# New Light on Phtyoremediation: The Use of Luminescent Solar Concentrators
## 3 Results
### Second Phase: Outdoor Comparison between LSC and Polycarbonate Boxes  
As described above, the microcosm test was conducted outdoor using two boxes, one in transparent polycarbonate and the other consisting of red LSC panels. In this case, the lighting conditions of the plants in the microcosms are significantly different from those of the first phase of the experiments. Indeed, there is no longer the shielding due to the greenhouse under which the first phase tests were conducted: the two boxes were placed outdoor, directly under the sunlight. In addition, for the LSC box all sides are made of red LSC panels, condition that should simulate on a small scale the effect of a hypothetical greenhouse made up exclusively of red LSC panels (in the comparison box all sides are made of polycarbonate). In general, the plants grew well, even after adding EDTA. Additionally, in this case, the results obtained show that the production of fresh biomass, especially in the aerial part, is higher for plants grown under the red box (Figure 9). Figure 8: Total accumulation of As and Pb in the aerial part of plants grown under and outside the red panel. Values are reported as mean \(\pm\) standard deviation. The trend of dry weight of the biomass of the plants is similar to that of the fresh weight; the data has been reported in Table 6.  
A picture of plants grown under the two different boxes before EDTA addition is reported in Figure 10. As an example, for each of the three plant species, two microcosms grown in the LSC box (on the left of the viewer) are compared with two microcosms grown in the polycarbonate box (on the right). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Aerial Part** & \multicolumn{4}{c}{**Roots**} \\ \hline  & **Mean** & **SD** & **Diff. \%** & **Mean** & **SD** & **Diff. \%** \\ \hline B & 749 & 65.1 & — & 197 & 82.7 & — \\ B LSC & 877 & 71.0 & +17.1 & 230 & 73.0 & +16.6 \\ B T & 712 & 69.8 & — & 242 & 74.1 & — \\ B LSC T & 959 & 96.9 & +34.7 & 261 & 80.7 & +8.0 \\ H & 489 & 97.3 & — & 224 & 26.7 & — \\ H LSC & 615 & 141 & +25.8 & 228 & 38.2 & +1.8 \\ H T & 484 & 97.2 & — & 239 & 29.4 & — \\ H LSC T & 560 & 117.0 & +15.7 & 220 & 28.8 & \(-8.1\) \\ L & 1051 & 58.6 & — & 309 & 12.2 & — \\ L LSC & 1310 & 212 & +24.7 & 308 & 83.0 & \(-0.5\) \\ L T & 1120 & 82.9 & — & 296 & 19.3 & — \\ L LSC T & 1220 & 117.1 & +8.9 & 432 & 63.5 & +45.9 \\ \hline \hline \end{tabular} Note: Diff% is the increased percentage of the mean values of biomass grown under the LSC panel compared to the plants grown outside the panel.  
\end{table} 
Table 6: Dry weight (mg) of the biomass of the aerial part and of the roots of plants. Values are reported as mean \(\pm\) standard deviation (SD). Figure 9: Fresh biomass production of shoots and roots. LSC the plants grown under the red panels and T the plants that have been treated with Ethylene Diamine Tetraacetic Acid (EDTA). Values are reported as mean \(\pm\) standard deviation. It must be emphasized that the addition of EDTA (not reported in Figure 10) did not show a negative effect on biomass production. This result can be attributed to both the fractional addition of the chelating agent and the short growth period of the plants in the microcosm tests. The concentration values of As and Pb in the aerial part and in the roots of the plants are shown in Table 7.  
From the results obtained, it can be seen that the concentration of Pb and As is in general very similar for the plants grown under the red box and under the polycarbonate one. In some cases, the plants under the red box even showed a slightly improvement in the absorption of the contaminants. In general, the present experiment results showed that in all plants, EDTA addition increased Pb concentrations in shoots compared with the control. The addition of EDTA increased the Pb content in the Brassica plants in the aerial part by more than four times, without notable differences between the plants grown under the red box and those under the polycarbonate box.