PRACTICAL EXPERIENCE WITH COMBINED CARBON OXIDATION AND NITRIFICATIONIN PLASTIC MEDIA TRICKLING FILTERS

Long-term data from three full-scale trickling filters installations a ccomplishing combined carbon oxidation and nitrification are presented . Analysis of these data indicates that the oxidation of organic matte r and ammonia-nitrogen in the trickling filter can be characterized by a single parameter which is calculated as the trickling filter organi c loading (expressed in terms of BOD, or biodegradable COD) plus the a mmonia-nitrogen oxidized converted to oxygen equivalents using the con version factor 4.6 kgO/kg NO3-N. This parameter, which is referred to as the volumetric oxidation rate and is expressed in the units of kgO/ m(3)-day, characterizes trickling filter performance over a wide range of process loading and effluent quality conditions. The method of ana lysis presented in this work differs from the one traditionally used t o characterize combined carbon oxidation and nitrification in tricklin g filters, and it suggests that oxidation may be oxygen transfer limit ed throughout such a trickling filter.