Aspects of phytoremediation for chromium contaminated sites using common plants Urtica dioica, Brassica napus and Zea mays

As chromium is widely used in many industries of which leather industries are the biggest consumers, wastes from tanneries pose a serious threat to the environment. Present research conducted greenhouse pot experiments on several plants using different solutions to find out their phytoextraction potential. Among the plants, Urtica dioica found to be very effective due to its higher uptake capacity for chromium. The analyses showed that with 500 mg/l solutions Cr concentration in roots was 38.9% higher (average 20 mg/kg) than plants fed with 200 mg/l solutions (phytostabilisation), while with 200 mg/l solutions more Cr was transported to leaves (phytoextraction), 10.52% higher (average 9.5 mg/kg) concentration than plants fed with 500 mg/l solutions, but also means that plants were less affected by toxicity. Zea mays showed high tolerance towards Cr with negligible concentration in leaves. Although average Cr concentration in Brassica napus is lower (25% and 21% for 200 mg/l and 500 mg/l solutions respectively) than Urtica dioica which still could account for phytoextraction, but due to its high vulnerability to insects its potentiality has downgraded. Among other elements, K being a component of the salt, played significant role for plants growth and survival-opening new avenue for phytoremediation of contaminated sites.