Biochar, a promising additive in biological wastewater treatment, has garnered attention for its environmental benefits. Yet, its impact on anaerobic ammonium oxidation (anammox) processes remains unclear, particularly regarding the differential effects of undissolved biochar (UDB) and dissolved biochar (DB) at varying pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More temperatures. A recent study aimed to elucidate these effects and their implications for nitrogen removal efficiency (NRE).

The study evaluated anammox systems amended with UDB and DB produced at different pyrolysis temperatures (300 °C, 550 °C, and 800 °C). Results showed that the DB800-amended group exhibited superior NRE, with a total nitrogen removal efficiency of 92.8 ± 1.4 %. In contrast, lower pyrolysis temperature DB imposed suppression on NRE. Notably, molecular-level analysis revealed that DB released dissolved organic matter dominated by CHO compounds, with lignin-like and carboxylic-rich molecules prevalent in DB800.

The introduction highlighted the importance of anammox processes in wastewater treatment and the potential of biochar as a promoter. Despite over 200 full-scale anammox plants globally, challenges persist, motivating research into enhancing anammox bacteria activity and system stability. Biochar, with its eco-friendly properties, offers a promising avenue for improvement.

The study’s objectives included assessing nitrogen removal performance, exploring metabolic and electrochemical activities, and determining microbial spatial structure distribution. By contrasting UDB and DB effects, the research aimed to deepen understanding of biochar’s role in anammox processes, potentially informing strategies for enhanced nitrogen removal.

In conclusion, this study sheds light on the contrasting roles of UDB and DB in anammox processes, providing valuable insights for optimizing biochar applications in wastewater treatment. Further research in this area could contribute to more efficient and sustainable nitrogen removal technologies.