Effects of the filtration flux and pre-treatments on the performance of a microfiltration drinking water treatment system

Abstract

This study was performed to investigate the effects of flux and pre-treatment on the operation performance of a microfiltration drinking water treatment system through a pilot scale operation using lake water as raw water. The pilot plant had a capacity of 500 m3/day with a five membrane module and was operated for 1 year to carry out the experiments for the variation of filtration flux, physical cleaning conditions and pre-treatment conditions. Also, an experiment was performed when raw water with high turbidity flowed into the system as well as that pretreated with powdered activated carbon (PAC). When the MF system was operated with filtration flux of 2 m3/m2 day, it could not be operated more than 500 h due to the continuous TMP (Trans-membrane pressure) increase. In case of filtration flux of 1 m3/m2 day, the system could be operated continuously for more than 1300 hours without the increase in the TMP. During this experimentation period, raw water with high turbidity (above 400NTU) was fed into the membrane system. Therefore, the TMP increased by approximately 4.90 kPa compared to the TMP for the previous raw water with lower turbidity. In the case of the PAC pretreated membrane filtration process, the TMP tended to increase slightly. However, the TMP was reduced by performing coagulation and mixing after injecting PAC.