New Developments in Complete Nitrogen Removal with Biological Aerated Filters

Abstract

Biological aerated filters combine bacterial degradation of pollution by fixed biomass with physical filtration in a single reactor.Several full-size plants with the BIOCARBONE process have established the compactness, ease of operation and high removal rates achievable with this advanced treatment system. Based on large-scale industrial experiences, a new biofilter design offering simplified operation and increased performance is presented. Design data for carbon and nutrient removal were collected during extensive pilot tests. Hydraulic conditions and pollution loadings were varied in order to optimize the biological and operational parameters of the filter. Carbon and ammonia oxidation as well as denitrification and suspended solids retention could be achieved with an overall hydraulic retention time of two hours.