▎ 摘　　要

In this study, novel beads were prepared based on calcium alginate caged graphene oxide (GO) functionalized with metformin (Alg@GMet). Beads were fabricated by a one-step method and applied for effective removal of As(III) and As(V) ions from water samples. The adsorbent beads were characterized with FTIR, SEM, EDX, and XRD techniques. The effective parameters on As(III) and As(V) removal efficiency were carried out and the best conditions were obtained as Met to GO ratio 1:0.5, pH 4, dosage 30 mg, and contact time 120 min with the initial concentration of 50 mg/L at room temperature. The isotherm study was performed and the experimental data were best fitted with the Langmuir isotherm (R-2 > 0.99). The adsorption rate was studied and kinetics models followed a pseudo-second-order (R-2 > 0.99) and the adsorption process reached to be equilibrium at 120 min. The maximum adsorption capacity under the Langmuir model was 64.1 mg/g and 84.5 mg/g for As(III) and As(V), respectively. The removal efficiency was 81% for As(III) and 92% for As(V), respectively. Beads were successfully regenerated by using diluted NaOH solution and reused for multiple cycles. Hence, GO modified metformin entrapped with alginate provides high removal for As(III) and As(V) in aqueous media.