5. Conclusion
The three-stage experimental process provided suitable conditions especially in the aerobic state for nitrogen transformation so
that effluent TN met the standard for Class-III surface water. However, being a greenhouse gas, N2O generated from co-respiration
is to be monitored and its application reduced in order to meet the
global warming challenge. The surface area of the SMOP section
should be limited to avoid an increase in TN probably arising from
algal N fixation. Simultaneously, an area reduction of the SSVFW
section is recommended by using a slow release carbon material
for denitrification