The Effect of Backwashing on Microbial Ecosystem of the BEAC Filter

The invasion of indigenous flora from the open system into the biological enhanced activated carbon(BEAC) system can inhibit the development of dominant bacteria and also decrease the biodegradability and biological activity of dominant bacteria. Therefore, this study aimed to investigate the effect of backwashing on the indigenous flora and dominant bacteria in the BEAC system and to study the optimal operation process of backwashing. In order to control the inhibition of the indigenous flora, the optimal backwashing conditions were set as 7-10d of operation period and 8-10 L/(m²•s) of air backwashing intensity. In addition, the PCR-DGGE results showed the indigenous flora could be removed under the optimal backwashing process, and the dominant bacteria could also be updated to maintain the biological stability well in this system.