Strategy for rapid recovery of simultaneous sulfide and nitrite removal under high substrate inhibition

The paper deals with the strategy for a quick recovery of reactor treating sulfide and nitrite simultaneously under inhibition caused by high substrate concentration. For influent sulfide concentration of 360 mg S/L, respective sulfide and nitrite removal percentages dropped to 74.19% and 14.33% due to inhibition caused by high sulfide and nitrite concentrations. It was found that reduction in the influent substrate concentration (300 mg S/L) could not revive the nitrite removal performance in 4 days' operation, which still showed a declining tendency from 47.16% to 18.52%. Regulating the influent pH around 6.70 +/- 0.10, it only took 4 days to recover the performance for 300 mg S/L. Furthermore, at influent sulfide concentration increased to 360 mg S/L, respective sulfide and nitrite removal percentages were 99.76 +/- 0.27% and 100.00%. The strategy of regulating influent pH could recover the process performance in a short term, which would provide great convenience for subsequent process research.