Table 3: Factors and their levels which were studied by Taguchi method.

FactorLevel 1Level 2Level 3Level 4

A: initial pH5.56.57.58.5
B: moisture content (mL)10203050
C: weight of grape fruit (%)1235
D: weight of NaNO3 (%)0.5123
E: weight of waste (g)5101520