Australian Centre for Water
and Environmental Biotechnology

Project Dates: 2020 to 2023


Wastewater management is undergoing a strong paradigm shift from pollutants removal to resource recovery. One of the most promising configurations for bioenergy recovery from wastewater is the upfront conversion of organic carbon in wastewater to biogas, using anaerobic processes, followed by autotrophic nitrogen removal. This configuration boasts a high energy yield, and is therefore of considerable interest to the water industry including our partners. However, it has two well-known technology barriers, which prevent widespread adoption:

1. Up to 50% of methane produced remains dissolved in the effluent discharged from the anaerobic treatment reactor. Stripping of methane to the atmosphere in the subsequent aerobic treatment process causes not only a substantial loss of bioenergy but also a sharp increase of the carbon footprint of the treatment process.

2. The autotrophic nitrogen removal process has limited efficiency, often below 70% removal, as will be further discussed, and the effluent generally does not meet stringent nitrogen discharge standards in areas with sensitive receiving waters.

In this project, we aim to develop an innovative solution to simultaneously remove both of these technology barriers. The solution involves the use of dissolved methane to support denitrification, thus simultaneously enhancing nitrogen removal, avoiding methane emission and achieving beneficial use of dissolved methane.