Januarti Jaya Ekaputri, Adi Drajad Budiman, Nathaniel Nico Prawira, Royce Giovano Sutikno, Fadhilah Aditya Ahmad, Yusif Fikri Ihza Mahendra, Andika Ade Indra Saputra, Adrian Gunawan, Yudha Gusti Wibowo, Himawan Tri Bayu Murti Petrus, Reini Djuhraeni Wirahadikusumah, Jessica Sjah, Irwan Katili, Andri Kusbiantoro
The accelerated advancement of Indonesia’s forthcoming capital, Ibu Kota Nusantara (IKN), intensifies environmental challenges related to acid mine drainage (AMD) and the accumulation of circulating fluidized bed combustion fly ash (CFA) alongside palm oil fuel ash (POFA). This study proposes a circular dual-valorization strategy by synthesizing Na-P1 (gismondine-type) zeolite from low-grade CFA and high-silica POFA through alkali activation, followed by steam curing and calcination, to enable simultaneous AMD remediation and material reuse in concrete applications. Mineralogical analyses confirmed the formation of crystalline aluminosilicate frameworks. The synthesized zeolite demonstrated high remediation efficiency, increasing AMD pH from 2.1 to 8.5 and achieving near-complete removal of Fe, Mn, and sulfate ions, along with significant reduction of total suspended solids within 24 h. Post-treatment characterization revealed partial structural transformation of the zeolite; however, its functionality as an artificial aggregate was retained, contributing to internal curing and achieving compressive strengths of 18.4–18.9 MPa at 10% replacement in conventional concrete, and up to 44.4 MPa in self-compacting concrete. The results further indicate that alkali molarity critically governs the competition between zeolitization and geopolymeric gel formation, thereby controlling both adsorption capacity and mechanical performance. Unlike conventional studies that treat adsorption performance and structural reuse separately, this work demonstrates a coupled mechanism in which AMD-reacted zeolite undergoes controlled physicochemical evolution while remaining functionally viable as a construction material. This work presents a scalable circular solution for integrated waste valorization, AMD remediation, and sustainable construction material development, addressing both environmental pollution and resource scarcity in emerging urban regions. © 2026 The Authors.
Sepuluh Nopember Institute of Technology, Civil Engineering Department, Surabaya, Indonesia; Kalimantan Institute of Technology, Civil Engineering Department, Balikpapan, Indonesia; Kalimantan Institute of Technology, Chemical Engineering Department, Balikpapan, Indonesia; Department of Mining Engineering, Faculty of Technology and Industry, Institut Teknologi Sumatera, Lampung, Indonesia; Sustainable Mineral Processing Research Group, Department of Chemical Engineering, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia; Civil and Environmental Engineering Department, Institut Teknologi Bandung, Bandung, Indonesia; Civil and Environmental Engineering Department, Universitas Indonesia, Jakarta, Indonesia; Department of Civil Engineering Technology, Faculty of Engineering Technology, Universiti Tun Hussein Onn Malaysia, Hab Pendidikan Tinggi Pagoh, KM 1, Jalan Panchor, Panchor, 84600, Malaysia