Sulfide removal by simultaneous autotrophic and heterotrophic desulfurization-denitrification process.
An anaerobic attached-growth bioreactor (AAGBR) of 3.52 L was operated for 510 days to treat sulfide-laden organic wastewater where nitrate and nitrite were introduced as electron acceptors. When the influent sulfide was kept at 200mg S(2-)-S/L and organic carbon was increased from 20 to 33.6 mg C/L, and the hydraulic retention time decreased from 41.4 to 2.67 h, the removal rates of sulfide and organic carbon reached 99.9% and 91.8% at the loading rates of 1800 mg S(2-)-S/(Ld) and 302.4 mg C/(Ld), respectively. Simultaneously, the introduced electron acceptors of nitrate and nitrite were, respectively, removed by 99.9% and 99.9% at the loading rates of 472.5 mg NO(3)(-)-N/(Ld) and 180 mg NO(2)(-)-N/(Ld). Inside the AAGBR, both autotrophic and heterotrophic denitrification processes were noted to take place. When the influent organic carbon was increased from 20 to 33.6 mg C/L, the nitrate and nitrite consumed for heterotrophic denitrification accounted for 27.3% and 48.5%, respectively. This simultaneous autotrophic and heterotrophic desulfurization-denitrification process has provided a demonstration of the possibility to eliminate sulfide and organic carbon with the presence of nitrate and nitrite.
Li
Wei
W
State Key Laboratory of Urban Water Resources and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 202 Haihe Road, Nangang District, Harbin 150090, PR China.
Zhao
Qing-Liang
QL
Liu
Hao
H
D000693:Anaerobiosis; D019149:Bioreactors; D008855:Microscopy, Electron, Scanning; D009566:Nitrates / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry*; D013440:Sulfides / Q000302:isolation & purification*; D013455:Sulfur / Q000737:chemistry*
D009566:Nitrates; D009573:Nitrites; D013440:Sulfides; D013455:Sulfur