Qurrota A’yuni, Vika Ayu Devianti, Ika Fitri Ulfindrayani, Hamizah Haula’, Demet Ozer
Volcanic mud from the Lapindo company disaster in Indonesia was activated with acid and heated using microwave irradiation at various power levels. A comparative analysis of the physical and structural properties of Lapindo volcanic mud (LVM) in its raw and activated forms was conducted using XRF, XRD, FTIR, SEM-EDX, and N₂ adsorption–desorption. The XRF results indicated that silica was the predominant component in the mud, accounting for almost half of its total content. Iron (III) oxide is also contained in LVM, contributing to its grey colour. The XRD patterns revealed that microwave treatment affects its crystallinity and crystallite size. The FTIR spectra exhibited T–O–T (T = Si or Al) stretching vibration. Activated LVM exhibited larger particle diameters in micrometre clusters, a more uniform size distribution, and a flake-like morphology. The LVM isotherms were classified as type IV, indicating that the adsorbent possessed mesoporous characteristics. The surface area of LVM increased as the microwave power was raised. The optimal irradiation is at a power of 600 W. To evaluate the efficacy of the activated LVM in removing cationic and anionic dyes from an aqueous solution, the adsorption of methylene blue and methyl orange dyes was examined separately. The adsorption capacity (qe) and removal efficiency were up to 189.02 mg g−1 and 95.27% for methylene blue, 128.29 mg g−1 and 64.15% for methyl orange, respectively. As a low-cost and naturally abundant adsorbent material, activated LVM presents a promising and sustainable alternative to more costly adsorbent materials. © 2026 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Department of Chemistry, Faculty of Science and Technology, Universitas Airlangga, Campus C UNAIR, Mulyorejo, Surabaya, 60115, Indonesia; Department of Chemistry, Faculty of Science, Hacettepe University, Beytepe, Ankara, 06800, Turkey; Department of Pharmacy, Akademi Farmasi Surabaya, Surabaya, Gayungan, 60232, Indonesia; Postgraduate School, Universitas Negeri Surabaya, Lakarsantri, Surabaya, 60213, Indonesia
