Figs. 5. Total Kjeldahl Nitrogen (graph a) and conversion ratio of nitrogen (graph b) according to the time. c=
Effluent treated by S. = Effluent treated by PS. ¡= Effluent treated by P. The points are means of Total
Kjeldahl Nitrogen yields and conversion ratio of nitrogen. Vertical bars indicate standard deviation (±) (n=5).
For the sake of clarity, only the halves of the interval bars have been represented. Different letters, for the
same date, over points indicate significant differences according to Tukey test at p