Vertical Flow Constructed Wetland for Treatment of Nitrogen Under Mesocosm Level Phragmites and Calamus Ecosystem of Gomutra

Abstract

This Vertical Flow Constructed Wetland (VFCW) system was evaluated for removal efficiency of Ammonium Nitrogen and Nitrate Nitrogen from Gomutra collected from cowsheds of Ujjain. The VFCW of mesocosm scale had a rectangular size and covered an effective area of 1.88 m² with a water retention capacity of 0.206 m^3. Two such units were combined together in series for better treatment performance. The VFCW was fabricated in a Reinforced Concrete Cement (RCC) tank below the ground level. The filter media was composed of coarse river sand supported below by coarse Gravel. Three sets were fabricated out of which – 

• The first set was initially planted with locally available grass Phragmites;
• Second set was planted with Calamus at the rate of 10-12 plants per sq. m.
• Third set no plantation was there and considered as control. 

In all the three sets, inlet and outlet arrangements were placed at top and bottom of the RCC tank respectively. The diluted Gomutra (1:4) was kept in dosing tank and allowed to pass through the VFCW; treated effluent was collected from each outlet. Phragmites bed NH₄ –N and NO₃ -N gets reduced by 71.6% and 51.96% respectively from inlet to outlet. Calamus bed causes a maximum reduction of 75.58% of NH₄ –N from inlet to outlet and for NO₃ –N it shows a reduction of 80.35% from inlet to outlet. The control reduces NH₄ –N by 13.94% and NO₃ –N by 14.28% from inlet to outlet. 

The VFCW results established that

• This system is highly efficient for Gomutra treatment.
• Calamus bed system is most efficient in treatment of Gomutra in comparison to all three systems.