Phytoremediation of heavy metal contamination is of course an cost wise effective approach. So can you mention current plants showing better heavy metal adsorption
Aquatic macrophytes is an important class of plants used for phytoremediation in which water hyacinth (Eicchornia crassipes) an invasive aquatic plant was studied in detail followed by Potamogeton lucens, Salvinia hergozi,
Some of the explored hyperaccumulators are 1. Helianthus annus, 2. Hemidesmus indicus 3.Sesbania species 4. Brassica specoies and astragalus species.
More than this an important medicinal plant Catharanthus roseus yielding anticancer alkaloids is also well known for phytoremediation with chromium metal.
Check the link to get details on aquatic macrophytes.