Assessment of the Transfer of Trace Metals to Spontaneous Plants on Abandoned Pyrrhotite Mine: Potential Application for Phytostabilization of Phosphate Wastes

Abstract

The abandoned Kettara pyrrhotite mine (Marrakech region, Morocco) is a real source of acid mine drainage (AMD) and heavy metal pollution from previous mining operations—which has spread, particularly because of wind erosion. A store-and-release cover system made of phosphate wastes was built on the site for preventing AMD. To ensure the integrity of this cover and its durability, it is desirable to revegetate it (phytostabilization) with plants adapted to the edaphoclimatic conditions of the region. In this paper, a study was carried out on the spontaneous vegetation around the phosphate cover in order to consider the selection of plants to promote the stabilization of the Kettara mine tailings pond. Nine species of native plants with their rhizospheric soils growing in agricultural soils and tailings from the Kettara mine were collected, and metals (As, Cd, Co, Cu, Pb, Zn, Ni, Cr) were analyzed. The soil analysis showed that the tailings contained high concentrations of Cu (177.64 mg/kg) and Pb (116.80 mg/kg) and that the agricultural soil contained high concentrations of As (25.07 mg/kg) and Cu (251.96 mg/kg) exceeding the toxicity level (Cu > 100 mg/kg, Pb > 100 mg/kg, As > 20 mg/kg). The plant analysis showed low trace metal accumulation in Scolymus hispanicus, Festuca ovina, Cleome brachycarpa, Carlina involucrata and Peganum harmala. These species had a bioconcentration factor (BCF) greater than 1 and a translocation factor (TF) less than 1, demonstrating a high tolerance to trace metals. Therefore, they are good candidates for use in the phytoremediation of the Kettara mine tailings. These species could also potentially be used for the phytostabilization of the phosphate waste cover of the Kettara mine, thus completing the rehabilitation process of this area.

Alkaloid production and response to natural adverse conditions in Peganum harmala : in silico transcriptome analyses

“…These orthologs may justify how P. harmala tolerates and responds to heavy metal stress (Ghasemi et al, 2014). They might be the key genes in heavy metal accumulation in P. harmala as it grows in abandoned areas where heavy metals are present in excess (el Berkaoui et al, 2022). As discussed before, the homology search for stress-responsive genes showed a high similarity with E. salsugineum (Fig.…”

A Review on Remediation of Iron Ore Mine Tailings via Organic Amendments Coupled with Phytoremediation

“…Phytostabilisation allows vegetation to be established on the surface of polluted soils/tailings by reducing the bioavailability/mobility of contaminants and their availability and thus preventing the transmission of elements into the food chain [68] by certain mechanisms including adsorption by roots, precipitation, and complexation in the root zone [57,66,69]. Phytostabilisation can be enhanced by using organic soil amendments that immobilise metal(loid)s when combined with plant species tolerant of a high level of contaminants while simultaneously improving the physical, chemical and biological properties of mine tailings [70].…”

Physiological Aspects of Absorption, Translocation, and Accumulation of Heavy Metals in Silphium perfoliatum L. Plants Grown in a Mining-Contaminated Soil

“…Namely, Cu is an enzymatic cofactor in photosynthesis and respiration, and Zn is an essential trace element in development processes, a component of important classes of enzymes such as cytochrome oxidase, polyphenol oxidase, ascorbic acid oxidase [95]; both elements therefore play a key role in the plant's growth and development [94]. Relative to the entire experiment, the dynamics of Zn accumulation were 153% above those of Cu, according to most research [96][97][98][99][100][101].…”