Cleaning of soil contaminated with heavy metals using red clovers

Abstract

Soil contamination with heavy metals is a relevant problem worldwide to which no universal solution has been found. Phytoremediation is a new and prospective technology for cleaning soils of low contamination rate using plants. To clean heavy metals off soil, this work has chosen the red clovers Arimaičiai grown under laboratory conditions. After Cu application on soil it was noticed that after six months the content of Cu in soil had been threefold lower than at the beginning of the experiment. After soil application with Mn it was determined that the Arimaičiai had absorbed 30 % of it from soil after six months. When Ni concentration in soil reached 75 mg/kg it was noticed that after six months the Arimaičiai had absorbed 32 % of Ni from soil. It was also determined that the red clovers had adsorbed up to 31 % of Cr from soil during the same period. After permanent application of Zn on soil the plant absorbed 17 % of zinc from soil during the six-month period. When Pb concentration in soil reached 100 mg/kg it was noticed that after six months the plants had absorbed 23 % of Pb from soil.