Conventional municipal waste-water treatment processes are based on aeration, which is energy intensive.
Now, researchers have developed an alternative waste-water treatment process. In addition to avoiding the use of aeration in favour of filtration/biofiltration and encapsulated denitrification (the application of capsules containing nitrifiers, which convert ammonium into nitrate), the process also uses waste biosolids to generate electrical energy. The process has been tested in a pilot facility and found to require just 15% of the energy required for conventional approaches. Moreover, the process is energy positive, as the biosolids are able to generate more than enough energy to power the treatment plant. If this technology could be scaled up to the municipal level, it could significantly reduce the energy use and environmental impacts of wastewater treatment.