Ozonation application in activated sludge systems for a textile mill effluent.
The study investigates the effect of partial ozonation of textile wastewater, both at the inlet (pre-ozonation) and the outlet (post-ozonation) of biological treatment, for the optimization of COD and color removals, both typical polluting parameters associated with the textile industry. Pre-ozonation provides at optimum contact time of 15 minutes 85% color removal, but only 19% COD reduction. Removal of the soluble inert COD fraction remains at 7%, indicating selective preference of ozone for simpler compounds. Post-ozonation is much more effective on the breakdown of refractory organic compounds and on color removal efficiency. Ozonation after biological treatment results in almost complete color removal and a 14% soluble inert COD reduction. The polishing effect of post-ozonation also proves quite attractive from an economical standpoint, involving approximately 50% of the ozone utilization at the same ozone flux rate and contact time, yet providing a lower soluble residual COD level.
Environmental Engineering Department, Istanbul Technical University, I.T.U. Inşaat Fakültesi, 80626 Maslak, Istanbul, Turkey.
D
D
Orhon
H
H
Dulkadiroğlu
S
S
Doğruel
I
I
Kabdaşli
S
S
Sozen
F Germirli
FG
Babuna
D019149:Bioreactors; D004396:Coloring Agents / Q000737:chemistry / Q000378:metabolism; D010083:Oxidants, Photochemical / Q000737:chemistry*; D010100:Oxygen / Q000378:metabolism; D010126:Ozone / Q000737:chemistry*; D013783:Textile Industry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014872:Water Movements
D004396:Coloring Agents; D010083:Oxidants, Photochemical; D010126:Ozone; D010100:Oxygen