Microbial Electrochemical Fluidized Bed Reactor: A Promising Solution for Removing Pollutants From Pharmaceutical Industrial Wastewater

Abstract

The capacity of electroactive bacteria to exchange electrons with electroconductive materials has been explored during the last two decades as part of a new field called electromicrobiology. Such microbial metabolism has been validated to enhance the bioremediation of wastewater pollutants. In contrast with standard materials like rods, plates, or felts made of graphite, we have explored the use of an alternative strategy using a fluid-like electrode as part of a microbial electrochemical fluidized bed reactor (ME-FBR). After verifying the low adsorption capacity of the pharmaceutical pollutants on the fluid-bed electrode [7.92 ± 0.05% carbamazepine (CBZ) and 9.42 ± 0.09% sulfamethoxazole (SMX)], our system showed a remarkable capacity to outperform classical solutions for removing pollutants (more than 80%) from the pharmaceutical industry like CBZ and SMX. Moreover, the ME-FBR performance revealed the impact of selecting an anode potential by efficiently removing both pollutants at + 200 mV. The high TOC removal efficiency also demonstrated that electrostimulation of electroactive bacteria in ME-FBR could overcome the expected microbial inhibition due to the presence of CBZ and SMX. Cyclic voltammograms revealed the successful electron transfer between microbial biofilm and the fluid-like electrode bed throughout the polarization tests. Finally, Vibrio fischeri-based ecotoxicity showed a 70% reduction after treating wastewater with a fluid-like anode (+ 400 mV), revealing the promising performance of this bioelectrochemical approach.

Fluid-like cathode enhances valuable biomass production from brewery wastewater in purple phototrophic bacteria

“…Samples were filtered (0.22 micrometer) and Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD) were measured. COD was quantified using a commercial kit (Merck Millipore, Germany) as previously described ( Asensio et al, 2021 ). TOC was measured by a TOC-VCSH Shimadzu analyzer.…”

“…In contrast with conventional electrode-based cultivation of electroactive bacteria (rods, felt, plates) the use of fluid-like electrodes has been demonstrated for growing electroactive planktonic cells ( Tejedor-Sanz et al, 2018 ). Actually, fluid-like anodes can be used for treating brewery wastewater with both non-photosynthetic bacteria ( Tejedor-Sanz et al, 2020 ; Asensio et al, 2021 ) and PPB ( Manchon et al, 2023b ) as part of a photo-electrofermentation process where pollutant removal is maximized while a valuable product is recovered: the biomass of PPB.…”

Study on the removal characteristics and degradation pathways of highly toxic and refractory organic pollutants in real pharmaceutical factory wastewater treated by a pilot-scale integrated process

“…Different techniques have been used to reduce the toxicity of pharmaceutical wastewater and increase its biodegradability ( Chen et al, 2008 ; Shi et al, 2017 ; Yi et al, 2017 ; Liu et al, 2020 ; Asensio et al, 2021 ; Oberoi et al, 2022 ). The hydrolytic acidification process has been widely used in practical engineering because it can balance water quality, generate less sludge, and improve the biodegradability of pharmaceutical wastewater.…”

Ecotoxicity characterization assisted performance assessment of electro‐bioremediation reactors for nitrate and arsenite elimination

“…In the case of microbial electrochemical remediation systems, in particular those applied to nitrate and arsenite removal (Guo et al, 2021), such ecotoxicological test batteries have been scarcely used besides chemical analysis and microbiological studies (Alka et al, 2021; Li et al, 2020; Pun et al, 2019; Zhang et al, 2019). In recent years, the use of the high‐throughput Aliivibrio fischeri bioluminescence inhibition assay has been increasing in similar publications, but complex ecotoxicological characterization is scarce (Asensio et al, 2021; Lóránt et al, 2021; Zou et al, 2021, 2022) and even if an ecotoxicological characterization is carried out, it is done with a single chosen test organism (Fernandes et al, 2019). Because of the multiplicity of pollutants and their transformation within the electro‐bioremediation processes, chemical analysis alone cannot provide a full picture of the processes and environmental efficiency during technology monitoring due to the interaction with the complex surrounding matrix.…”