The ability of Pensi (Corbicula moltkiana) shell to adsorb Cd(II) and Cr(VI) ions

The biosorption of Cd(II) and Cr(VI) ions from aqueous solutions using Pensi (Corbicula moltkiana) shell activated with HNO3 0,01 M was studied in batch method. The optimum conditions were reached at concentration 100 mg/L, particle size 32 µm, and biosorbent mass 0.1 gram for both Cd(II) and Cr(VI) ions. At pH 6 and contact time 120 minutes, biosorbent was warmed at 28°C with the sorption capacity of 6.073 mg/g for Cd(II), while at pH 3, contact time 15 minutes, biosorbent was warmed at 80°C with the sorption capacity of 1.286 mg/g. The adsorption of Cd(II) and Cr(VI) ions follows the Langmuir isotherm models with R2 0.9389 for Cd(II) ions and 0.9972 for Cr(VI) ions. The Langmuir Isotherm Method indicates an adsorption process occurrs as chemicals formed monolayer. This result showed that Pensi shell can be used to overcome Cd(II) and Cr(VI) content in wastewater.