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Construction and demolition waste, along with discarded PET plastic bottles, have evolved into a widespread global resource. However, their current disposal in landfills poses a significant environmental pollution challenge. This research is centered on evaluating the performance of cement mortar composed by larger PET particles in conjunction with sand, construction and demolition waste, and lightweight expanded polystyrene aggregates. The primary objective of this study is to formulate a blend suitable for non-structural elements that can be easily manufactured for social housing construction. This modified blend extends upon the original certified mixture employed at CEVE for brick production, which encompasses cement and 3 mm-long PET particles. The experimental analysis revealed that blend containing 8 mm-long PET particles, in combination with fine aggregates of construction and demolition waste, attained a required mechanical strength of 2 MPa, while preserving the bulk density and hydric properties of the initial PET bricks developed at CEVE in Argentina.
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Materiais de Construção , Reciclagem , Resíduos Industriais , Instalações de Eliminação de Resíduos , ArgentinaRESUMO
Plastic pollution is a critical environmental issue with far-reaching and not yet fully explored consequences. This study uncovered a significant source of plastic contamination arising from improper application and management of expanded polystyrene (EPS) utilised as expansion joints at a construction site near the coast of Antofagasta, Chile. Through meticulous field observations and calculations, we estimate that a staggering 82.9 million EPS spheres have the potential to be released into the environment from the 7.62 m3 of this material used for the construction of this coastal promenade, constituting a chronic source of pollution. Despite the ongoing construction, we have already evidenced mechanical fragmentation and dispersion of EPS microplastic pollution in the surrounding natural environment. To our knowledge, this is the first study that documents misused construction materials contributing to plastic pollution. In addition to the EPS pollution, our findings reveal an alarming accumulation of litter - an acute pollution source - including plastic cups, bottles, carrier bags, and several other construction materials (e.g. plastic nets, films) that are exacerbating the pollution problems within the region and potentially endangering marine and terrestrial organisms. These observations highlight the urgent need for mitigating measures and intervention policies targeting construction-related plastic and microplastic pollution, along with a more robust regulatory framework for construction activities as well as adequate surveillance and enforcement.
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The use of plastic as material in various applications has been essential in the evolution of the technology industry and human society since 1950. Therefore, their production and waste generation are high due to population growth. Pyrolysis is an effective recycling method for treating plastic waste because it can recover valuable products for the chemical and petrochemical industry. This work addresses the thermal pyrolysis of expanded polystyrene (EPS) post-industrial waste in a semi-batch reactor. The influence of reaction temperature (350-500 °C) and heating rate (4-40 °C min-1) on the liquid conversion yields and physicochemical properties was studied based on a multilevel factorial statistical analysis. In addition, the analysis of the obtaining of mono-aromatics such as styrene, toluene, benzene, ethylbenzene, and α-methyl styrene was performed. Hydrocarbon liquid yields of 76.5-93% were achieved at reaction temperatures between 350 and 450 °C, respectively. Styrene yields reached up to 72% at 450 °C and a heating rate of 25 °C min-1. Finally, the potential application of the products obtained is discussed by proposing the minimization of EPS waste via pyrolysis.
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The search for sustainability has pointed to the need to transition from a linear to a circular model. However, such a transition is not trivial. Modifying production chains with the focus on reducing virgin raw materials consumption, cut emissions, and prevent waste generation implies implementing new processes and services, which can add considerable environmental impacts to the supply chain. This paper analyzes a real case from a production system aligned with circular economy principles. The production system consists of the manufacturing of baseboards made of recycled Expanded Polystyrene (EPS), obtained from an extensive reverse logistics system composed of different recycling processes. The system's potential environmental impacts were assessed by two widely used methodologies, Life Cycle Assessment (LCA) and Emergy Analysis (EMA). For comparison purposes, the analysis was carried out for a fictional linear production system, in which the baseboard would be made of virgin EPS. EMA attributed a lower emergy load to the circular scenario compared to the linear scenario (8.62E+15 seJ to recycled EPS versus 1.26E+16 seJ to virgin EPS). LCA results indicate both scenarios as environmental preferable depending on the impact category under analysis (e.g. circular system has better performance regarding global warming, while the linear scenario demonstrated better results under water consumption). For the circular scenario, EMA identified the main impact drivers, such as transportation and electricity consumption. From LCA perspective impacts are also driven by electricity consumption. However, differently from EMA, logistics were only significant for Land Use impact category whereas Liquefied Petroleum Gas consumption and, landfill air emissions were identified as impact hotspots. These convergences and differences between the findings of LCA and EMA have demonstrated potentially complementation to broaden available information related to systems, enabling decision makers to act effectively in improving the environmental performance of their production processes, especially when implementing circular practices.
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In this work, waste expanded polystyrene (WEPS) was irradiated with gamma rays, ranging doses from 100 kGy to 1,000 kGy. After irradiation, the WEPS had decrease on its glass transition temperature (Tg), as consequence of the scissions of its polymer chains. Then, the irradiated WEPS was sulfonated, and its degree of sulfonation (DS) was measured. The highest DS value, 46.6%, was obtained for an irradiation dose of 200 kGy. The sulfonated and irradiated polystyrene (denominated as iS-WEPS), was used as a support of iron oxide nanoparticles. Such composite system was denominated (FeO-NPs + iS-WEPS). The results show nanoparticle sizes of 31.5 nm containing 21.97% iron oxide. The composites followed a pseudo-second order model, with a maximum adsorption capacity of 20 mg/g, and an equilibrium time of 30 min, according to the Langmuir model. Moreover, the optimal conditions followed by the Fenton process were: pH = 3.2, H2O2 concentration = 0.32 mM/L, composite concentration (FeO-NPs + iS-WEPS) = 2 g/L, and a reaction time 20 min. Finally, 99% removal of indigo carmine dye was achieved, and a reduction of 83% of COD in textile wastewater.
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En el proceso de fabricación de autopartes se incluye el polipropileno (PP) como materia prima principal y la fibra de vidrio como insumo para la producción de ventiladores utilizados en los sistemas de refrigeración de los automotores. Los estándares de fabricación deben garantizar la resistencia de los productos en condiciones a las que estarán sometidos dentro del motor. Para lograrlo, el polipropileno es mezclado con fibra de vidrio en el proceso de inyección para aumentar la resistencia y la dureza del producto final, debido a que está expuesto a cambios de temperatura, choques con otras piezas, desgaste e impactos inesperados en el vehículo. Este estudio sintetizó y caracterizó un material obtenido a partir de la mezcla polipropileno puro-poliestireno expandido (EPS) (icopor) reciclado como una alternativa de aprovechamiento para el icopor dentro del proceso de fabricación de autopartes a modo de sustituto de la fibra de vidrio en el proceso de producción, siguiendo pasos como el tamizaje de los tamaños de material, la mezcla de los mismos, la obtención de probetas y la realización de ensayos mecánicos y térmicos. El objetivo fue comparar las propiedades mecánicas y térmicas del material obtenido (PP-EPS) con el material actualmente utilizado (PP-fibra de vidrio) para el que no se tenían estudios previos y de esta forma determinar la viabilidad de incorporación de un residuo a un proceso productivo y evitar su disposición directa favoreciendo el reciclaje del mismo. Las mezclas se caracterizaron mediante ensayos de tensión-deformación, dureza Shore A y análisis termogravimétrico (TGA) de los cuales se obtuvo favorecimiento en las propiedades térmicas y reducción de la resistencia mecánica en el uso de icopor, resaltando por supuesto el ahorro significativo en el cambio de insumos del proceso productivo.
Polypropylene (PP) as main raw material and fiberglass as input for the production of fans used in the cooling systems of motor is included in the process of manufacturing parts. Manufacturing standards must guarantee the resistance of the product in conditions that will be subject within the engine. To achieve this, the polypropylene is mixed with fiberglass in the injection process to increase the strength and hardness of the final product, as it is exposed to temperature changes, impacts with other parts, wear and unexpected impacts on the vehicle. This study synthesized and characterized a material obtained from the pure-polypropylene blend expanded polystyrene (EPS) (polystyrene) recycling as an alternative use for polystyrene in the auto parts manufacturing process as a substitute for fiberglass production process, following steps as screening media sizes, the mixture thereof, and obtaining specimens performing mechanical and thermal tests. The aim was to compare the mechanical and thermal properties of the material obtained (PP-EPS) with the material currently used (PP-fiberglass) for which they had no previous studies and thus determine the feasibility of incorporating a waste to a production in order to avoid direct disposal and thus promote the recycling process itself. The blends were characterized by stress-strain tests, Shore A hardness and thermogravimetric analysis (TGA) of which was obtained favoring the thermal properties and mechanical strength reduction in the use of polystyrene, of course emphasizing the significant savings in change of inputs in the production process.
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Humanos , Resíduos Sólidos , Poliestirenos , Resíduos , ReciclagemRESUMO
Introducción: el problema de la vivienda tiene un alcance mundial. La solución del déficit cualitativo y cuantitativo de la vivienda en Cuba transita a través de diferentes soluciones. Varios asentamientos del país se han erigido con vivienda industrial prefabricada de cloruro de polivinil PVC- conocidas por Petrocasas. Algunos estudios reportan estrés térmico en estas viviendas, vinculado a débil ventilación y calentamiento de cierres expuestos al sol. Objetivo: realizar una evaluación de salud ambiental en factores de riesgos físicos en el ambiente interior de las viviendas relativo a la intemperie, tras un cambio del material de cubierta. Método: se plantea un estudio experimental evaluativo de factores de riesgos físicos en el ambiente interior de las viviendas petrocasas a partir de una propuesta de modificación del material de la cubierta con la intención de reducir el estrés térmico de las mismas. Fueron edificadas con este propósito dos viviendas petrocasas con igual orientación de fachada principal y diferente cubierta; ;una fue sustituida por poliestireno expandido y la otra mantiene cubierta original (aluminio y papel de asfalto).Se evaluaron comparativamente factores de riesgos físicos: ruido, componente magnético del campo electromagnético de baja frecuencia, iluminación natural, artificial, ventilación y, principalmente, microclima para valorar la eficacia del cambio introducido. La evaluación estadística se efectuó por descriptores, modelos de regresión y espectro de potencia bivariado con los paquetes estadísticos SPSS v. 17.0 y Statistica 8.0. Resultados: la vivienda Petrocasa con cubierta de aluminio asfalto presenta un clima interior algo más desfavorable al bienestar térmico que aquella de poliestireno; la ventilación en ambas resulta deficiente. Conclusiones: el cambio de material de la cubierta ligera de la vivienda Petrocasa proporciona un clima interior algo más favorable al bienestar de sus residentes(AU)
Introduction: the housing problem is global in scope. Solution to qualitative and quantitative housing deficit in Cuba has been addressed from various different perspectives. Several settlements in the country have been built with prefabricated industrial houses made of polyvinyl chloride (PVC). These are known as petrohouses. Some studies have reported thermal stress inside these houses, resulting from insufficient ventilation and the heating of roofs exposed to the sun. Objective: carry out an environmental health evaluation of physical risk factors present in the indoor environment of petrohouses as compared with the outside environment after roof replacement. Method: an experimental evaluative study was conducted of physical risk factors present in the indoor environment of petrohouses based on a proposal of modification of the roof material with the purpose of reducing thermal stress. For this purpose, two petrohouses were built with the same orientation of their main facade, but different roof material. One was roofed with expanded polystyrene, while the other retained its original roof (aluminum sheets and asphalt paper). The following physical risk factors were evaluated comparatively: noise, magnetic component of the low frequency electromagnetic field, natural and artificial lighting, ventilation, and mainly microclimate, to evaluate the efficacy of the change made. Statistical evaluation was conducted with descriptors, regression models and bivariate power spectrum, using the statistical software packages SPSS v. 17.0 and Statistica v. 8.0. Results: indoor environment in the petrohouse with an aluminum-asphalt roof is somewhat more unfavorable in terms of thermal welfare than in the polystyrene-roofed house. Ventilation is deficient in both. Conclusions: roof replacement in petrohouses provides an indoor environment somewhat more favorable to the welfare of dwellers(AU)