Volcanic rock powder residues as precursors for the synthesis of adsorbents and potential application in the removal of dyes and metals from water

Abstract

The present study verified the potential of volcanic rock powder residues originating from the extraction of semi-precious rocks in the state of Rio Grande do Sul, Brazil, as precursors or adsorbents for dyes and metallic ion removal from water. In this way, it is possible to add value and give an adequate destination to this waste. Volcanic rock powder residues from Ametista do Sul (AME) and Nova Prata (NP) were the starting materials. These were used naturally or submitted to the alkaline activation process at 60 °C and alkaline fusion at 550 °C. The analysis of the starting samples by X-ray fluorescence (XRF) revealed that they are mainly composed of aluminum, calcium, iron, and silicon oxides, which corroborates the presence of numerous crystalline phases observed in the X-ray diffraction spectra (XRD). Moreover, by XRD analysis of the synthesized samples, alkaline fusion proved to be more efficient in the dissolution of crystalline phases and consequently in the formation of the amorphous phase (more reactive). Furthermore, the adsorption tests with acid green and acid red dyes and Ag + , Co 2+ , and Cu 2+ ions indicated the viability of using residual volcanic rock powder as raw material for the production of adsorbents functionalized with sodium hydroxide, being that the samples synthesized by alkaline fusion showed better results of removal and adsorption capacity for all the contaminants used in the study.

SYNTHESIS AND CHARACTERIZATION OF NANOSILICA (SiO2) VOLCANIC ROCK OF MOUNT BATUR IN BALI

“…Minerals are a resource that can be found in rocks which are abundant in Indonesia. If processed they will produce metals and various materials needed in industrial processes and have economic value [7]. One of the minerals that is often contained in rocks is the mineral silica (SiO2) ranging from 44.89-47.76% and 71.62%, as it is known that silica is formed from the weathering of rocks that contain main minerals, such as quartz and feldspar.…”

Experimental and computational analyses for advanced wastewater treatment by volcanic rocks

“…The high adsorption efficiency of VR with heavy metals was also proved by assays elsewhere (Alemayehu et al, 2011). A study on the potential use of VR powder as adsorbent for removing dyes and metals from water showed that using VR powder showed better results of removal capacity for all these contaminants from water (Rossatto et al, 2022).…”