Bioelectrochemical Treatment of Ibuprofen-Contaminated Wastewater Using Hypersaline Sediment Microbiomes: Emergence of Chromohalobacter as a Key Degrader

Abstract

Ibuprofen (IBU), a widely used anti-inflammatory drug, is increasingly found in aquatic environments, particularly in pharmaceutical wastewater, raising concerns about its persistence and ecological risks. This study investigates IBU removal using a bioelectrochemical system (BES) under laboratory conditions with synthetic pharmaceutical wastewater (SPWW) and halophilic microbiomes from two hypersaline sediments of Chott El-Djerid (CJ–S1 and CJ–S2). Three bioanode reactors were operated at +0.1 V/SCE for 15 days with IBU concentrations of 60 and 150 ppm, with or without glucose (Glc) (20 ppm) as a co-substrate. IBU degradation was confirmed by LC-MS, COD removal, and FTIR analyses, showing removal efficiencies approaching 100%. Electrochemical performance varied with the inoculum: CJ–S2 produced a higher current density (38.02 ± 0.15 mA m−2) than CJ–S1. Metataxonomic analysis revealed strong enrichment of Chromohalobacter spp., while the combination of CJ–S2, 60 ppm IBU, and Glc promoted a more diverse consortium dominated by Halomonas spp. and Bacillus shackletonii. These findings highlight that microbial origin and co-substrate availability critically shape bacterial community structure, electroactivity, and degradation efficiency. The CJ–S2 microbiome is a promising candidate for developing robust electroactive bioanodes for treating pharmaceutical wastewater.