The N-conversions calculated from Eq. (9) were multiplied by 2 and 15 to get the N-converted by the two surfaces of all the 15 baffles. The total biofilm N-conversion was obtained by summing the N-conversion of Eqs. (7 and 9) and that converted by the pond
walls; these were subsequently used in the TKN mass balance (Eq. (1)).