RESUMO
Barium is present within the clay-derived therapeutic mud packs deposed on the patient's skin for treating some rheumatologic conditions. We studied in twenty-four young healthy volunteers the diffusion of Ba from mud wrapped in micro-perforated polyethylene bags and soaked in mineral water. No significant systematic increase in plasma or urine Ba levels was evidenced when comparing pre- and post-treatment samples using inductively-coupled plasma mass spectrometry. These levels were markedly inferior to the recommended thresholds in nearly all the participants. Noticeably variability in blood and especially urine Ba concentrations was large and mainly explained by environmental exposure (alimentation). Interestingly, we evidenced an intense Ba accumulation within the therapeutic mud at the end of the regimen. Because we chose a clay with one of the highest Ba content available in France for medical therapy and participants with an optimal transcutaneous diffusion capacity (young individuals with low-fat mass), we conclude unambiguously that there is no risk of Ba overexposure in patients receiving pelotherapy according to the procedure used in French medical spas.
Assuntos
Águas Minerais , Peloterapia , Humanos , Bário/urina , Polietileno/análise , Argila , Exposição Ambiental/análise , Águas Minerais/análise , Peloterapia/efeitos adversosRESUMO
Estuarine contamination by Microplastics (MPs) is a mater of serious concern since these areas offer the society valuable ecosystem, economic, and recreational services such as breeding and feeding ground for fish, carbon fixation, nutrients recycling and port development. The Meghna estuary, located along the Bengal delta coast, provides livelihoods for thousands of peoples in Bangladesh, and served as breeding ground for national fish, Hilsha shad. Therefore, knowledge and understanding on any kind of pollution including MPs of this estuary is essential. In this study, the abundance, characteristics and contamination assessment of MPs from the surface water of a Meghna estuary were investigated for the first time. The results demonstrated that MPs were present in all samples and the abundance ranged from 33.33 to 316.67 item/m3 with a mean value of 128.89 ± 67.94 item/m3. Morphological analyses resulted in four types of MPs such as fibers (87%), fragments (6%), foam (4%), and films (3%) with the majority of these being colored (62%) and smaller (<0.5 mm) in size (88%). On the other hand, FTIR analysis for chemical characteristics confirmed five types of polymers, including polythene (PE), polystyrene (PS), polythene terephthalate (PET), polypropylene (PP), and polyvinyl chloride (PVC). The area was determined to be moderately to severely contaminated with MPs based on contamination factor (CF) values (6.18 ± 2.08 to 2.50 ± 1.0) and the pollutant load index (PLI) value (1.94 ± 0.33) as these values were > 3-6 for CF, and >1 for PLI. These results can be utilized to develop policy for the protection of this important environment.
Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Animais , Microplásticos/análise , Plásticos , Estuários , Ecossistema , Água , Polietileno/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Peixes , Poluentes Ambientais/análise , Sedimentos GeológicosRESUMO
Studies in recent years have shown that aquatic pollution by microplastics (MPs) can be considered to pose additional stress to amphibian populations. However, our knowledge of how MPs affect amphibians is very rudimentary, and even more limited is our understanding of their effects in combination with other emerging pollutants. Thus, we aimed to evaluate the possible toxicity of polyethylene MPs (PE-MPs) (alone or in combination with a mix of pollutants) on the health of Physalaemus cuvieri tadpoles. After 30 days of exposure, multiple biomarkers were measured, including morphological, biometric, and developmental indices, behavioral parameters, mutagenicity, cytotoxicity, antioxidant and cholinesterase responses, as well as the uptake and accumulation of PE-MPs in animals. Based on the results, there was no significant change in any of the parameters measured in tadpoles exposed to treatments, but induced stress was observed in tadpoles exposed to PE-MPs combined with the mixture of pollutants, reflecting significant changes in physiological and biochemical responses. Through principal component analysis (PCA) and integrated biomarker response (IBR) assessment, effects induced by pollutants in each test group were distinguished, confirming that the exposure of P. cuvieri tadpoles to the PE-MPs in combination with a mix of emerging pollutants induces an enhanced stress response, although the uptake and accumulation of PE-MPs in these animals was reduced. Thus, our study provides new insight into the danger to amphibians of MPs coexisting with other pollutants in aquatic environments.
Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Animais , Microplásticos , Polietileno/toxicidade , Polietileno/análise , Plásticos/toxicidade , Larva , Poluentes Ambientais/análise , Poluentes Químicos da Água/análise , AnurosRESUMO
In aquatic environments, microplastics (MPs) are pervasive which could have a considerable negative impact on the environment, organisms and pose a risk to human health. However, knowledge about the exposure and ecological risk of MPs in the coastal ecosystems of developing countries is limited. In this study, we analyzed salt samples from five commonly consumed processed and unprocessed sea salts of different commercial brands originated from 15 salt pans in Bangladesh to assess the abundance, characteristics and potential risks of MPs. The quantities of MPs in unprocessed salts (average 195 ± 56 item/kg) were higher than those in the processed salts (average 157 ± 34 item/kg). One-way analysis of variance (ANOVA) showed significant (p < 0.05) differences among the average numbers of MPs in both processed and unprocessed salts. MP levels in this study were 2-3 times higher than those reported from some other countries. Fiber-shaped and transparent MPs were dominant in both cases. MPs less than 0.5 mm in size were the most abundant in both unprocessed (58.2%) and processed (62.2%) salts. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed five types of polymers, including polyethylene terephthalate (PET-35%), polypropylene (PP-27.5%), polyethylene (PE-25%), polystyrene (PS-10%), and Nylon (2.5%) in the studied salts. The sea salts were classified as potential hazard index (PHI) levels IV to V, indicating serious MP contamination, whereas potential ecological risk factor (Ei), potential ecological risk index (RI), and pollutant load index (PLI) indicated moderate levels of pollution of MPs. Domestic and municipal wastewater effluents to Bay of Bengal and fishing activities may attributed to presence of MPs in the sea salt. These findings can be used by consumers, salt industries and policy makers to reduce MPs levels during consumption, production and policymaking.
Assuntos
Microplásticos , Poluentes Químicos da Água , Países em Desenvolvimento , Ecossistema , Monitoramento Ambiental , Humanos , Nylons , Plásticos/química , Polietileno/análise , Polietilenotereftalatos , Polímeros , Polipropilenos/análise , Poliestirenos/análise , Medição de Risco , Sais/análise , Águas Residuárias/análise , Poluentes Químicos da Água/análiseRESUMO
Microplastics are a widespread environmental contaminant that raises serious concern for aquatic organisms. Hence, the present study was conducted to investigate the spatial and seasonal variation of microplastics, their characteristics, polymer types and the risk assessment caused by the microplastics in six sampling sites along the Thoothukudi region. The average microplastic abundance ranged from 32 ± 26 to 232 ± 229 items/kg and 54 ± 41 to 619 ± 377 items/l in sediment and surface water, respectively, and they exhibited a significant spatial difference among the sampling sites. The microplastic abundance also showed a significant difference among the seasons with the monsoon significantly recording the highest mean microplastic abundance in sediment (160 ± 130 items/kg) and surface water (454 ± 374 items/l). In sediment and surface water, fragment (sediment: 52.72%, surface water: 40.89%), 0.5-1 mm (sediment: 43.96%, surface water: 31.11%) and blue-coloured (sediment: 52.33%, surface water: 41.85%) microplastics were dominant with no significant difference both spatially and seasonally. Polyethylene, the dominant polymer, was observed in both the sediment and surface water, accounting for about 47.58% and 49.83%, respectively, and it showed no significant difference among the selected sites. This signifies that they are homogenously distributed along the coast and further suggests that these particles persisted in the sediment and surface water for a longer period of time. The results of the polymer hazard index show that the sediment (PHI = 1181.63) and surface water (PHI = 1018.66) were severely contaminated (hazard level V) with microplastic polymers such as PE, PP, PS, PET and PA. It was also found that the degree of the microplastic contamination in sediment (PLI = 3.57) and surface water (PLI = 3.84) was lower (hazard level I). The overall risk index (RI) for sediment (253.48) and surface water (444.74) falls under the higher risk category. From the correlation analysis, a significantly positive relationship was observed between microplastics in sediment and surface water based on each classification (abundance, shape, size, colour and polymer). This suggests that microplastics rejoin the water column from the sediment through resuspension, which occurs due to the circulation, tides and sedimentation rate. This might be the reason for the higher microplastic abundance in the surface water than in the sediment. As a result, proper management measures to reduce plastic waste disposal in the marine environment should be implemented to lessen the effects of microplastics on marine biota and on public health.
Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Sedimentos Geológicos , Índia , Plásticos/análise , Polietileno/análise , Medição de Risco , Estações do Ano , Água/análise , Poluentes Químicos da Água/análiseRESUMO
Microplastics had been collected at two sites namely Trou d'eau Douce (TD) and La Cambuse (LC) public beaches, lying in the east coast and south-east coast of Mauritius, respectively, over 6 months from September 2019 to February 2020. The sizes of the latter varied from 180 µm to 4 mm. A higher amount of microplastics collected/6-kg sand sample was recorded at LC. Two-way ANOVA revealed that (1) there was a considerable gap in the variability regarding quantity and size distribution of microplastics on the two beaches. The post-hoc analysis showed that the majority of the microplastics at LC were > 1.40 mm, whereas the smaller plastic fragments < 1.40 mm were more dominant at TD. (2) There was a significant interaction between location and event (p value = 0.025). The post-hoc analysis showed that the torrential rain hitting the island prior to sampling week 7 had decreased the microplastic counts at both TD and LC, but not significantly. Interestingly, the two hurricanes, prior to weeks 8 and 9, had appreciably reduced the microplastic counts at TD and, on the other hand, there was an increase in the amount of microplastics at LC, but not to a significant effect. The chemical nature (qualitative analysis) of microplastics was determined by density flotation and FTIR spectroscopy. Microplastics at TD were exclusively high-density polyethylene (HDPE) in origin, whereas, at LC, microplastics were both HDPE and polypropylene (PP) in origin.
Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental/métodos , Maurício , Plásticos/análise , Polietileno/análise , Poluentes Químicos da Água/análiseRESUMO
Microplastics accumulation on beaches raises a serious concern worldwide. Hence, the present study was conducted with the focus of investigating the abundance, characteristics, risk assessment, surface morphology and elemental composition of microplastics (MPs) in the beach sediments of the Thoothukudi region, situated on the south-east coast of India, Gulf of Mannar region. The MPs abundance ranged between 19 ± 18.62 and 78.55 ± 95.17 items/kg with a mean abundance of 33.82 ± 26.11 items/kg and the spatial distribution of MPs showed insignificant variation. Fragments (59.48%), 0.5-1 mm (43.66%) and blue-coloured MPs (45.61%) were highly predominant in the sediments. Attenuated total reflection - Fourier transform infrared (ATR-FTIR) spectroscopy showed the dominance of polyethylene polymers in sediments (52.26%) and their sources could be attributed to the direct inflow of sewage, recreational and fishing activities and accidental loss. The current study revealed that microplastics (< 5 mm) are ubiquitous along the Thoothukudi coast, posing a serious threat to the marine environment and marine organisms. The ecological risk assessment of MPs in sediments was calculated by adopting 3 models: the polymer hazard index (PHI), pollution load index (PLI) and potential ecological risk assessment (RI). The overall PHIsediments = 698.96 exhibited a hazard level of IV, which was mainly due to the varying abundance of polymer composition in sediments. The value of PLIsediments is 2.51, which mainly depends on the MPs abundance in sediments and yields the hazard level of I. The ecological risk posed by MPs in beach sediments along the Thoothukudi coast (RIsediments = 241.06) falls into the medium category, indicating that steps must be taken to reduce the flow of plastics through management measures such as proper wastewater treatment practices, recycling of plastic waste and proper waste disposal. Field emission scanning electron microscopy (FESEM) images revealed that MPs surfaces were strongly weathered and energy dispersive X-ray (EDX) spectroscopy spectra showed that the presence of inorganic elements associated with the surface MPs might be derived from the surrounding environment or additives in plastics. Hence, further research has to be conducted in view of studying the combined effects of MPs pollution and organic pollutants, which will provide further understanding of the contamination of MPs in the marine environment.
Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Sedimentos Geológicos , Plásticos , Polietileno/análise , Polímeros , Medição de Risco , Esgotos , Poluentes Químicos da Água/análiseRESUMO
Considering the magnitude of pollution caused by marine plastics, the present study assessed their abundance, distribution, surface morphology and polymer type in ten sandy beaches spread across three states (Maharashtra, Karnataka and Goa) along the west coast of India (WCI). The total abundance of plastics (â¼1-100 mm) in the studied beaches ranged from 4.1 to 23.4% (19±1-346 ± 2 items/m2). Location-wise, the abundances of both micro (43.6 ± 1.1-346 ± 2 items/m2) and macroplastics (21.6±3-195 ± 6 items/m2) were relatively higher in beaches along the Maharashtra coast. Surface morphology-wise, fragments were predominantly abundant in both micro (76±2-346 ± 2 items/m2) and macroplastics (50.6 ± 1.5-195 ± 6 items/m2) followed by pellets (43.3 ± 2.5-245.6 ± 2 items/m2). Fourier-transform infrared spectroscopy (FT-IR) analysis of plastics revealed a dominance of polyethylene (PE) followed by polypropylene (PP). IR spectra of the collected plastics at absorption band at 1750-1700 cm-1 reflect minimal surface oxidation. White-colored plastics were observed most frequently, followed by pale-yellow, dark-brown, green, blue, transparent and red. A short-term (72 h) experimental study to assess the toxicity of PE microbeads (â¼1 mm) in a commercially important shrimp species, Litopenaeus vannamei revealed toxicological changes. An elevated level of lipid peroxidation (LPX)-the tagged biochemical marker, was recorded only at the maximum dose (0.15 mg/L) of PE microbeads. A moderate increase in the levels of enzymatic antioxidants (catalase and glutathione S-transferase) was also recorded at the same dose. Comprehensive information on marine plastics, including ecotoxicity provided in this study, would help in evolving strategies in minimizing plastic pollution along the WCI.
Assuntos
Monitoramento Ambiental , Plásticos/análise , Poluentes Químicos da Água/análise , Poluição Ambiental/análise , Poluição Ambiental/estatística & dados numéricos , Índia , Microplásticos , Polietileno/análise , Polímeros , Polipropilenos , Espectroscopia de Infravermelho com Transformada de Fourier , Resíduos/análiseRESUMO
In the last few years, several studies have investigated microplastics (MPs) in marine ecosystems, but data monitoring and assessing the occurrence in freshwater environments are still scarce. The present study aims to investigate the occurrence, distribution, and chemical composition of MP pollution in Vesijärvi lake and Pikku Vesijärvi pond close to the city of Lahti (Finland) in winter. Sediment, snow, and ice core samples were collected near the shore of these two aquatic systems. MPs were analysed and identified by a non-destructive method using Fourier transform infrared spectroscopy (FTIR) 2D imaging. The mean concentrations of MPs detected in sediment, snow, and ice samples were 395.5 ± 90.7 MPs/kg, 117.1 ± 18.4 MPs/L, and 7.8 ± 1.2 MPs/L, respectively. FTIR results showed the predominant abundance of microplastics, such as polyamides (up to 53.3%), polyethylene and polypropylene (up to 17.1%), and natural fragments such as cellulose (up to 45.8%) and wool (up 18.8%) in the same size range. The potential release of MPs arising from stormwaters and sport and recreational activities was evidenced.
Assuntos
Monitoramento Ambiental/métodos , Microplásticos/análise , Lagoas/química , Poluentes Químicos da Água/análise , Poluição Química da Água/análise , Animais , Celulose/análise , Ecossistema , Finlândia , Lagos/química , Nylons/análise , Polietileno/análise , Polipropilenos/análise , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Microplastics (MPs) in the environment have become an issue worldwide. However, data about MPs in freshwater systems are still limited so far. This study investigated sources, fate, and seasonal and spatial distribution of MPs in the main stream Pearl River and its tributaries, as well as in the Pearl River Estuary (PRE), China. MPs were widely detected in the river water, river bed sediment, and estuarine sediment, with abundances of 0.57⯱â¯0.71 items L-1, 685⯱â¯342 items kg-1 dry weight (dw), and 258⯱â¯133 items kg-1 dw, respectively. Sheet, fragmental, and fibrous polyethylene, polypropylene, and ethylene-propylene copolymers were predominant, suggesting that MPs in the Pearl River catchment be mainly derived from fragmentation of discarded plastic wastes. In addition, municipal wastewater was also an important MPs source, especially for polyethylene terephthalate (PET) fibers. Polymers of higher density, such as PET and polyvinyl alcohol were relatively more abundant in the sediment than in the river water, especially in the estuarine sediment. Upward increase of the MP abundance was observed in the sedimentary core, probably indicating increasing release of plastic wastes due to growing production and uses of plastic products. On the other hand, percentage of finer MPs increased with increasing depth. The results revealed persistence and potential downward dispersion of the fine MPs. The MPs abundance was positively related with population density and gross domestic product, demonstrating impacts of human activities and economic development on the MPs contamination. Higher MPs abundance was detected in dry season than in wet season in the river water, suggesting dilution effect of precipitation. It's estimated that 15963 tons of MPs could be released annually into the PRE from the main stream Pearl River and its tributaries.
Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Polietileno/análise , Polipropilenos/análise , Rios/química , Poluentes Químicos da Água/análise , China , Estuários , Nanoestruturas/análise , Estações do Ano , Águas Residuárias/químicaRESUMO
Microplastics have become a major environmental issue; their release from various products affects the aquatic environment. Personal care products such as toothpastes are recently being considered as a significant source of microplastics released to the aquatic environment. This study aims to assess the presence of microplastics found in toothpastes that are available in the drugstores and markets in Istanbul, Turkey. A total of 20 samples were tested. Following the extraction procedure, obtained particles were quantified and then characterized by microscopic evaluation and surface chemistry analysis. Twenty percent of the samples were found to contain microplastics in the structure of polyethylene at concentrations varying between 0.4 and 1%. In order to evaluate the release to environment, a risk assessment was conducted and yearly microplastic emission caused by toothpaste consumption was calculated based on the results.
Assuntos
Monitoramento Ambiental/métodos , Plásticos/análise , Polietileno/análise , Cremes Dentais/química , Poluentes Químicos da Água/análise , Medição de Risco , TurquiaRESUMO
Mariculture activities including enclosure, raft and cage cultures employ a variety of plastic gear such as fishing nets, buoyant material and net cages. The plastic gear poses a potential source of microplastics to the coastal environment, but relevant data on the impacts of mariculture are still limited. To this end, a semi-enclosed narrow bay (i.e., Xiangshan Bay, China) with a long-term mariculture history was investigated to assess how mariculture activities affect microplastics in seawater and sediment. The results indicated that mariculture-derived microplastics accounted for approximately 55.7% and 36.8% of the microplastics in seawater and sediment, respectively. The average microplastic abundances of seawater and sediment were 8.9⯱â¯4.7 (mean⯱â¯SD, nâ¯=â¯18) items/m3 seawater and 1739⯱â¯2153 (nâ¯=â¯18) items/kg sediment, respectively. The types of mariculture-derived microplastics included polyethylene (PE) foam, PE nets, PE film, polypropylene (PP) rope, polystyrene (PS) foam and rubber. PE foam had the highest proportion (38.6%) in the seawater samples. High usage rates and the porous structure of PE foam led to the high abundance. The average microplastic sizes of seawater and sediment are 1.54⯱â¯1.53â¯mm and 1.33⯱â¯1.69â¯mm, respectively. The spatial variations in the abundance and size of microplastics implied that the mariculture-derived microplastics in Xiangshan Bay were transported along the Bay to the open sea. The results of this study indicate that mariculture activity can be a significant source of microplastics. Further research is required to investigate how the high microplastic abundance in mariculture zone affects marine organisms, especially cultured seafood.
Assuntos
Aquicultura , Monitoramento Ambiental , Plásticos/análise , Poluentes Químicos da Água/análise , Organismos Aquáticos , Baías/química , China , Oceanos e Mares , Polietileno/análise , Polipropilenos/análise , Poliestirenos/análise , Alimentos Marinhos , Água do Mar/químicaRESUMO
Both macroplastic and microplastic contamination levels were assessed for the first time in a tropical river estuary system, i.e. the Saigon River, that traverses a developing South East Asian megacity, i.e. Ho Chi Minh City, Vietnam. The analysis of floating debris collected daily on the Nhieu Loc - Thi Nghe canal by the municipal waste management service shows that the plastic mass percentage represents 11-43%, and the land-based plastic debris entering the river was estimated from 0.96 to 19.91â¯g inhabitant-1 d-1, namely 350 to 7270â¯g inhabitant-1 yr-1. Microplastics were assessed in the Saigon River and in four urban canals by sampling bulk water for anthropogenic fiber analysis and 300⯵m mesh size plankton net exposition for fragment analysis. Fibers and fragments are highly concentrated in this system, respectively 172,000 to 519,000 items m-3 and 10 to 223 items m-3. They were found in various colors and shapes with smallest size and surface classes being predominant. The macroplastics and fragments were mainly made of polyethylene and polypropylene while the anthropogenic fibers were mainly made of polyester. The relation between macroplastic and microplastic concentrations, waste management, population density and water treatment are further discussed.
Assuntos
Monitoramento Ambiental , Plásticos/análise , Poluentes Químicos da Água/análise , Estuários , Plâncton , Polietileno/análise , Polipropilenos/análise , Rios/química , Vietnã , Resíduos/análise , Resíduos/estatística & dados numéricosRESUMO
Recently, there has been a growing interest in identifying suitable routes for the disposal of pharmaceutical wastes. This study investigates the potential of matrix materials composed of recycled polyethylene/polypropylene reclaimed from municipal solid wastes at immobilizing pharmaceutical solid wastes. Diclofenac (DF) drug product was embedded in boards of recycled plastic material, and leaching in water was assessed at various temperatures. DF concentrations were determined by high-performance liquid chromatography and revealed a maximum leachable fraction of 4% under accelerated conditions of 70°C, and less than 0.3% following 39 days of exposure at 20°C. The Ensemble Kalman Filter was employed to characterize the leaching behavior of DF. The filter verified the occurrence of leaching through diffusion, and was successful in predicting the leaching behavior of DF at 50°C and 70°C.
Assuntos
Diclofenaco/química , Polietileno/química , Polipropilenos/química , Reciclagem , Resíduos Industriais/análise , Polietileno/análise , Polipropilenos/análise , Eliminação de Resíduos/métodos , Resíduos Sólidos/análiseRESUMO
Plastics are the most common material of marine litter and have become a global pollution concern. They are persistent in the environment where they gradually degrade into increasingly smaller particles-microplastics (MP). Our study presents results of sea-surface monitoring for MP in the Slovenian part of the Trieste Bay in the Northern Adriatic Sea. In 17 trawls conducted over a 20-month period we found a high average concentration of 406×103MPparticles/km2. Over 80% of the particles were identified as polyethylene. The significant variability of MP concentrations obtained on different sampling dates is explained by use of surface current maps and a recently developed Markov chain marine litter distribution model for the Adriatic Sea.
Assuntos
Monitoramento Ambiental/métodos , Plásticos/análise , Água do Mar/análise , Resíduos/análise , Poluentes Químicos da Água/análise , Cadeias de Markov , Mar Mediterrâneo , Polietileno/análise , EslovêniaRESUMO
Identification and characterisation of microplastic (MP) is a necessary step to evaluate their concentrations, chemical composition and interactions with biota. MP ≥10µm diameter filtered from below the sea surface in the European and subtropical North Atlantic were simultaneously identified by visual microscopy and Raman micro-spectroscopy. Visually identified particles below 100µm had a significantly lower percentage confirmed by Raman than larger ones indicating that visual identification alone is inappropriate for studies on small microplastics. Sixty-eight percent of visually counted MP (n=1279) were spectroscopically confirmed being plastic. The percentage varied with type, colour and size of the MP. Fibres had a higher success rate (75%) than particles (64%). We tested Raman micro-spectroscopy applicability for MP identification with respect to varying chemical composition (additives), degradation state and organic matter coating. Partially UV-degraded post-consumer plastics provided identifiable Raman spectra for polymers most common among marine MP, i.e. polyethylene and polypropylene.
Assuntos
Monitoramento Ambiental/métodos , Plásticos/análise , Poluentes da Água/análise , Oceano Atlântico , Plásticos/química , Polietileno/análise , Polietileno/química , Polímeros/análise , Polímeros/química , Polipropilenos/análise , Polipropilenos/química , Análise Espectral Raman , Poluentes da Água/químicaRESUMO
Manufacturers have been increasingly considering the implication of materials used in commercial products and the management of such products at the end of their useful lives (as waste or as post-consumer secondary materials). The present work describes the application of the life cycle thinking approach to a plastic product, specifically an anti-glare lamellae (used for road safety applications) made with high-density polyethylene (HDPE). This study shows that optimal environmental and economic outcomes associated with this product can be realized by recovering the material at the end of its useful life (end of life, EoL) and by using the recycled HDPE as a raw material in the production of new similar products. The study confirmed the applicability of the life cycle thinking approach by industry in sustainable products development, supporting the development of robust environmental and economic guidelines.
Assuntos
Resíduos Industriais/análise , Polietileno/análise , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/métodos , Incineração/economia , Reciclagem/economia , Instalações de Eliminação de Resíduos/economiaRESUMO
A diffuser-incorporated transmission near-infrared (NIR) scheme that enables direct spectral collection of packed granular samples with reliable sample representation and reproducibility has been demonstrated. The analytical utility of this method has been evaluated for the determination of polyethylene (PE) pellet density and the discrimination of the geographical origin of rice samples. Based on the preliminary observation of transmission spectral features acquired from spherical polyoxymethylene (POM) packings composed of different particle sizes as well as packing thickness, a portion of the radiation was propagated through the void space in the packing without fully interacting with the POM pellets. This type of radiation, so-called non-fully interacted radiation (NFIR), adversely affected the sample representation as well as the reproducibility of transmission measurements. To maximize the interaction of NIR radiation with granular samples, a polytetrafluoroethylene (PTFE) diffuser was positioned in front of the sample packing to introduce isotropically diffused radiation into the sample. This diffuser-incorporated scheme resulted in highly reproducible transmission spectra for both packed granular samples. Consequently, the density determination of PE pellets as well as discrimination of rice samples according to geographical origin was more accurate using the proposed scheme.
Assuntos
Polietileno/análise , Espectrofotometria Infravermelho/métodos , Geografia , Análise dos Mínimos Quadrados , Método de Monte Carlo , Oryza/química , Tamanho da Partícula , Polietileno/química , Análise de Componente Principal , Propriedades de SuperfícieRESUMO
In this paper new analytical inspection strategies, based on hyperspectral imaging (HSI) in the VIS-NIR and NIR wavelength ranges (400-1000 and 1000-1700 nm, respectively), have been investigated and set up in order to define quality control logics that could be applied at industrial plant level for polyolefins recycling. The research was developed inside the European FP7 Project W2Plastics "Magnetic Sorting and Ultrasound Sensor Technologies for Production of High Purity Secondary Polyolefins from Waste". The main aim of the project is the separation of pure polyethylene and polypropylene adopting an innovative process, the magnetic density separation (MDS). Spectra of plastic particles and contaminants resulting from post-consumer complex wastes and of virgin polyolefins have been acquired by HSI and by Raman spectroscopy. The classification results obtained applying principal component analysis (PCA) on HSI data have been compared with those obtained by Raman spectroscopy, in order to validate the proposed innovative methodology. Results showed that HSI sensing techniques allow to identify both polyolefins and contaminants. Results also demonstrated that HSI has a great potentiality as a tool for quality control of feed (identification of contaminants in the plastic waste) and of the two different pure polypropylene and polyethylene flow streams resulting from the MDS-based recycling process.
Assuntos
Produtos Domésticos/análise , Campos Magnéticos , Polienos/análise , Reciclagem/métodos , Análise Espectral/métodos , Resíduos/análise , Polienos/classificação , Polietileno/análise , Polietileno/classificação , Polipropilenos/análise , Polipropilenos/classificação , Análise de Componente Principal , Controle de Qualidade , Reciclagem/economia , Análise Espectral/classificação , Análise Espectral/instrumentação , Análise Espectral Raman/instrumentação , Resíduos/classificaçãoRESUMO
Recent legislation has stressed the need to decide the best end-of-life (EoL) option for post-consumer products considering their full life-cycle and the corresponding overall environmental impacts. The life cycle assessment (LCA) technique has become a common tool to evaluate those impacts. The present study aimed to contribute to the better understanding of the application of this technique, by evaluating the influence of the selection of the life cycle impact assessment (LCIA) method in its results and conclusions. A specific case study was chosen, using previous information related to an anti-glare lamellae (AGL) for highway use, made with virgin and recycled high-density polyethylene (HDPE). Five distinct LCIA methods were used: Eco-indicator 99, CML 2 (2000), EPS 2000, Eco-indicator 95 and EDIP 97. Consistent results between these methods were obtained for the Climate change, Ozone layer depletion, Acidification and Eutrophication environmental indicators. Conversely, the Summer smog indicator showed large discrepancies between impact assessment methods. The work sheds light on the advantages inherent in using various LCIA methods when doing the LCA study of a specific product, thus evidencing complementary analysis perspectives.