Water hyacinth-assisted microbial fuel cells: A review on prospects for bioenergy and wastewater treatment

Abstract

Water hyacinth (WH) also known as Eichhornia crassipes is one of the most invasive water weeds in the world that multiplies rapidly in freshwater bodies, disturbing the ecosystem, biodiversity, and water quality. Conventional control methods are often costly and ineffective, prompting the need for sustainable alternatives. One promising approach is biomass valorization in microbial fuel cells (MFCs), simultaneously addressing invasive species management and renewable energy generation. Beyond its recognized phytoremediation potential, water hyacinth can be effectively integrated into MFCs as a substrate, electrode material, membrane, and catalytic agent. Its lignocellulosic structure and carbonized derivatives offer high surface area and improved electron transfer, while natural fibers and root systems facilitate ion exchange and microbial colonization. These properties enhance MFC performance by boosting conductivity, biocompatibility, and cost-effectiveness relative to conventional materials. Reported WH-based MFC systems have achieved chemical oxygen demand (COD) removal efficiencies exceeding 65% and power densities up to 9.7 W/m³, demonstrating their dual potential for wastewater treatment and bioelectricity generation. Such multifunctional roles highlight WH as a valuable, low-cost resource for advancing MFC technologies. This review critically evaluates recent progress in WH utilization for MFC applications, focusing on biomass conversion, electrode and membrane development, and catalytic improvements. Challenges such as pretreatment requirements, electrode stability, and large-scale feasibility are discussed, alongside strategies for mitigation. By consolidating current research, the paper underscores WH's potential as a cost-effective and sustainable material in MFC systems, offering new directions for efficient bioenergy recovery and invasive biomass management.