Biosorbents Ricestraw Dragon treeleaves
Term Effect Coef SE Coef T p Effect Coef SE Coef T p
Constant   46.51 1.652 28.16 0.000   52.55 0.5781 90.90 0.000*
Main Factors
X -31.00 -15.50 1.652 -9.39 0.000 -30.63 -15.32 0.5781 -26.49 0.000*
pH 28.60 14.30 1.652 8.66 0.000 22.93 11.46 0.5781 19.83 0.000*
BD 23.61 11.81 1.652 7.15 0.000 13.65 6.83 0.5781 11.81 0.000*
Two Factors Interaction
X.pH -2.45 -1.22 1.652 -0.74 0.480 3.20 1.60 0.5781 2.77 0.024*
X.BD 3.36 1.68 1.652 1.02 0.339 2.36 1.18 0.5781 2.04 0.076
pH.BD -2.03 -1.02 1.652 -0.61 0.556 -7.12 -3.56 0.5781 -6.16 0.000*
Three Factors Interaction
X.pH.BD 8.70 4.35 1.652 2.63 0.030 0.83 0.42 0.5781 0.72 0.491
* P>0.05
Table 3: Response surface regression for Cd(II) removal by rice straw and dragon tree leaves (T: t-test, p: probability value).