Simultaneous biosorption of acid violet and reactive yellow dyes by Cladosporium cladosporioides

The synthetic dye mixture of Acid Violet 90 and Reactive Yellow 145 was treated with dead Cladosporium cladosporioides biomass. The individual concentrations were calculated with the first-order derivative spectrophotometric method. The calibration curves were plotted at wavelengths of 578.4 nm and 318.2 nm in the derivative spectrum for Acid Violet 90 and Reactive Yellow 145, respectively. The calculated limit of quantitation value is similar to 2.5 mg/L for Acid Violet 90 and similar to 1.5 mg/L for Reactive Yellow 145. The achieved mean recovery percentage values are around 100%. The highest removal efficiency (100%) was obtained for both dyes at pH 4 using 0.25 g biomass and 50 mg/L of each dye in 60 min reaction time with 150 rpm shaking speed. The hydrochloric acid solution was used for biomass regeneration, and the removal efficiencies remained at 99% and 89% for Acid Violet 90 and Reactive Yellow 145 in the third cycle. [GRAPHICS]