Aquatic worms (Tubificidae) facilitate productivity of macrophyte Azolla filiculoides in a wastewater biocascade system

Due to high waste sludge disposal at wastewater treatment plants and increasing phosphorus scarcity, there is a need combine removal nutrient recovery. One way achieve this by incorporating ecological processes into treatment. Positive species interactions, such as facilitation, are critical increase productivity of biomass In study we showed the potential using principles including interspecific facilitation aquatic (Azolla filiculoides) worms (Oligochaeta, Tubificidae) in recovery production. This was investigated developing biocascade with monocultures that fed on activated sludge. Tubificidae had an average relative growth rate 0.02 g g−1 DW d−1 whereby predation resulted 45% reduction. When were present biocascade, A. filiculoides production significantly increased 0.15 d−1. The activity mostly affected total suspended solids, chemical oxygen demand ammonium concentration first compartment biocascade. Additionally, nitrification rates water acidified, leading carbon dioxide concentrations dissolved phosphorus-binding metals (zinc, iron, aluminium manganese) stimulated growth. reduction (45%) sequestration (133 mmol m−3 d−1) show strong for combined from wastewater.