Utilization of Metakaolin Based Geopolymer to Immobilize Geopolymeric hazardous Waste Matrix Containing Heavy Metals from the Wastewater Treatment

Elewa, Khaled; Tawfic, A.F.; Tarek, Mostafa; Al-Sagheer, Nabil Abdullah; Nagy, Nabil M.

doi:10.21608/ejchem.2025.389020.11819

Utilization of Metakaolin Based Geopolymer to Immobilize Geopolymeric hazardous Waste Matrix Containing Heavy Metals from the Wastewater Treatment

Articles in Press

Document Type : Original Article

Authors

¹ Civil Engineering Department – Military Technical College, Cairo - Egypt

² Nuclear Engineering Department, Military Technical college, Cairo – Egypt

³ Aluminum Sulfate Co. of Egypt, Cairo -Egypt

10.21608/ejchem.2025.389020.11819

Abstract

This research examines the utilization of the geopolymerization process for the immobilization of Cd2+, Pb2+, and Cr6+ adsorbed onto geopolymers generated from wastewater treatment units. The PDK utilized in this study was sourced from the aluminum sulfate facility, one of the largest chemical factories in Egypt. The geopolymeric waste was consolidated in a geopolymer matrix composed of (i) PDK and (ii) metakaolin. The waste proportion were 10%, 30%, 40%, to 50%. Leaching experiments were conducted. The chemical and mechanical properties of the geopolymer materials containing immobilized residue were examined. The geopolymerization technique has been demonstrated to facilitate effective immobilization of Cd2+, Pb2+, and Cr6+. Furthermore, it was observed that the geopolymer samples containing 10% waste had an average compressive strength of 39.7 MPa, which progressively diminished to 10.8 MPa with the inclusion of 50% the waste. Water absorption served as a reliable metric for assessing immobilization efficiency. The minimal water absorption (5.5%) correlates with maximal immobilization (98%). This study introduces a novel approach to immobilize substantial quantities of harmful heavy metals through the synthesis of geopolymer mortar of varying strengths, utilizing the geopolymeric waste containing Cd2+, Pb2+, and Cr6+, metakaolin, and PDK. The results indicate that a high level of immobilization has been attained. Based on the results obtained, the examined geopolymeric hazardous waste may be effectively utilized as robust barriers in landfills or to be recycled in manufacturing of mortar and binders.

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