Chelate-assisted phytoextraction of heavy metals in a soil contaminated with a pyritic sludge.
The occurrence of many polluted areas as that affected by the accident of the Aznalcóllar pyrite mine has promoted phytoremediation as a technology able to reduce the risk of heavy metal contamination at low cost. White lupin plant has been considered a good candidate for phytoremediation. We studied the capacity of several complexing agents to improve the ability of white lupin for heavy metal phytoremediation in soils with multi-elemental pollution from acid pyritic sludge. Solution-soil interaction was studied and pot experiments with sludge-affected soil were carried out to this end. The interaction experiments indicated that EDTA and NTA were more efficient than malate and citrate in solubilizing metals (Fe, Mn, Cu, Zn, Cd), with minimum differences between EDTA and NTA. The pot trial showed that NTA was able to mobilize toxic elements from sludge-polluted soil and hence increasing their concentrations in plant (Mn, Cu, Zn, As, Cd). However, the NTA treatment promoted an increase of toxic elements concentrations, especially for As, Cd, Pb, in the lixiviates exceeding the maximum permissible levels, so a careful management of chelate is necessary.
Peñalosa
Jesus Manuel
JM
Departamento de Química Agrícola, Facultad de Ciencias, Universidad Autónoma de Madrid, Ctra. Colmenar Km 15, 28049--Madrid, Spain. jesus.olivares@uam.es
Carpena
Ramón O
RO
Vázquez
Saúl
S
Agha
Ramsy
R
Granado
Ana
A
Sarro
María José
MJ
Esteban
Elvira
E
D001673:Biodegradation, Environmental; D002614:Chelating Agents / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D007220:Industrial Waste; D007501:Iron; D031297:Lupinus / Q000378:metabolism*; D008293:Malates / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry / Q000378:metabolism*; D008906:Mining; D009571:Nitrilotriacetic Acid / Q000737:chemistry; D012722:Sewage; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism*; D012995:Solubility; D013030:Spain; D013440:Sulfides
D002614:Chelating Agents; D007220:Industrial Waste; D008293:Malates; D019216:Metals, Heavy; D012722:Sewage; D012989:Soil Pollutants; D013440:Sulfides; C011342:pyrite; D019343:Citric Acid; C030298:malic acid; D004492:Edetic Acid; D007501:Iron; D009571:Nitrilotriacetic Acid