Towards a sustainable transformation of municipal wastewater treatment plants into biofactories using advanced NH-N recovery technologies: A review.

Ammonia (NH), as a prevalent pollutant in municipal wastewater discharges, can impair aquatic life and have a negatively impact on the environment. Proper wastewater treatment and management practices are essential to protect ecosystems and keep human populations healthy. Therefore, using highly effective NH-N recovery technologies at wastewater treatment plants (WWTPs) is widely acknowledged as a necessity. In order to improve the overall efficiency of NH removal/recovery processes, innovative technologies have been generally applied to reduce its concentration when discharged into natural water bodies. This study reviews the current status of the main issues affecting NH recovery from municipal/domestic wastewater discharges. The current study investigated the ability to recover valuable resources, e.g., nutrients, regenerated water, and energy in the form of biogas through advanced and innovative methods in tertiary treatment to achieve higher efficiency towards sustainable wastewater and resource recovery facilities (W&RRFs). In addition, the concept of paradigm shifts from WWTP to a large/full scale W&RRF has been studied with several examples of conversion to innovative bio-factories producing materials. On the other hand, the carbon footprint and the high-energy consumption of the WWTPs were also considered to assess the sustainability of these facilities.