Electroactive microbes is the driving force for the bioelectrochemical degradation of organic pollutants, but the underlying microbial interactions between electrogenesis and pollutant degradation have not been clearly identified. Here, we combined stable isotope-assisted metabolomics (SIAM) and 13C-DNA stable isotope probing (DNA-SIP) to investigate bisphenol S (BPS) enhanced degradation by electroactive mixed-culture biofilms (EABs). Using SIAM, six 13C fully labeled transformation products were detected originating via hydrolysis, oxidation, alkylation, or aromatic ring-cleavage reactions from 13C-BPS, suggesting hydrolysis and oxidation as the initial and key degradation pathways for the electrochemical degradation process. The DNA-SIP results further displayed high 13C-DNA accumulation in the genera Bacteroides and Cetobacterium from the EABs and indicated their ability in the assimilation of BPS or its metabolites. Collectively, network analysis showed that the collaboration between electroactive microbes and BPS assimilators played pivotal roles the improvement in bioelectrochemically enhanced BPS degradation.

The dispersibility of non-damaged carbon fibers and the stability of fiber position have a crucial influence on the properties of continuous carbon fiber reinforced aluminum matrix (Cf/Al) composites. In order to avoid the damage to the fiber caused by excessive infiltration pressure, which can be controlled by adjusting the distance from the vibration head to the fiber bundle. The effect of different binding force on the distribution and the fixed position of non-damaged carbon fibers in the matrix were studied. The results show that with the fiber binding force increases (0N, 2N and 4N), the carbon fiber bundles can be stably located in a predetermined position and gradually completely infiltrated, but with the binding force further increases (6N and 8N), the fiber clusters and uninfiltrated defects appeared again. It is found that the proper fiber binding force can ensure that the carbon fiber does not shift under the infiltration pressure, so that the fibers distribute uniformly in the composite, but the excessive binding forces can obviously inhibit the dispersion of the fibers. Tensile test results show that the tensile strength increases first and then decreases with the increasing of fiber binding force. When binding force reach to 4N, the tensile performance of the composites is 203 MPa at its best. The uniform distribution of carbon fibers in the matrix play an important role in improving the tensile performance of Cf/Al composites.