Fate of caffeine in mesocosms wetland planted with Scirpus validus

► Nearly all of the caffeine (>99%) was eliminated from solution after 21 d. ► Caffeine concentration ranged from 0.11 to 6.11 μg g−1 in the roots and 6.39 to 13.65 μg g−1 in the shoots. ► BAFs ranged from 0.18 to 3.06 and 3.22 to 16.92 for roots and shoots, respectively. ► Mass assimilation of caffeine by roots & shoots could account for 0.18-4.43% and 12-62%, respectively. ► Phytoremediation may play a significant role in caffeine removal in CWs.