Resources and waste management in Turin (Italy): the role of recycled aggregates in the sustainable supply mix

The ever increasing quantity of construction and demolition waste (C&DW) in Italy is presently challenging public administrators, which strive to ensure that collection and recycling are sustainably managed and need to understand whether and to what extent recycled aggregates can complement natural aggregates in a sustainable supply mix (SSM) for the construction industry. The paper presents a research aimed at analysing energy and environmental implications of the C&DW recycling chain in the administrative territory of Provincia di Torino in Northern Italy, with 2.25 million inhabitants and yearly generation of 1.8 million tons of C&DW. A combined Geographical Information System (GIS) and Life Cycle Assessment (LCA) model was developed using site-specific data and paying particular attention to land use, transportation and avoided landfill: crucial issues for sustainable planning and management. A GIS was used to handle data and information about 89 recycling plants, including technological features, output and physical–mechanical characteristics of recycled aggregate. The LCA methodology was used to identify and quantify energy and environmental loads, under different assumptions relevant to delivery distances, quality of recycled aggregates, local availability of natural aggregates and geographical coverage of market demand. The C&DW recycling chain was proved to be eco-efficient, as avoided impacts were found to be higher than the induced impacts for 13 out of 14 environmental indicators. It was also estimated that the transportation distance of recycled aggregate should increase 2–3 times before the induced impacts outweigh the avoided impacts.     

Comparative Life Cycle Assessment of four alternatives for using by-products of cane sugar production

Cane sugar production by-products can be considered either as waste, affecting the environment, or as a resource when an appropriate valorization technology is implemented.This study is made with the objective of identifying and quantifying the aspects which have the largest environmental impact of four alternatives for using by-products and wastes from the cane sugar process and suggest improvements in the systems.For this analysis a cane sugar mill was chosen in Cuba and four alternatives were designed for the by-product valorization. The first alternative represents the conventional sugar production; its main characteristics are the use of synthetic fertilizers, pesticides, the bagasse combustion and the usage of molasses and agricultural wastes as animal food. Other wastes constitute emissions to the environment. Alternatives II, III and IV incorporate more use of by-products and wastes. Alternative II considers the use of wastewater, filter cake and ashes for the substitution of synthetic fertilizers. In Alternative III, the filter cake and wastewater are used for biogas production and Alternative IV integrates alcohol and biogas production into the sugar production process.The assessment is done by means of Life Cycle Assessment, according to the ISO 14040 series by using the SimaPro 6.0 LCA software, Ecoinvent database and the Eco-indicator 99 methodology. As a functional unit the daily sugar production of the mill was defined (216 t/d). The sugar was selected as main product and all the by-products were assumed to substitute other products on the market, avoided products.For the four alternatives, the agricultural stage shows the greatest impact due to land use, fuel and agrochemicals consumption. In the industrial stage, the electricity cogeneration with bagasse has the highest impact as to respiratory effects due to the emission of tiny particle material into the atmosphere. The major difference between the alternatives is found in the resource impact category. The advantage of producing alcohol, biogas, animal food and fertilizers from the by-products is made obvious through the comparative study for resource savings.     

Short-term, real-time forecasting of hourly ozone, NO2 and NO levels by means of multiple linear regression modelling

Conclusions  The results are at least as good as those obtained with much more sophisticated models. Furthermore, the models can be easily run on a simple PC. This approach may provide a good diagnostic network (as seen in Bilbao) with real-time, short-term prognostic capabilities for a given location. The models have been built for Bilbao and are applicable only in this location. However, using the same methodology, similar results could be obtained in other environments if a good diagnostic network is available. The full paper is published in the Internet journal ‘Gate to EHS (Environmental and Health Science)’, in June 2001, and can be called up and cited by way of the DOI:http://dx.doi.org/10.1065/ehs2001.06.009     

GHG emission factors developed for the recycling and composting of municipal waste in South African municipalities

GHG (greenhouse gas) emission factors for waste management are increasingly used, but such factors are very scarce for developing countries. This paper shows how such factors have been developed for the recycling of glass, metals (Al and Fe), plastics and paper from municipal solid waste, as well as for the composting of garden refuse in South Africa. The emission factors developed for the different recyclables in the country show savings varying from ?290 kg CO₂ e (glass) to ?19 111 kg CO₂ e (metals – Al) per tonne of recyclable. They also show that there is variability, with energy intensive materials like metals having higher GHG savings in South Africa as compared to other countries. This underlines the interrelation of the waste management system of a country/region with other systems, in particular with energy generation, which in South Africa, is heavily reliant on coal. This study also shows that composting of garden waste is a net GHG emitter, releasing 172 and 186 kg CO₂ e per tonne of wet garden waste for aerated dome composting and turned windrow composting, respectively. The paper concludes that these emission factors are facilitating GHG emissions modelling for waste management in South Africa and enabling local municipalities to identify best practice in this regard.     

The content of metals in organisms of various trophic levels in freshwater and brackish lakes on the coast of the sea of Japan

Environmental Science and Pollution Research - The content of trace metals (Pb, Zn, Cd, Cu) was examined in water—in the suspended and dissolved forms, in the suspended material and organisms...     

A multi-objective programming model for assessment the GHG emissions in MSW management

In this study a multi-objective mathematical programming model is developed for taking into account GHG emissions for Municipal Solid Waste (MSW) management. Mathematical programming models are often used for structure, design and operational optimization of various systems (energy, supply chain, processes, etc.). The last twenty years they are used all the more often in Municipal Solid Waste (MSW) management in order to provide optimal solutions with the cost objective being the usual driver of the optimization. In our work we consider the GHG emissions as an additional criterion, aiming at a multi-objective approach. The Pareto front (Cost vs. GHG emissions) of the system is generated using an appropriate multi-objective method. This information is essential to the decision maker because he can explore the trade-offs in the Pareto curve and select his most preferred among the Pareto optimal solutions. In the present work a detailed multi-objective, multi-period mathematical programming model is developed in order to describe the waste management problem. Apart from the bi-objective approach, the major innovations of the model are (1) the detailed modeling considering 34 materials and 42 technologies, (2) the detailed calculation of the energy content of the various streams based on the detailed material balances, and (3) the incorporation of the IPCC guidelines for the CH₄ generated in the landfills (first order decay model). The equations of the model are described in full detail. Finally, the whole approach is illustrated with a case study referring to the application of the model in a Greek region.     

Past ownership makes crayfish more aggressive

There is plenty of evidence that resource value is one of the most important non-strategic variables in animal fighting behavior. Here, we tested whether the past ownership of a shelter might modify the agonistic behavior of the crayfish Austropotamobius pallipes, eventually increasing its probability to win when it reencounters a previously met conspecific away from that resource. The agonistic behavior of familiar pairs composed of size-matched males was observed for an hour; after that, the two contestants had been kept in isolation for 2 days, either in the presence or in the absence of a shelter. Specifically, in the isolation phase, a shelter was offered to (1) both crayfish, (2) no crayfish, (3) the dominant crayfish only, and (4) the subordinate crayfish only. The following combat was conducted in the absence of any refuge. The crayfish that previously owned a shelter showed a higher aggressive motivation to fight than the individuals kept without a shelter. Particularly, in the pairs (4), subordinate crayfish were even more aggressive than dominants but were never able to invert hierarchies. Taken together, our results confirm the role played by shelters as determinants of agonism and also show, for the first time, how the behavior of crayfish and their internal state may be affected by their past ownership of a resource.     

Pollution status and human health risk assessment of potentially toxic elements and polycyclic aromatic hydrocarbons in urban street dust of Tyumen city,Russia

Environmental Geochemistry and Health - This study investigated levels and sources of pollution and potential health risks associated with potentially toxic elements (PTEs) and polycyclic aromatic...