Insight into the effect of Tubificidae on dynamic membrane reactor: Membrane fouling mitigation and Tubificidae-ASM3-dynamic membrane coupled model

To gain insights into the effects of Tubificidae on dynamic membrane sequencing batch reactor (DMSBR), 4 identical DMSBRs were operated with different Tubificidae densities (i.e., 0, 1, 2, 3 g ww/L). Experimental results showed that Tubificidae had a minimal effect on carbon and nitrogen removal but varied effluent turbidity and sludge characteristics. An appropriate density (2 g ww/L) of Tubificidae significantly decreased effluent turbidity and mitigated membrane fouling, which was attributed to the minimized mixed liquor suspended solids (MLSS) and the maximized particle size. A Tubificidae-ASM3-dynamic membrane coupled model was developed by combining the biological model with the dynamic membrane resistance model, incorporating the extracellular polymeric substances (EPS) to characterize its contribution to membrane pore fouling, and introducing an inhibitory function to limit the unrestricted growth of membrane resistance. The model can be considered as a first attempt to describe the observed Tubificidae effects on dynamic membrane reactor.