Effects of tourmaline on the establishment, idling, and recovery of partial nitrification: Mechanistic understanding and performance evaluation

The effects of different doses of tourmaline (Tm) on the partial nitrification (PN) system were investigated in this study. Tourmaline − Partial Nitrification sequential batch reactor (TmPNSBR) aimed to optimize the efficiency of PN for nitrogen removal in wastewater treatment. These results showed that Tm could reduce the time for PN establishment with a maximum reduction of 67.71% (Tm 8), maintained the stability of microbial community structure during the idle period, increased the ammonia oxidation rate, and promoted nitrite accumulation. Tm stimulated microorganisms to secrete more EPS (increase 7.92%–22.43% in phase I), and microorganisms adhere closely to the surface of Tm. Microbial community analysis showed that adding Tm could change the microbial community abundance and diversity, Tm increased the ammonia-oxidizing bacteria (AOB) abundance (increase 7.92%–22.43% in phase I) and decreased the nitrite-oxidizing bacteria (NOB) abundance. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) predicted increased content of key enzymes associated with PN and electron transport-related complexes. This study delved into the potential of Tm to mitigate environmental pollution as an efficient and environmentally friendly new material that optimizes the PN process, thereby contributing to the energy-efficient treatment of sustainable wastewater.