Ternary magnetic silica–graphene oxide composite for remediation of textile dyes from aqueous environment and real samples

Abstract

Abstract Inadequate wastewater treatment infrastructure is a substantial worldwide concern, with implications for both the environment and public health. Specifically, the discharge of industrial effluents containing organic pollutants such as dyes represents a significant challenge due to their hazardous characteristics. Among these dyes, Bromophenol Blue (BPB) and Malachite green (MG) are extensively utilized in the industrial sector, contributing to environmental deterioration. In the current study, ternary-magnetic-silicate–graphene oxide [Fe3O4@SiO2–GO] was synthesized using the co-precipitation method and applied for the treatment of wastewater containing BPB and MG dyes. The point of zero charge and surface area of the adsorbent was estimated to be 5.7 and 253.8 m2 g−1, respectively. Energy dispersive X-ray was performed and the presence of iron, silicon, carbon, and oxygen was confirmed. The XRD analysis of GO, Fe3O4, and ternary Fe3O4@SiO2–GO composites were also performed to confirm the crystallinity of the composite. The SEM analysis showed a rough morphology with sheet-like appearance. The ternary composite was then applied for the adsorption of BPB and MG dyes. The maximum adsorption capacity for BPB and MG was 97.35 mg/g and 92.63 mg/g at pH 3 and 5, respectively. The results of the kinetics analysis showed that the pseudo-second-order kinetics model best explained the adsorption data for MG dye while pseudo-first-order kinetics for the BPB dyes. While the data best fitted the Langmuir adsorption isotherm with R 2 values of 0.994 and 0.998 for BPB and MG, respectively. These results demonstrate that Fe3O4@SiO2–GO serves as a promising adsorbent for the efficient removal of Bromophenol Blue (BPB) and Malachite Green (MG) from environmental water samples. Additionally, this adsorbent is environmentally friendly and chemically benign, and it can be reused efficiently for up to five cycles.