Modification of Calcium Oxide from Green Mussel Shell with Iron Oxide as a Potential Adsorbent for the Removal of Iron and Manganese Ions from Acid Mine Drainage

Abstract

Acid mine drainage (AMD) has the characteristics of high heavy metal ion content and low pH. This study aimed to synthesize the CaO/Fe 3 O 4 composite for the adsorption of iron and manganese ions from acid mine drainage. CaO was synthesized from the shells of green mussels (Perna viridis). The CaO/Fe 3 O 4 composites were characterized using XRD, BET surface area, SEM-EDS, and VSM. The functional groups of the composite before and after adsorption were analyzed using FTIR. The adsorption of Fe(II), Fe(III), and Mn(II) ions was carried out with the batch method to determine the effect of pH, contact time, and initial concentration of metal ions. The CaO/Fe 3 O 4 composite has magnetic properties, as indicated by the saturation magnetization value of 65.49 emu/g. The Langmuir and Freundlich isotherm models were used to describe the adsorption isotherm of the composite for Fe(II), Fe(III), and Mn(II) ions. Investigations were also conducted on adsorption kinetics, including pseudo-first-order and pseudo-second-order, as well as adsorption thermodynamics comprising free energy, enthalpy, and entropy. Pseudofirst-order and Langmuir isotherms are suitable to describe the adsorption of Fe(II), Fe(III), and Mn(II) ions with adsorption capacities of Fe(III) > Fe(II) > Mn(II). Moreover, the adsorption of all ions using the composite occurred spontaneously. The removal effectiveness for Fe and Mn ions from AMD using CaO/Fe 3 O 4 composite, reached 90.41 and 97.59%, respectively, in volume 100 mL AMD, composite mass 0.4 g, and a contact time of 60 minutes.

Synthesis and Characterization of Nanoparticle Composite CaO/Fe3O4 from Duck Egg Shells and Its Application for Congo Red and Procion Red MX-5b Dyes Adsorption

“…The adsorption of Congo red and Procion red MX-5b to CaO/Fe3O4 composite was studied using UV-Vis spectroscopy adapted from Purwaningrum et al [13]. Three parameters were set as variables in this study: contact time, dye concentration, and temperature.…”

Magnetic Composite for Efficient Adsorption of Iron and Magnesium Ions from Aqueous Solution

“…The production of CaO in this study adheres to the method detailed by Purwaningrum et al (2022). The process begins with the cleaning of green mussel shells to rid them of impurities.…”

“…For instance, cow bones (Ayodeji, 2018), eggshells (Hossain et al, 2021), cockle shells (Mohamed et al, 2016), fish bones (Mostofa et al, 2022), and mollusk shells (Thakur et al, 2021) have all been identified as viable sources. Additionally, mussel shells -a type of shellfish widely consumed in Indonesia -are also an abundant source of CaO (Purwaningrum et al, 2022). Approximately 20% of the shellfish constitute the edible portion, while the remaining 75-90% comprises the shell.…”