Pharmaceutical wastewater (PWW) is rapidly growing into one of the world’s most serious environmental and public health issues. Existing wastewater treatment systems carry numerous loopholes in supplying the ever-increasing need for potable water resulting from rises in population, urbanization, and industrial growth, and the volume of wastewater produced is growing each day. At present, conventional treatment methods, such as coagulation, sedimentation, oxidation, membrane filtration, flocculation, etc., are used to treat PWW. In contrast to these, the application of microbial fuel cells (MFCs) for decontaminating PWW can be a promising technology to replace these methods. MFC technologies have become a trending research topic in recent times. MFCs have also garnered the interest of researchers worldwide as a promising environmental remediation technique. This review extensively discusses the flaws in standalone conventional processes and the integration of MFCs to enhance electricity production and contaminant removal rates, especially with respect to PWW. This article also summarizes the studies reported on various antibiotics and wastes from pharmaceutical industries treated by MFCs, and their efficiencies. Furthermore, the review explains why further research is needed to establish the actual efficiency of MFCs to achieve sustainable, environmentally friendly, and cost-effective wastewater treatment. A brief on technoeconomic impacts has also been made to provide a glimpse of the way these technologies might replace present-day conventional methods.

Congo red is an azo dye widely used as a colouring agent in textile industries. It is a serious threat due to its carcinogenic effects. Its degradation has been challenging due to its complex yet stable structure. The present study was aimed to investigate the effective degradation of Congo red by bioremediating bacteria isolated from different environments. To investigate predominant microorganisms that degrade Congo red and its functions in microbial fuel cells (MFCs), strains isolated from cow dung (Enterococcus faecalis SUCR1) and soil (Pseudomonas aeruginosa PA1_NCHU) were used as a co-culture inocula. The remarkable results establish that E. faecalis as an excellent microbial source for the biological degradation of dye-contaminated wastewater treatment alongside bioactive treating wastewater with varied concentrations of congo red dye. The highest efficiency percentage of dye degradation was 98% after 3 days of incubation at pH 7 and 37 °C, whereas findings have shown that the decolorization at pH 5 and 6 was lower at 66% and 83.3%, respectively, under the same incubation conditions. Furthermore, the co-culture of E. faecalis SUCR1 and P. aeruginosa at a 1:1 ratio demonstrated improved power generation in MFCs. The maximum power density of 7.4 W/m³ was recorded at a 150 mg L⁻¹ concentration of Congo red, indicating that the symbiotic relation between these bacterium resulted in improved MFCs performance simultaneous to dye degradation.

Biosurfactant-producing microorganisms improve the efficacy of hydrocarbon biodegradation as the biosurfactant is essential in making hydrocarbons available for breakdown. The present study reports the isolation of biosurfactant-producing bacteria that can be used for crude oil remediation and to characterize the biosurfactant generated during the breakdown of crude oil. This study also reports evaluating the synergism and potentiality of biosurfactant-producing bacteria for simultaneous hydrocarbon biodegradation and power generation. Two bacterial strains (Bacillus subtilis strain B1 and Pseudomonas aeruginosa strain B2) were isolated from petroleum-contaminated soils, which are found effective in producing biosurfactants and degrading crude oil as the sole carbon source. B. subtilis B1 exhibited a higher potential for biosurfactant production and crude oil degradation than P. aeruginosa B2. The FTIR and GC-MS analysis were conducted for further characterization of the biosurfactant, which revealed that the surfactant produced by strain B1 and B2 was surfactin and rhamnolipid, respectively. The application of the B1 and B2 co-culture in microbial fuel cells (MFCs) showed synergism among them and resulted in a maximum power density production of 6.3 W/m³ with an open circuit voltage of 970 mV while degrading 2.5% v/v crude oil containing anolyte. The findings indicate that the co-culture of isolated crude oil-degrading strains has great potential for enhanced power generation and the bioremediation of hydrocarbon-contaminated environments. Moreover, the synergism of isolated strains in MFCs suggested their potent applicability in environmental, energy, and industrial sectors as an economical and feasible alternative to the existing technologies.

The current study investigated the development and application of lithium (Li)-doped zinc oxide (ZnO)-impregnated polyvinyl alcohol (PVA) proton exchange membrane separator in a single chambered microbial fuel cell (MFC). Physiochemical analysis was performed via FT-IR, XRD, TEM, and AC impedance analysis to characterize thus synthesized Li-doped ZnO. PVA-ZnO-Li with 2.0% Li incorporation showed higher power generation in MFC. Using coulombic efficiency and current density, the impact of oxygen crossing on the membrane cathode assembly (MCA) area was evaluated. Different amounts of Li were incorporated into the membrane to optimize its electrochemical behavior and to increase proton conductivity while reducing biofouling. When acetate wastewater was treated in MFC using a PVA-ZnO-Li-based MCA, the maximum power density of 6.3 W/m³ was achieved. These observations strongly support our hypothesis that PVA-ZnO-Li can be an efficient and affordable separator for MFC.