Enhanced lead (II) removal with low energy consumption in an electrocoagulation column employing concentric electrodes: process optimisation by RSM using CCD

The study aimed at complete elimination of lead with minimum energy consumption using electrocoagulation process employing concentric electrodes made of aluminium. The process was optimized using RSM for chosen variables: current intensity, initial pH, initial lead concentration and time. Quadratic models were generated and assessed using four factorial CCD. A significant quadratic regression model was obtained and validated using ANOVA. Complete removal was attained for optimised conditions having 6 pH, 0.3A current intensity, 41 mg/L initial Lead concentration,13 minutes of applied time duration using energy of 0.77 watt-hour per gram removal of lead. Adsorption followed pseudo I-st order kinetics with a good fitting of the Langmuir isotherm model. Overall process was well optimised with quite low operational cost of 0.00092 US $.