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- The effect on the GHG emissions of MSW management practices based on EU legislation targets: a municipal case studyPublication . Xará, Susana; Almeida, Manuel Fonseca; Silva, Margarida; Costa, Carlos
- The effect on the GHG emissions of MSW management practices based on EU legislation targetsPublication . Xará, Susana; Almeida, Manuel; Silva, Margarida; Costa, Carlos
- LCA as a tool or philosophy for Integrated Waste Management: opportunities in PortugalPublication . Xará, Susana; Almeida, Manuel Fonseca; Costa, Carlos
- The effect on the GHG emissions and energy consumption of MSW management practices on Porto CityPublication . Xará, Susana; Almeida, Manuel; Costa, Carlos
- Life cycle inventory analysis of spent alkaline batteries treatmentPublication . Xará, Susana; Almeida, Manuel F.; Silva, Margarida; Costa, Carlos
- The effect on the GHG emissions and energy consumption of MSW management practices on Porto CityPublication . Xará, S.; Almeida, M. F.; Silva, M.; Costa, C.The present case study was developed for the municipality of Porto, the second largest city of Portugal that has near 300 000 inhabitants. Due to legislative evolution, some changes have been implemented on MSW management practices since 1990 leading to meaningful improvements on energy consumption and greenhouse gases emissions. Two situations were compared: (i) the first one concerns the situation in 1990 where the MSW produced was collected, a meaningful fraction of it was composted and the residual waste dumped; and, (ii) the second situation where the EU legislation on recycling targets for packaging material and diversion of organic waste from landfills was taken into account, including an incineration plant on the management system. Greenhouse gas emissions from these two management scenarios were calculated based on an inventory model developed by White et al (1992). Weighting factors for the different gases based on the recommendations of the Intergovernmental Panel on Climate Change were used to aggregate the emissions values and obtain a simple and comparable result for each situation. Results show the advantage of the 2000 practices both in terms of energy consumption and emissions of gases with greenhouse effect.
- Porto 1990/2000: Evaluation of environmental burdens from MSW management using Life Cycle AssessmentPublication . Xará, Susana; Almeida, M. F.; Silva, M.; Costa, C.The environmental burdens to air and water resulting from the MSW management practices in the municipality of Porto were evaluated for 1990 and 2000 using the model developed by White et al (White et al, 1995). The operations considered in the study are collection, sorting, biological treatment, thermal treatment and landfilling. Savings from energy and recycling of recovered materials are also quantified. For each pollutant, the main source, among the operations considered, was identified. Results have shown that landfilling was the main source for air and water emissions in 1990, followed by collection. In 2000, thermal treatment was the main source for air pollutants and landfilling the main source of water pollutants, in both cases followed by collection. In 1990, collection was the main source for air emissions of particulates, CO, NOx, SOx to air, and of Organic compounds, Phenol and Fluoride to water. In 2000 it was the main source of NOx to air and TOC, phenol, total metals and fluoride to water. Biological treatment was the main source of N2O and nitrate to air in 1990 and of BOD, COD and ammonia to water in 2000.
- Laboratory study on the behaviour of spent AA household alkaline batteries in incinerationPublication . Almeida, Manuel F.; Xará, Susana M.; Delgado, Julanda; Costa, Carlos A.The quantitative evaluation of emissions from incineration is essential when Life Cycle Assessment (LCA) studies consider this process as an end-of-life solution for some wastes. Thus, the objective of this work is to quantify the main gaseous emissions produced when spent AA alkaline batteries are incinerated. With this aim, batteries were kept for 1 h at 1273 K in a refractory steel tube hold in a horizontal electric furnace with temperature control. At one end of the refractory steel tube, a constant air flow input assures the presence of oxygen in the atmosphere and guides the gaseous emissions to a filter system followed by a set of two bubbler flasks having an aqueous solution of 10% (v/v) nitric acid. After each set of experiments, sulphur, chlorides and metals (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Tl and Zn) were analyzed in both the solutions obtained from the steel tube washing and from the bubblers. Sulphur, chlorides and metals were quantified, respectively, using barium sulfate gravimetry, the Volhard method and atomic absorption spectrometry (AAS). The emissions of zinc, the most emitted metal, represent about 6.5% of the zinc content in the batteries. Emissions of manganese (whose oxide is the main component of the cathode) and iron (from the cathode collector) are negligible when compared with their amount in AA alkaline batteries. Mercury is the metal with higher volatility in the composition of the batteries and was collected even in the second bubbler flask. The amount of chlorides collected corresponds to about 36% of the chlorine in the battery sleeve that is made from PVC. A considerable part of the HCl formed in PVC plastic sleeve incineration is neutralized with KOH, zinc and manganese oxides and, thus, it is not totally released in the gas. Some of the emissions are predictable through a thermodynamic data analysis at temperatures in the range of 1200–1300 K taking into account the composition of the batteries. This analysis was done for most of potential reactions between components in the batteries as well as between them and the surrounding atmosphere and it reasonably agrees the experimental results. The results obtained show the role of alkaline batteries at the acid gases cleaning process, through the neutralization reactions of some of their components. Therefore, LCA of spent AA alkaline batteries at the municipal solid waste (MSW) incineration process must consider this contribution.
- The effect on the GHG emissions of MSW management practices based on EU legislation targetsPublication . Xará, Susana; Almeida, Manuel Fonseca; Silva, Margarida; Costa, Carlos
- A aplicação da análise do ciclo de vida no planeamento da gestão integrada de resíduos sólidos urbanosPublication . Xará, S.; Silva, M.; Almeida, M. F.; Costa, C.