The behavior of potentially toxic elements in the technogenic soil-plant system: A study of Salicornia europaea L. from sites affected by the soda industry

Abstract

Soils created or significantly transformed by human activity are called technogenic soils. They have specific morphological, physical, chemical, and biological characteristics resulting from introducing technogenic materials that are often not inert to the environment. Very little research is still conducted in technogenic or post-technogenic areas based on analyzing environmental samples (plants and soils). Experimental, model-based studies dominate and often have limited reference to actual environmental conditions. That is why this study was carried out in areas affected by waste from the soda industry referring to the living labs concept. We tested the hypothesis that the impact of highly saline industrial waste has contributed to the formation of a specific pattern of relocation and accumulation of potentially toxic elements (PTEs) in the plant-soil system. We applied halophyte Salicornia europaea as a model plant and analyzed the chemical properties of soil and plant materials collected from five study sites. Our results demonstrate that the highest bioconcentration factors for shoots or roots were observed in cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn), with a value of more than 1. Translocation factors for all metals were less than 1 meaning more parts of PTEs were accumulated in the roots. The lowest storage factors were related to Ba, Cd, Cu, and Zn, indicating more amounts of these metals were transferred to the shoots. We revealed that S. europaea could be used for phytoremediation of soils contaminated by PTEs adopting phytostabilization for Ba, Co, Ni, and lead (Pb), and phytoextraction for Cd, Cu, and Zn. In this way, our findings can have a significant contribution to achieving one of the Sustainable Development Goals of the UN 2030 Agenda (goal no. 15), focusing, among others, on halting and reversing land and natural habitat degradation and stopping biodiversity loss.