USING MATERIAL FROM CLAM SHELLS (UNDULATING VENUS) TO REMOVE Fe (III) AND Pb (II) IN WATER

Abstract

In this study, using the traditional method of calcination, powdered materials from crushed clam shells (Undulating Venus) were created, that were capable of treating heavy metals in water. By XRD, FTIR, SEM, and EDX analysis methods, identified clam shells with the main component CaCO₃ in the form of aragonite and calcite. This composition was changed if calcinating clam shells at a temperature above 400 ^oC, with mainly CaCO₃ in the form of calcite and CaO. It was determined that the crushed clam shell calcined at 700 ^oC (CSS_700) was optimal for the treatment of heavy metal ions in water. With the specified conditions: 0.3 g/L, pH 3; 25 ^oC and shaking time 40 minutes for Fe(III) and 0.3 g/L CSS_700, 25^oC, pH 6, shaking time 10 minutes for P(II), the maximum adsorption capacities achieved 170 mg/g from the Fe(III) concentration of 800 mg/L and 90 mg/g from the Pb(II) concentration of 600 mg/L Pb(II). EDX results demonstrated that the composition of Fe and Pb in the after-adsorption material accounted for about 9.79% and 42.40%, respectively, by mass, while in the before-adsorption material, weren't detected. The experimental results were well described according to the Freundlich isotherm model and pseudo second-order kinetic model. The research has shown feasibility, environmental friendliness, and low cost but high efficiency in using calcined materials from clam shells to treat heavy metals in water.