title: Uptake and distribution of metals by water lettuce (Pistia stratiotes L.).
abstract: OBJECTIVE
  Water quality impairment by heavy metal contamination is on the rise worldwide. Phytoremediation technology has been increasingly applied to remediate wastewater and stormwater polluted by heavy metals.
  
  
  METHODS
  Laboratory analysis and field trials were conducted to evaluate the uptake of metals (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn) by an aquatic plant, water lettuce (Pistia stratiotes L.), and metal distribution in the plant.
  
  
  RESULTS
  The growth of water lettuce reduced Al, Fe, and Mn concentrations in water by >20%, K and Cu by >10%, and Ca, Mg, Zn, and Na to a lesser extent. A larger proportion of Ca, Cd, Co, Fe, Mg, Mn, and Zn was adsorbed or deposited on the external root surfaces while more Al, Cr, Cu, Ni, and Pb were absorbed and accumulated within the roots.
  
  
  CONCLUSIONS
  Water lettuce has a great ability in concentrating metals from its surrounding water with a concentration factor (CF) ≥10(2). The bio-concentration factor (BCF), which excludes the part on the root surfaces, is a more appropriate index than the CF for the differentiation of hyperaccumulation, accumulation, or non-accumulation plants for metals.
  
  
  CONCLUSIONS
  Water lettuce is a hyperaccumulator for Cr, Cu, Fe, Mn, Ni, Pb, and Zn and can be applied for the remediation of surface waters.
  
  
  CONCLUSIONS
  Further study on the bioavailability of metals in the water lettuce is needed for the beneficial use of metal-enriched plant biomass.
authors.affiliation: Institute of Food and Agricultural Sciences, Indian River Research and Education Center, University of Florida, 2199 S Rock Rd, Fort Pierce, FL 34945, USA.
authors.forename: Qin
authors.initials: Q
authors.lastname: Lu
authors.forename: Zhenli L
authors.initials: ZL
authors.lastname: He
authors.forename: Donald A
authors.initials: DA
authors.lastname: Graetz
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Stoffella
authors.forename: Xiaoe
authors.initials: X
authors.lastname: Yang
mesh_terms: D029064:Araceae / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001682:Biological Availability; D008670:Metals / Q000032:analysis / Q000493:pharmacokinetics*; D019216:Metals, Heavy / Q000032:analysis / Q000493:pharmacokinetics*; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000493:pharmacokinetics*; D014877:Water Pollution, Chemical; D018508:Water Purification
chemical_list: D008670:Metals; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical