Statistical Optimization of Removal of Safranin Dye from Aqueous System Using Biosorbent Obtained from Leaves of Phlomis Cancellata Bunge by Response Surface Methodology

The biosorption performance of Phlomis cancellata Bunge as inexpensive, abundant and easily available adsorbent for safranin cationic dye removal from aqueous system has been evaluated in a batch process, using response surface methodology and employing a central composite design Experimental. The influence of different parameters such as, pH, contact time, agitation rate and sorbent dosage on the removal of safranin was examined. The significance of independent variables and their interactions were tested by analysis of variance (ANOVA). The optimum contact time, pH, agitation speed and adsorbent dose were found to be 39.96 min, 9.0, 331.18 rpm and 20 mg ml-1, respectively. Under these conditions, the maximum sorption capacity for safranin was found to be 99.60%. The kinetics of dye sorption fitted well with pseudo-first order kinetic model. The isotherm data of safranin could be well described by Langmuir model (R2 = 0.9924). The method was successfully applied for the removal of safranin from industrial wastewater and groundwater samples.