84 research outputs found
Assessing the correlation between contamination sources and environmental quality of marine sediments using multivariate analysis
No full textWater sea pollution is influenced mainly by anthropogenic causes due to industrial and municipal activities which affect the quality of sea water, sediments and the whole ecosystem. In this paper, the correlation between contamination sources and the environmental quality of marine sediments was analyzed through multivariate analysis, in particular Principal Components Analysis (PCA), Cluster Analysis (CA) and Correlation Analysis. Considering the case study of Mar Piccolo in Taranto (Ionian Sea, Southern Italy), it was performed first a PCA on the total matrix consisting of 1023 samples 3m deep and 20 variables (moisture content, granulometry, metals, metalloids and nutrients). Then, a PCA only for the superficial layers (0-50cm) was performed to better understand correlations with anthropogenic and natural impacts. Cluster and correlation analyses corroborated PCA results, identifying sub-clusters among the variables. The assessment showed how the type of pollution in Mar Piccolo of Taranto is widespread on superficial layers with some particular areas (hotspots) with a heavy and deeper contamination. Correlation between nutrients and metals, validated by CA analysis, showed that the excessive presence of nutrients and organic matter, in the Mar Piccolo water, acts as carrier for many contaminants that concentrate in the fine fraction of sediments with high percentage of organic matter
Recent Advances in Hydrophobic and Icephobic Surface Treatments of Concrete
No full textIn this review, we present a survey on hydrophobic surface treatments of concrete, important protection tools against deterioration and corrosion phenomena. In the frame of a standardized distinction in coatings, pore blockage, and impregnation methods, we highlight the huge variety of compounds and formulations utilized, and the different performances reached in terms of water contact angle, water absorption, chloride penetration, and, rarely reported, anti-icing/icephobic action. Our view covers the spectrum of the surface treatments, but also makes a comparison with hydrophobic bulk modifications of concrete, procedures often utilized as well; further, novel proposals of more sustainable routes are presented. We note that coating and impregnation, preferably when based on polyurethane and silane/siloxane, respectively, appear more effective against water ingress. The achieved wetting character is hydrophobic or, at most, overhydrophobic. Superhydrophobic coatings for concrete have been obtained by embedding nano-powders in hydrophobic emulsions, allowing to add a nanotexture to the preexisting complex roughness of the material. Concrete treated with this type of coating has also recently shown a pronounced icephobic character, a parameter that goes beyond the freeze–thaw characterization usually conducted on cement-based materials
An innovative holistic dpsir-based approach for the remediation of contaminated sites
No full textThe DPSIR model is anuseful guidance to decision-makersand itcon siders a chain of causal links starting from "Driving forces"(economic, environmental, human activities) through "Pressures"(emissions, waste, discharges etc.) to "States"(physical, chemical and biological situation of environment) and "Impacts"on targets such as human beings, eventually leading to political or technical "Responses".Despite its advantages, DPSIR does not explicitly state any direct cause-and-effect relationship and it is difficult to link the quality/quantity of certain pressures to the status indicators, as well as to establish a direct correspondence between a response and mitigation of impacts.In this context, thisstudy aimed to develop and apply an innovative holistic approach based on an implemented version of DPSIR to the case study of Mar Piccolo in Taranto (Southern Italy), one ofthe most contaminated areas in Europe. For this purpose,three toolboxes were developed
Evaluation of remediation technologies for contaminated marine sediments through multi criteria decision analysis
No full textRemediation of contaminated marine sediments present a difficult challenge for environmental decision-makers. In socially relevant situations, as in the Mar Piccolo of Taranto case study (Southern Italy), the decision-maker needs to explain to the citizens why some remediation technologies are adopted compared to others. Multi criteria decision analysis (MCDA) is a scientifically sound decision tool for management of contaminated sites, not only to denote effective or technologically and economically feasible remediation alternatives, but also to point out the most sustainable remediation alternatives. The aim of this study was to develop and apply a MCDA approach allowing the identification of the best remediation technologies for the decontamination of contaminated marine sediments of the Mar Piccolo of Taranto, one of most polluted areas in Europe. The main methodological steps were: (i) preliminary screening of technologies potentially applicable, (ii) detailed analysis of the technologies according to several evaluation criteria, and (iii) identification of the optimum technologies by means of the construction of a composite indicator. The 13 criteria, identified based on a literature study, have been used for the assessment of the technologies; these were classified in applicability aspects ones (e.g., type of sediments and contaminants) and technological ones (e.g., residuals produced and development status). The results of the MCDA showed how the most performing technologies were (i) in situ remediation with amendments, (ii) vitrification and (iii) stabilization/solidification. These solutions were then validated based on the full-scale remediation technologies generally applied. The adopted approach has proved to be an excellent tool to support the decision-maker. Transparency is its strength and suggests its application in contexts similar to that of the case study
Combined assessment of chemical and ecotoxicological data for the management of contaminated marine sediments
No full textSediments in coastal areas can accumulate a variety of contaminants, acting as both carriers and long-term secondary sources of contamination for aquatic ecosystems. Nowadays, there is a growing interest on developing new assessment criteria of sediment ecological quality for setting priorities and management strategies of contaminated materials. According to the literature, the weight of evidence (WOE) approach has been developed to provide a multidisciplinary characterization which combines different studies such as chemical analyses, laboratory and field-based studies to assess the bioavailability of pollutants and ecotoxicological assays. However, applications on complex case studies are limited. In order to strengthen the current literature, this study presents the first results of the application of a WOE model (Sediqualsoft) to a marine chronically polluted area. To this aim, a laboratory experimental investigation was carried out on the polluted sediments of the Mar Piccolo in Taranto (Southern Italy). The combination of chemical and ecotoxicological data confirmed the results obtained with the conventional approaches, highlighting sediment contamination. Even more, the obtained biological responses highlighted an unexpected toxic effect not revealed by conventional approaches: the level of contamination did not seem to be proportional to the ecotoxicological assessment. All these observations have raised numerous questions about the potential mobility of pollutants and additional risks to the environment. The Sediqualsoft model has proven to be a useful tool for processing complex scientific data, playing an important role in contaminated sediment risk assessment supporting stakeholders and decision makers
Biochar for sustainable immobilization of potentially toxic elements in contaminated farmland
No full textBiochar has variegated uses for sustainable immobilization of potentially toxic elements (PTEs) in contaminated farmland, which is described in this chapter. The effects of biochar on the mobility and phytoavailability of cationic PTEs (e.g., Al, Mn, Cd, Pb, Hg, Zn, Cu, Ni) and anionic PTEs (e.g., Cr, As, Se, Sb) in farmland soils and the main mechanisms relevant for this purpose are summarized. Moreover, the limitations and challenges of employing biochar for the remediation of PTEs-contaminated farmland soils are discussed. The directions for further study in this emerging frontier of biochar-related research are also proposed to facilitate the large-scale application of biochar. This review can offer important references to the development of biochar technologies for the remediation of and their safe application to PTEs-contaminated farmlands
Evaluation of remediation technologies for contaminated marine sediments through multi criteria decision analysis
No full textRemediation of contaminated marine sediments present a difficult challenge for environmental decision-makers. In socially relevant situations, as in the Mar Piccolo of Taranto case study (Southern Italy), the decision-maker needs to explain to the citizens why some remediation technologies are adopted compared to others. Multi criteria decision analysis (MCDA) is a scientifically sound decision tool for management of contaminated sites, not only to denote effective or technologically and economically feasible remediation alternatives, but also to point out the most sustainable remediation alternatives. The aim of this study was to develop and apply a MCDA approach allowing the identification of the best remediation technologies for the decontamination of contaminated marine sediments of the Mar Piccolo of Taranto, one of most polluted areas in Europe. The main methodological steps were: (i) preliminary screening of technologies potentially applicable, (ii) detailed analysis of the technologies according to several evaluation criteria, and (iii) identification of the optimum technologies by means of the construction of a composite indicator. The 13 criteria, identified based on a literature study, have been used for the assessment of the technologies; these were classified in applicability aspects ones (e.g., type of sediments and contaminants) and technological ones (e.g., residuals produced and development status). The results of the MCDA showed how the most performing technologies were (i) in situ remediation with amendments, (ii) vitrification and (iii) stabilization/solidification. These solutions were then validated based on the full-scale remediation technologies generally applied. The adopted approach has proved to be an excellent tool to support the decision-maker. Transparency is its strength and suggests its application in contexts similar to that of the case study
DPSIR Model Applied to the Remediation of Contaminated Sites. A Case Study: Mar Piccolo of Taranto
No full textThe study critically analyses the complex situation of the Mar Piccolo of Taranto (South of Italy), considered one of the most polluted marine ecosystems in Europe. In order to investigate possible cause–effect relationships, useful to plan appropriate planning responses or remediation technologies to be adopted, the Driver–Pressure–State–Impact–Response (DPSIR) model was applied. Methodologically, about 100 references have been considered, whose information was organized according to the logical scheme of the DPSIR. The results showed how the Mar Piccolo is the final receptor of pollutants coming from all industrial and agricultural activities, especially due to its natural hydrogeological network conformation. The anthropic activity represents a critical impact on the ecosystem due to the subsequent marine litter. The mobility of contaminants from sediments to the water column showed the potential risk related to the bioaccumulation of organisms from different trophic levels, posing a threat of unacceptable magnitude to human safety. The paper concludes by discussing the actions currently implemented by the authorities in response to the anthropogenic impacts as well as the need for new ones concerning both plans, programs, and remediation interventions. The case study shows how the DPSIR is a useful framework to organize extensive and heterogeneous information about a complex environmental system, such as the one investigated. This preliminary organization of the available data can represent the starting point for the development of a DPSIR-based Environmental Decision Support System (EDSS) with robust cause–effect relationships
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