Decoloring Mechanisms of Dye Stuff by Chemical Oxidation
This study utilizes sodium hypochlorite (NaOC1) to reduce the color of synthetic dye solutions. Five dyes including methyl red (MR), methyl violet (MV), methyl blue (MB), malachite green (MG) and methyl orange (MO) were studied. The color was measured using an automatic ADMI (American Dye Manufacturer Institute) measurement system. A visible spectrophotometer is connected to a personal computer so that samples can be scanned and the results are recorded automatically. During the batch decoloring study, several factors: ADMI, ORP, temperature and pH were also monitored continuously using the computer and makes it possible to have an automated decoloring process.
A modified Nernst equation was used to delineate the relationship between the degree of decoloring reaction and the solution ORP value. A “decoloring coefficient” (S) was proposed to represent the oxidative potential (or decoloring property) of the dyes studied. In this study, the oxidative or decoloring potential can be shown in the following order: MG>MV>MO> MR>MB. Using the on-line measurements of ORP, color and pH, the oxidation process can be automated to achieve a pre-selected percentage of color removal.
KeywordsQuartz Hydroxyl Chromium Sludge Ozonation
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- 1.Weeter, D. W. and A. G. Hodgson, (1977), “ Alternative for Biological Waste Treatment of Dye Wastewater”, American Dyestuff Report, Vol. 8, pp. 32–40.Google Scholar
- 2.Kreye, W. C., (1974), “Polymer Acided Alum Coagulation of Textile Dyeing and Finishing Wastes”, Proceeding the 29th Industrial Waste Conference, Purdue, pp.174 —182.Google Scholar
- 3.Shelley, M. C., (1976), “Evaluation of Chemical-Biological and Chemical-Physical Treatment for Textile Dyeing and Fishing Waste”, Journal WPCF, Vol. 48, No. 4, pp.35 — 41.Google Scholar
- 4.Perkins, W. S., J. F. Judkins and W. D. Perry, (1980), “Removation of Dyebath Water by Chlorination or Ozonation”, Auburn University.Google Scholar
- 5.APHA, AWWA and WPCF, (1992), “Standard Method for the Examination of Wastewater”, 18th Ed., Method 2120, pp.2–1–2–8.Google Scholar
- 6.Allen, W., W. B. Prescott, R. E. Derby Jr., C. E. Garland, J. M. Peret and Saltzman M., (1973), “Determination of Color of Water and Wastewater by Means of ADMI Color Values”, Proceedings of the 28th Purdue Industrial Waste Conference, Ann Arbor Science Publisher, Ann Arbor, MI., pp. 66l - 670.Google Scholar
- 7.Chang, C. N., W. L. Shang, S. J. Yeh and Y. S. Huang, (1992), “The Development of Auto–matie Water Color Measurement Technique”, 8th ASPAC–IWSA Regional Water Supply Conference & Exhibition, Malaysia, pp.6a2–1–6a2–12.Google Scholar
- 8.Weber, J. W., (1972), “Redox Control in Breakpoint Chlorination of Amine Complexes”, Wat. Res., Vol. 18, No. I, pp. 21–24.Google Scholar
- 9.Charpentier, J. H. G. M. Godart and Y. Mogno, (1989), “Oxidation-Reduction Potential (ORP) Regulation as a Way to Optimize Aeration and C, N and P Removal: Experimental Basis and Various Full-Scale Examples”, Wat. Sci. & Tech.. Vol. 21, Brighton, pp.1209-Google Scholar
- 11.Chang, C. N., R. F. Yu, A. C. Chao and Seishu Tojo, (1994), “On-line Monitoring and Control of the Textile Wastewater Color Removal Process”, Wat. Sci. & Tech., Vol. 30, pp. 264–274.Google Scholar