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Quantification and exposure assessment of microplastics in Australian indoor house dust
2021
Soltani, Neda Sharifi | Taylor, Mark Patrick | Wilson, Scott Paton
Limited attention has been given to the presence of MPs in the atmospheric environment, particularly in indoor environments where people spend about 90% of their time. This study quantitatively assesses the prevalence, source and type of MPs in Australian homes with the goal of evaluating human health exposure potential. Thirty-two airborne indoor deposited dust samples were collected in glass Petri dishes from Sydney (Australia) homes, over a one-month period in 2019. Participants completed a questionnaire on their household characteristics. Samples were analysed using a stereomicroscope, a fluorescent microscope and micro-Fourier transform infrared (FTIR) spectroscopy for their colour, size, shape and composition. Inhalation and ingestion rates were modelled using US EPA exposure factors. Microplastic fibre deposition rates ranged from 22 to 6169 fibres/m²/day. Deposited dust comprised 99% fibres. The highest proportion of fibres (19%) were 200–400 μm in length. The majority were natural (42%); 18% were transformed natural-based fibres; and 39% were petrochemical based. A significant difference was observed between the deposition rate and the main floor covering (p-value <0.05). Polyethylene, polyester, polyamide, polyacrylic, and polystyrene fibres were found in higher abundance in homes with carpet as the main floor covering. Where carpet was absent, polyvinyl fibres were the most dominant petrochemical fibre type, indicating the role of flooring materials (e.g. wood varnishes) in determining MP composition. Vacuum cleaner use was significantly related to MP deposition rates (p-value <0.05). MP ingestion rates peaked at 6.1 mg/kg-Bw/year for ages 1–6, falling to a minimum of 0.5 mg/kg-Bw/year in >20 years age group. Mean inhaled MP weight and count was determined to be 0.2±0.07 mg/kg-Bw/year and 12891±4472 fibres/year. Greatest inhalation intake rates were for the <0.5-yr age group, at 0.31 mg/kg-Bw/year. The study data reveal that MPs are prevalent in Australian homes and that the greatest risk of exposure resides with young children. Notwithstanding the limited number of global studies and the different methods used to measure MPs, this study indicates Australian deposition and inhalation rates are at the lower end of the exposure spectrum.
Показать больше [+] Меньше [-]Sustainable functionalized metal-organic framework NH2-MIL-101(Al) for CO2 separation under cryogenic conditions
2021
Bābar, Muḥammad | Mubashir, Muhammad | Mukhtar, Ahmad | Saqib, Sidra | Ullah, Sami | Bustam, Mohamad Azmi | Show, Pau Loke
In this study, a sustainable NH₂-MIL-101(Al) is synthesized and subjected to characterization for cryogenic CO₂ adsorption, isotherms, and thermodynamic study. The morphology revealed a highly porous surface. The XRD showed that NH₂-MIL-101(Al) was crystalline. The NH₂-MIL-101(Al) decomposes at a temperature (>500 °C) indicating excellent thermal stability. The BET investigation revealed the specific surface area of 2530 m²/g and the pore volume of 1.32 cm³/g. The CO₂ adsorption capacity was found to be 9.55 wt% to 2.31 wt% within the investigated temperature range. The isotherms revealed the availability of adsorption sites with favorable adsorption at lower temperatures indicating the thermodynamically controlled process. The thermodynamics showed that the process is non-spontaneous, endothermic, with fewer disorders, chemisorption. Finally, the breakthrough time of NH₂-MIL-101(Al) is 31.25% more than spherical glass beads. The CO₂ captured by the particles was 2.29 kg m⁻³. The CO₂ capture using glass packing was 121% less than NH₂-MIL-101(Al) under similar conditions of temperature and pressure.
Показать больше [+] Меньше [-]Cigarette butts in beach litter: Snapshot of a summer holiday
2021
Araújo, Maria Christina Barbosa de | Costa, Monica Ferreira da
Cigarette butts are considered the most common form of personal litter around the world. It is estimated that 5.5 trillion cigarettes are consumed globally each year and that 4.95 trillion are discarded in some natural or anthropic environment around the world. This study evaluated the pollution of urban beaches in the Brazilian Northeast by cigarette butts in relation to other types of litter. Samplings were conducted in a month of high season (January 2016), at eight heavily used beaches. In the place with the highest concentration of users in each beach, a 200 m transect (3 m width) was established parallel to the water on the most recent strandline. All items >1 cm were counted and classified into categories according to composition (plastic, cigarette butts, wood, glass, metal, paper and organic, such as food leftovers and coconuts) using a standard worksheet. Cigarette butts were considered as an isolated category of litter. A total of 10,880 items was registered. The most abundant items were plastics (44.96%) and cigarette butts (38.36%). Among plastics, the most abundant items were straws, metallic food packaging, sticks (lollipop and popsicle) and cups. Plastic fragments were also abundant in all beaches evaluated, corresponding to 14.5% of the total plastics.
Показать больше [+] Меньше [-]The distribution of marine debris along the Pahang coastline, Malaysia during the Southwest and Northeast Monsoons
2021
Azman, Muhammad Afiq | Ramli, Muhammad Zahir | Che Othman, Siti Fairuz | Shafiee, Saiful Arifin
This study investigated the accumulation of debris at four sites, namely, Gebeng, Batu Hitam, Cherok Paloh, and Air Leleh, along the Pahang coastline, Peninsular Malaysia from March 2019 to February 2020. Plastic was the dominant debris (86.1%) and followed by cloth/fabric-based debris (6.0%), processed lumber debris (3.3%), rubber (2.7%), glass (1.5%), and metal (0.4%). The land-based debris (82.0%) was the major source of the deposition of marine waste. A statistically significant relationship was found between the seasonal variation and marine debris density in tidal and seasonal current along the Pahang coastline. In general, the Northeast Monsoon season had a higher amount of debris than the Southwest Monsoon season.
Показать больше [+] Меньше [-]Insights into seasonal shift in the homogeneity of periphytic protozoan fauna in coastal waters of the Yellow Sea, northern China
2021
Rahman, Mohammad Shafiqur | Kazmi, Syed Shabi Ul Hassan | Uroosa, | Xu, Henglong
The seasonal shift in the homogeneity of the periphytic protozoan fauna was studied based on a four-season baseline survey in the coastal waters of the Yellow Sea, northern China. Samples were collected using glass microscope slides as an artificial substratum at a depth of 2 m after the immersion time of 14 days during each of the four seasons (winter, spring, summer, and autumn, 2017). The protozoan fauna showed a clear seasonal shift in species composition and a significant variation in homogeneity in terms of both compositional and community structure during four seasons. The dispersion measures and β-diversity index represented an increase in the trend from spring to winter. These findings suggest that the homogeneity of the periphytic protozoan fauna was subject to a significant variability shaped mainly by species composition during a four-season cycle in marine ecosystems.
Показать больше [+] Меньше [-]Marine litter pollution on coral reefs of Darvel Bay (East Sabah, Malaysia)
2021
Santodomingo, Nadiezhda | Perry, Chris | Waheed, Zarinah | Syed Hussein, Muhammad Ali bin | Rosedy, Allia | Johnson, Kenneth G.
Marine litter is recognized as an increasing component of marine ecosystem pollution. In this baseline study, we document the magnitude, types, sources, and potential impacts of litter on six coral reefs in East Sabah. We applied a simplified classification of litter to extract abundance data from video transects. The average density was 10.7 items per 100 m². Plastics represent 91% and the remaining 9% were metal, glass, and wood. Most (~70%) plastics are single-use items derived from dumping. Discarded fishing gear accounts for ~25%. Litter pollution increases closer to urban developments, with Sakar reef having higher densities (51 items per 100 m²), and higher Clean Coast Index (CCI = 10.2, dirty) and higher Plastic Abundance Index (PAI = 4.68) scores. This method could and should be readily integrated into ongoing monitoring programs to support assessments of the extent and magnitude of marine litter pollution on reefs worldwide.
Показать больше [+] Меньше [-]Chemical characterization of variably degraded fibre glass reinforced plastic from the marine environment
2021
Hopkinson, Laurence | Ostapishin, Stanislav | Kristova, Petra | Hamilton, Katy | Ciocan, Corina
Glass reinforced plastic (GRP) constitutes the commonest component of small sea going craft of all descriptions. This study provides a baseline molecular and elemental account of GRP's recovered from the marine environment. Fourteen samples of GRP sourced from scrapyards and one sample sourced from a GRP boat manufacturer were examined. Samples were analysed by x-ray fluorescence and mid infrared (MIR). The latter technique confirmed that all samples contained the same polyester resin, poly diallyl phthalate (PDP). The two techniques in combination indicate the presence of aluminium calcium borosilicate E-glass fibres (E denotes electrical) of variable origins. MIR results are consistent with hydrolysis of polyester, weakening of the glass fibre resin interface facilitating exposure of e-type fibres to water which accelerates fibre breakage. The implication being that aging of GRP in the marine environment represent sources for micro (<5 mm) and macro plastic release, plus fragmented asbestiform-like silicate fibres.
Показать больше [+] Меньше [-]Marine litter on a highly urbanized beach at Southeast Brazil: A contribution to the development of litter monitoring programs
2021
Ribeiro, Victor V. | Pinto, Mariana A.S. | Mesquita, Raul K.B. | Moreira, Lucas Buruaem | Costa, Monica F. | Castro, Ítalo Braga
Seasonal distribution of Marine Litter (ML) on Santos beaches was assessed using a citizen science strategy. Plastics and cigarette butts (CB) were the dominant items in all sampling campaigns. Seasonal distribution did not result in significant differences for most items. Plastic and CB amounts were high in summer compared to autumn. For all sampled sites the presence of beach users influenced ML densities. However, results showed that some sites presented an additional influence of local hydrodynamic. Moderate amounts of hazardous items including metal, glass, CB, sanitary waste and plastic tubes used to pack and market illicit drugs represented between 20.8 and 31% of all ML over the seasons. The beaches of Santos were classified as dirty in autumn and spring and as extremely dirty in winter and summer. These findings can serve as a baseline to support mitigating actions by public authorities and start monitoring programs of ML not only in Santos but also in other urbanized beaches.
Показать больше [+] Меньше [-]Simulation study on thermal performance of a Solar box Cooker using nanocomposite for natural Food invention
2021
Bhavani, Sundararajan | Shanmugan, Sengottaiyan | Chithambaram, Venkatesan | Essa, Fadl Abdelmonem Elsayed | Kabeel, Abd-Elnaby | Selvaraju, Periyasami
The double glass cover analysis of a solar box cooker has been implemented in an internal heat transfer using MoS₂–Fe₂O₃–Cr₂O₃ nanomaterials. A nanocomposite material’s essential role is its higher surface/volume ratio which agrees in small area size of a high ductility without strength loss and an enhanced optical property. The nanocomposite materials have an average particle size of 0.2 - 0.5 μm. Compared to the overall thermal energy efficiency of the solar cookers used, the samples with and without this study’s modification are 56.21–31.77% and 33.90–24.90%. The design used nanomaterials’ performance with and without coating materials achieved by the bar plate temperature of about 163.74 °C and 113.34 °C below solar radiation of 1037W/m². The simulation model is conducted on the fuzzy intelligent logic and Cramer’s rules. It agreed with the experimental results by 91%.
Показать больше [+] Меньше [-]Transient behavior of non-toxic natural and hybrid multi-layer desiccant composite materials for water extraction from atmospheric air
2021
Jawarneh, Ali M. | AL-Oqla, Faris M. | Jadoo, Anas Abu
Producing clean water via renewable solar energy and available low-cost natural resources is one of paramount issues for the near future sustainable cleaner production theme to promote civilization. This work investigates the transient behavior of a solar-driven clean water extraction system from air by various desiccant natural and hybrid composite materials. Different single composite desiccant materials, hybrid single composite desiccant material, and hybrid multi-layers composite desiccant materials were examined using an efficient design of a solar glass box with four glass faces and square base setup. Nine different single composite desiccant materials were compared for water production from atmospheric air considering jute, wool, cotton, and maize starch host materials. The effect of CaCl₂ solution concentration on the hybridization of such materials was also investigated to examine and optimize their water productivity efficiency. Thirteen hybrid multi-layer starch-based composite desiccant material types were utilized. Different layer combinations and weight percentages of hybrid composite desiccant materials were optimized based on the performance in the single hybrid composites stages including wool/CaCl₂/starch, jute/CaCl₂/starch, and cotton/CaCl₂/starch. Results have indicated that the transient behavior of water productivity of composite desiccants increased as the wool percentage by mass in the composite has been increased. The transient behavior of water productivity of both single and hybrid multi-layer composites reached its maximum at 1:00 o’clock PM. The quality of extracted water was analyzed using total dissolved solids (TDS) test and found to be within the excellent category of clean water suitable for human being. Water generated from the samples that contain only natural fibers and starch was the cleaner and non-toxic.
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