Exploring the phytoremediation potential of indigenous flora for the rehabilitation of the artisanal gold mining sites in Kokumbo, Cote d’Ivoire

Abstract

Abstract Artisanal and small-scale gold mining (ASGM) generates significant environmental and public health concerns through potential toxic elements (PTEs). In this context, the present study aims to (i) assess soil contamination by PTEs in three ASGM areas in Kokumbo, namely a gold washing area (zone A), an abandoned ASGM (zone B), and an active ASGM (zone C), and (ii) to analyze the PTEs accumulation potential by native plant species in these areas and to suggest phytoremediation strategy. Twelve native plant species and their rhizospheric soil were collected and analyzed. The content of PTEs was determined by inductively coupled plasma mass spectrometry. The study showed that rhizospheric soil in zone A was substantially more contaminated, particularly with Mn (1444.6 mg/kg dry wt) and Cr (379.1 mg/kg dry wt). Various pollution indexes indicate As and V as the most polluted of the three zones. This contamination is of anthropogenic origin according to the enrichment factor. Among the plant species studied, Digitaria horizontalis showed a notable ability for Cr translocation. Indigofera hirsuta exhibited significant potential for the phytoextraction of Cu, and Mn. Tridax procumbens showed promise for potential for As phytoextraction, but it also shares with Croton hirtus, Porophyllum ruderale, and Chromolaena odorata, a remarkable potential for translocation of As, and Cu. These species are crucial in addressing soil contamination caused by PTEs, thereby preserving biodiversity and health.