In situ fabrication of gold nanoparticles into biocathodes enhance chloramphenicol removal

Abstract The development of highly conductive biofilms is a key strategy to enhance antibiotic removal in bioelectrochemical systems (BESs) with biocathodes. In this study, Au nanoparticles (Au-NPs) were in situ fabricated in a biocathode (Au biocathode) to enhance the removal of chloramphenicol (CAP) in BESs. The concentration of Au(III) was determined to be 5 mg/L. CAP was effectively removed in the BES containing a Au biocathode with a removal percentage of 94.0% within 48 h; this result was 1.8-fold greater than that obtained using a biocathode without Au-NPs (51.7%). The Au-NPs significantly reduced the charge transfer resistance and promoted the electrochemical activity of the biocathode. In addition, the Au biocathode showed a specifical enrichment of Dokdonella, Bosea, Achromobacter, Bacteroides and Petrimonas, all of which are associated with electron transfer and contaminant degradation. This study provides a new strategy for enhancing CAP removal in BESs through a simple and eco-friendly electrode design.