Microbial fuel cells (MFC_S) is a promising and expanding technology able to eliminate various pollutants of wastewater while converting its chemical energy into power energy using biocatalysts. The potential application of double-chamber microbial fuel cell (DC-MFC) for chemical oxygen demand (COD) removal and generated power from wastewater in the different conditions is investigated. DC-MFC is operated with anaerobic sludge as an active biocatalyst in an anode section, an aerobic cathode section and a Nafion117 membrane as a separator. The performance of the bioreactor is determined with different concentrations of chemical oxygen demand (COD) loadings in the MFC process, in terms of COD removal, power generation and columbic efficiencies. The results illustrated that COD removal efficiency increased at the high concentrations of organic matter. So that at COD concentration of 2000.0 mg/L the highest COD removal efficiency (84%) was obtained. But with increasing substrate initial concentration to 10000.0 mg/L the efficiency decreased to 79%. The important outputs of the system like the highest voltage, maximum generated power, current density, and energy efficiency with the 100,000 mg/L COD are 447 mV, 50.7 mW/m², 570.0 mA/m², and 18.6%, respectively. The optical density levels increased due to bacterial growth while pH severely decreased in the anode chamber when using high-concentration substrates in the MFC. GRAPHICAL ABSTRACT

In this new insight, the potential application of the Bio-Electro-Fenton system was surveyed with the aim of simultaneous degradation of tetracycline and in situ generation of renewable bioenergy without the need for an external electricity source.

Bio-electro-Fenton system is a promising technology for the environmental organic pollutants degradation and bioelectricity generation.

Microbial fuel cells (MFCs) are a self-sustaining and environmentally friendly system for the simultaneous was tewater treatment and bioelectricity generation. The type and material of the electrode are critical factors that can influence the efficiency of this treatment process. In this study, graphite plates and carbon felt were modified through the electrodeposition of nickel followed by the formation of a biofilm, resulting in conductive bio-anode thin film electrodes with enhanced power generation capacity. The structural and morphological properties of the electrode surfaces were characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy, elemental mapping, and field-emission scanning electron microscopy techniques. Maximum voltage, current density, and power generation were investigated using a dual-chamber MFC equipped with a Nafion 117 membrane and bio-nickel-doped carbon felt (bio-Ni@CF) and bio-nickel-doped graphite plate (bio-Ni@GP) electrodes under constant temperature conditions. The polarization and power curves obtained using different anode electrodes revealed that the maximum voltage, power and current density achieved with the bio-Ni@CF electrode were 468.0 mV, 130.72 mW/m² and 760.0 mA/m² respectively. Moreover, the modified electrodes demonstrated appropriate stability and resistance during successful runs. These results suggest that nickel-doped carbon-based electrodes can serve as suitable and stable supported catalysts and conductors for improving efficiency and increasing power generation in MFCs.

The bio-electro-fenton (BEF) system is a novel technology that can be utilized to degrade both emerging and persistent pollutants while producing clean, green, and sustainable energy. Various catalysts that have a high active surface area are employed in these systems to enhance the oxygen reduction reaction (ORR) efficiency. In this study, the Nickel/Cobalt metal–organic framework (Ni/Co BTC-MOF) as heterogeneous catalyst was synthesized and deposited by the cathodic electrochemical deposition method on the carbon felt (CF) and graphite plate (GP) electrodes. The results of FT-IR, Field Emission Scanning Electron Microscopy (FE-SEM), X-ray Diffraction (XRD), and Energy Dispersive X-ray spectroscopy (EDS) analysis proved that the synthesis of Ni/Co-BTC MOF successfully carried out. The performance and positive effect of the modified electrodes in ORR were investigated and compared in electrical energy generation. Finally, bio-electro-degradation of bisphenol-S (BPS) as one of the endocrine-disrupting compounds (EDCs) was studied by the optimal modified electrode. According to the results of electrochemical experiments, the highest maximum power density is equal to 133.6 mW/m², which is related to Ni/Co-BTC@CF, and the highest production voltage is related to Ni/Co-BTC@CF, Ni/Co-BTC@GP, CF, and GP, respectively. The removal efficiency levels of bisphenol S in this system at different concentrations of 1.0, 5.0, and 10.0 mg/l after 24 h were 98.0%, 84.0%, and 41.0%, respectively. Based on the obtained results, the improved BEF system with Ni/Co-BTC@CF catalyst can be a suitable technology to achieve more electricity flow and at the same time have a positive effect on the decomposition of bisphenol S pollutant.