Phytoremediation and metal uptake in food plants

Abstract

This paper reviews some of our resent findings on metal uptake in phytotechnology and food
plants. The Cd concentration in wheat grains can be decreased by pytoextraction by Salix
prior to wheat cultivation. Water spinach commonly grown in nutrient rich waste water are
able to form methyl-Hg in new leaves, but high nutrient level in cultivation medium decreases
the metal concentration in the plant. Wetland plants grown on mine tailings are able to
decrease the formation of acid mine drainage from the tailings. Submerged plants can increase
the retention of metals in wetlands treating metal polluted water, but the efficiency depends
on the quality of the inlet water. Plants can be used to prevent leakage of metals and nutrients
from dry covers containing sewage sludge on mine tailing impoundments. If the sealing layer
below the cover layer consists of fly ash root penetration can be prevented while if it contains
a mixture of sewage sludge and fly ash roots will grow into the sealing layer. Macro algae as
fertilizers in agriculture increase the biomass production but also transfer Cd to the crop.
Therefore, algae should be used in production of non food crops, however, not suitable for
hemp cultivation.