کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
584114 | 1453179 | 2007 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Anoxic sulfide biooxidation using nitrite as electron acceptor
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بهداشت و امنیت شیمی
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چکیده انگلیسی
Biotechnology can be used to assess the well being of ecosystems, transform pollutants into benign substances, generate biodegradable materials from renewable sources, and develop environmentally safe manufacturing and disposal processes. Simultaneous elimination of sulfide and nitrite from synthetic wastewaters was investigated using a bioreactor. A laboratory scale anoxic sulfide-oxidizing (ASO) reactor was operated for 135 days to evaluate the potential for volumetric loading rates, effect of hydraulic retention time (HRT) and substrate concentration on the process performance. The maximal sulfide and nitrite removal rates were achieved to be 13.82 and 16.311Â kg/(m3Â day), respectively, at 0.10 day HRT. The process can endure high sulfide concentrations, as the sulfide removal percentage always remained higher than 88.97% with influent concentration up to 1920Â mg/L. Incomplete sulfide oxidation took place due to lower consumed nitrite to sulfide ratios of 0.93. It also tolerated high nitrite concentration up to 2265.25Â mg/L. The potential achieved by decreasing HRT at fixed substrate concentration is higher than that by increasing substrate concentration at fixed HRT. The process can bear short HRT of 0.10 day but careful operation is needed. Nitrite conversion was more sensitive to HRT than sulfide conversion when HRT was decreased from 1.50 to 0.08 day. Stoichiometric analyses and results of batch experiments show that major part of sulfide (89-90%) was reduced by nitrite while some autooxidation (10-11%) was resulted from presence of small quantities of dissolved oxygen in the influent wastewater. There was ammonia amassing in considerably high amounts in the bioreactor when the influent nitrite concentration reached above 2265.25Â mg/L. High ammonia concentrations (200-550Â mg/L) in the bioreactor contributed towards the overall inhibition of the process. Present biotechnology exhibits practical value with a high potential for simultaneous removal of nitrite and sulfide from concentrated wastewaters at shorter HRT.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hazardous Materials - Volume 147, Issues 1â2, 17 August 2007, Pages 249-256
Journal: Journal of Hazardous Materials - Volume 147, Issues 1â2, 17 August 2007, Pages 249-256
نویسندگان
Qaisar Mahmood, Ping Zheng, Jing Cai, Donglei Wu, Baolan Hu, Jinye Li,