A geo-chemo-mechanical study of a highly polluted marine system (Taranto, Italy) for the enhancement of the conceptual site model

Abstract

The paper presents the results of the analysis of the geo-chemo-mechanical data gathered through an innovative multidisciplinary investigation campaign in the Mar Piccolo basin, a heavily polluted marine bay aside the town of Taranto (Southern Italy). The basin is part of an area declared at high environmental risk by the Italian government. The cutting-edge approach to the environmental characterization of the site was promoted by the Special Commissioner for urgent measures of reclamation, environmental improvements and redevelopment of Taranto and involved experts from several research fields, who cooperated to gather a new insight into the origin, distribution, mobility and fate of the contaminants within the basin. The investigation campaign was designed to implement advanced research methodologies and testing strategies. Differently from traditional investigation campaigns, aimed solely at the assessment of the contamination state within sediments lying in the top layers, the new campaign provided an interpretation of the geo-chemo-mechanical properties and state of the sediments forming the deposit at the seafloor. The integrated, multidisciplinary and holistic approach, that considered geotechnical engineering, electrical and electronical engineering, geological, sedimentological, mineralogical, hydraulic engineering, hydrological, chemical, geochemical, biological fields, supported a comprehensive understanding of the influence of the contamination on the hydro-mechanical properties of the sediments, which need to be accounted for in the selection and design of the risk mitigation measures. The findings of the research represent the input ingredients of the conceptual model of the site, premise to model the evolutionary contamination scenarios within the basin, of guidance for the environmental risk management. The study testifies the importance of the cooperative approach among researchers of different fields to fulfil the interpretation of complex polluted eco-systems.

Multivariate tools to investigate the spatial contaminant distribution in a highly anthropized area (Gulf of Naples, Italy)

“…The data show a positive correlation of the TOC concentration versus the finest grain size fractions (clay and/or silt). The close association of the two components can be explained by (1) the capacity of the finest particles to hinder the diffusion of the oxygen into the sediments, which induces the preservation of organic matter, and (2) the adsorption of organic particles onto the charged surfaces of the clay minerals (Mayer 1994 ; Hedges and Klein 1995 ; Cotecchia et al 2021 ). In turn, the adsorption process helps to preserve the organic matter and gives rise to a generally positive correlation between TN or TOC and % finest sediment (Hedges and Klein, 1995 ).…”

“…Sediments are often used as the best indicator for assessing the quality of marine environment as they are integrated components of the aquatic ecosystems and recognized as sinks of all contaminants accumulated in the bottom seafloor generated by the different sources: atmospheric pollution or direct discharges of contaminants in the sea-water column. Additionally, sediments also act as a source of contaminants by natural and anthropogenic processes (Chapman 1986 , 2007 ; DelValls et al 1998 ; Wenning et al 2005 ; Chapman 2007 ; Piva et al 2011 ; Rubio et al 2011 ; Chapman and Smith 2012 ; Regoli et al 2013 ; Chapman et al 2013 ; Mali et al 2016 , 2017a , b , c , 2018 ; 2019 ; Cotecchia et al 2021 ).…”

“…Different indices have been developed for contamination assessment tools for the monitoring of sediments in aquatic ecosystems (MacDonald et al 1996 ; Long et al 1995a , b , 2006 ; Casado-Martìnez et al 2009 ; Varol 2011 ; Chapman and Smith 2012 ; Chapman et al 2013 ; Mali et al 2016 ; 2017a , b ). Nevertheless, when the investigation campaign addresses multi-source contamination such as the case of highly anthropized areas, the interpretation of the generated large dataset becomes awkward (Cotecchia et al 2021 ). Definition of the hot spot areas and the recognition of factors controlling the spatial distribution of contaminants require data analysis approaches able to summarize the information content of the huge dataset and to individuate “summary indices” that can be easily visualized and understand.…”

Improved identification of pollution source attribution by using PAH ratios combined with multivariate statistics

“…The numerous port and harbors operating alongside the shoreline have progressively modified the coast morphology, consequently influencing the quality of the port basins. The ports are subjected to different activities (industrial, commercial, and touristic) that, along with activities occurring in the surrounding areas, have seriously affected the quality of port sediments 11,12,[27][28][29][30][31] . It is worth noting that the sediment contaminant spectrum of a port reveals the impact of the port activity [32][33][34][35][36][37][38] .…”

Evaluating the Parameters of a Systematic Long-Term Measurement of the Concentration and Mobility of Air Ions in the Environment inside Císařská Cave

“…The bar graph shows that very fine aerosol particles-or, more concretely, ones sized 0.3 μm and less-require over a day to settle. Regarding the correlation between the size and the time, we can claim that the larger the aerodynamic radius of an aerosol particle, the shorter the settling period [81,82]. A more detailed, two-hour measurement procedure immediately following the physical exercises revealed intensive settling of particles with the radii of 5 μm and 10 μm (Figure 19, left-hand image); particles having the radii of 1 μm and 2.5 μm constantly floated through the air (Figure 19, right-hand image).…”