Optimization of environmental parameters by Plackett-Burman design and response surface methodology for the adsorption of Malachite green onto Gracilaria edulis

Abstract Gracilaria edulis, marine red seaweed was harvested from the coastal area of South Tamil Nadu, Rameswaram and was evaluated for the adsorption of Malachite Green. The algal biomass which is used as the adsorbent was pretreated for the activation of the binding sites on its surface. The environmental factors for the degradation process involve the pH (4–8), Biomass concentration (1 to 5 g/L), Dye concentration (10 to 20%), Time (120–180 min), Temperature (30–40 °C), and agitation-static were evaluated using Minitab 18 software. For the optimization process, the statistical techniques Plackett–Burman Design (PBD) and Response Surface Methodology (RSM) approaches were used. Plackett-Burman Design was performed for Malachite Green (MG) gave twelve trials and resulted in three significant parameters such as pH, temperature, and dye concentration. RSM was further used to determine the optimum parameters for the degradation. The maximum decolorization of Malachite Green was attained at pH = 4.5, dye concentration = 17, Temperature = 37 °C.