Effect of sulfide on the nitrogen removal performance and microbial community of low-substrate Anammox process.

Anammox is one of the most innovative nitrogen removal technologies, while its functional bacteria-anaerobic ammonia-oxidizing bacteria (AAOB) is sensitive to the impurities in the wastewater. In this study, the long-term effects of sulfide at different concentrations (0, 5, 10, 20, 30, 50, 25 mg L) on low substrate Anammox process were studied. The results showed that when the sulfide was 25-30 mg L, AAOB was well coupled with sulfide-denitrifying bacteria and the total nitrogen removal efficiency (TNRE) reached a maximum of 91.0%. The hydroxylamine oxidoreductase activity and Heme-c reached 1.678 EU g SS and 0.0023 mmol g SS, respectively, with the and gene concentrations as 2.52 × 10 and 4.45 × 10 copies mL. 50 mg L sulfide inhibited the nitrogen removal by AAOB, resulting in the TNRE decreasing to 81.7%. The experimental results provide a reference for the practical application of Anammox in treating sulfur-containing wastewater.