We studied the possibilities of combining wastewater treatment in constructed wetlands
with the production of crop plants biomass. The idea was to use the surface of trickling filters to grow crop plants, to combine the processes of nutrient transformation (mainly nitrification) and nutrient recycling. The original concept was established by aquaponic producers [3,4], which achieved remarkable fish to plant production ratios in market-scale production systems. For each kilogram of fish produced in feedlot aquaculture, the nutrients in the resulting wastewater allowed a vegetable biomass production of 7 kg [5].