Removal of Cr (VI) from synthetic effluents using hydrochar from waste açaí (Euterpe precatoria Mart.) seeds as a low-cost biosorbent

ABSTRACT Chromium (Cr) is a common contaminant in aquatic ecosystems, and in its hexavalent form (Cr (VI)) can cause serious risks to human health. This study utilized açaí waste to prepare a novel hydrochar (AWR) for Cr (VI) removal. AWR was characterized by Boehm titration, point of zero charge, i...

Full description

Saved in:
Bibliographic Details
Main Authors: Railane Inácio Lira dos SANTOS, Luís Fernando Lira SOUTO, Nathiely Andrade de MORAES, Ana Clara de Sousa MENDES, Naelly Nayllén Alves ARAÚJO, Flávio Augusto de FREITAS
Format: Article
Language:English
Published: Instituto Nacional de Pesquisas da Amazônia 2025-08-01
Series:Acta Amazonica
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672025000103500&lng=en&tlng=en
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:ABSTRACT Chromium (Cr) is a common contaminant in aquatic ecosystems, and in its hexavalent form (Cr (VI)) can cause serious risks to human health. This study utilized açaí waste to prepare a novel hydrochar (AWR) for Cr (VI) removal. AWR was characterized by Boehm titration, point of zero charge, infrared spectroscopy, thermogravimetric analysis, specific surface area measurement, scanning electron microscopy, and elemental analysis. A 23 factorial design examined the influence of key factors (pH, hydrochar mass, and Cr (VI) concentration). Results showed that acidic functional groups predominate on the surface of AWR. Under optimal conditions (pH = 2, hydrochar mass = 0.150 mg, and solution concentration = 150 mg L−1), Cr (VI) removal exceeded 96% with maximum adsorption capacity (Qmax) = 20.60 mg g−1 at 35°C. Adsorption kinetics followed a pseudo-second-order model, and the Tenkin isotherm best described the data. Thermodynamic analysis indicated that Cr (VI) adsorption is spontaneous and endothermic. This study demonstrated that AWR is a novel, effective, and cost-effective adsorbent for removing Cr (VI) from water environments.
ISSN:0044-5967