Bio accumulation factor (BCF), translocation factor (TF), metal
extraction amount and phytoremediation time were used to
evaluate phytoextraction efficiency and were calculated by
the following equations It is assumed that the king grass
can be mowed 3 times each year and metal pollution occurs
only in the active rooting zone, namely the top 20 cm layer of
soil (assuming a soil bulk density of 1.3 tm3), giving a total
soil mass of 2600 t ha1