Anodic biofilms on a bioelectrochemical system-based trickling filter bioreactor

In this study, we proposed an aerobic bioelectrochemical system (BES)-based trickling filter (TF) bioreactor for current generation and wastewater treatment. The wastewater treatment efficiencies of this bioreactor were also evaluated. It is important to understand the mechanism of community-structure formation, therefore, the microbial communities on the whole carbon fiber anode (CFA) were investigated. Reactor 1 (R1) and reactor 2 (R2) were set up in duplicates. For each reactor, 5 samples of biofilms taken from different sites were analyzed for each reactor, which were biofilms for the planktonic-cell fraction in the solution of the reactor (PC), biofilms on the outer part of the lower anode (Outer-Low), biofilms on the outer part of the upper anode without immersion (Outer-Up), biofilms in the inner layer of the lower anode (Inner-Low), and biofilms in the inner layer of the upper anode without immersion (Inner-Up). The microbial community on the CFA was analyzed using Illumina high throughput sequencing targeting on amplicons of 16S rRNA gene.