Garlic Peel Surface Modification and Fixed-Bed Column Investigations towards Crystal Violet Dye

Abstract

Garlic peel, a low-cost agro-waste, was explored as an adsorbent for the remediation of wastewater containing the crystal violet (CV) cationic dye. The garlic peel was treated with NaOH at 1: 1.5 ratios in order to modify the surface and increase its porosity. The surface-modified garlic peel was ground to a smaller size in order to increase its surface area and used as an adsorbent in the continuous column investigations. Column parameters such as bed height, flow rate, and initial concentration were optimised and found that optimal removal efficiency was achieved at 3 ml rate of flow, 3 cm column depth, and 100 mg l-1 initial concentration. The surface-modified garlic peel exhibited a higher loading capacity of 99.9 mg g-1 towards CV at optimised conditions. SEM investigations confirmed the surface modification and increase in porosity of the garlic peel. The column data was tending to fit well with Thomas and Yoon-Nelson's models suggesting the scalability to an industrial level. Regeneration of MGP was successful with 0.01 M HCl solution. These results conclude that garlic peel is a potential agro-waste material that can be used to mitigate water pollution.