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Utilizzo di piante agrarie nel fitorisanamento di suoli contaminati da metalli pesanti: (ii) primi risultati della sperimentazione in situ di Torviscosa (Udine)
No full textDue colture annuali da biomassa – Sorghum bicolor e Helianthus annuus – sono state allevate in un suolo inquinato
da ceneri di pirite. Lo scopo di questo lavoro era quello di osservare l’accumulo di metalli pesanti durante il
ciclo vegetativo e la loro asportazione dal sito inquinato mediante la raccolta della biomassa prodotta.
Two annual high biomass yield crops – Sorghum bicolor and Helianthus annuus – were grown in a soil p
La prova in situ è stata organizzata secondo uno schema a blocchi randomizzati. La concentrazione dei metalli pesanti
nel suolo era la seguente: As 309, Cd 4.90, Co 50.9, Cu 1527, Pb 233 e Zn 980 mg kg-1. I trattamenti imposti
prevedevano la fertilizzazione minerale e la concimazione organica, mentre le piante di controllo sono state allevate
sul terreno tal quale. Il potenziale di fitoestrazione di S. bicolor e H. annuus è stato osservato per tutta la durata
del ciclo mediante prelievi di biomassa e successive analisi ICP. Vengono riportate le concentrazioni di metalli
pesanti rilevate nelle frazioni vegetali e due fattori di bioconcentrazione. Il miglioramento delle condizioni nutrizionali
delle piante si è dimostrato efficace consentendo un incremento della produzione di biomassa, ma non ha
avuto effetti sulla concentrazione dei metalli pesanti assimilati dalle piante. Le asportazioni di metalli pesanti dal
suolo inquinato sono state confrontate con dati di letteratura. S. bicolor si è dimostrato più efficace di H. annuus;
la raccolta della biomassa epigea del sorgo ha consentito l’asportazione di 220 g ha-1 di As, 5.6 g ha-1 di Cd, 30.2 g
ha-1 di Co, 820 g ha-1 di Cu, 107 g ha-1 di Pb e 1944 g ha-1 di Zn
Removal of trace metals by Sorghum bicolor and Helianthus annuus in a site polluted by industrial wastes: A field experience
No full textUsing the perspective of full scale application of phytoremediation techniques, research is focusing on the optimization of agronomic practices. Two annual high biomass yield crops, Sorghum bicolor and Helianthus annuus, were grown in a polymetallic soil. The experimental site, polluted by pyrite cinders, is located in an industrial site that has been listed in the clean-up national priority list since 2001. Specific aims of this work were to observe the concentration of metals in plants during the crop cycle and to establish the amount of metal removed by the crops. The field trial, arranged in a randomized block design, started in 2005. The concentrations of heavy metals in the soil were: As 309, Cd 4.29, Co 50.9, Cu 1527 and Zn 980 mg kg1. The crops grown on the polluted soil received mineral fertilization (Fert) and organic amendment (Org), while plants in control soil (Ctrl) did not receive anything. The plots were watered during the crop cycle during two drought periods, using a sprinkler rrigation system. The phytoextraction potential of crops was estimated during the whole growth cycle and the plant biomass that was collected in each sampling date was ICP-analyzed. Plantebiomass growth curves were obtained. The concentrations of the metals in the shoots and in the total plant biomass were recorded. Finally, the metal removal was calculated for the harvestable parts of the crops. The amelioration of the nutritive status of the substrate that resulted, was highly effective for the biomass yield. However, fertilization and soil amendment did not heighten the concentration of metals in the harvestable tissue of the plants during the crop cycle. In some cases, organic matter appeared to bind the elements making them less available for the plants. The evaluation of the potential of phytoremediation of our plants compared to other crops in terms of metal removal was positive. Our results of metal removal are consistent with the results from other in situ experiments. The Zn removal by S. bicolor and H. annuus reached about 2000 g ha1 and 1000 g ha1, respectively
The application of phytoremediation technology in a soil contaminated by pyrite cinders
No full textA research project dealing with the phytoremediation of a soil polluted by pyrite cinders is
currently running. The case study is represented by a polluted area located in an industrial
site; since 2001, the site has been listed in the clean-up national priority list. Before the
beginning of the in situ trials, two experiments in controlled conditions were carried out.
The first pot experiments were performed growing Glycine max, Sorghum bicolor, Zea mays
and Helianthus annuus on substrates polluted by different levels of pyrite cinders, containing
As, Cd, Cu, Pb and Zn. In a second experiment, the possible influence of fertilization on the
uptake of As and heavy metals by S. bicolor and H. annuus was observed.
The potential of phytoextraction of crops was evaluated considering the plant biomass,
the concentration of As and heavy metals in the plant tissues and also the bioconcentration
factor (BCF) and the translocation factor (TF).
In the most polluted substrate, S. bicolor appeared more efficient than H. annuus in the
uptake of metals; the transport of the metals from roots towards stems and leaves was less
efficient in S. bicolor
RIMOZIONE DI METALLI PESANTI DA UN SUOLO MULTICONTAMINATO MEDIANTE FITOESTRAZIONE IN SITU DI TORVISCOSA
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Simplex Optimization Procedure for Evaluating Equivalence Points in Sigmoidal and Segmented Titration Curves.
No full textFitoestrazione di metalli pesanti nel sito di interesse nazionale “Laguna di Grado e Marano”
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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