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Accueil du site → Doctorat → Espagne → 2007 → Movilidad de metales pesados en sustratos de restos de poda y bisólidos : ensayos de fitoextracción con "Rosmarinus officinalis" y "Atriplex halimus"

Universidad Autónoma de Madrid (2007)

Movilidad de metales pesados en sustratos de restos de poda y bisólidos : ensayos de fitoextracción con "Rosmarinus officinalis" y "Atriplex halimus"

Tapia Fernández, Yasna

Titre : Movilidad de metales pesados en sustratos de restos de poda y bisólidos : ensayos de fitoextracción con "Rosmarinus officinalis" y "Atriplex halimus"

Auteur : Tapia Fernández, Yasna

Université de soutenance : Universidad Autónoma de Madrid

Grade : Tesis doctoral 2007

Résumé
The environmental problematic posed by the increase generation of organic wastes in large cities, particularly yard trimmings of gardening and urban sewage sludge or biosolids, is in urgent need of recovery in an effective manner, to minimize the impact caused by the these deposit waste in the landfill. One of the major limiting factors in the value biosolids is the content of pollutants such as heavy metals. This study aims to evaluate the mobility and bioavailability of heavy metals in composted yard trimmings+biosolids, make its use as a growing media in a container, and also assess the ability for phytoextraction of heavy metals in plants of Rosmarinus officinalis and Atriplex halimus when they are grown in this growing media. trimmings+biosolids) and forest residues (compost of pine bark). Physicochemical characterizations and hydro-chemical materials were determinated with special emphasis on heavy metals, to including determination by estimating the mobility and bioavailability leaching. The compost of yard trimmings+biosolids have a much higher concentration of heavy metals that composted pine bark, but not beyond the limits established for the agronomic use of these materials. To carry out the objectives were performed 4 experiments. The first trial was conducted through leaching columns, in laboratory conditions, where the materials were added cadmium, as metal model pollutant concentrations and in different solutions were applied irrigation. Once evaluated the leaching of cadmium and other heavy metals, were conducted the experiments with plants in greenhouse conditions. In the second experiment, we selected perennial plants, native to the Mediterranean area and tolerant to growing media contaminated with heavy metal. Plants were grown Atriplex halimus, Phillyrea angustifolia, Rhamnus alaternus and Rosmarinus officinalis in growing media of composted pine bark, which was presented cadmium added highly bioavailable. Selected plants Rosmarinus officinalis and Atriplex halimus, in the third experiments to evaluate the compost of yard trimmings + biosolids as a growing media in container for Rosmarinus officinalis because this species has a great interest from the point ornamental, nutritional and medicinal. Composted of yard trimmings + biosolids was used without mixing with other ingredients and containing heavy metals naturally present in the material. Results were compared with pine bark. Finally in the fourth experiment, to evaluate ability for phytoextraction of Rosmarinus officinalis and Atriplex halimus, growing media of yard trimmings + biosolids was sprinkled on a continuous basis with citric acid dissolution and nutritious. The results of these experiments allow note that the compost of yard trimmings + biosolids is a material with a high capacity retention of heavy metals, compared with composted pine bark. The main features that contributed to this capability was a high pH value, a higher degree of humification and increased cation exchange capacity, attributed to greater composition of carboxyl groups submitted this material. Heavy metals, cadmium and lead were found mainly associated with the organic fraction. Its use as a substrate for growing media in a container, compost of yard trimmings + biosolids proved to be a good material for Rosmarinus officinalis, after correction for salinity. The continuing addition of citric acid compost yard trimmings + biosolids a significant increase in the leaf content of manganese, iron and copper, for Rosmarinus officinalis, and manganese for Atriplex halimus. However, considering the time of application for 2 months, citric acid proved to be a low degree of efficiency to mobilize metals in this substrate. Atriplex halimus proved to be a plant with high ability for translocate the heavy metals from roots to leaves. This plant is a species is suitable for use in technical phytoremediation of contaminated soil

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