The dye removal by $mathrm{TiO}_{2}$ adsorption (at $mathrm{pH}$ 5.5) is given by (Anupam K. et al. 2011) [text { dye removal }=13.08left(mathrm{TiO}_{2} ight)+15.77(text { Time

The dye removal by $\mathrm{TiO}_{2}$ adsorption (at $\mathrm{pH}$ 5.5) is given by (Anupam K. et al. 2011)

\[\text { dye removal }=13.08\left(\mathrm{TiO}_{2}\right)+15.77(\text { Time })-9.996\left(\mathrm{TiO}_{2}\right)^{2}-12.347(\text { Time })^{2}\]

Plot the contour and find the maximum dye removal using Grid Search method.