Metal and metalloid removal in constructed wetlands, with emphasis on the importance of plants and standardized measurements: A review.
This review integrates knowledge on the removal of metals and metalloids from contaminated waters in constructed wetlands and offers insight into future R&D priorities. Metal removal processes in wetlands are described. Based on 21 papers, the roles and impacts on efficiency of plants in constructed wetlands are discussed. The effects of plant ecotypes and class (monocots, dicots) and of system size on metal removal are addressed. Metal removal rates in wetlands depend on the type of element (Hg > Mn > Fe = Cd > Pb = Cr > Zn = Cu > Al > Ni > As), their ionic forms, substrate conditions, season, and plant species. Standardized procedures and data are lacking for efficiently comparing properties of plants and substrates. We propose a new index, the relative treatment efficiency index (RTEI), to quantify treatment impacts on metal removal in constructed wetlands. Further research is needed on key components, such as effects of differences in plant ecotypes and microbial communities, in order to enhance metal removal efficiency.
Marchand
L
L
UMR BIOGECO INRA 1202, Ecologie des communautés, Université Bordeaux 1, Bat B8 RDC Est, Avenue des facultés, F-33405 Talence, France. lilian.marchand@hotmail.fr
Mench
M
M
Jacob
D L
DL
Otte
M L
ML
D004784:Environmental Monitoring / Q000592:standards*; D019015:Geologic Sediments / Q000737:chemistry; D058955:Metalloids / Q000009:adverse effects / Q000302:isolation & purification*; D008670:Metals / Q000009:adverse effects / Q000302:isolation & purification*; D063245:Plant Development; D014874:Water Pollutants, Chemical / Q000009:adverse effects / Q000302:isolation & purification*; D014876:Water Pollution; D053833:Wetlands
D058955:Metalloids; D008670:Metals; D014874:Water Pollutants, Chemical