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1.
Environ Res ; 247: 118131, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38215920

RESUMEN

Directive 2000/53/EC and the European Circular Economy Package (2018) required the Member States to take all the necessary measures to reach the reuse-recycling goal of 85% for end-of-life vehicles (ELVs). In 2019, Europe achieved 89.6% of reuse-recycling, but most EC countries are still not completely compliant, Italy standing, for example, at only 84.2%. For this reason, actions are necessary to increase reuse-recycling for the waste generated in the operations of ELV shredding and separation, known as automobile shredded residues (ASRs). This study was aimed at assessing if the assimilation of ASRs to a solid recovered fuel (SRF) was a feasible solution. That would allow the waste to lose its status (end-of-waste, EoW), thus increasing the recycling rate. The assimilation of ASRs to SRFs requires the compliance with a series of parameters, namely net calorific value (NCV), content of chlorine (Cl), mercury (Hg) and selected heavy metals. The above-mentioned parameters were analyzed in the principal ASR fractions, namely textile, plastic and foam rubber, found in the samples collected during four sampling campaigns (2017-2021) performed at the same ELV treatment plant. Notwithstanding the great variability observed in the four samples, the results of the analyses revealed that the three fractions were compliant with NCV, Cl and Hg content. Conversely, the heavy metals' content was found a more critical parameter, in fact only the plastic fraction was suitable for SRF assimilation. Textiles presented criticality for the content of copper (Cu), nickel (Ni) and antimony (Sb). The heavy metals' contamination of foam rubber was found to be strongly related to particles' dimensions. A model which put particle size and metals' content into relationship was developed and validated. Removing particles of <40 mm significantly improved the quality of the material, however the content of Cu and Ni remained a critical issue for particles up to 200 mm. The SRF assimilation of the plastic fraction would increase the reuse-recycling rate of approx. 2.4-3.3%, thus allowing the achievement of the EC goals concerning the ELV management.


Asunto(s)
Mercurio , Metales Pesados , Automóviles , Goma , Reciclaje/métodos
2.
Environ Res ; 243: 117806, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38043899

RESUMEN

Non-targeted analysis (NTA) has great potential to screen emerging contaminants in the environment, and some studies have conducted in-depth investigation on environmental samples. Here, we used a NTA workflow to identify emerging contaminants in used tire particle (TP) leachates, followed by quantitative prediction and toxicity assessment based on hazard scores. Tire particles were obtained from four different types of automobiles, representing the most common tires during daily transportation. With the instrumental analysis of TP leachates, a total of 244 positive and 104 negative molecular features were extracted from the mass data. After filtering by a specialized emerging contaminants list and matching by spectral databases, a total of 51 molecular features were tentatively identified as contaminants, including benzothiazole, hexaethylene glycol, 2-hydroxybenzaldehyde, etc. Given that these contaminants have different mass spectral responses in the mass spectrometry, models for predicting the response of contaminants were constructed based on machine learning algorithms, in this case random forest and artificial neural networks. After five-fold cross-validation, the random forest algorithm model had better prediction performance (MAECV = 0.12, Q2 = 0.90), and thus it was chosen to predict the contaminant concentrations. The prediction results showed that the contaminant at the highest concentration was benzothiazole, with 4,875 µg/L in the winter tire sample. In addition, the joint toxicity assessment of four types of tires was conducted in this study. According to different hazard levels, hazard scores increasing by a factor 10 were developed, and hazard scores of all the contaminants identified in each TP leachate were summed to obtain the total hazard score. All four tires were calculated to have relatively high risks, with winter tires having the highest total hazard score of 40,751. This study extended the application of NTA research and led to the direction of subsequent targeting studies on highly concentrated and toxic contaminants.


Asunto(s)
Automóviles , Goma , Goma/química , Goma/toxicidad , Transportes , Benzotiazoles/toxicidad
3.
Chem Rec ; 22(11): e202200186, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35959940

RESUMEN

Plastics have been an indispensable material of choice in automobiles with wide range of applications such as interior, exterior, under the hood, and lighting/wiring applications. The prime motive of inclusion of these materials is increase in fuel efficiency and reduction in carbon footprint by replacing the energy intensive metallic counterparts. The current decade i. e., the 2020s has seen a recent surge in the sales of electronic vehicles. Although these numbers are promising, the growth in the rest of the parts of the world is not encouraging. It is primarily due to the skepticism involving battery life and efficiency, profitability, and environmental footprint when compared to conventional and hybrid vehicles. Also, a more concerted effort is needed in the lagging areas in order to install the required infrastructure. The emergence of plastics in the development and acceptance of e-vehicles is going to be pivotal especially when the efficiency and profitability are considered as they give the required freedom to the engineers for the design and development of various parts and sizes by replacing the bulkier and more dense materials. Also, the research on bionanocomposites has received great interest from the research community due to their versatility in application along with their eco-friendly nature throughout the lifecycle starting from feedstock up to end-of-life treatment. This review paper will be one of its kind to present a critical review of the recent developments of polymers suitable for use in e-vehicles. Also, a comprehensive discussion comprising of newer research areas for polymers in their use for e-vehicles will be presented.


Asunto(s)
Automóviles , Polímeros , Electricidad , Suministros de Energía Eléctrica , Plásticos
4.
J Appl Microbiol ; 133(6): 3596-3604, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36000381

RESUMEN

AIMS: Legionella pneumophila (Lp), a human pathogen, has been detected in windscreen wiper fluid reservoirs (WWFRs) where commercial screen washes (CSWs) are commonly added. Limited information is available on CSWs against planktonic Lp; however, responses of sessile Lp and planktonic Lp pre-acclimated in nutrient-limited water to CSWs remain unknown. This study thus investigates the antibacterial effects of CSWs on sessile and starved planktonic Lp, in comparison with unstarved Lp. METHODS AND RESULTS: Lp biofilms were produced on glass and WWFR materials of high-density polyethylene (HDPE) and polypropylene (PP). Planktonic Lp with and without acclimation in tap water were prepared. Log reductions in cell counts averaged 0.4-5.0 for 10 brands of CSWs against sessile Lp and 1.0-3.9 and 0.9-4.9, respectively, against starved and unstarved planktonic Lp for five CSWs. Both biofilm formation and acclimation in tap water enhanced Lp resistance to CSWs. Significantly different log-reduction values among CSW brands were observed for sessile Lp on HDPE and planktonic Lp regardless of acclimation (p < 0.05). CONCLUSIONS: Biofilm formation, starvation acclimation and CSW brand are crucial factors influencing Lp response to CSWs. SIGNIFICANCE AND IMPACT OF STUDY: This study advances the knowledge of Lp reaction in anthropogenic water systems with CSWs.


Asunto(s)
Antiinfecciosos , Legionella pneumophila , Humanos , Automóviles , Polietileno , Biopelículas , Plancton , Agua/farmacología , Antiinfecciosos/farmacología , Microbiología del Agua
5.
Int J Environ Health Res ; 32(12): 2653-2664, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34933623

RESUMEN

The aim of this study was to investigate the effects of bottled water left in the car and those left in the refrigerator on the physiological and biochemical parameters of male rats. Eighteen male albino rats were randomly divided into control, warmed bottled water (WBW), and cooled bottled water (CBW) groups. The concentrations of bisphenol A (BPA) and antimony (Sb) in the water samples were measured. Results showed that the levels of BPA and Sb were higher in bottled water left in the car and those kept at room temperature (control), relative to the bottled water samples kept in the fridge. Bodyweight, some metabolic indicators, cTnT and CRP levels, hematological parameters, testosterone level, and sperm quality were significantly affected by storage conditions. These results indicate that storage conditions can potentially affect the quality of bottled water, which in turn can affect the biological parameters of living organisms. Moreover, since the concentrations of BPA and Sb were least in bottled water kept in the refrigerator, we recommend that manufacturers and households should endeavor to keep bottled water under cold storage.


Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Animales , Masculino , Ratas , Automóviles , Agua Potable/química , Tereftalatos Polietilenos/análisis , Tereftalatos Polietilenos/química , Semen/química , Contaminantes Químicos del Agua/análisis
6.
Waste Manag Res ; 40(12): 1757-1765, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35708148

RESUMEN

Although the use of plastic components is increasing in the automotive industry, yet the recovery rates of these materials in end-of-life vehicle (ELV) is lower compared to metals. One of the main problems of ELV plastic waste is poor separation and sorting. Large car plastic parts consist of fibre-reinforced plastics, whereas other components end up in the automotive shredder residue (ASR), featuring a very heterogeneous mix of light materials that contains mostly non-metallic materials such as textiles, plastics, cartridges and wood. Generally, ASR was disposed in landfill or diverted to thermal treatments, such as pyrolysis or gasification, for energy recovery. Currently, the recovery of raw materials from various waste streams plays a key role in new European strategy for plastics in a circular economy. The approach of physical recycling methods described in this mini-review helps to maintain the value of polymer materials in the value chain allowing the reuse in the original or similar application.


Asunto(s)
Automóviles , Plásticos , Reciclaje/métodos , Instalaciones de Eliminación de Residuos , Polímeros
7.
Sensors (Basel) ; 21(21)2021 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-34770300

RESUMEN

The functionality of products increases when more sensors are used. This trend also affects future automobiles and becomes even more relevant in connected and autonomous applications. Concerning automotive lightweight design, carbon fibre-reinforced polymers (CFRP) are suitable materials. However, their drawbacks include the relatively high manufacturing costs of CFRP components in addition to the difficulty of recycling. To compensate for the increased expenditure, the integration of automotive sensors in CFRP vehicle structures provides added value. As a new approach, established sensors are integrated into fibre-reinforced polymer (FRP) structures. The sensors are usually mounted to the vehicle. The integration of sensors into the structure saves weight and space. Many other approaches specifically develop new sensors for integration into FRP structures. With the new approach, there is no need for elaborate development of new sensors since established sensors are used. The present research also showed that the range of applications of the sensors can be extended by the integration. The present paper outlines the functional behaviour of the integrated sensor utilized for crashing sensing. First of all, the integration quality of the sensor is relevant. Different requirements apply to the usual mounting of the sensor. The self-sensing structure must fulfil those requirements. Moreover, unfamiliar characteristics of the new surrounding structure might affect the sensing behaviour. Thus, the sensing behaviour of the self-sensing composite was analyzed in detail. The overarching objective is the general integration of sensors in products with reasonable effort.


Asunto(s)
Polímeros , Reciclaje , Automóviles , Fibra de Carbono
8.
Molecules ; 25(6)2020 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-32204539

RESUMEN

Subzero automotive cold-starts of proton exchange membrane fuel cell (PEMFC) stacks require accelerated thermal rises to achieve nominal operating conditions and close-to-instantaneous usable output power. Advances in the material, structure and operational dependence on the balance between the maximum power output and the electrochemical conversion of hydrogen and oxygen into water requires validation with subzero cold-starts. Herein are presented the design and validation of a quasi-adiabatic PEMFC to enable single-cell evaluation, which would provide a more cost-effective option than stack-level testing. At -20 °C, the operational dependence of the preconditioned water content (3.2 verse 6.2) for a galvanic cold-start (<600 mA cm-2) was counter to that of a laboratory-scale isothermal water fill test (10 mA cm-2). The higher water content resulted in a faster startup to appreciable power output within 0.39 min versus 0.65 min. The water storage capacity, as determined from the isothermal water fill test, was greater, for the lower initial water content of 3.2, than 6.2, 17.4 ± 0.3 mg versus 12.8 ± 0.4 mg, respectively. Potentiostatic cold-starts produced usable power in 0.09 min. The versatility and reproducibility of the single cell quasi-adiabatic fixture avail it to future universal cold-start stack relevant analyzes involving operational parameters and advanced materials, including: applied load, preconditioning, interchanging flow field structures, diffusion media, and catalyst coated membranes.


Asunto(s)
Automóviles , Diseño de Equipo/métodos , Membranas Artificiales , Catálisis , Difusión , Suministros de Energía Eléctrica , Hidrógeno/química , Industrias , Protones , Termodinámica , Agua/química
9.
Molecules ; 25(13)2020 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-32605301

RESUMEN

Friction and wear are the main factors in the failure of the piston in automobile engines. The objective of this work was to improve the tribological behaviour and lubricant properties using hybrid Cellulose Nanocrystal (CNC) and Copper (II) oxide nanoparticles blended with SAE 40 as a base fluid. The two-step method was used in the hybrid nanofluid preparation. Three different concentrations were prepared in a range of 0.1% to 0.5%. Kinematic viscosity and viscosity index were also identified. The friction and wear behavior were evaluated using a tribometer based on ASTM G181. The CNC-CuO nano lubricant shows a significant improvement in term of viscosity index by 44.3-47.12% while for friction, the coefficient of friction (COF) decreases by 1.5%, respectively, during high and low-speed loads (boundary regime), and 30.95% during a high-speed, and low load (mixed regime). The wear morphologies results also show that a smoother surface was obtained after using CNC-CuO nano lubricant compared to SAE 40.


Asunto(s)
Celulosa/síntesis química , Cobre/química , Lubricantes/síntesis química , Automóviles , Fenómenos Biomecánicos , Celulosa/química , Lubricantes/química , Ensayo de Materiales , Nanopartículas , Propiedades de Superficie
10.
Waste Manag Res ; 38(1): 35-43, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31470764

RESUMEN

The medium temperature pyrolysis process using a fixed-bed reactor at atmospheric pressure was utilised to recover carbon black from motorcycle and automobile tyres. Experimental results have shown that the ash and volatile contents of several recovered carbon blacks are high, the elongation at break of the vulcanised natural rubber filled with recovered carbon blacks from motorcycle tyres is better than that from motorcycle tyres and standard carbon black 7#, while the other mechanical properties are worse. In order to improve the reinforcing effect of recovered carbon blacks, the modification of recovered carbon black was performed by high-energy electron bombardment and non-oxidising acid. The specific surface area of the pyrolytic carbon blacks increased after high-energy electron bombardment. The ash content of the pyrolytic carbon black was reduced from 22.5% to 8.4% after rinsing with hydrochloric acid, and the tensile stress at 300% was increased by about 2.2 MPa.


Asunto(s)
Pirólisis , Hollín , Automóviles , Carbono , Goma , Temperatura
11.
J Eur Acad Dermatol Venereol ; 33(10): 1993-2000, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31087433

RESUMEN

BACKGROUND: Chronic lead toxicity is a worldwide public health problem. Lead possesses deleterious effects on many organ systems. However, little is known regarding its clinical and biophysical effects on the skin. OBJECTIVE: To investigate mucocutaneous signs and biophysical property changes in skin after chronic lead toxicity. METHODS: One hundred and eighty-seven patients who were car battery workers participated in the study. Complete history and physical examination were performed. Blood was collected for laboratory analyses. Thorough skin examination by dermatologists was carried out in 134 subjects. Additionally, 96 patients with blood lead levels (BLL) >70 µg/dL were further evaluated for skin elasticity, sebum content, transepidermal water loss (TEWL), hydration, pH and pigmentation. An equal number of age-, sex- and skin-type-matched subjects were recruited as controls. RESULTS: The mean BLL of all subjects was 74.15 ± 11.58 µg/dL. The most frequently observed signs were gingival brown pigmentation in 112 (83.6%), gingivitis in 111 (82.8%) and lead line in 66 (49.3%) patients. The lead line was found in subjects with significantly higher BLLs (adjusted mean difference 6.45, 95% CI 2.30-10.60 µg/dL, P = 0.003) and in association with gingivitis (adjusted OR 7.32, 95% CI 2.08-25.74, P = 0.002). Mean BLL of the patients who underwent biophysical assessment was 82.77 ± 9.80 µg/dL. Patients exhibited a statistically significant lower skin hydration observed by corneometer as well as elasticity. The adjusted ORs of having dry skin and lower elasticity were 15.32 (95% CI 4.41-53.24), P < 0.001) and 1.96 (95% CI 1.06-3.60), P = 0.031), respectively. These differences were not significant for sebum content, TEWL, pH and pigmentation. CONCLUSION: Importantly, even in normal-appearing skin, level of hydration and elasticity decreased in lead-intoxicated patients. These results suggest that lead might possess harmful effects on the skin at measurable levels.


Asunto(s)
Gingivitis/inducido químicamente , Intoxicación por Plomo/complicaciones , Industria Manufacturera , Exposición Profesional/efectos adversos , Piel/fisiopatología , Adulto , Automóviles , Elasticidad/efectos de los fármacos , Femenino , Encía/efectos de los fármacos , Encía/fisiopatología , Humanos , Concentración de Iones de Hidrógeno , Plomo/sangre , Plomo/toxicidad , Intoxicación por Plomo/fisiopatología , Masculino , Sebo/metabolismo , Piel/química , Pigmentación de la Piel/efectos de los fármacos , Agua/metabolismo , Pérdida Insensible de Agua/efectos de los fármacos
12.
Water Sci Technol ; 78(3-4): 467-475, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30207988

RESUMEN

Forward osmosis (FO) is a potential membrane technology to treat wastewater energy efficiently with low fouling. In laboratory-scale experiments, six effluents from a dairy and an automobile production plant were tested to find out if FO is an applicable treatment technology. Permeate flux and reverse salt flux were determined in nine test series with three subsequent 5 h experiments each. In between, the membrane was cleaned with deionized water. Membrane performance tests before each experiment were used to monitor membrane performance and fouling. Samples were analysed and the T/M-value was introduced to indicate which substances caused fouling. Dairy cheese brine was a suitable DS. Here, permeate fluxes were 21.0 and 15.1 L/(m²·h). Automobile cooling tower water and wastewater from cathodic dip painting were also used as DS. However, permeate fluxes were below 1.1 L/(m²·h). The tested FS, reverse osmosis concentrate from dairy wastewater treatment, rinsing water and wastewater from automobile cathodic dip painting, as well as wastewater from automobile paint shop pre-treatment, showed good performance regarding the permeate flux of between 7.9 and 19.4 L/(m²·h). Membrane performance test showed that some of the effluents lead to permeate flux reduction due to fouling. Different cleaning-in-place methods were examined. Eventually, permeate flux was restored.


Asunto(s)
Residuos Industriales , Purificación del Agua , Automóviles , Industria Lechera , Membranas Artificiales , Ósmosis , Aguas Residuales
13.
Waste Manag Res ; 35(1): 110-119, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27881804

RESUMEN

Stricter regulatory requirements concerning end-of-life vehicles and rising disposal costs necessitate new ways for automobile shredder residue utilisation. The shredder granulate and fibres, produced by the VW-SICON-Process, have a high energy content of more than 20 MJ kg-1, which makes energy recovery an interesting possibility. Shredder fibres have a low bulk density of 60 kg m-3, which prevents efficient storing and utilisation as a refuse-derived fuel. By mixing fibres with plastic-rich shredder granulate and heating the mixture, defined granules can be produced. With this 'ReGran' process, the bulk density can be enhanced by a factor of seven by embedding shredder fibres in the partially melted plastic mass. A minimum of 26-33 wt% granulate is necessary to create enough melted plastic. The process temperature should be between 240 °C and 250 °C to assure fast melting while preventing extensive outgassing. A rotational frequency of the mixing tool of 1000 r min-1 during heating and mixing ensures a homogenous composition of the granules. During cooling, lower rotational frequencies generate bigger granules with particles sizes of up to 60 mm at 300 r min-1. To keep outgassing to a minimum, it is suggested to melt shredder granulate first and then add shredder fibres. Adding coal, wood or tyre fluff as a third component reduces chlorine levels to less than 1 wt%. The best results can be achieved with tyre fluff. In combination with the VW-SICON-Process, ReGran produces a solid recovered fuel or 'design fuel' tailored to the requirements of specific thermal processes.


Asunto(s)
Automóviles , Administración de Residuos/métodos , Residuos , Plásticos
14.
Environ Sci Technol ; 50(6): 3002-9, 2016 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-26871002

RESUMEN

Recent literature on material flow analysis has been focused on quantitative characterization of past material flows. Fewer analyses exist on past and prospective quantification of stocks of materials in-use. Some of these analyses explore the composition of products' stocks, but a focus on the characterization of material stocks and its relation with service delivery is often neglected. We propose the use of the methods of human demography to characterize material stocks, defined herein as stock demographics, exploring the insights that this approach could provide for the sustainable management of materials. We exemplify an application of stock demographics by characterizing the composition and service delivery of iron, steel, and aluminum stocks of cars in Great Britain, 2002-2012. The results show that in this period the stock has become heavier, it is traveling less, and it is idle for more time. The visualization of material stocks' dynamics demonstrates the pace of product replacement as a function of its usefulness and enables the formulation of policy interventions and the exploration of future trends.


Asunto(s)
Aluminio/economía , Automóviles/economía , Acero/economía , Demografía , Humanos , Estudios Prospectivos , Reino Unido
15.
Contact Dermatitis ; 75(1): 14-9, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26940399

RESUMEN

BACKGROUND: Allergic contact dermatitis caused by polyester resin is considered to be rare. OBJECTIVES: To describe 11 new patients diagnosed with occupational contact allergy to components of polyester resin systems in 1994-2009. METHODS: Data on occupations, patch test results, symptoms and exposure to polyester products were retrieved from patient files, covering 1994 to February 2015. RESULTS: Five patients reacted to unsaturated polyester resin putties. In 3 of these cases, putties were considered to be the main cause of the dermatitis. Four patients had cobalt allergy resulting from cobalt salts that were used as accelerators in polyester resins. Three patients were sensitized to triglycidyl isocyanurate (TGIC), a cross-linker in polyester powder paints. CONCLUSIONS: Two product types are of particular importance in contact allergy to polyester resin: powder paints cured by heat with TGIC as the cross-linker, and car putties. Car putties are used not only in repair car painting, but also in some industrial trades to smoothen surfaces before painting. As commercial patch test substances of polyester resin putties are lacking, patients' own products need to be tested. Cobalt salts are used in several types of polyester resin product as accelerators, and these must be considered as a possible cause of cobalt sensitization.


Asunto(s)
Cobalto/efectos adversos , Dermatitis Alérgica por Contacto/etiología , Dermatitis Profesional/etiología , Pintura/efectos adversos , Poliésteres/efectos adversos , Triazinas/efectos adversos , Automóviles , Dermatosis Facial/etiología , Finlandia , Dermatosis de la Mano/etiología , Humanos , Estudios Retrospectivos
17.
Ecotoxicol Environ Saf ; 131: 37-44, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27179608

RESUMEN

Organic friction materials are standardly used in brakes of small planes, railroad vehicles, trucks and passenger cars. The growing transportation sector requires a better understanding of the negative impact related to the release of potentially hazardous materials into the environment. This includes brakes which can release enormous quantities of wear particulates. This paper addresses in vitro detection of toxic and mutagenic potency of one model and two commercially available low-metallic automotive brake pads used in passenger cars sold in the EU market. The model pad made in the laboratory was also subjected to a standardized brake dynamometer test and the generated non-airborne wear particles were also investigated. Qualitative "organic composition" was determined by GC/MS screening of dichloromethane extracts. Acute toxicity and mutagenicity of four investigated sample types were assessed in vitro by bioluminescence assay using marine bacteria Vibrio fischeri and by two bacterial bioassays i) Ames test on Salmonella typhimurium His(-) and ii) SOS Chromotest using Escherichia coli PQ37 strain. Screening of organic composition revealed a high variety of organic compounds present in the initial brake pads and also in the generated non-airborne wear debris. Several detected compounds are classified by IARC as possibly carcinogenic to humans, e. g. benzene derivatives. Acute toxicity bioassay revealed a response of bacterial cells after exposure to all samples used. Phenolic resin and wear debris were found to be acutely toxic; however in term of mutagenicity the response was negative. All non-friction exposed brake pad samples (a model pad and two commercial pad samples) were mutagenic with metabolic activation in vitro.


Asunto(s)
Escherichia coli/efectos de los fármacos , Formaldehído/toxicidad , Metales/toxicidad , Compuestos Orgánicos/toxicidad , Fenoles/toxicidad , Polímeros/toxicidad , Salmonella typhimurium/efectos de los fármacos , Automóviles , Carcinógenos , Escherichia coli/genética , Cromatografía de Gases y Espectrometría de Masas , Metales/química , Pruebas de Mutagenicidad , Mutágenos , Compuestos Orgánicos/química , Material Particulado/toxicidad , Salmonella typhimurium/genética
18.
J Environ Manage ; 170: 1-7, 2016 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-26775155

RESUMEN

This paper aims at the sustainable development of activated carbons for value-added applications from the waste tyre pyrolysis product, tyre char, in order to make pyrolysis economically favorable. Two activation process parameters, activation temperature (900, 925, 950 and 975 °C) and residence time (2, 4 and 6 h) with steam as the activating agent have been investigated. The textural properties of the produced tyre char activated carbons have been characterized by nitrogen adsorption-desorption experiments at -196 °C. The activation process has resulted in the production of mesoporous activated carbons confirmed by the existence of hysteresis loops in the N2 adsorption-desorption curves and the pore size distribution curves obtained from BJH method. The BET surface area, total pore volume and mesopore volume of the activated carbons from tyre char have been improved to 732 m(2)/g, 0.91 cm(3)/g and 0.89 cm(3)/g, respectively. It has been observed that the BET surface area, mesopore volume and total pore volume increased linearly with burnoff during activation in the range of experimental parameters studied. Thus, yield-normalized surface area, defined as the surface area of the activated carbon per gram of the precursor, has been introduced to optimize the activation conditions. Accordingly, the optimized activation conditions have been demonstrated as an activation temperature of 975 °C and an activation time of 4 h.


Asunto(s)
Carbón Orgánico/química , Incineración , Goma/química , Automóviles , Calor , Humanos , Residuos Industriales , Reciclaje/métodos
19.
Anal Bioanal Chem ; 407(12): 3357-76, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25757825

RESUMEN

The problem of interpretation of common provenance of the samples within the infrared spectra database of polypropylene samples from car body parts and plastic containers as well as Raman spectra databases of blue solid and metallic automotive paints was under investigation. The research involved statistical tools such as likelihood ratio (LR) approach for expressing the evidential value of observed similarities and differences in the recorded spectra. Since the LR models can be easily proposed for databases described by a few variables, research focused on the problem of spectra dimensionality reduction characterised by more than a thousand variables. The objective of the studies was to combine the chemometric tools easily dealing with multidimensionality with an LR approach. The final variables used for LR models' construction were derived from the discrete wavelet transform (DWT) as a data dimensionality reduction technique supported by methods for variance analysis and corresponded with chemical information, i.e. typical absorption bands for polypropylene and peaks associated with pigments present in the car paints. Univariate and multivariate LR models were proposed, aiming at obtaining more information about the chemical structure of the samples. Their performance was controlled by estimating the levels of false positive and false negative answers and using the empirical cross entropy approach. The results for most of the LR models were satisfactory and enabled solving the stated comparison problems. The results prove that the variables generated from DWT preserve signal characteristic, being a sparse representation of the original signal by keeping its shape and relevant chemical information.


Asunto(s)
Automóviles , Modelos Teóricos , Pintura/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Análisis de Varianza , Funciones de Verosimilitud , Polipropilenos/análisis , Procesamiento de Señales Asistido por Computador , Análisis de Ondículas
20.
Environ Res ; 142: 615-23, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26318256

RESUMEN

Due to strong binding, optical clarity, adhesion to many surfaces, toughness and flexibility polyvinyl butyral (PVB) resin films are commonly used in the automotive and architectural application as a protective interlayer in the laminated glass. Worldwide million tons of PVB waste generated from end-of-life automotive associated with various environmental issues. Stringent environmental directive, higher land cost eliminates land filling option, needs a study, we have developed a mechanochemical separation process to separate PVB resins from glass and characterized the separated PVB through various techniques, i.e., scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Commercial nonionic surfactants D201 used for the mechanochemical separation purpose. Through parameter optimization following conditions are considered to be the optimum condition; 30v ol% D201, stirring speed of 400 rpm, 35 °C temperature, operation time 1h, and dilute D201 volume to waste automotive laminated glass weight ratio of ≈25. The technology developed in our laboratory is sustainable, environmentally friendly, techno-economical feasible process, capable of mass production (recycling).


Asunto(s)
Automóviles , Contaminantes Ambientales/análisis , Vidrio , Polivinilos/química , Reciclaje , Contaminantes Ambientales/química , Microscopía Electrónica de Rastreo , República de Corea , Análisis Espectral/métodos
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