The ranges used for the experimental variables were: coagulant dose (83 166 mg L−1 of Al3+), coagulation mixing time (5 30 min), stirring rate (60 300 rpm), contamination level of the wastewater (Wastewater II COD ≈ 2000 mg O2 L−1, Wastewater III COD ≈ 3000 mg O2 L−1), and pH (5 11).
In order to analyze the effect of using the stronger connections in a full-scale structure, fragility curves were constructed using the experimental results, and then the demand variable was converted to the wind speed by conducting structural analysis of a model structure.
In the variable screening, a 25 1 fractional factorial design was used to examine the experimental variables.
Box-Behnken experimental design and response surface methodology (RSM) were used to optimize the experimental variables of the SPEF process.
A three factor central composite design (CCD) was used to predict the experimental variables (POMSE concentration, Vetiver plant density and time).
A central composite rotatable design and response surface methodology (RSM) were used to optimize the experimental variables of the solar photoelectro-Fenton (SPEF) treatment of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA).
A central composite rotatable design and response surface methodology were used to optimize the experimental variables of the electro-Fenton (EF) and solar photoelectro-Fenton (SPEF) degradations of 2.5 L of sulfanilic acid solutions in 0.05 M Na2SO4.
The fitted polynomial equation was expressed in the form of three-dimensional surface plots in order to illustrate the relationship between responses and the experimental variables used.
The fitted polynomial equation was then expressed in the form of three-dimensional surface plots, in order to illustrate the relationship between gelatinolytic enzyme production and the experimental variables used.
Response surface methodology and central composite design were used for modelling and optimisation with the experimental variables being the motor power (MP), air fluidizing pressure (AFP) (psi) and solid feed rate (SFR) (g/min).
