Ozonation reduces sludge production and improves denitrification

The effectiveness of partial ozonation of return activated sludge for enhancing denitrification and waste sludge minimization were examined. A pair of nitrifying sequencing batch reactors was operated in either aerobic or alternating anoxic/aerobic conditions, with one control and one ozonated react...

Full description

Saved in:
Bibliographic Details
Published in:Water research (Oxford) 2007-02, Vol.41 (3), p.543-550
Main Authors: Dytczak, Magdalena A., Londry, Kathleen L., Siegrist, Hansruedi, Oleszkiewicz, Jan A.
Format: Article
Language:English
Subjects:
activated sludge
aerobic conditions
anaerobic conditions
Applied sciences
autotrophs
biodegradation
Biodegradation, Environmental - drug effects
Biomass
Bioreactors
chemical oxygen demand
cytolysis
Denitrification
denitrifying microorganisms
Exact sciences and technology
Nitrification
Nitrites - chemistry
Nitrogen - chemistry
Other industrial wastes. Sewage sludge
ozonation
Ozone
Ozone - chemistry
Ozone - pharmacology
Pollution
pollution control
Sewage - analysis
Sewage - chemistry
Sewage - microbiology
Sludge minimization
Waste Disposal, Fluid - methods
Wastes
Wastewater
wastewater treatment
water pollution
Water treatment and pollution
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The effectiveness of partial ozonation of return activated sludge for enhancing denitrification and waste sludge minimization were examined. A pair of nitrifying sequencing batch reactors was operated in either aerobic or alternating anoxic/aerobic conditions, with one control and one ozonated reactor in each set. The amount of solids produced decreased with the ozone dose. Biomass in the anoxic/aerobic reactor was easier to destroy (up to 25% of the initial excess sludge) than in the aerobic (10%) one, generating approximately twice as much soluble COD by cell lysis. Denitrification rate improved up to 60% due to additional carbon released by ozonation. Nitrification rates deteriorated much more in the aerobic than in the alternating reactor, possibly as a result of direct destruction of nitrifying autotrophs as well as competition created by growth of heterotrophs receiving the additional COD. Overall, ozonation provided the expected benefits in denitrification and had less impact on nitrification in the alternating reactors.
ISSN:0043-1354
1879-2448
DOI:10.1016/j.watres.2006.11.009