments for denitrifiers and buffers the increasing alkalinity during denitrification .…”

Study of a three-dimensional biofilm-electrode reactor (3D-BER) that combined heterotrophic and autotrophic denitrification (HAD) to remove nitrate from water

“…17 Huang constructed a 3D-BER for tertiary denitrication, indicating that the approach increased the efficiency of denitrication and eliminated some dissolved organic matter by microbial electro hydrolysis. 18 In an attempt to further improve denitrication efficiency, the researchers added some soluble organic carbon sources to the BER, enabling the co-existence of autotrophic denitrication (AD) and heterotrophic denitrication (HD). Given the synergistic relationship between HD and AD, the combined use of heterotrophic and autotrophic denitrication (HAD) was more effective at removing nitrate from groundwater.…”

“… 17 Huang constructed a 3D-BER for tertiary denitrification, indicating that the approach increased the efficiency of denitrification and eliminated some dissolved organic matter by microbial electro hydrolysis. 18 …”