Novel dual-particle sulfur-driven partial denitrification coupled with anammox for robust nitrogen removal at ambient temperature
摘要
To address the current shortage of organic matter and enable the effective utilization of inorganic carbon resources in wastewater, a dual-particle carrier system was developed by integrating elemental sulfur (S0) particles with anammox granular sludge, aiming to establish a S0-driven partial denitrification coupled with anammox (S0PDA) process for the simultaneous removal of NH4+ and NO3−. Under seasonal temperature fluctuations (11.9–26.6 °C, average 17.5 °C), the system achieved a total inorganic nitrogen removal efficiency (TINRE) of 95.7% ± 4.6%. Kinetic and mechanistic analyses revealed that NO3− was preferentially reduced over NO2− by sulfur-oxidizing bacteria (SOB), while anammox bacteria (AnAOB) competitively utilized NO2−, thereby enhancing NH4+ reduction. Thiobacillus and Candidatus Brocadia were identified as the dominant bacterial genera, with both genera exhibiting niche differentiation under ambient temperature: Thiobacillus predominantly colonized S0 particle surfaces, whereas Candidatus Brocadia was preferentially enriched in granular sludge, thereby minimizing substrate competition. Overall, the dual-particle S0PDA system demonstrated robust performance under ambient conditions, providing a sustainable solution for low C/N wastewater treatment.