Effect of flux fluctuation on the fouling in membrane water treatment system for smart water grid

Abstract

Smart water grid is a water network with communication to save water and energy. In smart water grid, decentralized water management system is more suitable than the conventional centralized system. Membrane process can be a potent option of water treatment system for decentralized water management system due to stable product water quality regardless of periodic changes in water production rate (flux fluctuation) to meet a real-time water demand. In this study, the effect of flux fluctuation on membrane fouling was investigated using a simple microfiltration (MF) fouling model for field application. The fouling model was verified by operation data of a pilot-scale MF plant with two commercial MF membrane modules (72m(2) of membrane area). From the MF simulation results, we found that periodic change in flux can induce higher fouling than the constant flux and the fouling becomes more severe as the range of the fluctuation increases. It was also found that the frequency of flux fluctuation was not related to fouling, if the average flux and the fluctuation range were not changed. Therefore, the range of flux fluctuation should be carefully designed when flux fluctuation in inevitable in membrane water treatment for smart water grid.