Backwashing affects the removal of micropollutants and the dynamic changes in the microbial community in sand filters

Sand filters are commonly applied in drinking water treatment and can efficiently remove suspended solids, organic matter, and microorganisms from source water. During the process, particulate matter and microbes can attach to filter sands and develop a thick biofilm in both rapid and slow sand filters. To prevent clogging and restore pollutant removal efficiency, backwashing using air, water, or a combination of both is usually required for sand filters.