Experiment no. Parameters Adsorption Capacity (mg g-1) pH Adsorbent Dose (g L-1) Time (in mins) 1 7 5 37.5 1.001 2 4 10 30 1.064 3 4 5 37.5 1.034 4 5.5 7.5 33.75 1.068 5 5.5 7.5 33.75 1.004 6 4 10 37.5 1.068 7 5.5 11.7 33.75 1.004 8 2.98 7.5 33.75 1.068 9 7 10 37.5 1.004 10 5.5 3.3 33.75 1.018 11 5.5 7.5 33.75 1.028 12 5.5 7.5 40.06 1.048 13 7 10 30 1.068 14 5.5 7.5 33.75 1.015 15 5.5 7.5 27.44 1.068 16 4 5 30 1.068 17 8.02 7.5 33.75 1.000 18 5.5 7.5 33.75 1.072 19 5.5 7.5 33.75 1.068 20 7 5 30 1.021

Table 2: Central composite design (CCD) for optimization of three independent experimental factors guiding phenol adsorption onto soil along with the results obtained.