Abstract:

The date seeds (DS) biochar produced at 550°C was found to be appropriate for remediation of metalcontaminatedwater. This was evident in the data, which showed that applying the biochar toRaphanus sp. and Arabidopsis sp. reduced metal stress and toxicity. The LC50 of all tested metalssolutions on seed germination was increased significantly (P<0.05) in Raphanus sp. by 10.4, 2.3, 5,1.8, and 3 folds, respectively, for Cu, Zn, Cd, Pb, and metals combination, and by 5, 3.4, 6, 5.5, and2.5 folds in Arabidopsis sp. For seedling growth, the DS biochar enhanced the LC50 significantly(P<0.05) of the same metals in Raphanus sp. by 9.6, 9.2, 13.8, 12.1, and 1.6 folds, and in Arabidopsissp. by 7, 3, 2.3, 2.9, and 2.7 folds, respectively. The LC of all metals was increased by 1.5 to 8 timesand 1.5 to 12 times, respectively, for the seed germination and seedling growth of Raphanus sp. andArabidopsis sp. Both plants were able to grow shoots at higher metal concentrations when the DSbiochar was employed, as compared to the case when no DS biochar was utilized. In terms of shootlength, similar results were achieved, with the DS biochar application significantly enhancing shootlength (P<0.05), as compared to the case when no biochar was applied. Despite the fact thatArabidopsis sp. was more sensitive to metals than Raphanus sp., both plants raised their RGR and TIand reduced their phytotoxicity values in all metals following the DS biochar application, and sproutedat higher metal concentrations than before. These findings introduce a successful eco-friendlyadsorbent for metal removal from aquatic environments, paving the way for more investigations.