Biochar derived from Syzygium cumini seed embedded nanohybrid structure for eco-friendly remediation of Cr (VI) and As (III) ions: Adsorption and modeling analysis

Abstract

Hexavalent Chromium and trivalent Arsenic are among the most common hazardous elements found in wastewater, posing life-threatening risks due to their abundance. Despite efforts to mitigate their presence, the effectiveness of numerous micro adsorbents in lowering the levels of Cr (VI) and As (III) in wastewater remains inadequate. In this study, biochar derived from Syzygium cumini seed (SCB) and its nanocomposite with lanthanum ferrite (SCB/NC) were investigated for their potential in removing Cr (VI) and As (III) from water. The properties of the nanocomposite including its nature, surface composition and functionality were analysed using various techniques such as FTIR, XRD, FESEM, BET, EDX, TGA and XPS. Batch experiments were conducted to evaluate the adsorption kinetics, equilibrium isotherms, and thermodynamic characteristics of Cr (VI) and As (III) removal. The study examined various parameters including adsorbent dosage, initial metal ions concentration, pH, temperature and agitation time. Results revealed that SCB/NC exhibited significant potential for adsorbing Cr (VI) and As (III), with approximately 98.58 % of Cr (VI) and 94.16 % of As (III) being adsorbed within the pH range of 2.0–6.0 at 65 °C. Furthermore, adsorption capacity of adsorbent remained unaffected up to five cycles of reuse, indicating its potential for practical applications. The adsorption of micro-pollutants from water system was confirmed through FTIR and EDX analysis, providing further insights into the removal mechanism. This research underscores the promising role of SCB/NC in addressing the challenge of heavy metal contamination in water bodies and its potential for environmental remediation.