Visconti, Donato (2017) Using native species and perennial grasses for characterization, remediation/securing and monitoring of contaminated sites. [Tesi di dottorato]


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Item Type: Tesi di dottorato
Lingua: English
Title: Using native species and perennial grasses for characterization, remediation/securing and monitoring of contaminated sites
Date: 3 December 2017
Number of Pages: 135
Institution: Università degli Studi di Napoli Federico II
Department: dep01
Dottorato: phd073
Ciclo di dottorato: 30
Coordinatore del Corso di dottorato:
Fagnano, MassimoUNSPECIFIED
Date: 3 December 2017
Number of Pages: 135
Uncontrolled Keywords: Phytoremediation; native species; compost
Settori scientifico-disciplinari del MIUR: Area 07 - Scienze agrarie e veterinarie > AGR/02 - Agronomia e coltivazioni erbacee
Date Deposited: 27 Dec 2017 09:40
Last Modified: 12 Apr 2019 08:47


The main objectives of the first part of the research were: 1. To evaluate the potential of native vegetation for analysis of environmental risks due to soil contamination in industrial and agricultural contexts. 2. To study the potential of native plant species in extracting and accumulating soil PTEs from two contaminated sites. 3. To identify the extraction method that better represents the PTEs availability for plants by studying the relations between PTEs in the plants and total and bioavaila-ble PTEs content of soils. 4. To evaluate if some plant can be used as a bioindicator of PTEs bioavailability by studying the relationships between PTEs upake of different plant species and dif-ferent analytical methods for assessing PTEs bioavailability.. 5. To identify the probable origin of contaminants by analizing the soils of each plot using Hierarchical Cluster Analysis and Principle Component Analysis. In the second part of the research, two pots experiments were carried out by using industrial site sediments with the aim to evaluate the efficacy of different agro-nomical techniques of assisted phytoremediation (i.e. compost fertilization, biopromoters). The main objective of these pot experiment were the evaluation of the effects of organic amendment and commercial biopromoters on resistance of grass species to PTEs contami-nation and on PTEs phytoextraction/phytostabilization in a context aimed to reduce the environmental and sanitary risks of industrial contaminated sites by avoiding dispersion of contaminated soil particles. From the results of the three experiments described in this thesis, it’s possible to achieve the following conclusions. From the first experiment regarding the analysis of natural plants and soils for the charac-terization of two potentially contaminated sites, we concluded that: 1. Phytoscreening of native plants of polluted sites can be carried out to identify plant species that can tolerate very high PTEs concentrations and can be used for phy-toremediation. 2. Bioaccumulation coefficient of shoots (BACs), Bioaccumulation coefficient of roots (BACR) and a modified bioaccumulation coefficient (mBAC) that considers only the bioavailable fractions of contaminants (DTPA), can be used for assessing the relationships between weeds and the contaminants into the soil. 3. Artemisia vulgaris and Dittrichia viscosa in industrial site were able to transfer the potential bioavailable fraction of Pb to the aerial part and thus they could be con-sidered interesting candidates for phytoextraction; Epilobium tetragonum, Artemi-sia annua and Silene latifolia reported a high mBACR so they could be suitable for Pb phytostabilization. In the agricultural site, Cyperus rotundus showed the ability to transfer the potential bioavailable fraction of Cd to the aerial part, so it could be interesting for phytoextraction purpose while Cirsium arvense, Cynodon dactylon, Rumex sp., Piptatherum thomasii and Echium vulgare reported the ability to trans-fer Cd to the roots with a high mBACR so they could be suitable for Cd phytostabi-lization; 4. PCA and HCA can be used to identify the different PTE pollution sources. Princi-pal component analysis and hierarchical cluster analysis suggest that Pb, Cd, As, Cu and Zn seems form different pollution sources while Sb and Tl seems mainly of ge-ogenical origins. In the agricultural site, Cr and Cd are considered of anthropogenic origins while Pb, As and Zn mostly from geogenical origins; 5. It is possible to identify the extraction method that better represents the metal bio-availability and to know the relation between specific plant species and soil contam-ination. In the industrial site, only the Pb and Sb shoot concentrations well predict-ed by DTPA extraction. The ammonium nitrate extraction well predicted the shoot content of Pb, Sb, and Tl. The total soil PTEs content (TPTEs) were satisfactorily related to Sb and Tl shoot concentrations and in minor part to Pb. In agricultural site, TPTEs well predicted only the Zn shoot concentration. 6. Elymus. repens in industrial site can be used as indicator of soil Zn contamination while Lolium perenne in the agricultural site, can be used as indicator of As and Cd contamination. The second experiment, made on a potentially contaminated soil (Pb, Zn) allowed to get the following conclusions: 1. Application of compost and Biopromoters increased the plant growth, nutrient and Zn uptake; 2. The plant species used in this experiment resulted suitable for a phytostabilization purpose reducing the leaching of PTEs in the soil profile. Furthermore the biomass taken from the harvest can be used in no food chains and the complete coverage of the soil prevents the dispersion of the contaminated soil particles, thus allowing to reduce the risk for human health. The third experiment, made on a highly contaminated soil (Pb, Cd), allowed to get the fol-lowing conclusions: 1. The application of first dose of compost and biopromoters increased the growth, N uptake and Cd uptake; 2. The application of TA (consortium called “Panoramix” – Koppert b.v. ® containing Endomycorrhiza and Trichoderma species along with humic and fulvic acids) re-duced the bioavailable Pb as compared to control and to TB and reduced the bioa-vailable Pb from the initial conditions and the bare soil. 3. The combination of compost and biopromoters reduced the Cd soluble fraction as compared highlighting the importance of a vegetal soil cover for avoiding PTEs leaching in the soil profile. 4. The combination grass species-organic amendments-biopromoters can be successful-ly used in a phytoremediation project increasing the biomass production and PTEs uptake. The grass species can ensure the soil capping necessary for securing contam-inated sites, but also for improving soil structural aggregation that also prevents the dispersion of the contaminated soil particles. 5. The differences in the results between Pb and Zn in the second experiment and Pb and Cd in the third experiment highlighted the need to make preliminary studies to found the most suitable technique in relation to the specific contamination of a site.

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