Sequestration of heavy metals in the soil and leaves of Eucalyptus Micro theca, Cupressus arizonica and Robinia Pseudo Acasia around Ilam city's cement plant

Phytoremediation of heavy metals from polluted sites could be an efficient and cost-effective alternative in removing heavy metals from soil. This study aimed to investigate the sequestration of Cd, Zn, Pb and Mn in the leaves and soil of Eucalyptus Micro theca, Cupressus arizonica Green and Robinia Pseudo Acasia, which have been planted around the Cement factory of Ilam.
Atomic absorption spectrometry was used to measure the accumulation of metals in leaves and in the soil at a depth of 0-10 and 10-20 cm in three species as well. Furthermore, the amounts of precipitated metals in Electro filter of factory were measured.
The results showed that Cd (0.55 mg/kg), Zn (3.92 mg/kg), Pb (40.25 mg/kg) and Mn (3.74 mg/ kg) sequestration occurred in electro filter; which were totally more than the amounts of them in soils and leaves of tree species. Results of metals sequestration in the soil revealed that increasing soil depth leads to decrease of Pb sequestration rate in all three species. The most sequestration of Cd and Zn both in the soil and leaves were observed in Robinia Pseudo Acasia. Likewise, the most sequestration of Pb and Mn in the soil at both depth and also in leaves were observed in Eucalyptus microtheca.
Eucalyptus microtheca and Robinia Pseudo Acasia demonstrated the most sequestration of heavy metals, and thus are suitable species for planting and green space development around the factory.