Experimental Design Approach with Response Surface Methodology for Removal of Indigo Dye by Electrocoagulation

Treatmentof Indigo dye (leuco form), reduced in the industrial conditions of theSITEX (Textile Industrial Company), by a batch electrocoagulation usingaluminum electrodes. Response Surface Methodology (RSM) and Box-Behnken designwere used to optimize for Color Removal (CR(%)). Our results showed that thequadratic second order equation provided the best correlation for thedecolorization of Indigo dye (CR(%)). On the other hand, the ANOVA analysisproved the large interaction between the current intensity and the initialconcentration of the dye. Experiments were conducted to find the desiredconditions for removal of particular concentration of the dye and lowerOperation Cost. The results showed that CR(%) = 88.3% (R2) of colorremoval for initial dye concentration of 12.31 mg/l, with a current density of2.81 A/m2, solution concentration of NaCl of 2.67 g/l. Under theseconditions, Electrical Energy Consumption (EEC) and Electrode Consumption (EMC)and Operation Cost were 0.01999 kWh/m3 (R2 = 93.1%),0.00142768 Kg/m3 (R2 = 79.4%) and 0.000558 US$/m3,respectively.