Comparative adsorption studies of methylene blue and ramazol brilliant green 6B on silica nanocapsules

Abstract Synthetic dyes, extensively utilised across various industrial sectors, including textiles, leather processing, cosmetics, plastics, and food processing, constitute a significant source of water contamination. Anionic and cationic dyes, like remazol brilliant green 6B and methylene blue, have harmful, poisonous, carcinogenic, and mutagenic properties, posing health risks through contact, inhalation, and ingestion, emphasising the need for their removal from wastewater. The research investigated the process of MB and RBG 6B adsorption on silica nanocapsules (SNCT) using FTIR, BET, TEM, and FE-SEM analysis. The adsorption process was carried out in batch to determine the optimal conditions for dye adsorption based on the solution’s pH. The findings showed that MB adsorption efficiency increases at higher pH levels due to a negatively charged surface, enhancing electrostatic attraction. In contrast, a positively charged surface increases RGB 6B adsorption efficiency at lower pH. The study found that SNCT had a high dye removal efficiency of 93.23% for MB and 80.04% for RBG 6B, achieved at a concentration of 0.05 mmol/l and pH levels of 12 and 2, respectively. The Temkin isotherm model accurately described MB’s adsorption behavior onto SNCT, while the Langmuir isotherm model better fit RBG 6B’s experimental data. The results suggested that SNCT is a potential adsorbent material for the purification of water that contains dyes.

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