MANAGEMENT OF FILTRATION AND IDLE PERIODS IN A MULTI-CELL BIOFILTER TO OPTIMIZE PERFORMANCE

A pilot-scale study was conducted to evaluate the performance of a biological denitrifying filtration process when subjected to various filter run and idle periods with the objective of determining the length of time a denitrifying filter cell can practically remain out of service and the recovery time necessary to produce good quality effluent following idle periods of varying duration. The filter was subjected to runs ranging from 6 to 24 hours and idle periods of 12 to 48 hours. Backwash was performed following every 24-hours of filter run time.The biological denitrifying filter process recovered in less than 30 minutes from startup following all idle periods tested, including a maximum idle time of 48 hours. The study demonstrates the robust nature of the biological denitrification filter that can be designed to meet the challenges of real-world operational constraints.