Adsorption of carmoisine and malachite green on silicon dioxide-based stones nanosized by ball milling

Abstract

Industries extensively use synthetic dyes, and it is crucial to eliminate them from effluents to prevent their accumulation in nature. The elimination of synthetic dyes is effectively achieved through the well-established method of adsorption; previous researchers have developed a range of materials dedicated to the adsorption of such dyes. In this regard, natural materials have received much attention as environmentally friendly. This study examined the ability of SiO2-based stone samples, including silica, zeolite, pumice, and scoria, to adsorb carmoisine and malachite green dyes from water. The ball-milling method was utilized to prepare the nanosized adsorbents. Physicochemical properties were evaluated by analytical methods, including dynamic light scattering (DLS), X-ray diffraction (XRD), X-ray fluorescence (XRF), Brunauer-Emmett-Teller (BET), and Fourier transform infrared spectroscopy (FTIR). The removal of dyes was experimentally undertaken utilizing both granular and nanosized adsorbents with conditions of 30°C temperature, pH 7, and initial dye concentrations set at 45 mg/l. Adsorption isotherm models and kinetic models were evaluated for dye adsorption. The highest levels of adsorption capacities for carmoisine and malachite green were 54.42 and 19.01 mg/g, respectively. The findings of this research demonstrated that nanosized scoria and silica have the potential to be used as efficient adsorbents in cationic and anionic dye removal, respectively.

Keywords

• synthetic dyes
• adsorption
• wastewater
• silica
• natural porous materials