Sustainable Biohydrogen Production From Agrifood Wastewater Using a MFC‐Assisted MEC System: A Circular Bioelectrochemical Approach

Microbial fuel cells and microbial electrolysis cells have been widely studied for their potential in wastewater remediation and renewable energy generation, yet most reviews and prior research address these bioelectrochemical systems as independent configurations. However, the integration of MFCs and MECs forming hybrid systems has not been systematically reviewed, despite emerging evidence that such integration offers unique synergies for energy‐neutral operation, enhanced biohydrogen recovery, and resource‐efficient wastewater treatment. The absence of focused analyses on operational mechanisms, integration strategies, and scale‐up challenges of MFC–MEC hybrids represents a critical gap in current literature. This review critically examines recent advances in integrated MFC–MEC systems, contrasting their performance and process advantages against standalone devices. It discusses how the electrical output of MFCs can partially offset the energy input required by MECs, facilitating more energy‐efficient biohydrogen production. The review also explores advances in electrode materials, microbial community engineering, and the valorization of diverse wastewater streams, particularly from agrifood and high‐strength industrial sources. By consolidating current findings, this work identifies both the opportunities and limitations associated with integrated BES technologies and outlines research directions needed for their practical implementation.