Complex but intriguing iron sulfide-based autotrophic denitrification

Treating wastewater to a high standard before discharge into lakes, rivers, and seas is essential for achieving the Sustainable Development Goals (SDGs) and maintaining environmental and ecological integrity. In this context, iron sulfide-based autotrophic denitrification (ISAD) presents a promising alternative to conventional heterotrophic denitrification, offering effective simultaneous removal of nitrogen and phosphorus from wastewater. I will present our findings on the ISAD process applied to the treatment of secondary effluent from municipal wastewater treatment plants. Building on these results, I propose a next-generation sustainable wastewater treatment approach — NEO-GREEN (Iron Sulfide-Based Biotechnology for Advanced Wastewater Treatment). This innovative process has the potential to harness bioenergy from wastewater, facilitate resource recovery (phosphorus and iron), and achieve simultaneous removal of nutrients and emerging contaminants.

Several intriguing and challenging phenomena exist in iron sulfide-based autotrophic denitrification systems. For instance, the crystallinity of iron sulfides significantly influences both chemical and biochemical denitrification processes. Understanding these mechanisms not only provides valuable insights into nitrogen, sulfur, iron, phosphorus, and carbon cycling in natural environments but also contributes to our understanding of life's resilience in harsh conditions.