Amine activated diatom xerogel hybrid material for efficient removal of hazardous dye

The effective removal of organic pollutants from aqueous media is still an eminent challenge. In the present work, naturally available diatomaceous earth (DE) particles was surface modified with mesoporous silica xerogel denotes as diatom xerogel material. Subsequently amine functionality has been successfully introduced on diatom xerogel (DXEA) for the efficient removal of hazardous dye, Eriochrome Black T (EBT). The adsorbents before and after EBT adsorption were characterized using various techniques such as XRD, FE-SEM, FTIR and BET. The adsorption process was conducted by varying many parameters such as pH, dosage, initial concentration of dye and time. The designed adsorbent, DXEA showed increased removal efficiency (similar to 99 %) in comparison with neat DE (similar to 58 %) due to the presence of amine functional group, which favours the rapid adsorption of EBT. This study showed that adsorbent DXEA was adequate to remove 50 mg/L and 100 mg/L of aqueous EBT in 5 and 60 min of contact time respectively. The maximum dye adsorption capacity of DXEA was found to be similar to 62 mg/g whereas, for DE it was similar to 56 mg/g. The dye adsorption kinetics of EBT onto both the DXEA and the DE follow the pseudo-second-order model. Also, DXEA was used for selective removal of EBT in the presence of other dyes and recycle studies were discussed. These studies showed that DXEA is a promising material for EBT removal by adsorption in real sample.