Fourteenth National Congress of the Environmental and Cultural Heritage Chemistry Division, "Chemistry in a Sustainable Society," held in Rimini (Italy) in June 2013.

This report briefly presents the aims and the fields of interest of the Environmental and Cultural Heritage Division (Italian Chemical Society) and the issues addressed during its national congress, held in Rimini in June 2013. The broad range of topics raised by different speakers, the variety of affiliations and institutions participating at the conference, the scientific organisations and private companies co-sponsoring the different sessions give a clear picture of the interdisciplinarity which is a hallmark of this division.

Environmental impact assessment of a WtE plant after structural upgrade measures.

The study focuses on analysing the evolution of environmental impacts caused by a medium-large Italian WtE plant before and after revamping and maintenance operations, with the aim of providing an evaluation of how much these structural upgrade measures may affect the total environmental performance. LCA methodology was applied for the modelling and comparison of six WtE scenarios, each describing the main structural upgrades carried out in the plant over the years 1996-2011. The comparison was conducted by adopting 1ton of MSW as the functional unit, and the net contribution from energy recovery to power generation was distinguished by defining consistent national grid electricity mixes for every year considered. The Ecoindicator99 2.09 impact assessment method was used to evaluate the contribution to midpoint and endpoint categories (e.g. carcinogens, respiratory inorganics and organics, climate change, damage to human health). Lastly, the "Pedigree quality matrix" was applied to verify the reliability and robustness of the model created. As expected, the results showed better environmental scores after both the implementation of new procedures and the integration of operations. However, while a net reduction of air emissions seems to be achievable through dedicated flue gas treatment technologies, outcomes underscored potentials for improving the management of bottom ash through the adoption of alternative options aimed to use that solid residue mainly as filler, and to decrease risks from its current disposal in landfill. If the same effort that is put into flue gas treatment were devoted to energy recovery, the targets for the WtE plant could be easily met, achieving a higher sustainability. This aspect is even more complex: national policies for implementing greener and renewable energy sources would result in a lower impact of the national energy mix and, hence, in a lower net avoided burden from energy recovery. The study confirmed the expected improvements, indicating quantitatively the lower environmental impact resulting from structural upgrade operations in a WtE plant. Furthermore, the work highlights the importance of considering the evolution of the national energy mix in LCA studies, especially during the present years of transition from fossil fuels to renewable sources.

Auto shredder residue recycling: Mechanical separation and pyrolysis.

Directive 2000/53/EC sets a goal of 85% material recycling from end-of-life vehicles (ELVs) by the end of 2015. The current ELV recycling rate is around 80%, while the remaining waste is called automotive shredder residue (ASR), or car fluff. In Europe, this is mainly landfilled because it is extremely heterogeneous and often polluted with car fluids. Despite technical difficulties, in the coming years it will be necessary to recover materials from car fluff in order to meet the ELV Directive requirement. This study deals with ASR pretreatment and pyrolysis, and aims to determine whether the ELV material recycling target may be achieved by car fluff mechanical separation followed by pyrolysis with a bench scale reactor. Results show that flotation followed by pyrolysis of the light, organic fraction may be a suitable ASR recycling technique if the oil can be further refined and used as a chemical. Moreover, metals are liberated during thermal cracking and can be easily separated from the pyrolysis char, amounting to roughly 5% in mass. Lastly, pyrolysis can be a good starting point from a "waste-to-chemicals" perspective, but further research should be done with a focus on oil and gas refining, in order both to make products suitable for the chemical industry and to render the whole recycling process economically feasible.

PCDD/Fs atmospheric deposition fluxes and soil contamination close to a municipal solid waste incinerator.

Bulk depositions and surface soil were collected in a suburban area, near the Adriatic Sea, in order to assess the contribution of a municipal solid waste incinerator to the area's total contamination with polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs and PCDFs). Samples were collected at two sites, situated in the area most affected by plant emissions (according to the results of the Calpuff air dispersion model), and at an external site, considered as a reference. Results show that the studied area is subject to low contamination, as far as these compounds are concerned. Deposition fluxes range from 14.3 pg m(-2)d(-1) to 89.9 pg m(-2)d(-1) (0.75 pg-TEQ m(-2)d(-1) to 3.73 pg-TEQ m(-2)d(-1)) and no significant flow differences are observed among the three monitored sites. Total soil concentration amounts to 93.8 ng kg(-1) d.w. and 1.35 ng-TEQ kg(-1)d.w, on average, and confirms a strong homogeneity in the studied area. Furthermore, from 2006 to 2009, no PCDD/Fs enrichment in the soil was noticed. Comparing the relative congener distributions in environmental samples with those found in stack emissions from the incineration plant, significant differences are observed in the PCDD:PCDF ratio and in the contribution of the most chlorinated congeners. From this study we can conclude that the incineration plant is not the main source of PCDD/Fs in the studied area, which is apparently characterized by a homogeneous and widespread contamination situation, typical of an urban area.

Indicators of waste management efficiency related to different territorial conditions.

The amount of waste produced and the control of separate collection are crucial issues for the planning of a territorial Integrated Waste Management System, enabling the allocation of each sorted waste fraction to the proper treatment and recycling processes. The present study focuses on assessing indicators of different waste management systems in areas characterized by different territorial conditions. The investigated case study concerns the municipalities of Emilia Romagna (northern Italy), which present a rather uniform socioeconomic situation, but a variety of geographic, urban and waste management characteristics. A survey of waste generation and collection rates was carried out, and correlated with the different territorial conditions, classifying the municipalities according to altitude and population density. The best environmental performances, in terms of high separate collection rate, were found on average in rural areas in the plain, while the lowest waste generation was associated with rural hill towns.

End-of-Life Vehicles management: Italian material and energy recovery efficiency.

Each European Member State must comply with Directive 2000/53/EC recycling and recovery targets by 2015, set to 85% and 95%, respectively. This paper reports a shredder campaign trial developed and performed in Italy at the beginning of 2008. It turns out to be the first assessment about the critical aspects belonging to the Italian End-of-Life Vehicles (ELVs) reverse supply chain involving 18 dismantling plants, a shredder plant and 630 ELV representatives of different categories of vehicles treated in Italy during 2006. This trial aims at improving the experimental knowledge related to ELVs added waste, pre-treatment, part reuse, recycling and final metal separation and car fluff disposal. Finally, the study also focuses on the calculation of the effective Italian ELV recycling rate, which results equal to 80.8%, and auto shredder residue (ASR) characterization. According to the results obtained in this work, ASR still contains up to 8% of metals and 40% of polymers that could be recovered. Moreover, physical-chemical analysis showed a Lower Heat Value of almost 20,000 kJ/kg and revealed the presence of pollutants such as heavy metals, mineral oils, PCBs and hydrocarbons.

Risk assessment applied to air emissions from a medium-sized Italian MSW incinerator.

Risk assessment is a well established procedure for the analysis of the adverse impacts of pollutant substances emitted by waste treatment plants. The aim of the present study was the determination of the impact on human health associated with the activities of an incinerator in the Emilia-Romagna region (Northern Italy). The dispersion of heavy metals and organic pollutants monitored at plant stacks was predicted by the Gaussian model ISC3 (US-EPA). This analysis led to the estimation of risk, connected with various pollutants showing toxic and carcinogenic activities, for different receptors. The values obtained were first compared with the acceptability limits set by US-EPA, and then graphically represented as a territorial dispersion. A cautious approach was followed to calculate risk, by considering the worst, albeit realistic and reliable, estimate for the different parameters. The calculated exposure pathways resulted in different contributions depending on the receptor category (children and adults), even if direct exposure (via inhalation) is generally predominant. However, the resulting risk for both single pollutants studied and their combination all together proved to be within the acceptable limits (all lifetime individual risks being below 10(-6)), according to the procedure followed. The obtained results highlight the importance of using reliable monitoring data on the studied contamination source and, in particular, suggest the advisability of a more in-depth study on the pollution from incineration stacks.

Automotive shredder residue (ASR) characterization for a valuable management.

Car fluff is the waste produced after end-of-life-vehicles (ELVs) shredding and metal recovery. It is made of plastics, rubber, glass, textiles and residual metals and it accounts for almost one-third of a vehicle mass. Due to the approaching of Directive 2000/53/EC recycling targets, 85% recycling rate and 95% recovery rate in 2015, the implementation of automotive shredder residue (ASR) sorting and recycling technologies appears strategic. The present work deals with the characterization of the shredder residue coming from an industrial plant, representative of the Italian situation, as for annual fluxes and technologies involved. The aim of this study is to characterize ASR in order to study and develop a cost effective and environmentally sustainable recycling system. Results show that almost half of the residue is made of fines and the remaining part is mainly composed of polymers. Fine fraction is the most contaminated by mineral oils and heavy metals. This fraction produces also up to 40% ashes and its LHV is lower than the plastic-rich one. Foam rubber represents around half of the polymers share in car fluff. Moreover, some chemical-physical parameters exceed the limits of some parameters fixed by law to be considered refuse derived fuel (RDF). As a consequence, ASR needs to be pre-treated in order to follow the energy recovery route.

Chemical characterisation of spent rechargeable batteries.

A chemical characterisation of used batteries can give useful information to implement suitable recycling techniques and to estimate the flux of the different materials recovered. This work is aimed to provide quantitative data about the composition of mixed batteries (in particular, Ni-Cd, Ni-MH and Li-ion batteries) collected in a Northern Italian town in order to evaluate the feasibility of recovery processes applied to the selected material. The higher concentration of metals in the <3mm fraction suggested that significant quantities of valuable elements could be recovered: in particular, for a kg of the <3mm fraction deriving from disassembled batteries, about 390 g Ni and 330 g Cd can be recovered from Ni-Cd, 630 g Ni, 80 g Co from Ni-MH and 250 g Co, 110 g Ni, 120 g Cu from Li-ion ones. Leaching tests applied to the same fractions, to assess possible contaminant releases, resulted in low metal content in aqueous solutions (except for Al and Fe, the concentrations of all metals remained below 1mg/kg). Even so, great care is required in all handling activities due to the high pH values of leachate solutions.

Environmental impacts of waste incineration in a regional system (Emilia Romagna, Italy) evaluated from a life cycle perspective.

The advisability of using incineration, among the other technologies in Municipal Solid Waste Management, is still a debated issue. However, technological evolution in the field of waste incineration plants has strongly decreased their environmental impacts in the last years. A description of a regional situation in Northern Italy (Emilia Romagna Region) is here presented, to assess the impacts of incinerators by the application of Life Cycle Assessment (LCA) methodology and to stress the most impacting steps in incineration process. The management of solid residues and heavy metal emission resulted the most important environmental concerns. Furthermore, a tentative comparison with the environmental impact of landfill disposal, for the same amount of waste, pointed out that incineration process must be considered environmentally preferable.

Investigating morphological changes in treated vs. untreated stone building materials by x-ray micro-CT.

Calcareous stones have been largely used to build historical buildings. Among these, the calcarenites are usually characterized by a high content of calcite and a high open porosity, which make them very sensitive to the weathering caused by physical and chemical agents. In order to prevent their deterioration and to retard their decay, different protective products-mainly polymers-are applied on the stone artefact surfaces. In this work we apply the methodology tested in a preliminary study to investigate the morphological changes of the internal structure of a biocalcarenite (Lecce stone) by micro x-ray computed tomography (micro-CT). The porosity and other morphological parameters of the rock before and after the conservation treatment were calculated on a significant number of samples. The Student's t test was applied for statistical comparison. The results reveal that the treatment with Paraloid B72 (PB 72) is homogenously distributed and causes small changes to the natural properties of the rock, whereas the application of a fluoroelastomer (NH) causes an appreciable decrease in porosity and variation in terms of wall thickness distribution, probably resulting from its inhomogeneous distribution.

Assessment and comparison of the environmental performances of a regional incinerator network.

In Emilia-Romagna region (Northern Italy) the integrated waste treatment system consists of material collection and recycling, incineration with energy recovery and landfill as final disposal. In particular, at least one incineration plant is working in almost every province of the region. In this work, a screening life cycle assessment approach is applied to seven different incinerators, to compare the different plant technologies and identify the most relevant environmental impacts and processes. The characterization method used in the life cycle impact assessment step is Eco-indicator 99. The functional unit is 1 ton of waste input. As a first result, it can be noted that while the combustion systems are rather similar, the main variables are ascribable to gas cleaning options and efficiency in energy recovery, which result in quite different environmental performances. Among heavy metals, particular attention must be paid to Cd and As, due to their high toxicity, despite their low quantities. The impact due to dioxin emission is orders of magnitude lower than other contaminants (e.g., heavy metals). Furthermore, a catalytic system could be useful for a complete removal of organic contaminants and for a more effective abatement of nitrogen oxides. Finally, the environmental impact assessment sorts the various plants according to their age, i.e., the most recent plants provide the best environmental performances for the same quantity of combusted waste.

Critical loads for Cd and Pb in the province of Bologna.

Atmospheric deposition represents a significant source of heavy metals entering soil and aquatic ecosystems. The evaluation of their vulnerability can be carried out by the Critical Load criterion. In this work we focus the attention on the terrestrial ecosystems in the Province of Bologna, estimating the maximum tolerable load of cadmium and lead they are able to bear without sustain the occurrence of harmful ecotoxicological effects. To this aim the Steady-State Mass Balance method is applied on a small scale (10 x 10 Km EMEP grids) and the more suitable approach to define critical limits for the Province condition, effect-base or stand-still, is discussed. The opportunity of simplifying the input data collection is also considered, trying to deduce soil properties from geological information. Finally, the environmental risk due to the present deposition of Pb and Cd on provincial soils is described as exceedances over the critical loads.

Heavy metals monitoring at a Mediterranean natural ecosystem of Central Italy. Trends in different environmental matrixes.

The study deals with the evaluation of the impact of heavy metal pollution on a Mediterranean natural ecosystem, and presents the results derived from a monitoring of heavy metals in different environmental matrixes (atmospheric dry depositions, suspended particulate matter (SPM) and stemflow of forest trees). Two sites in Castelporziano Presidential Estate (Rome), one internal and one near the sea-side, were chosen in order to assess the differences in pollutant load. Results showed that heavy metal contamination can arise from local anthropogenic activities, in particular road traffic, and long-range pollution, from industrial and artisan activities near Rome.

Soluble and insoluble fractions of heavy metals in wet and dry atmospheric depositions in Bologna, Italy.

Atmospheric depositions were collected monthly using a modified wet and dry sampler (dry deposition was collected on a water surface) located in Bologna, a northern Italian urban area, to evaluate the impact of airborne heavy metals on the local pollution load. Wet deposition samples were filtered and heavy metal contents in soluble and insoluble fractions were determined. The same procedure was applied to the water samples which collected dry deposition. The entire procedure was tested using a certified reference material (CRM), which provided satisfying recovery results. The percentage of heavy metal soluble fraction in dry deposition was generally lower than in wet one; Cd, V, Cu and Zn showed a higher average solubility than Cr, Ni and Pb both in wet and dry deposition. Factor analysis, after a varimax rotation of principal components, suggested possible anthropogenic sources which explain different metal deposition patterns. This data analysis also allowed to distinguish different clusters formed by monthly fluxes of heavy metals.

The atmospheric monitoring in a protected area.

A multi-annual research program was carried out to study the environmental quality of Castelporziano Presidential Estate (Rome, Italy). Within this program, in the field of air quality, a methodological approach was defined and applied, even by means of proper Environmental Indicators for the identification of anthropogenic contribution and the quantification of degradation. By means of mobile laboratories, macro and micro-pollutant concentrations were assessed in order to define Indexes of Atmosphere Quality and Diffuse Contamination, by relating them to possible short or long-range emission sources. Wet and dry atmospheric depositions were collected and analysed for the determination of heavy metal and acid species fluxes. Critical Load and relative Exceedance maps were elaborated, for the purpose of better underline the areas characterized by a higher environmental vulnerability.

The environmental fate of heavy metals arising from a MSW incineration plant.

Pollutant fluxes from municipal solid waste (MSW) incinerators are of a certain concern, especially gaseous emissions from the stack, which constitute the major effluent from the plant. In this work, heavy metals in soil and vegetation sampled in different sites around the plant are compared with those found in the gaseous emissions from an incinerator: the suspected source and environmental matrices are observed together, in order to detect a possible relationship of cause and effect, using statistical methods. The incinerator examined, regarding dimension and technology, can be considered a typical Italian one. Heavy metal concentrations in soil and vegetation show a clear dependence on sampling year; similar behaviour can be found in emission fluxes referring to the same years. A dependence on the distance from the incinerator is also apparent. This study supplies a methodological approach that can be easily extended and applied to other suspected contamination sources.