Optimization Studies on Degradation of Congo Red Dye using Nerium oleander

Dyes are harmful for living organisms. Nerium oleander was used to degrade the synthetic Congo red dye. Optimization process was carried out for better degradation of synthetic dye using Placket-Burman design. Among the six parameters (Temperature, Incubation time, pH, Agitation speed, Biomass concentration, Dye concentration), pH (5), Temperature (35 °C) and Incubation time (60 min) were found to increase the dye degradation (92.33 %). The global optimum levels of dye degradation were analyzed using Plackett-Burman design. The effects of pH, Temperature and Incubation time on degradation were further optimized by statistical
analysis using Response Surface Methodology (RSM). RSM was used to optimize dye degradation by implementing the Central Composite Design (CCD). The optimal conditions for higher degradation were pH: 5, Temperature: 35°C, and Incubation time: 90 min. Under these conditions, the model predicted a dye degradation of 98.23 %. Verification of the optimization showed that dye degradation of 97.18 % was observed under the optimal conditions in the shake flasks experiment.