During operation, the system must be supervised by professional operators (SANIMAS 2005). Maintenance includes lubrication of moving parts, motors and bearings; replacing seals, motors, servicing bearings; and cleaning the attached-growth media (spray-washing of discs and purging of settled sludge) (METCALF & EDDY Inc. 2003; WSP 2007). The discs may be also checked for debris accumulation, ponding and excessive or not sufficient biomass accumulation (U.S.EPA 2002).
Although fixed film units such as RBC and trickling filters are operation- and maintenance-intensive, they do not require seeding with bacterial cultures (as do anaerobic processes such as anaerobic baffled reactors, septic tanks, upflow anaerobic sludge blanket reactors or anaerobic digesters) and the start-up phase is therefore considerably shorter. However, it takes 6 to 12 weeks for the biofilm to establish for a good treatment performance (U.S.EPA 2002).