Highly efficient removal of aluminum, iron, and manganese ions using Linde type-A zeolite obtained from hazardous...

Coal acid mine drainage (AMD) contaminates natural water to form mine-impacted water (MIW), which is characterized by high levels of acidity, sulfate, and metallic ions. This study investigates the use of a Linde Type-A (LTA) zeolite obtained from a hazardous industrial waste for Al³⁺, Fe²⁺, and Mn²⁺ removal from synthetic aqueous solutions. The aim of this study is to stablish a basis for the subsequent treatment of MIW in order to obtain reuse water. In a central composite rotatable design (CCRD) study, 8.25 g L^-1 zeolite and 147 rpm were the optimal conditions for treating the multicomponent solution, yielding 99.9, 99.9 and 99.3% removal for Al³⁺, Fe²⁺, and Mn²⁺, respectively. Isothermal studies showed that the affinity of the ions by the zeolite were ranked as Al³⁺>Mn²⁺>Fe²⁺. The best fitting isothermal models for monocomponent solutions were Tóth, Freundlich, and Sips for Al³⁺, Fe²⁺, and Mn²⁺, respectively. In the multicomponent solution, Sips and Freundlich were the better fitting models for Al³⁺ and Mn²⁺, respectively, indicating a weakness of the sorbate-sorbent interactions. Kinetic studies revealed that the quantitative removal of Al³⁺ was achieved in 5 min. The multicomponent solution was transformed into water that was suitable for non-potable use after an optimal time of 60 min. The results demonstrate that LTA zeolite synthetized from hazardous waste has a high potential for remediating contaminated water by metallic ions at low dosages and short times. Using LTA zeolite for remediating contaminated water could make a positive contribution to the circular economy and environmental sustainability.