Bioelectrochemical Treatment: Present Trends and Prospective

Advances in Biological Wastewater Treatment Processes: Focus on Low-Carbon Energy and Resource Recovery in Biorefinery Context

“…In the context of addressing sustainability and the limitations of conventional electrochemical processes, the integration of microbial and electrochemical processes (bioelectrochemical treatment (BET)/electrochemical oxidation (EO) process) has arisen as a promising alternative for industrial wastewater treatment with near-zero carbon/micropollutant discharge [ 42 , 48 , 55 , 56 ]. Bioelectrochemical treatment processes (BET/EO/electrodeposition/biomineralization) have significantly influenced wastewater treatment because of their relatively high efficiency with integrated microbeelectrode interactions [ 20 , 22 , 43 , 56 , 57 ]. These integrated processes evaluate industrial wastewater treatment at multiple levels of assessment, with the influence of symbiotic reactions increasing the process efficiency.…”

“…Anodic biofilm attachment and microbial community entities in relation to the synergy with the electrode play a crucial role in complex (pollutants/contaminants/toxins/metals) treatment by metabolically biocatalyzed electrochemical oxidation [ 61 ]. Anodic complex degradation in BET usually takes place by the mechanisms of direct anodic oxidation (DAO) and indirect anodic oxidation (IAO) processes [ 10 , 20 ]. DAO involves microbial metabolism utilizing simple organic molecules for electron (e − ) and proton (H + ) production, creating a gradient through their movement to the electrode surface and in situ biopotential generation [ 7 ].…”

“…These electrochemical interactions between the primary oxidants and wastewater complexes on the anode surface result in secondary oxidant production in the system. The IAO process usually involves the mediation of secondary oxidants (hydroxyl radicals (OH *), chlorine dioxide (ClO 2 ), ozone (O 3 ), hypochlorite (OCl - ), and hydrogen peroxide (H 2 O 2 )), whose formation is proportional to the primary oxidant production [ 7 , 20 , 55 ]. Both the primary and secondary oxidants have a huge influence as mediators/redox intermediates during complex/industrial wastewater treatment.…”

“…These integrated biological/electrochemical/bioelectrochemical wastewater treatments can also benefit in energy and resource recovery, along with low-carbon generation [ 6 , 18 ]. Resources such as nitrogen, phosphorus, and sulfur can be removed from wastewater by biological processes, such as nitrification, denitrification, phosphorus accumulation, and sulfate reduction [ 19 , 20 ]. These nutrients can be recovered as valuable products, such as fertilizers, bioplastics, or chemicals, for agricultural or industrial applications.…”