Effect of shock and mixed loading on the performance of SND based sequencing batch reactors (SBR) degrading nitrophenols
DSpace at IIT Bombay
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Title |
Effect of shock and mixed loading on the performance of SND based sequencing batch reactors (SBR) degrading nitrophenols
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Creator |
KULKARNI, PM
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Subject |
Nitrophenols
Thiosphaera pantotropha Heterotrophic nitrification Aerobic denitrification SBR SND THIOSPHAERA-PANTOTROPHA NITROAROMATIC COMPOUNDS 4-NITROPHENOL BIODEGRADATION HETEROTROPHIC NITRIFICATION P-NITROPHENOL DENITRIFICATION 4-CHLOROPHENOL PEAKS WATER |
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Description |
The effect of nitrophenolic shock loads on the performance of three lab scale SBRs was studied using a synthetic feed. Nitrophenols were biotransformed by Simultaneous heterotrophic Nitrification and aerobic Denitrification (SND) using a specially designed single sludge biomass containing Thiosphaera pantotropha. Reactors R1, R2 and R3 were fed with 200 mg/L concentration of 4-nitrophenol (4-NP), 2,4-dinitrophenol (2,4-DNP), and 2,4,6-trinitrophenol (2,4,6-TNP) whereas reactor R was used as a background control. Three nitrophenolic shock loadings of 400, 600 and 800 mg/L d were administrated by increasing the influent nitrophenolic concentration while keeping the hydraulic retention time as 48 h. The shocks were given continuously for a period of 4 days before switching back to normal nitrophenolic loading (200 mg/L d). The reactors were allowed to recover to normal performance level before administrating the next nitrophenolic shock load. The study showed that a nitrophenolic shock load, as high as 600 mg/L d was completely degraded by the 4-NP & 2,4-DNP bioreactors while almost half degraded by the 2,4,6-TNP bioreactor without affecting the reactor's performance irreversibly. After resuming the normal nitrophenolic loading, it took almost 8-10 days for the reactors to recover from the shock effect. The study was further extended to evaluate the maximum possible mixed nitrophenolic loading (4-NP:2,4-DNP:2,4,6-TNP 1:1:1) to which a reactor (R3) containing 2,4,6-TNP acclimated single sludge biomass can be exposed without hampering the reactor performance irreversibly. The reactor was able to achieve pseudo-steady-state at a mixed nitrophenolic loading of 300 mg/L d with more than 90% removal of all the three nitrophenols, but could remove half of the mixed nitrophenolic loading of 600 mg/L d. (C) 2012 Elsevier Ltd. All rights reserved.
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Publisher |
PERGAMON-ELSEVIER SCIENCE LTD
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Date |
2014-10-16T05:57:08Z
2014-10-16T05:57:08Z 2012 |
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Type |
Article
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Identifier |
WATER RESEARCH, 46(7)2405-2414
http://dx.doi.org/10.1016/j.watres.2012.02.008 http://dspace.library.iitb.ac.in/jspui/handle/100/15394 |
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Language |
en
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