Treatment of a Textile Dye Wastewater by an Electrochemical Process

Abstract

This study explored the effectiveness of an electrochemical process to treat a sulfur dye wastewater from a textile industry. The treatment system included a 4.0 L reactor equipped with five steel electrode plates, and a separate sedimentation tank of equal liquid volume. The experimental part involved two distinct, sequential stages. In the first stage, the effect of initial pH and electrical charge (i.e., current times reaction time) on the treatment process was explored. Experiments were conducted in a factorial mode, involving three initial pH values (3, 4 and 5), and six electrical charges (ranging from 150 to 1,350 coulomb), respectively. Results indicated that chemical oxygen demand (COD), total suspended solids (TSS), and color removal efficiency improved with a decrease in initial pH and an increase in electrical charge. Overall, high percent removal values were observed ranging from 63% to 80% for COD, 81% to 96% for TSS, and 93% to 99% for color. During the second stage, the electrode corrosion pattern was investigated for a period of 45 days. Under stable operating conditions, electrode consumption was found to conform to Faraday's law. Moreover, process performance regarding COD, TSS, and color reduction was comparable to that obtained in the first stage of the study.

Keywords:

• Sulfur dye wastewater
• Electrochemical treatment
• pH
• Electrical charge
• Electrode corrosion

ACKNOWLEDGMENTS

The authors wish to acknowledge the excellent technical assistance provided by the staff at the Environmental Research Center Laboratory, Department of Health, Ratchaburi, Thailand as well as the staff at the Sanitary Engineering Laboratory, Faculty of Public Health, Mahidol University Bangkok, Thailand.

Notes

*Chemical oxygen demand

**Total suspended solids,

***American Dye Manufacturers Institute.

*Chemical oxygen demand,

**Total suspended solids,

***American Dye Manufacturers Institute.

*Chemical oxygen demand,

**Total suspended solids,

***American Dye Manufacturers Institute.