Title:	Removal of Inorganic Contaminants Using Sodalite Synthesized From Alum Sludge.
Authors:	MACHADO, R. C. MAJARON, V. F. MARTINS JUNIOR, A. A. F. BARRIOS, N. L. CINTRA JUNIOR, W. de A. RIBEIRO, C.
Affiliation:	UNIVERSITY OF SÃO PAULO (USP); FEDERAL UNIVERSITY OF SÃO CARLOS (UFSCAR); FEDERAL UNIVERSITY OF SÃO CARLOS (UFSCAR); UNIVERSITY OF RIBEIRÃO PRETO (UNAERP); CAUE RIBEIRO DE OLIVEIRA, CNPDIA.
Date Issued:	2026
Citation:	Particle & Particle Systems Characterization, v. 43, e00235, 2026.
Pages:	9 p.
Description:	The growing concern over water contamination by potentially toxic metals underscores the need for sustainable and cost-effective remediation strategies. In this study, sodalite (SOD-Na) was synthesized from alum sludge (AS), a by-product of water treatment plants rich in Si and Al, through a hydrothermal process in an autoclave. Zeolitic concentrate was characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray fluorescence (XRF), Brunauer Emmet Teller (BET) method, and zeta potential analysis, confirming the formation of sodalite with mesoporous structure and surface charge favorable to cation adsorption. Adsorption experiments demonstrated high affinity for Pb2 + (189 mg g− 1 ), Cd2 + (121 mg g− 1 ), and Ni2 + (58.4 mg g− 1 ), whereas limited adsorption was observed for Cr6 + (Cr2 O7 2 − ) (8.2 mg g− 1 ), consistent with the material’s negative surface charge and ion-exchange mechanism. Tests with real wastewater confirmed the material’s applicability, showing Ni2 + removal capacity of 26.5 mg g− 1 despite competitive interactions with coexisting ions. These findings highlight the potential of sodalite synthesized from alum sludge as an effective and sustainable adsorbent for wastewater treatment, contributing to circular economy strategies and reducing environmental liabilities.
Keywords:	Alum sludge Hydrothermal treatment Sodalite
DOI:	https://doi.org/10.1002/ppsc.202500235
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPDIA)