Constructed wetlands and denitrifying bioreactors for on-site and decentralised wastewater treatment: Comparison of five alternative configurations

► Hybrid vertical-flow constructed wetlands and denitrifying bioreactor performance. ► Five different configurations compared side-by-side treating same wastewater. ► Intermediate stages of treatment trains sampled and flows monitored. ► Mass removal, role of component stages and nitrogen processing rates quantified. ► Advanced levels of effluent quality achieved.