NITRIFICATION IN SINGLE-STAGE TRICKLING FILTERS

An assessment of nitrification of municipal wastewater in trickling fi lters was performed using operating data from wastewater treatment fac ilities currently in operation. A survey of trickling filter use in th e United States found twenty-seven plants accomplishing some degree of nitrification. Of the twenty-seven plants ten were identified as havi ng operating data sufficient for further analysis. Although most of th e plants evaluated were not designed as single-state systems they all provided sufficient data to evaluate trickling filter performance as a single-state system. The evaluated plants were generally meeting thei r permit requirements, including ammonia-nitrogen limits when applied. Analysis of the data compared favorably with the BOD5 loading rates s uggested by the EPA Process Design Manual for Nitrogen Control.