Enhanced elemental sulfur recovery and nitrogen removal through coupling of sulfide-dependent denitrification and anammox processes during ammonium- and sulfide-laden waste stream treatment.

Influence of anammox process on autotrophic denitrification was investigated in this study, during simultaneous ammonium, nitrate and sulfide treatment. Elemental sulfur production and nitrogen removal by sulfide-dependent denitrifier (S-den) and mixed culture (S-den-anammox) were compared. Accumulation of nitrite (100%) and elemental sulfur (46.3%) was achieved at pH 7.0 and 30 °C with S 2 O 3 2−/NO 3 − ratio of 1:1 by autotrophic denitrifier. Enhanced elemental sulfur production (56.5%–99.5%) by autotrophic denitrifier was obtained after coupling with anammox process. Total nitrogen removal increased to 80.5% in mixed culture reactor, which was 72.0% in anammox reactor. N 2 O emission in anammox reactor was not affected (<0.5% gaseous nitrogen) after coupling with autotrophic denitrification. Therefore, this study demonstrated enhanced elemental sulfur recovery and nitrogen removal through coupling of sulfide-dependent denitrification and anammox processes, which might be a potential technology for water eutrophication and corrosion control, and atmospheric acid rain, PM 2.5 and global warming control. Image 1 • Removal of NO 3 −, S2− and NH 4 + was achieved in sulfide-dependent DEAMOX process. • Elemental sulfur production was enhanced 26.8% after cooperation with anammox. • TN removal increased about 10% in sulfide-dependent DEAMOX reactor. • NO x was lower than 0.5% gaseous nitrogen in sulfide-dependent DEAMOX reactor. [ABSTRACT FROM AUTHOR]