Biosorption process using Cereus jamacaru DC, Cactaceae for Pb²⁺ removal from aqueous systems

ABSTRACT

Lead is a highly toxic metal associated with many human health diseases that can be caused by several environmental changes. Innovative sustainable solutions for water remediation have been recently encouraged by using renewable, low-cost and earth-abundant biomass materials to ensure public health conditions. In this article, Cereus jamacaru DC (popularly known as Mandacaru) was investigated as a biosorbent in the Pb²⁺ removal from aqueous solution using a two-level factorial design. The analysis of variance suggested a significant and predictive model (R² = 0.9037). The maximum efficacy of Pb²⁺ removal in the experimental design was 97.26%, being the optimized conditions: pH 5.0, contact time 4 h without adding NaCl. The Mandacaru was divided into three types according to the plant structure and this parameter did not present a significant interference in the biosorption process. This result corroborates with slight differences in the total soluble proteins, carbohydrates and phenolic compounds found in the Mandacaru types investigated. FT-IR analysis revealed the presence of O–H, C–O and C = O groups that were responsible for the ion biosorption process. The optimized procedure was capable to remove 97.28% of the Pb²⁺ added in the Taborda river water sample. The kinetic adsorption results show the pseudo-second-order model, suggesting chemisorption process. Thus the treated water sample can be considered in accordance with technical standards issued by CONAMA Resolution Num. 430/2011 and Ordinance GM/MS Num.888/2021 of WHO. In this way, the Mandacaru proved to be an efficient, fast and easy-to-apply bioadsorbent in Pb²⁺ removal and has great environmental application potential.

GRAPHICAL ABSTRACT

KEYWORDS:

• Experimental planning
• biosorption
• Cereus jamacaru
• metal toxic water contamination

Acknowledgments

The authors acknowledge the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes) for the financial support, the Graduate Program in Chemistry of the Federal University of Rio Grande do Norte (PPgQ-UFRN), the Analytical Center (Chemistry Institute -UFRN) and the Primary Processing Center and Reuse of Produced Water and Waste (NUPPRAR-LABPROBIO).

Disclosure statement

No potential conflict of interest was reported by the author(s).