LAUSR

ABSTRACT Biochar, is a low-cost material that can be used as an alternative adsorbent for the removal of heavy metals. In this study, a low-cost and efficient adsorbent synthesised from Jatropha curcas seeds was used for the uptake of Cu2+ from aqueous solutions. The as-prepared adsorbent was characterised by scanning electron microscopy and Brunauer–Emmett–Teller analysis post calcination at 500 °C, its BET surface area and total pore volume were 39.62 m2 g−1 and 0.049 m3 g−1, respectively. Subsequently, the effects of initial pH of the solution, contact time, and adsorbent material dosage on the adsorption of Cu2+ by the prepared adsorbent were investigated. The as-prepared adsorbent exhibited a high performance, with a maximum adsorption amount of 32.895 mg g−1 for Cu2+ at pH 5.0 and 25 °C, owing to the presence of −OH, C=O, C–O, Si-O-Si, and O-Si-O on its surface. The predominant Cu2+ adsorption mechanism was assumed to be ion exchange. Notably, the Cu2+ adsorption could attain equilibrium within 90 min. In addition, the fact that the Langmuir model was a better fit than the Freundlich model for the isotherm data of Cu2+ adsorption by the as-prepared adsorbent suggested that the adsorption of Cu2+ was a monolayer adsorption process.