Corrigendum to “Use of free nitrous acid from partial nitrification reactor for the sanitization of digester effluents and Class A biosolids production” (Biochemical Engineering Journal, (2026), 226, C, (109993), (S1369703X25003675), 10.1016/j.bej.2025.109993)

The authors regret that, in the originally published version of this article, several figure captions (Figs. 3, 4, 5, 6, 7, and 8) contained formatting errors in which the symbols and series identifiers were displayed in black instead of their corresponding colors. This affected the correct visual distinction of the graphical data. The captions have now been corrected to reflect the appropriate color assignments. These corrections do not affect the results or conclusions of the article. The authors would like to apologise for any inconvenience caused. Fig. 3. a) Ammonium oxidation efficiency (Image 1) and pH value inside the partial nitrification (PN) reactor (Image 2); b) NO₂^--N/NH₄⁺-N ratio in the effluent of the PN reactor (Image 3) and yield of nitrate over ammonia oxidized (Image 4) for different hydraulic retention times (HRT) tested. Fig. 4. a) Free nitrous acid (FNA) (Image 1) and free ammonia (FA) (Image 2) concentrations; b) Ammonium loading rate (ALR) applied for different HRT values tested. Fig. 5. Concentrations of soluble chemical oxygen demand (COD) in the Inlet (Image 1) and outlet (Image 2) for different HRT values tested. Fig. 6. X-ray diffraction (XRD) diffractogram corresponding to a sample of the PN reactor effluent (Image 5 Quartz (SiO₂);Image 6 Calcite (CaCO₃); Image 7 Dolomite (CaMg(CO₃)₂); Image 8 Albite (NaAlSi₃O₈)). Fig. 7. Total coliform concentration in the PN reactor effluent (Image 1) and their removal efficiency (Image 2) for different HRT values tested. Fig. 8. Total coliform concentration profile over time in the presence of A) 650 mg NO₂^–N/L (pH: 4 (Image 9); 5 (Image 10); 6 (Image 3)) and B) 1300 mg NO₂^–N/L (pH: 4 (Image 9); 5 (Image 10); 6 (Image 3)).