Remediation through the coordinated use of local rice husk residues for the selective adsorption of iron and nickel in real landfill leachate

• Published in: Journal of environmental management Vol. 358; p. 120893
• Main Authors: dos Santos, Bárbara Luiza Brandenburg, Vieira, Yasmin, Abou Taleb, Manal F., Ibrahim, Mohamed M., Reis, Mirela Araujo, do Nascimento, Bruna Figueiredo, Oliveira, Marcos Leandro Silva, Silva, Luis Felipe Oliveira, Dotto, Guilherme Luiz
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-05-2024
• Subjects: Activated carbon; Adsorbent recycling; Environmental remediation; Metal adsorption; Wastewater treatment; Environmental remediation; Metal adsorption; Adsorbent recycling; Wastewater treatment; Activated carbon
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2024.120893

Herein, we demonstrate the prospects of tackling several environmental problems by transforming a local rice husk residue into an effective adsorbent, which was then applied for the treatment of real landfill leachate (LL). The study focused on establishing (i) the effect of simple washing on morphological aspects, (ii) evaluating target adsorption capacity for total iron (Fe) and nickel (Ni), (iii) determining regeneration and reuse potential of the adsorbent and (iv) complying to the requirements of worldwide legislations for reuse of treated LL wastewater. The adsorbent was prepared by employing a simple yet effective purification process that can be performed in situ. The LL was collected post-membrane treatment, and the characterizations revealed high concentrations of Fe, Ni, and organic matter content. The simple washing affected the crystallinity, resulting in structural alterations of the adsorbents, also increasing the porosity and specific surface. The adsorption process for Ni occurred naturally at pH 6, but adjusting the pH to 3 significantly improved removal efficiency and adsorption capacity for total Fe. The kinetics were accurately described by the pseudo-second-order model, while the Langmuir model provided a better fit for the isotherms. The adsorbent was stable for 5 reuses, and the metals adsorbed were recovered through basic leaching. The removal capacities achieved underscore the remarkable effectiveness of the process, ensuring the treated LL wastewater meets rigorous global environmental legislations for safe use in irrigation. Thus, by employing the compelling methods herein optimized it is possible to refer to the of solving three environmental problems at once.
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•Simple and effective adsorbent production that can even be performed in situ.•Simple washing process resulted in a structured and homogeneous surface.•Adsorption occurs in monolayer through complexation and electrostatic interactions.•AC-T is highly reusable and selective towards the removal of Fe and Ni.•Treated LL sample in compliance with strict environmental legislation for reuse.