Modelling and Optimization of Biochar-Based Adsorbent Derived from Wheat Straw Using Response Surface Methodology on Adsorption of Pb2+

The removal of Pb2+ from wheat straw-derived biochar produced at 600 & DEG;C was studied. Proximate, Ultimate, FTIR, SEM, TG-DTA, and BET surface area analyses were carried out to determine the morphology of the wheat straw biochar. The wheat straw biochar was found a larger surface area, pore volume, and pore diameter to be around 70.12 m(2)/g, 0.076 cm(3)/g, and 1.5 nm. The interactive effect of three process variables viz. the biochar dosage (1-3 g/l), heavy metal concentration (0.02-0.06 mg/g), and contact time (120-360 min) for reduction of Pb2+ were considered taking 15 sets of runs. The optimum value Pb2+ (99%) was found at 2.90 (g/l) biochar dose, 0.022 (mg/g) heavy metal concentration, and 309 (minutes) time using Box Behnken Experimental Design. The Response Surface Methodology (RSM) employing the Box-Behnken design was used for experimentation. The derived second-degree polynomial regression model shows the strong individual and interactive effects of biochar dosage, heavy metal concentration, and contact time with a higher regression coefficient (R-2 = 0.9987).