Effects of Dodecyl Trimethyl Ammonium Bromide Surfactant on Decolorization of Remazol Blue by a Living Aspergillus versicolor Strain

The effect of dodecyl trimethyl ammonium bromide (DTAB) cationic surfactant on Remazol Blue reactive dye bioremoval properties of a growing Aspergillus versicolor strain in a molasses medium was investigated in a batch system as a function of pH, dye and surfactant concentrations. To determine the optimal pH value in the presence of 0.5?mM DTAB pH 3 to 7 was examined and pH 6 was selected. The dye concentrations of 50, 100, 200, 400 and 800?mg/L were examined with 0.5?mM DTAB and maximum decolorization occurred in 100?mg/L dye (98.8?%). The surfactant concentration of 0.1, 0.5, 1 and 2?mM DTAB was performed in 100 and 800?mg/L dye. The effect of surfactant concentration (0.1 to 2?mM DTAB) in a fungal growth experiment has shown that DTAB inhibited fungal growth. The decolorization was increased from 53.6?% (dry weight: 1.31?g/L) to 100?% (dry weight:0.93?g/L) while the surfactant concentrations were increased from 0.1 to 1?mM. A. versicolor (dry weight: 0.93?g/L) showed its maximum dye removal activity, namely 100?% in 100?mg/L dye with 1?mM DTAB at pH 6 in 3?days. The use of surfactants in biological wastewater treatment process will save energy and lower energy costs (such as the required energy for treat techniques) by shortening the incubation period. The results showed that the A. versicolor strain, which produces laccase enzyme, can effectively decolorize reactive dyes by the enhancement of DTAB. Surfactant enhanced decolorization technology is one of the feasible approaches to remove textile dye from wastewater.