Kinetics of Potentially Toxic Elements decontamination of soil at Komabangou gold mine using indigenous plants

• Soils from the Komabangou sites are polluted with PTEs and contaminate crop fields. • Phytoremediation with Datura v, Ameranthus v, Cenchrus b is a new technique. • The power of these plants means that PTEs can be extracted from soils efficiently. • The root part of plants extracts more of the PTEs than the aerial part. • Datura i and Amaratus v are the plants that hyper-accumulate PTEs at Komabangou. Mining activities, as essential components of industrial development, play an important role in the global economy. However, in West Africa they often entail significant environmental consequences, notably soil contamination by potentially toxic elements (PTEs). The release of untreated wastewater from gold processing onto soils poses significant risks to public health, and to the ecological stability of agricultural land. After decades of operation, sites are polluted with PTEs and abandoned, contaminating peripheral areas and affecting agricultural crop fields. This study examines the importance of phytoremediation of PTE-contaminated soils at the Komabangou mining sites in Niger. It begins by examining the impact of contamination on the soil. Various methods for managing pollution by PTEs exist, encompassing thermal, chemical and physical approaches. These techniques are very expensive and require a source of Energy, unfortunately they cannot be applied to the realities of our African countries. Datura, Cenchrus and Ameranthus were chosen as depolluting plants. They were grown in 3 types of mining soil sampled from 0 to 30 cm depth, namely polluted soil, peripheral soil and control soil. The samples were pre-treated before analysis by inductively coupled plasma mass spectrometry (ICP-MS) for the soil samples and for the plants. The results showed the potential of these species to accumulate PTEs in polluted soil through plant roots and leaves. Remarkable results are expressed in (mg.kg -1 ), the largest quantities extracted were 369.97; 28.38; 8.16; 62.36 and 32.98, respectively, for Zn, Cu, Co, Mn, and Cr. These results show that phytoremediation is a promising method for treating polluted soils, particularly suited to underdeveloped countries such as Niger. Finally, these plants are good candidates for research into phytoremediation and phytoextraction.