DECOLORIZATION OF CONTAMINATED WATER CONTAINING C.I. DIRECT BLUE 53 BY MACROALGAE CHARA SP. AND OPTIMIZATION OF DECOLORIZATION PROCESS

Abstract

Dye wastewater is considered as a major pollutant of surface water. In recent years, biological treatment with the use of micro and macro organisms has been used as a good method for removing various organic and inorganic pollutants. In the present study, the potential of a macroalgae Chara sp., was investigated as a viable biomaterial for the biological treatment of Direct Blue 53 solution. The effects of operational parameters such as temperature, pH, initial dye concentration, the amount of algae, salinity, and light-darkness on the efficiency of biological decolorization were studied. In optimal conditions, with an initial value for live algae of 3.5 g, temperature of 25ºC, pH = 2, for a solution containing 15 ppm of Direct blue 53, the dye removal efficiency obtained was of 63%. Dye removal increased with an increase in the amount of biomass. The efficiency of the biological treatment of Direct Blue 53 decreased as the temperature and initial dye concentration increased. The salinity of the solution had an inverse relationship with the decolorization efficiency, and the dye was removed more easily in darkness. The results of FTIR and GCMass spectroscopy showed that the decolorization mechanism of the solution in the presence of live algae was biodegradation.