Impact of Intermittent Operation on Biofilter Performance

Project Update

The main focus of the project to-date has been monitoring the biological acclimation of pilotscale filters prior to evaluating alternative operating conditions. The control biofilter, operated without exposure to chlorine, has been in operation since April 2018, while a pilotscale experimental biofilter began operation in December 2018. These two biofilters, along with pilot- and full-scale filters that were backwashed with chlorinated water, have been sampled every two weeks for biomass density (as measured by adenosine triphosphate, ATP) and enzyme activity on the filter media. Water samples have been analyzed for organics reduction (dissolved organic carbon and UV254), nutrient uptake (phosphorus, ammonia, nitrate and nitrite) and disinfection byproduct formation potential control. Biomass characterization and water quality results from the control and experimental biofilters have been compared to determine when they are performing similarly, such that impact of operational changes can be elucidated.