Removal of golden yellow dye from aqueous solution using layered double hydroxide: Optimization using Response Surface Methodology

Abstract

The magnesium-aluminium layered double hydroxide (MAN-LDH) is used as an adsorbent to remove golden yellow dye from aqueous solutions. The Response surface methodology (RSM) based on a four-level-four variables Central Composite Rotatable Design (CCRD) has been employed to evaluate the interactive effects of the various optimization parameters. The parameters are contact time (1-3 h), solution pH (4 – 10), adsorbent dosage (0.02 – 0.04 g) and dye concentration (75-200 mg/L). Simultaneously by increasing the contact time, the initial concentration and the amount of dosage, the quantity of golden yellow dye removal is increased. The optimum conditions derived via RSM for the removal of golden yellow dye are a reaction time of 2.98 h, a dye concentration of 185.74 mg/L, a solution pH of 5.24 and an adsorbent dosage of 0.03 g. The experimental percentage removal is 89.58% under optimum conditions, which compared well with the maximum predicted value of 87.83%.