I'm a high school student doing a project on rhizofiltration, the use of plants to filter pollution. I've chosen to use water hyacinths because they are commonly used for such purposes (plus they are cheap). I'll be testing the ability of water hyacinths to 'accumulate' heavy metals from their water sources, so I have to prepare some polluted water and figure out how to measure the concentration of heavy metals in the water. I'm having some trouble figuring out how to pollute water with heavy metals (probably copper/lead), and then measuring it. I think I could find some pipes and flush water through them or something, and there are some commercial heavy metal testing kits available, but I if anyone has any suggestions that'd be great :).
copper sulphate or copper oxychloride should be available as a fungicide in most garden centers. Sold at a specific % content it should be easy to apply and measure with some basic math to account for amount per volume. an EC meter (electrical conductivity) should be able to give you a relative measure for percentage of volume mineral content, before, during and after your experiment.
You can also get copper-bearing water-soluble compounds (like Copper (II) Sulfate and its relatives) at chemical supply houses; you may also be able to get lead-bearing water-soluble compounds there (like Lead Nitrate.) You can also ask your school's chemistry labs for Copper (II) Nitrate; it's a common reagent so they should have it on hand. Paul's process for testing absorption is an excellent one; you can also take the plant matter (ie the hyacinths) to an environmental testing lab and have them run an analysis.
