POTENTIAL USE OF WATER HYACINTH (Eichhornia crassipes) IN XOCHIMILCO FOR METAL PHYTOREMEDIATION

Water hyacinth (Eichhornia crassipes) is a plant considered as a pest in the canals of the Xochimilco Protected Natural Area (PNA), nevertheless it could be used for phytoremediation. Since phytoremediation is a plant-site system specific technology, this study evaluated the potential use of water hyacinth as an accumulating plant for metals in the Xochimilco canals. For this purpose, we performed statistical analyses comparing the metal concentrations in the roots and shoots; also we calculated the translocation and bioaccumulation coefficients. We collected water hyacinth in tourist, agricultural and urban activity areas. After the acid digestion of samples, we quantified the concentration of 14 metals and a metalloid (As) in the areal and underwater structure of the plant using ICP-MS, ICP-OES and GF-AAS techniques. The underwater structure accumulated higher concentrations of metals than the shoots, except Sr. Bioaccumulation coefficients showed that water hyacinth from Xochimilco could be used as a remedial plant for metals, however it must be periodically removed from the canals. Furthermore, statistical cluster analysis showed that urban-influenced site (El Potrero) is the most polluted with metals.