Ammonia removal was monitored in a waste stabilisation pond complex comprising ponds
of different geometries and depths under two different operational regimes. It was found that
a high degree of ammonia removal commenced in the secondary maturation ponds, with the
highest removals occurring in the shallowest ponds as a consequence of improved aerobic
conditions. The tertiary maturation ponds produced effluents with mean ammonia
concentrations of< 5 mg N/l, the maximum permitted recommended by Brazilian …