Removal of Color and COD from a Mixture of Four Reactive Azo Dyes Using Fenton Oxidation Process

摘要

This study was designed to decolorize and to reduce COD content in a mixture of four reactive dyes, i.e., Remazol Black 5 (RB5), Remazol Red RB (RR), Remazol Yellow 84 (RY), Remazol Brilliant Blue (RB) using Fenton Oxidation Process (FOP). Optimum pH, temperature, and the doses of FeSO_4 and H_2O_2 were determined. Experiments were conducted on the samples containing a total concentration of 100 mgL~(-1) (RB + RY), 200 mgL~(-1) (RB5 + RR), 300 mg L~(-1) (RB5 + RR + RB+ RY), and 400 mg L~(-1) (RR + RB + RY) dyes considering their actual application doses in dyehouses. Optimum pH was observed as 2.5 at 30℃ using 400 mg L~(-1) FeSO_4 and 800 mg L~(-1) of H_2O_2 resulting in more than 96% COD and 99% Pt-Co unit of color removal for the mixture of RB5 and RR. The optimum conditions determined were 4.0 pH, 50℃, and 500 mg L~(1) FeSO_4 applying 1000 mg L~(-1) H_2O_2 for the mixture of (RB5 + RR + RB + RY). A 100 mg L~(-1) solution of a mixture of RB and RY at equal amounts was oxidized using 200 mg L~(-1) FeSO_4 and 300 mg L~(-1) H_2O_2 at 3.0 pH and 50℃.