Simultaneous removal of ammonia and nitrate by coupled S-driven autotrophic denitrification and Anammox process in fluorine-containing semiconductor wastewater.

To achieve the simultaneous removal of NH-N and NO-N in F-containing semiconductor wastewater by coupled S-driven autotrophic denitrification and Anammox process, the effect of variable F concentration on the Anammox process was investigated by batch experiments. The denitrifying ammonium oxidation (Deamox) reactor was then started-up to explore the feasibility of the coupling of Anammox and sulfur autotrophic denitrification (SADN) for the treatment of semiconductor wastewater. Short-term variation of F concentration has an obviously effect on the activity of Anammox sludge, but didn't affect the nitrogen conversion rate. The activity of Anammox obviously decreased after long-term operation of the Deamox reactor when influent F concentrations reached 552 mg/L. The sensitivity of Anammox bacteria to F concentration is stronger than that of SADN bacteria. Total nitrogen removal efficiency of 98% and total nitrogen removal rate of 4.11 kg/(m·d) were achieved in the Deamox reactor, when the F was pre-treated by calcium ions. Moreover, the high-throughput 16S rRNA gene sequence analysis indicated that variation in F concentrations could influence the structure and functional of microbial communities in the Deamox process. Candidatus Kuenenia, Thiobacillus and Sulfurimonas were main functional bacteria that achieved symbiotic.