# New Light on Phtyoremediation: The Use of Luminescent Solar Concentrators
## 1 Introduction
The interest in these phytotechnologies has increased over time, given some significant advantages in their use compared to traditional remediation technologies: low cost, simplicity of operation, environmental benefits. Recent contributions based on Life Cycle Assessment (LCA) comparison of different technologies clearly show the major advantage of phytoremediation in environmental impact and ecological footprint with respect to consolidated technologies or excavation and landfill disposal [14]. Phytotechnologies fall entirely within the green remediation category [15], and given their minimal environmental impact, have been proposed as an effective nature-based solution (NBS), as they ensure environmental remediation in a sustainable and economically efficient way [16; 17]. Phytoremediation includes several decontamination processes; the most used are:  
* Phytoextraction: process of contaminants extraction (organic and inorganic) from the soil through roots and subsequent translocation and accumulation in plant tissues (roots and shoots);
* Phytodegradation: degradation of organic contaminants through plant biochemical processes by the increase in the microbial activity, which promotes the degradation of a contaminant in the soil;
* Rhizofliltration: decontamination of polluted water carried out by aquatic plants either floating or submerged which uptake and concentrate, by their roots, the contaminants, removing them from aqueous environments;
* Phytostabilization: containment or immobilization of contaminants in the rhizospheric region of plants by adsorption or precipitation preventing the leaching of dissolved contaminants and the aerial dispersion of contaminated soil particles;
* Phytoval utilization: adsorption of contaminants by the root system, followed by translocation into the shoots and release into the atmosphere through the leaves' transpiration process. Among the various phytotechnologies in contaminated sites, phytoextraction is the most important for the removal of heavy metals. In the last twenty years, several innovative strategies have been developed to maximize the efficiency of the approach, which depends both on the biomass produced and the quantity of metal absorbed by the plants [18]. These strategies are aimed both to improve the performance of plants by using species with high biomass production and by increasing the bioavailability of contaminants through appropriate soil treatments with additives capable of increasing the concentration of metals in the liquid phase of the soil [19; 20]. Among these innovative strategies, the possibility of relying on plant growth-promoting bacteria (PGPB) to improve the effectiveness of phytoextraction processes is of particular interest. These beneficial plant bacteria living in close association with roots have several positive effects on plant growth and develop PGPB can significantly contribute to increase plants metal uptake and, consequently, the efficiency and the rate of phytoextraction [20; 21]. The increase in uptake is often further enhanced by simultaneous addition of metals mobilizing agents such as chelating compounds [22], to be selected and dosed appropriately in order not to penalize the sustainability of the approach, and possibly monitor with non-invasive approaches to avoid uncontrolled diffusion in the environment [23]. However, since phytoremediation is a highly site-specific approach, each innovation requires preliminary tests on an increasing scale to verify its effectiveness before full-scale applicability, including the setting up of dedicated greenhouses as a suitable environment for feasibility tests to optimally prepare full-scale interventions [24]. These increasing-scale trials mostly take place in greenhouses that are subject to considerable costs when they require the maintenance of optimal temperature conditions. In a controlled environment, it is possible to better study the use of additives that increase the bioavailability of contaminants.