Treatment of Dyeing Wastewater by TiO₂/H₂O₂/UV Process: Experimental Design Approach for Evaluating Total Organic Carbon (TOC) Removal Efficiency

Abstract

Optimal operating conditions in order to treat dyeing wastewater were investigated by using the factorial design and responses surface methodology (RSM). The experiment was statistically designed and carried out according to a 2² full factorial design with four factorial points, three center points, and four axial points. Then, the linear and nonlinear regression was applied on the data by using SAS package software. The independent variables were TiO₂ dosage, H₂O₂ concentration and total organic carbon (TOC) removal efficiency of dyeing wastewater was dependent variable. From the factorial design and responses surface methodology (RSM), maximum removal efficiency (85%) of dyeing wastewater was obtained at TiO₂ dosage (1.82 gL⁻¹), H₂O₂ concentration (980 mgL⁻¹) for oxidation reaction (20 min).

Keywords:

• Factorial design
• Responses surface methodology (RSM)
• TiO₂
• H₂O₂
• Total organic carbon

ACKNOWLEDGMENTS

This work was supported by grant no. R-01-2002-000-00305-0 from the Basic Research Program of the Korea Science and Engineering Foundation.

Notes

*Not detectable.

*Not significant.

*Experiment was repeated three times.

^a N.D. Not detectable.

^b Only with chemical coagulation and pH control.

^c TiO₂/H₂O₂/UV process with chemical coagulation and pH control using RSM.