142 research outputs found

    Relationship between element concentrations and body size in the Lake Maggiore population of Unio pictorum mancus (Mollusca, Bivalvia)

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    The study focused on using a fresh-water mussel (Unio pictorum mancus) as a bioindicator of various pollutants, and particularly metals. The elements considered were: Al, As, Ca, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V and Zn. This research was carried out at a site where various other studies have been conducted on important characteristics of the same population of Unio. This site is a small bay called "Sabbie d\u27Oro" located on the south-east coast of Lake Maggiore. Our study involved quantifying the capacity of this mollusc to concentrate large amounts of metal in its body without evident consequences by using detoxification mechanisms. We analysed not only element concentrations, but also their variability (expressed as CV%) in the soft tissues and in the shell, for two main reasons: i) the sampling design should include a preliminary analysis to determine how many specimens is necessary collect to ensure a specified level of precision; ii) the sample variability value may be combined with the value of analytical precision (BCR) to obtain an estimate of the "experimental" precision. In soft tissue, Ca accumulation tended to increase with size, and Al accumulation decreased with size. In shell, Ca and Ni were stored more than in soft tissue, but not proportionally to size. V, Cr and Mo tended to accumulate in the shell progressively over the years, whereas Co and Al are "diluted" during growth, or are absorbed mainly during the juvenile stage. Partition between shell and soft tissue resulted roughly the same in the juvenile and adult stages for the following elements: Fe, Al, Co, As, Pb. The relationships among the various elements were schematized in a hierarchical tree plot

    Seasonal variations in metal content of two Unio pictorum mancus (Mollusca, Unionidae) populations from two lakes of different trophic state

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    To assess the impact of lake trophy on trace element accumulation by Unio pictorum mancus, a population from the mesooligotrophic Lake Maggiore was compared with a population from the eutrophic Lake Candia. The element content in soft tissue and shell biomass, the seasonal variations of element concentrations in soft tissues and shell, and the relationship between element concentrations in the water and those in the tissues were estimated in pursuit of this objective. Thirteen mussel samplings were performed in Lake Maggiore between May 2003 and September 2004 and in Lake Candia between June 2003 and August 2004. Filtered water samples were collected seasonally. Water, shell and soft tissue samples were analysed by ICP-OES and ICP-MS for the measurement of following elements: Zn, Cu, Fe, Mn, Ni, As, Pb, Co, Cr, Mo, V, Cd, Be and Ca. The element concentrations in the mussel tissues and shell from Lake Maggiore were higher than those from Lake Candia. Due to the higher population density and higher element concentrations in the mussels of Lake Maggiore, the element content in the biomass per m2 in this lake far exceeded that in Lake Candia

    Gamma-spectrometric measurement of radioactivity in agricultural soils of the Lombardia region, northern Italy

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    Abstract This work is part of a wider monitoring project of the agricultural soils in Lombardia, which aims to build a database of topsoil properties and the potentially toxic elements, organic pollutants and gamma emitting radionuclides that the topsoils contain. A total of 156 agricultural soils were sampled according to the LUCAS (Land Use/Cover Area frame statistical Survey) standard procedure. The aim was to provide a baseline to document the conditions present at the time of sampling. The results of the project concerning soil radioactivity are presented here. The aim was to assess the content of 238U, 232Th, 137Cs and 40K by measuring soil samples by gamma spectrometry. 238U, 232Th and 40K activities range 24–231, 20–70, and 242–1434 Bq kg−1 respectively. The geographic distribution of 238U reflects the geophysical framework of the Lombardia region: the soils with high content of uranium are distributed for the most part in the South Alpine belt, where the presence of magmatic rocks is widespread. These soils show an higher activity of 238U than of 232Th. The 238U activities become lower than 232Th when soils are located in the plain, originating from basic sedimentary rocks. 137Cs activity ranges 0.4–86.8 kBq m−2. The lowest activity of 137Cs is in the plain, whereas the highest is in the North on soils kept as lawn or pasture. The 137Cs activity of some samples suggests the presence of accumulation processes that lead to 137Cs enriched soils. This is the first survey of gamma emitting radionuclides in Lombardia that is based on the LUCAS standard sampling. The results from this monitoring campaign are important for the human radiation exposure and provide the zero point, which will be useful for assessing future effects due to external factors such as human activities

    Il Suolo della Provincia di Pavia (Parte due)

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    Il presente Rapporto completa lo studio effettuato sul territorio della Provincia di Pavia, giĂ  pubblicato come EUR Report nel 2006. Questo rapporto presenta in modo completo i dati di metalli pesanti e diossine ottenuti attraverso l'analisi di campioni di sedimento. I dati relativi ai suoli superficiali sono stati integrati con gli elementi Co, Mn e alcuni macroelementi. I dati ottenuti non evidenziano valori anomali per tutto il territorio indagato. Per quanto riguarda l'utilizzo dei bioindicatori e dei concetti di biodiversitĂ , batteri e muschi, i dati sono stati ampliati presentando la distribuzione spaziale della loro concentrazione nelle aree a valenza prevalentemente industriale. In conclusione l'apporto dato da questo rapporto completa in modo significativo il Precedente EUR report. I dati ottenuti sono sovrapponibili a quanto giĂ  descritto e confermano la buona qualitĂ  dei suoli pavesi.JRC.H.7-Land management and natural hazard

    A flowsheet-based model approach to reduce water consumption and improve water networks management in the steel sector

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    Resource consumption is an important topic for steelmaking industry, which is spending significant efforts to reduce its environmental impact and improve its competitiveness. Water is largely exploited in steelworks for indirect and direct cooling, specific surface treatment, and fumes washing and cooling. It is already reused and recycled after restoring its quality through treatments for temperature and/or pollutant reduction. However, sometimes water networks are not optimized due to outdated water treatments, lack of continuous monitoring, and water network management strategies often based on experience without automation. In recent years, new water treatments, simulation, and optimization tools are becoming available, together with a stronger awareness of the importance of online parameters monitoring. Therefore, improvement of water cleaning, reuse, recycling, and consequent reduction of impact related to water exploitation are potentially achievable. The introduction of innovative treatments must be tested before their implementation in steel plants and the exploration of their behavior in different operating conditions is fundamental. The presented work addresses this topic through the application of several models of operational units, developed in OpenModelica environment and aggregated into a plant simulator. The simulator was used in different case studies related to an Italian plant to assess the impact of new filtering technology for reducing suspended solids on the analyzed water networks and test the effects of different operating configurations on the treatment efficiency. The introduction of new filtration technology leads to environmental and economic advantages due to freshwater intake reduction and water management improvemen

    Effect of Milling and Parboiling Processes on Arsenic Species Distribution in Rice Grains

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    This study identified the role of milling and parboiling on arsenic (As) content and its species in large numbers of rice samples. Total As contents were 108 \ub1 33 \u3bcg/kg in polished rice grains (PR), 159 \ub1 46 \u3bcg/kg in unpolished rice grains (UR), 145 \ub1 42 \u3bcg/kg in parboiled polished rice grains (PPR) and 145 \ub1 44 \u3bcg/kg in parboiled unpolished rice grains (PUR). The percentages of inorganic As (iAs) were 66% \ub1 8% in PR and from 72% to 77% in other grain categories. The polishing process reduced the As content in the rice grains, removing outer part of the UR with high amount of As, whereas the parboiling technique transferred the semimetal content within the grain. Total As and iAs contents were not significantly different in UR, PPR and PUR, homogenizing its distribution inside the grains. The results allowed to understand how different operations affect As fate and its chemical forms in grains

    In vitro evaluation of the inhibitory activity of different selenium chemical forms on the growth of a fusarium proliferatum strain isolated from rice seedlings

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    In this study, the in vitro effects of different Se concentrations (5, 10, 15, 20, and 100 mg kg−1) from different Se forms (sodium selenite, sodium selenate, selenomethionine, and selenocystine) on the development of a Fusarium proliferatum strain isolated from rice were investigated. A concentration‐dependent effect was detected. Se reduced fungal growth starting from 10 mg kg−1 and increasing the concentration (15, 20, and 100 mg kg−1 ) enhanced the inhibitory effect. Se bioactivity was also chemical form dependent. Selenocystine was found to be the most effective at the lowest concentration (5 mg kg−1 ). Complete growth inhibition was observed at 20 mg kg−1 of Se from selenite, selenomethionine, and selenocystine. Se speciation analysis revealed that fungus was able to change the Se speciation when the lowest Se concentration was applied. Scanning Electron Microscopy showed an alteration of the fungal morphology induced by Se. Considering that the inorganic forms have a higher solubility in water and are cheaper than organic forms, 20 mg kg−1 of Se from selenite can be suggested as the best combination suitable to inhibit F. proliferatum strain. The addition of low concentrations of Se from selenite to conventional fungicides may be a promising alternative approach for the control of Fusarium species

    Monitoraggio Ambientale di un'Area Contaminata nella Provincia di Pavia

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    Lo scopo di tale indagine è stato quello di valutare il livello di contaminazione, l'estensione e l'entità di contaminanti presenti nei suoli superficiali a suo tempo riscontrati mediante il Progetto Pavia. Il monitoraggio ambientale ha interessato un'area di circa 12 ettari che si trova nel comune di Carpiano. Complessivamente sono state identificate 33 aree di campionamento dove sono stati prelevati campioni di suolo sino alla profondità di 30 cm. In ciascun campione di suolo, dopo adeguati trattamenti, è stata valutata la concentrazione di metalli pesanti, metalloidi, macroelementi, sostanza organica, pH, densità apparente, contenuto d'acqua. In alcuni campioni, precisamente 11, si è analizzata la concentrazione di diossine e furani e si è approntato uno studio che ha visto l'utilizzo dei batteri e dei loro prodotti. Lo studio condotto attraverso l'uso dei batteri ha evidenziato anomalie in alcuni punti ad elevata contaminazione. I risultati analitici ottenuti hanno identificato la presenza di una importante contaminazione di metalli pesanti, metalloidi, diossine e furani che interessa un area di alcuni ettari. Tale livello di contaminazione, per la presenza di sostanza organica e per valori ridotti di acidità dei suoli stessi, potrà arrecare danni ingenti all'ambiente.JRC.DDG.H.7-Land management and natural hazard
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