Acid Dye Removal from Wastewaters using Rice Husk Ash Functionalized with Organic Amine Groups as Adsorbent

Abstract

The use of rice husk ash functionalized with organic amine groups (RHA-NH2) as an adsorbent for acid dye adsorption from wastewater was studied. The RHA–NH2 was synthesized successfully via the grafting method using (3-Aminopropyl)-triethoxysilane (APTES) as amine group precursors. The synthesized adsorbents were characterized by using X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), N2 adsorption-desorption analysis, and Scanning Electron Microscopy (SEM). The RHA-NH2 exhibited an amorphous silica structure and possessed the organic amine group functionalized on the silica surface. The adsorption was studied by using Acid Blue 225 as an acid dye. The amount of acid dye remaining in the aqueous solution was measured by ultraviolet-visible spectrophotometer (UV-Vis). The RHA-NH2 revealed a higher adsorption capacity (~82 mg/g) than RHA because the amine group enhanced the chemisorption energy.