Abstract
Adsorption Kinetics, Isotherms, and Thermodynamics of Heavy Metal Selective Bioaccumulation by Nephrolepis biserrata in Tropical Soils
Laboratory of Environmental Sciences and Technologies (LSTE), Jean Lorougnon Guédé University, Daloa, 1National Laboratory for Quality Testing, Metrology and Analysis (LANEMA), Abidjan, 2Department of Mathematics, Physics and Chemistry, UPR of Organic Chemistry, Faculty of Biological Sciences, Peleforo Gon Coulibaly University, Korhogo, 3Laboratory of Matter Constitution and Reaction (LCRM), Félix Houphouët-Boigny University, Abidjan, 4Félix Houphouët-Boigny National Polytechnic Institute, Yamoussoukro, Cote d’Ivoire
Correspondence Address:
Nongbe Medy Camille, National Laboratory for Quality Testing, Metrology and Analysis (LANEMA), Abidjan, Yamoussoukro, Cote d’Ivoire, E-mail: medycamille@gmail.com
Soil contamination by heavy metals represents a major environmental challenge in tropical regions due to their toxicity, persistence, and bioaccumulation in ecosystems. This study investigates the potential of the tropical fern Nephrolepis biserrata for the phytoremediation of soils artificially contaminated with chromium, copper, zinc, and arsenic. Plants were cultivated for 56 d in moderately acidic, low-salinity soil and analysed by inductively coupled plasma mass spectrometry to quantify metal accumulation in roots and shoots. Results revealed strong bioaccumulation of zinc and copper, with bio concentration factors reaching 33.7 and 19.0 at 20 mg/kg, confirming hyper accumulation behaviour. Chromium showed moderate uptake, whereas as was weakly accumulated. Kinetic modelling indicated that chromium followed a first-order model, while copper and zinc fitted a pseudo-second-order model (R2>0.96), suggesting chemisorption through specific interactions with cell wall functional groups. Langmuir isotherms provided the best fits (R2>0.96), highlighting monolayer adsorption on homogeneous sites. Thermodynamic analysis demonstrated spontaneous (ΔG°<0), exothermic (ΔH°<0), and entropy-increasing (ΔS°>0) processes, confirming favourable metal-plant interactions. Overall, Nephrolepis biserrata emerges as a promising candidate for selective phytoremediation of tropical soils, particularly effective for copper and zinc contamination.
PDF
