Integrated approach for concurrent desalination, phenol degradation, and bioelectricity generation in MDCs using seaweed Biochar–Fe₃O₄ nanocomposite anodes and halotolerant exoelectrogenic bacteria

Microbial desalination cells (MDCs) are an emerging technology capable of simultaneous wastewater treatment, desalination, and bioelectricity generation. In this study, a seaweed biochar/Fe₃O₄ nanocomposite was prepared and used as a modified anode to improve the performance of an MDC. The nanocomposite anode exhibited enhanced physicochemical and electrochemical characteristics, offering a biocompatible and conductive surface that facilitated microbial attachment and electron transfer. The performance of the system for simultaneous phenol degradation, desalination of saline water, and electricity generation was assessed. The MDC system was successful in degrading phenol, desalinating saline water, and generating bioelectricity, and the role of the nanocomposite anode in improving the performance of the system was evident. In addition, in order to ensure success in the microbial activity at high salinity, a halotolerant exoelectrogenic bacterial strain ( Bacillus paralicheniformis RKMSU_1; GenBank accession no. PZ379936) was isolated from Sambhar Lake and applied as bioaugmentation. This strain enhances microbial stability and activity under salt stress. The material-microbial combination approach demonstrated in this study is a key strategy for improving the performance and stability of MDC. This study demonstrates the feasibility of using nanomaterial-based electrodes combined with halotolerant microbial communities for the successful treatment of saline and phenol-laden wastewater.