Sulfidation forwarding high-strength Anammox process using nitrate as electron acceptor via thiosulfate-driven nitrate denitratation

A single up-flow thiosulfate-driven nitrate denitratation coupled with the sulfurized Anammox (TDSA) with the core-shell structure (S0@ Anammox granules) provided a chemical/energy-saving way for the removal of highcontent ammonium with nitrate as electron acceptor. Approximately 83.66% total nitrogen removal efficiency (TNRE) could be achieved by the sulfurized Anammox encrusted by S0/Sn2- at a high loading rate (2.6 kg-N/ (m3.d)) via resisting high concentration of free ammonia (FA) (22.35 mg/L), mainly through S2O32-, S0/Sn2-driven partial denitrification-Anammox (PDN-Anammox) process. Moreover, S0/Sn2- -PDN-Anammox was largely restricted when intermittently aerated, but still resulting in 74.47% TNRE due to the partial nitrificationAnammox (PN-Anammox). The sequencing analysis revealed that Anammox bacterium (Candidatus_Kuenenia) and sulfur-oxidizing bacterium (Thiobacillus) coexisted, in which Anammox process occurred mainly via NO instead of NH2OH. This study provided a new perspective for high concentration nitrogen wastewater removal in engineering applications.

Automated summary

The study demonstrated that a single up-flow thiosulfate-driven nitrate denitratation coupled with the sulfurized Anammox process showed promising results in removing high-content ammonium with nitrate as electron acceptor. The process achieved a total nitrogen removal efficiency of approximately 83.66% and provided insights for engineering applications in high concentration nitrogen wastewater treatment.