Fig. 2. Total ammonia nitrogen (TAN) concentrations measured after spiking at time 0 with NH4Cl in five experimental moving bed biofilters operated at increasing long-term loadings (Table 1). Two spiking rounds were carried out as indicated by white and black symbols. Circles and triangles refer to data included for calculating zero and first order removal rate constants, respectively (fitted lines shown), while squares () indicate start and end values of nitrate-N.
Table 2 Zero and first order rate constants k (g/m2 /d) and k (m/d) for TAN, nitrite-N and urea-N, respectively, at increasing long-term loading (see Table 1 shown as averages