Decolorization of textile dyes by yarrowia lipolytica

One of the major environmental problems we have today is dye pollution, primarily caused by the textile industry. Biological approaches play a crucial role in addressing dye pollution due to their environmental friendliness and significant effect on dye removal. In this study, degradation and adsorption techniques using Yarrowia lipolytica NBRC1658 were examined as two different biological approaches to remove azo dyes from an aqueous environment. In degradation approach different parameters were investigated. The highest decolorization percentage 97% was observed at pH 7 for reactive yellow18(RY18), at pH 9 for acid red 18(AR18) and 92% at pH3 for basic blue41(BB41). When examining the impact of carbon and nitrogen sources in the degradation process, it was observed that glucose and fructose are the optimal carbon sources, while ammonium sulfate, peptone, and ammonium chloride are the preferred nitrogen sources. The experimental findings revealed that the optimal conditions for the decolorization process are as follows: a temperature of 30 ˚C, a rotation speed of 150 rpm, a dye concentration of 50 mg/L and an inoculum size of 3 ml. adsorption studies were carried out using biomass and fungal cells entrapped in alginate beads as biosorbent. The rate of decolorization was found to be higher in biomass compared to cells entrapped within alginate beads. The highest adsorption capacities were observed at pH 2, pH 2 and pH 9 for RY18, AR18 and BB41, respectively. The adsorption capacity was significantly improved by increasing the adsorbent dosage and initial concentration. Adsorption isotherm experiments showed that the adsorptive behaviour fits the Langmuir model which shows that the dye and adsorbent's interaction was a monolayer adsorption and the adsorbent's surface was homogeneous. The obtained results from the kinetic experiment indicated that the decolorization process was achieved through chemical adsorption, as evidenced by the fitting of the pseudo-second order kinetic model. According to thermodynamic outcomes, adsorption of dyes was increased as the temperature was increasing.