Effect of pH on anoxic sulfide oxidizing reactor performance.
The effects of pH on the performance of anoxic sulfide oxidizing (ASO) reactor were evaluated. Performance was investigated under various operational conditions at influent pH range of 4-11. At the influent pH of 7-7.5 during loading tests and HRT tests, the sulfide oxidation was partial. In general, the amount of sulfate formed decreased with the increasing sulfide and nitrite loadings. The bacterial communities in ASO reactors were more sensitive to acidic pH compared with alkaline pH, as nitrite and sulfide removal rates dropped significantly when exposed to acidic pH 3. High dissolved bisulfide ions, nitrite and excess of sulfate (>300 mg/L) might have inhibited the sulfide oxidation under highly acidic and alkaline conditions in the ASO reactor. Based on sulfide and nitrite removal efficiencies, the ASO reactor can be operated in a wide range of pH, i.e. 5-11.
Mahmood
Qaisar
Q
Department of Environmental Engineering, Zhejiang University, Hangzhou 310029, China.
Zheng
Ping
P
Hayat
Yousaf
Y
Islam
Ejazul
E
Wu
Donglei
D
Ren-cun
Jin
J
D018533:Biomass; D019149:Bioreactors; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000032:analysis*; D009573:Nitrites / Q000032:analysis*; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D013440:Sulfides / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods* / Q000592:standards
D009566:Nitrates; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D013440:Sulfides