Decomposition of two types of electric wires considering the effect of the metal in the production of pollutants

Combustion runs at 700 °C in a horizontal laboratory furnace were carried out on two different electric wires (PVC and halogen-free wire). Tests were performed in the presence and in the absence of the metal conductor of the wires. The analyses of the polycyclic aromatic hydrocarbons (PAHs), chlorobenzenes (CBzs), chlorophenols (CPhs), mono- to octa-chlorodibenzo-p-dioxin and dibenzofurans (PCDD/Fs), and dioxin-like PCBs are shown. Regarding semivolatile compounds, PAHs production decreases in the presence of metal, while a higher amount of chlorinated compounds are emitted. Respect to the PCDD/Fs, the PVC wire in the presence of metal presents the highest emission, with a much more emission of furans than dioxins. The maximum emission is with 2 or 3 chlorine atom PCDD/Fs. PCBs emission correlates with PCDD/F production and represents 3–4% of total toxicity, determined by using WHO2005 factors.Support for this work was provided by the Generalitat Valenciana (Spain) with Projects PROMETEO/2009/043/FEDER, and by the Spanish MCT CTQ2008-05520

Pollutant Formation During the Thermal Decomposition of Electrical and Electronic Wastes

Paper submitted to the 7th International Symposium on Feedstock Recycling of Polymeric Materials (7th ISFR 2013), New Delhi, India, 23-26 October 2013.In this contribution we present the results of the research done at the University of Alicante in the last four years [1-7] about the thermal decomposition of waste electrical and electronic equipment (WEEE). Several materials have been studied, including PVC and halogen-free wires, printed circuit boards and casing from mobile phones, as well as brominated flame reatardants used in the EEE preparation such as TBBPA (tetra-bromo-bisphenol-A). Several experiments were performed in a nitrogen atmosphere (pyrolysis runs) and also in an oxidative atmosphere with different oxygen concentrations. Thermogravimetric runs were used to characterize samples, and a horizontal laboratory reactor was used to study the formation and destruction of pollutants during the thermal decomposition of these samples. More than 150 compounds, including carbon oxides, light hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), chlorophenols (ClPhs), chlorobenzenes (ClBzs) and bromophenols (BrPhs) have been identified and quantified. Furthermore, polychlorodibenzo-p-dioxin and polychlorodibenzofurans (PCDD/Fs), polybromodibenzo-p-dioxin and polybromodibenzofurans (PBDD/Fs), and dioxin-like PCBs produced were analyzed.Generalitat Valenciana: PROMETEO/2009/043/FEDER. Ministerio de Educación y Ciencia: CTQ2008-05520

Thermogravimetric study of the decomposition of printed circuit boards from mobile phones

Thermal decomposition of printed circuits boards (PCB) is studied, using thermogravimetric analysis to compare the thermal behavior of PCB of mobile phones before and after the removal of the metallic fraction by acid washing. Several dynamic and dynamic + isothermal runs have been carried out at different heating rates (5, 10 and 20 K min−1), from room temperature to more than 1100 K. Also runs in the presence and in the absence of oxygen were performed (combustion and pyrolysis runs). Moreover, TG–MS experiments were performed (both in inert and oxidizing atmosphere) in order to better understand the thermal decomposition of these wastes and identify some compounds emitted during the controlled heating of these materials. Different reaction models are proposed, one for pyrolysis and one for combustion of the two kinds of wastes studied, which proved to simulate appropriately the experimental results at all the heating rates simultaneously.Support for this work was provided by the Generalitat Valenciana (Spain), research project Prometeo/2009/043/FEDER, and by the Spanish MCT, research project CTQ2008-05520

Thermal Decomposition of Mobile Phones

Paper submitted to the 31st International Symposium on Halogenated Persistent Organic Compounds (Dioxin 2011), Brussels, Belgium, 21-25 August 2011.Mobile phones are used for a variety of purposes, including keeping in touch with family members, conducting business, and having access to a telephone in the event of an emergency. Some people carry more than one cell phone for different purposes. In 2006 more than one billion mobile phones were shipped worldwide, 22.5 % more than the quantity shipped in 2005. By 2008 the number of mobile phone users around the world was predicted to reach two billion.Support for this work was provided by the Generalitat Valenciana (Spain) with projects Prometeo/2009/043/FEDER and ACOMP2011/224, and by the Spanish MCT CTQ2008-05520

Humans Share More Preferences for Floral Phenotypes With Pollinators Than With Pests.

Studies on the selection of floral traits usually consider pollinators and sometimes herbivores. However, humans also exert selection on floral traits of ornamental plants. We compared the preferences of bumblebees (Bombus terrestris), thrips (Frankliniella occidentalis), and humans for flowers of snapdragon. From a cross of two species, Antirrhinum majus and Antirrhinum linkianum, we selected four Recombinant Inbred Lines (RILs). We characterised scent emission from whole flowers and stamens, pollen content and viability, trichome density, floral shape, size and colour of floral parts. We tested the preferences of bumblebees, thrips, and humans for whole flowers, floral scent bouquets, stamen scent, and individual scent compounds. Humans and bumblebees showed preferences for parental species, whereas thrips preferred RILs. Colour and floral scent, in combination with other floral traits, seem relevant phenotypes for all organisms. Remarkably, visual traits override scent cues for bumblebees, although, scent is an important trait when bumblebees cannot see the flowers, and methyl benzoate was identified as a key attractant for them. The evolutionary trajectory of flowers is the result of multiple floral traits interacting with different organisms with different habits and modes of interaction

Polyvinyl chloride and halogen-free electric wires thermal decomposition

A kinetic model for the pyrolysis and combustion of PVC and halogen-free electric wires has been obtained. One set of parameters can explain all the experiments at the different atmospheres and at the three different heating rates used. Thermal analysis of different parts of the cable, cover, insulation and conductive metal, both separately and combined, has allowed for understanding of the interaction between the different materials