Mathematical modelling of 4-chlorophenol inhibition on COD and 4-chlorophenol removals in an activated sludge unit.
A mathematical model was developed for an activated sludge unit treating 4-chlorophenol (4-CP) containing synthetic wastewater composed of diluted molasses, urea, KH(2)PO(4) and MgSO(4) with COD and 4-CP contents of 2500 and 500 mg l(-1), respectively. The model included 4-CP inhibition on COD and 4-CP removals. Experimental data obtained at different hydraulic residence times (HRT=5-30h) and sludge ages (SRT, 3-30 days) were used to estimate the kinetic and inhibition constants for COD and 4-CP removal rates. 4-CP inhibition on COD removal was negligible while the inhibition on 4-CP removal was significant. The specific rate constant (k), saturation constant (K(s)) for COD oxidation were found to be 2.64 day(-1) and 559 mg l(-1), respectively. A similar model was used for 4-CP oxidation in the activated sludge unit and the constants were found to be k'=1.44 day(-1), K'(s)=25.7 mgl(-1), K"(CP)=559 mg l(-1),and K(I,CP)=17 mg l(-1). Increases in death rate constant because of 4-CP inhibition was also quantified and the inhibition constants were determined for both COD and 4-CP removals. Model predictions with the estimated kinetic constants were in good agreement with the experimental data. Developed model can be used to estimate the performance of an activated sludge unit treating 4-CP containing wastewater under the specified experimental conditions.
Konya
Isil
I
Department of Environmental Engineering, Dokuz Eylul University, Buca, Izmir, Turkey.
Eker
Serkan
S
Kargi
Fikret
F
D001673:Biodegradation, Environmental; D002733:Chlorophenols / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D012722:Sewage / Q000382:microbiology; D018505:Waste Management / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D002733:Chlorophenols; D012722:Sewage; D014874:Water Pollutants, Chemical; C029107:4-chlorophenol