The effects of low-EPS producing bacteria on the performance of the membrane aerated biofilm reactors (MABRs) and membrane bioreactor (MBRs): Experimental and modeling study

The objective of this study was to see the effects of EPS on the kinetic, performance, biofilm structure, and biofouling of membrane reactor. We used Pseudomonas aeruginosa was as a target organism. P. aeruginosa produces three main types of EPS: alginate, Pel and PsI. The effect of EPS was studied by comparing the wild type with the genetically modified P. aeruginosa with suppressed Pel production (mutant). At steady-state for the MABR reactor, the biofilm thickness for the mutant culture was smaller than the wild type, while the quality effluent sCOD for the mutant culture was better than the wild type. Also, the effluent suspended solids decreased with the GMO culture. For ultrafiltration membrane reactor (UMR), there was no significant difference of sCOD between the wild type and mutant culture. However, the significant biofouling occurred much later for the mutant culture than the wild type.