Decolorization and Biological Degradation of AZO Dye Reactive Red2 in Anaerobic Baffled Reactors

Document Type : Research Paper

Authors

1 Faculty Member of Environmental Health, Northern Khorasan School of Medical Sciences

2 Associate Professor of Environmental Health, Isfahan University of Medical Sciences

Abstract

Azo compounds are molecules with one or more azo (-N=N-) bridges linking substituted aromatic structures. They represent the largest class of dyes used in textile-processing and other industries. In the textile industry, about 15 percent of the dyestuff annually consumed in the dying process finds its way into plant effluent. Release of these compounds into the environment is undesirable because many azo dyes and their products are toxic and/or mutagenic to life. There are several physicochemical and biological methods for dye removal in aquatic environments. Removal of azo dyes in biological systems is based on anaerobic reduction of azo dyes and then mineralization of aromatic amines by aerobic systems. ABR is an anaerobic reactor with a high organic load consisting of 3 to 8 compartments across which wastewater flows. It is the aim of this investigation to study the dye and COD removal efficiencies of the ABR system. An ABR reactor with a capacity of 13.5 L and aretention time of 24 hours was used in this study. After starting up, seeding, and loading with synthetic wastewater, Reactive Red 2 (commonly used in the textile industry) was introduced into the ABR reactor. Following the start-up period, dye and COD removal efficiencies of the reactor were assessed by measuring COD and dye concentrations in the flow using standard methods. Results showed that average dye removal efficiency in the anaerobic baffled system was 89.5 percent while that of COD removal was 54.5 percent. The higher dye removal efficiency of the anaerobic systems is due to their ability to break up azo bonds. It was also revealed that increasing influent dye concentration did not have any considerable effect on COD removal efficiency. The highest dye removal percentage was observed in the primary compartment of the reactor.

Keywords

References

1- Pisczek, J. C. (2005). “An evaluation of anoxic/aerobic treatment for the removal of chemical oxygen demand and fiber reactive azo dye color.” MS. thesis, Faculty of North Carolina State University, 39-50.
2-Vnder zee, F. P. (2002). “Anaerobic azo dye reduction.” PhD. thesis, Wagering University, Netherlands.
3- Eui, S. Y. (2000). “Biological and chemical mechanisms of reductive decolorization of azo dyes.” MS. thesis, Department Environmental Berlin University, Berlin.
4- Sponza, D. T., and Isik, M. (2002). “Decolorization and azo dye degradation by anaerobic /aerobic sequential process.” Enzyme and Microbial Technology, 31, 102-110.
5- Wallace, T. (2001). “Biological reduction of synthetic dye water and a industrial textile wastewater containing azo dye compounds.” MS. thesis, Department of Civil an Environmental Engineering Blacksburg, Virginia, USA.
6- Mustafa, K., and Sponza, D. T. (2006). “Biological treatment of acid dyeing wastewater using a sequential anaerobic/aerobic reactor system.” Enzyme and Microbial Technology, 38, 887-892.
7- Frijters, C. T., Vos, R. H., Scheffer, G., and Mulder, R. (2006). “Decolorizing and detoxifying textile wastewater, containing both soluble and insoluble dyes, in a full scale combined anaerobic/aerobic system.” Water Resrearch, 40, 1249-1257.
8- Esther, F., Tibor, C., and Gyula, O. (2004). “Removal of synthetic dye from wastewater.” Environmental International, 30, 953-971.
9- Albuquerque, M. G. E., Lopes, A. T., Serralheiro, M. L., Novais, J. M., and Pinheiro, M. H. M. (2005). “Biological sulphate reduction and redox mediator effects on azo dye decolourisation in anaerobic–aerobic sequencing batch reactors.” Enzyme and Microbial Technology, 36, 790-799.
10- Bell, J., and Buckley, C. N. (2002). “Treatmeant of a textile dye in the anaerobic baffled reactor.” Water South of Africa, 29, 129-133.
11- Barber, W., and Stuckey, D. (1999). “The use the anaerobic baffled reactor (ABR) for wastewater treatment.” Water Research, 33, 1559-1578.
12- امیرفخرایی ج., و شایگان، ج. (1383). ”بررسی ویژگیهای راکتور بافل‌دار بی‌هوازی (ABR) درتصفیه پسابهای صنعتی وشهری.“ م. آب وفاضلاب، 50، 59-62.
13- Bell, J., Buckley, C. N., and Plumb, J. (2002). “Treatmant and decolourisation of food dyes in the anaerobic baffled reactor.” PhD. thesis, Chemical Engineering University of Natal Durbal, South Africa.
14- APHA, AWWA, WPCF. (1995). Standard methods for the examination of water and wastewater, Washington, D.C.
Journal of Water and Wastewater; Ab va Fazilab ( in persian )
Volume 19, Issue 1 - Serial Number 1
Serial number:65
March 2008
Pages 30-37

Files

Share

How to cite

Statistics