Application of Response Surface Methodology to Enhance Phenol Removal from Refinery Wastewater by Microwave Process

Table 1

The considered levels of independent variables for the phenol removal by CCD.

Independent variables	Symbol	Variable levels
		−1	0	+1
(1) MW Power (Watt)	𝐴	300	450	600
(2) MW Irradiation Time (min)	𝐵	10	20	30
(3) Salinity (mg/L)	𝐶	200	600	1000
(4) pH	𝐷	5	7	9
(5) H2O2 (% v/v)	𝐸	1	5.5	10