Removal of malachite green (MG) from aqueous solution by using eggshell as adsorbent

Batch adsorption studies for the removal of Malachite green (MG) dye using eggshell was conducted. Response Surface Methodology (RSM) was applied to investigate the effect of significant operating parameters on the uptake of the dye molecule. The objective of this study is to determine the potential of eggshell as an adsorbent for NIG removal and determine the optimum conditions for the adsorption process by using RSM with CCD. A 2³ full factorial Central Composite Design (CCD) was generated by using Design Expert version 9.0. The effects and interactions of different parameters were assessed which are contact time (20-60 minutes), pH (4-8) and adsorbent dosage (0.5-2.0 g). Based on CCD, a quadratic model was developed for IVG percentage removal. Analysis of variance (ANOVA) was used to determine the significant factors on experimental design response. The predicted results obtained were found to be a good agreement (R² = 0.9388) with the results of actual experiments. The Fourier transform infrared spectroscopy (FTIR) analysis was revealed that functional groups such as carbonyl, carboxyl, hydroxyl and amine on eggshells can be
used as adsorbent for removal of NIG. The maximum percentage removal of IVG was found to be 90.66% with the conditions of contact time in 40 minutes, pH 6 and 1.25 g
of adsorbent dosage.