PubMed | ERSAF, Irccs Instituto Of Ricerche Farmacologiche Mario Negri, University of Rome La Sapienza, Municipality of Brescia Museum of Natural science and 2 more.
Type: | Journal: Environmental pollution (Barking, Essex : 1987) | Year: 2017
Cities and contaminated areas can be primary or secondary sources of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and other chemicals, into air and soil and can influence the regional level of some of these pollutants. In a contaminated site, the evaluation of such emissions can be crucial in the choice of the remediation technology to be adopted. In the city of Brescia (Northern Italy), more than 100ha of agricultural areas were contaminated with PCBs, PCDD/Fs and heavy metals, originating from the activities of a former PCB factory. In order to evaluate the current emissions of PCBs and PCDD/Fs from the contaminated site, in a location where other current sources are present, we compared measured and predicted air concentrations, resulting from chemical volatilization from soils as well as fingerprints of Brescia soils and of soils contaminated by specific sources. The results confirm that the contaminated area is still a current and important secondary source of PCBs to the air, and to a lesser extent of PCDFs (especially the more volatile), but not for PCDDs. PCBs in soils have fingerprints similar to highly chlorinated mixtures, indicating contamination by these mixtures and/or a long weathering process. PCB 209 is also present at important levels. PCDD fingerprints in soil cannot be related to current emission sources, while PCDFs are compatible to industrial and municipal waste incineration, although weathering and/or natural attenuation may have played a role in modifying such soil fingerprints. Finally, we combined chemical and microbiological analyses to provide an integrated approach to evaluate soil fingerprints and their variation in a wider perspective, which accounts for the mutual effects between contamination and soil microbiota, a pivotal hint for addressing in situ bioremediation activities.
Brambilla M.,University of Milan |
Brambilla M.,Italian Agricultural Research Council |
Araldi F.,ERSAF |
Marchesi M.,ERSAF |
And 3 more authors.
Biomass and Bioenergy | Year: 2012
Improving the knowledge of anaerobic digestion process parameters can lead to a reduction of anaerobic digestion units' start-up phase with subsequent increase of their competitiveness. For this reason the start up phase of a pilot scale biogas plant fed with cattle manure underwent a six weeks fully monitoring during which we recorded daily and specific biogas and methane productions as well as process parameters like temperature of the biomass inside the fermenter, feeding amount, digestate pH and FOS/TAC value (the ratio between organic acids content, expressed as g m -3 of equivalent acetic acid, and total inorganic carbon content of the fermenting biomass, expressed as g m -3 of CaCO 3). All data underwent multivariate statistical data processing based on principal component analysis (PCA) and linear discriminant analysis (LDA). At varying of the time required by the settling of biogas production (six weeks) different moments were differentiated and classified: according to multivariate analysis, among all the monitored process parameters, the FOS/TAC value was the one which better gave account of anaerobic digestion establishment and stabilization. © 2011 Elsevier Ltd.