CC-BY-NC-NDNujkić, MajaTasić, ŽaklinaMedić, DraganaMilić, SnežanaStanković, Sonja2023-12-252023-12-2520231450-718810.2298/APT2354187Nhttps://repozitorijum.tfbor.bg.ac.rs/handle/123456789/793In this study, the potential of the walnut shell as a biosorbent for biosorption of Cu(II), Pb(II), and As(III)/(V) ions from river water samples was investigated. The effects of various conditions of water samples such as the initial ion concentration, sample pH, and contact time at a constant tempe-rature and biosorbent dosage, on biosorption of Cu(II), Pb(II), and As(III)/(V) were investigated. Walnut shells, as the material with a high potential for removal of investigated ions, have biosorption efficiency of up to 99.6%, under the applied experimental conditions. The best adsorption time was obtained at 4 h for Cu(II), Pb(II), and As(III)/(V) ions. The maximum removal of 97.6% (Cu(II)), 82.9% (Pb(II)), and 99.6% (As(III)/(V)) was obtained at pH=4.43, pH=8.55, and pH=7.84, respecti-vely. Hence, the walnut shell shows potential of a cost-effective biosorbent that could be used for the treatment of contaminated rivers. However, further investigation is needed to fully explore this po-tential.enbiosorptionwalnut shellmetal/oidsnatural materialwastewaterarticle