Backwashing of granular media filters and membranes for water treatment: a review

Filter backwashing is a supplemental part of a drinking water treatment (DWT) facility to wash the filter bed at regular intervals using water or air scour/water by fluidizing the filter bed. Suspended sediments that are retained by the filter bed consist of different particles such as sand, anthracite, and granular activated carbon (GAC) that decline the water flow rate of the filter, and hence consequently the filter bed must be cleaned using a backwashing procedure. Biofiltration has been extensively utilized to decrease organic matter and manage the occurrence of disinfection by-products within drinking water sources. Biological rapid sand filters are frequently utilized to eliminate ammonium from groundwater provinces with the purpose of meeting drinking water requirements. Biological activated carbon (BAC) filters require to be backwashed to wash and enhance the treatment capability by detaching both restrained materials and residual biomass. The reclamation of activated carbon-used backwash water (UBW) was managed by exercising an ultrafiltration (UF) procedure.