Investigation of decolorization in leather industry wastewaters by biosorption method

In this study, the efficacy of decolorization of Acid Black 210 dye, by Aspergillus niger, by biosorption method was designated. In the first stage of the work in the batch mixing system; In order to determine the optimum conditions, studies were carried out in six different pH ranges between pH 4 - 6.5 to determine the optimum pH, respectively, and the optimum pH = 4.0 was determined. By examining four different biosorbent doses varying between 1 and 10 g/L, the optimum amount of biosorbent substance was determined as 1.0 g/L. In order to determine the optimum temperature, the study was carried out at three different temperatures between 20 - 40 °C and the optimum temperature was determined as 40oC. Finally, in order to determine the effect of the mixing speed, studies were carried out with three different mixing speeds between 100 and 150 rpm and the optimum mixing speed was determined as 130 rpm. All studies were continued under the determined optimum conditions. In the second stage of the study; Temkin, Freundlich and Langmuir Isotherm Models were applied. Accordingly, it was determined that the biosorption study was compatible with the Langmuir Isotherm. In the third stage of the study, thermodynamic and kinetic parameters were calculated and it was concluded that the reaction was endothermic. In the thesis study; In the experimental studies carried out under optimum conditions, the decolorization efficiency was calculated as 58.96% in the biosorption of AB 210 dyestuff by A. niger. As a result of this study; It was concluded that A. niger biosorbent is not a suitable biosorbent due to its low removal efficiency in the biosorption of AB 210 dyestuff by A. niger, which has filamentous mold fungus properties. Because; It was concluded that the usability of the same biosorbent for different dyestuff removal should be investigated or that different biosorbent should be used for AB 210 dyestuff removal.