Evaluation of Graphene Nanoplatelets and Graphene Oxide Quantum Dots Added to a Polymeric Fiber Matrix Used as Biofilm Support in Anaerobic Systems

This study aimed to evaluate the incorporation of graphene-based additives, graphene nanoplatelets (GNPs) and graphene oxide quantum dots (GOQDs), into polymeric fiber matrices used as biofilm supports in anaerobic digestion systems, determining additive specific effects by benchmarking the impregnated matrices against the same nylon carrier without additives under identical operational conditions. Modified matrices were assessed through BMP assays using the liquid fraction of fruit and vegetable waste (LF-FVW) as substrate. Intermediate GNP and GOQD loadings (FM50 and FMDOT50) achieved the highest methane yields (317.9 ± 20.2 and 348.4 ± 20.0 mL CH4/g COD(rem)) compared with the control fiber matrix (301.0 ± 20.1 mL CH4/g COD(rem)). Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analyses confirmed nanomaterial retention on the matrix surface and interaction with microbial aggregates. Embedding the nanostructures within the fiber enhanced biofilm formation and methane yield while minimizing nanomaterial washout. Future work will focus on advanced physicochemical characterization (XRD, XPS, BET, and EDX mapping), leaching tests to assess long term stability, and scale up evaluation for full scale anaerobic digestion applications.