Phytoremediation systems for treatment of contaminant mixtures in soil

Plant-based remediation techniques that can address mixtures of heavy metals and organic contaminants in soil warrant investigation due to their cost effectiveness and public acceptability. The potential of phytoremediation to remediate mixtures of heavy metals and hydrocarbons in soil is presented in two papers. A hydropic screening of twenty-seven forage grasses, grown in a solution containing 100 muM Zn, 5 muM Cu and 1 muM Cd, provided six species that were exceptionally metal tolerant. These six species were examined for their growth response and root phenolic secretion at five levels of hydroponic heavy metal contamination. Phenolic secretion, an indicator of a plant's capacity to promote polycyclic aromatic hydrocarbon (PAH) degradation, increased with heavy metal contamination, however, the values were low (