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Jumping on the bed and associated increases of PM10, PM2.5, PM1, airborne endotoxin, bacteria, and fungi concentrations Full text
2019
Yen, Yu-Chuan | Yang, Chun-Yuh | Mena, Kristina Dawn | Cheng, Yu-Ting | Yuan, Chung-Shin | Chen, Pei-Shih
Jumping on the bed is a favorite behavior of children; however, no study has investigated the increased air pollutants resulting from jumping on the bed. Therefore, we aimed to investigate the elevated concentrations of particulate matter (PM) and bioaerosols from jumping on the bed and making the bed. Simulation of jumping on the bed and making the bed was performed at sixty schoolchildren's houses in Taiwan. PM10, PM2.5, PM1 (PM with aerodynamic diameter less than 10, 2.5, and 1 μm, respectively) and airborne bacteria, fungi and endotoxin concentrations were simultaneously measured over simulation and background periods. Our results show the increase of PM10, PM2.5, PM1, airborne bacteria and fungi through the behavior of jumping on the bed (by 414 μg m-3, 353 μg m-3, 349 μg m-3, 6569 CFU m-3 and 978 CFU m-3, respectively). When making the bed, the PM10, PM2.5, PM1, airborne bacteria and fungi also significantly increased by 4.69 μg m-3, 4.09 μg m-3, 4.15 μg m-3, 8569 CFU m-3, and 779 CFU m-3, respectively. Airborne endotoxin concentrations significantly increased by 21.76 EU m-3 following jumping on the bed and making the bed. Moreover, when jumping on the bed, higher PM2.5 and PM1 concentrations in houses with furry pets rather than no furry pets, and less airborne fungi in apartments than in townhouses were found. For making the bed, lower airborne fungi was found in houses using essential oils rather than no essential oils using. The airborne endotoxin concentrations were positively associated with furry pets and smokers in the homes and negatively correlated to the home with window opening with a statistical significance during the periods of jumping on the bed and making the bed. In conclusion, significant increases of PM and bioaerosols during jumping on the bed and making the bed may need to be concerned.
Show more [+] Less [-]Marine litter from fishery activities in the Western Mediterranean sea: The impact of entanglement on marine animal forests Full text
2019
Consoli, Pierpaolo | Romeo, Teresa | Angiolillo, Michela | Canese, Simonepietro | Esposito, Valentina | Salvati, Eva | Scotti, Gianfranco | Andaloro, Franco | Tunesi, Leonardo
The anthropogenic marine debris, especially abandoned, lost or otherwise discarded Fishing Gear (ALDFG), represents a rising concern, because of its potential harmful impact on the marine animal forests. We carried out 13 km of video recordings, by means of a remotely operated vehicle, from 10 to 210 m depth, in an anthropised area of the Tyrrhenian Sea (Mediterranean Sea). This site, for its high ecological importance and biodiversity value, has been identified for the establishment of a new marine protected area (MPA). The aim of this paper was to assess marine litter abundance and its effects on the benthic fauna. The debris density, in the study area, ranged from 0.24 to 8.01 items/100 m2, with an average of 3.49 (±0.59) items/100 m2. The derelict fishing gear, mainly fishing lines, were the main source of marine debris, contributing 77.9% to the overall litter. The impacts of debris on the benthic fauna were frequently recorded, with 28.5% of the litter entangling corals and impacting habitats of conservation concern. These impacts were exclusively caused by the derelict fishing gear (91.2% by longlines), and the highest percentage (49.1%) of ALDFG causing impacts was observed from 41 to 80 m depth, in the coralligenous biocenosis. The results of the present study will help the fulfilment of “harm” monitoring, as recommended by the Marine Strategy Framework Directive (MSFD) and the UN Environment/MAP Regional Plan on the marine litter management in the Mediterranean Sea. Regarding the actions to reduce the derelict fishing gear, preventive measures are usually preferred instead of the extensive removals based on cost-effectiveness and sustainability. The establishment of a new MPA in the area could be a good solution to reduce ALDFG, resulting in the improvement of the ecological status of this coastal area.
Show more [+] Less [-]Trophic status affects the distribution of polycyclic aromatic hydrocarbons in the water columns, surface sediments, and plankton of twenty Chinese lakes Full text
2019
Tao, Yuqiang | Liu, Donghong
The influence of trophic status on the distribution of hydrophobic organic contaminants (HOCs) in different subtropical shallow waters at large spatial scales remains largely unknown. In this study, samples of surface sediments, water, total suspended particles, phytoplankton, and zooplankton were simultaneously collected from 83 sampling sites in 20 subtropical oligotrophic to hyper-eutrophic shallow lakes in China to investigate the influence of trophic status on the spatial distribution and sinking fluxes of 16 polycyclic aromatic hydrocarbons (PAHs). The total concentration of the 16 PAHs (ΣPAH₁₆) in the water columns of these lakes varied from 0.22 to 5.81 μg L⁻¹, and increased with the trophic state index (TSI) and phytoplankton biomass. Phytoplankton were the dominant reservoir for the PAHs in the water column. However, the fraction of ΣPAH₁₆ in phytoplankton decreased with the TSI. The average sinking flux of ΣPAH₁₆ of the individual lakes varied from 2257.1 to 261674.1 mg m⁻² d⁻¹, and increased with the TSI of the lakes. The concentration of ΣPAH₁₆ in the surface sediments ranged from 385.77 to 3784.37 ng gdw⁻¹, and increased with the TSI and the ratio of phycocyanin/sediment organic carbon. It suggested that cyanobacterial biomass affected by trophic status dominated the occurrence of the PAHs in the surface sediments of these lakes. Biomass dilution and the biological pump affected the accumulation of the PAHs in phytoplankton, and zooplankton, and had more influence on the PAHs with higher hydrophobicity. Both the bioconcentration factors and bioaccumulation factors of the PAHs decreased with the TSI. No biomagnification was observed for the PAHs from phytoplankton to zooplankton in these lakes in spring. Our study provided novel knowledge for the coupling between eutrophication and HOCs in 20 subtropical shallow lakes with different trophic status.
Show more [+] Less [-]Facile synthesis of GO and g-C3N4 nanosheets encapsulated magnetite ternary nanocomposite for superior photocatalytic degradation of phenol Full text
2019
Rehman, Ghani Ur | Ṭāhir, Muḥammad | Goh, P.S. | Ismail, A.F. | Samavati, Alireza | Zulhairun, A.K. | Rezaei-DashtArzhandi,
In this study, the synthesis of Fe₃O₄@GO@g-C₃N₄ ternary nanocomposite for enhanced photocatalytic degradation of phenol has been investigated. The surface modification of Fe₃O₄ was performed through layer-by-layer electrostatic deposition meanwhile the heterojunction structure of ternary nanocomposite was obtained through sonicated assisted hydrothermal method. The photocatalysts were characterized for their crystallinity, surface morphology, chemical functionalities, and band gap energy. The Fe₃O₄@GO@g-C₃N₄ ternary nanocomposite achieved phenol degradation of ∼97%, which was significantly higher than that of Fe₃O₄@GO (∼75%) and Fe₃O₄ (∼62%). The enhanced photoactivity was due to the efficient charge carrier separation and desired band structure. The photocatalytic performance was further enhanced with the addition of hydrogen peroxide, in which phenol degradation up to 100% was achieved in 2 h irradiation time. The findings revealed that operating parameters have significant influences on the photocatalytic activities. It was found that lower phenol concentration promoted higher activity. In this study, 0.3 g of Fe₃O₄@GO@g-C₃N₄ was found to be the optimized photocatalyst for phenol degradation. At the optimized condition, the reaction rate constant was reported as 6.96 × 10⁻³ min⁻¹. The ternary photocatalyst showed excellent recyclability in three consecutive cycles, which confirmed the stability of this ternary nanocomposite for degradation applications.
Show more [+] Less [-]Influence of titanium dioxide nanoparticles on the transport and deposition of microplastics in quartz sand Full text
2019
Cai, Li | He, Lei | Peng, Shengnan | Li, Meng | Tong, Meiping
The influence of titanium dioxide nanoparticles (nTiO₂) on the transport and deposition of polystyrene microplastics (MPs) in saturated quartz sand was investigated in NaCl solutions with ionic strengths from 0.1 to 10 mM at two pH conditions (pH 5 and 7). Three different-sized polystyrene (PS) MPs (diameter of 0.2, 1, and 2 μm) were concerned in present study. We found that for all three different-sized MPs in NaCl solutions (0.1, 1 and 10 mM) at both pH 5 and 7, lower breakthrough curves and higher retained profiles of MPs with nTiO₂ copresent in suspensions relative to those without nTiO₂ were obtained, demonstrating that the copresence of nTiO₂ in MPs suspensions decreased MPs transport and increased their deposition in quartz sand under all examined conditions. The mechanisms contributing to the increased MPs deposition with nTiO₂ in suspensions at two pH conditions were different. The formation of MPs-nTiO₂ heteroaggregates and additional deposition sites provided by previously deposited nTiO₂ were found to drive to the increased MPs deposition with nTiO₂ in suspensions at pH 5, while the formation of MPs-nTiO₂ aggregates, additional deposition sites and increased surface roughness induced by the pre-deposited nTiO₂ on quartz sand surfaces were responsible for the enhanced MPs deposition at pH 7. The results give insights to predict the fate and transport of different-sized MPs in porous media in the copresence of engineered nanoparticles.
Show more [+] Less [-]Modeling study of ozone source apportionment over the Pearl River Delta in 2015 Full text
2019
Yang, Wenyi | Chen, Huansheng | Wang, Wending | Wu, Jianbin | Li, Jie | Wang, Zifa | Zheng, Junyu | Chen, Duohong
In recent years, the concentration of fine particulate matter has decreased gradually in the Pearl River Delta (PRD) region, but the ozone (O₃) concentration remains high and has become the primary air pollutant. In this study, using a three-dimensional numerical model [nested air quality prediction modeling system (NAQPMS)] coupled with an on-line source apportionment module, the contribution of different source regions and source categories to the O₃ concentration in the PRD region was quantified. A comparison with observation data confirmed that the NAQPMS adequately reproduced surface O₃ concentrations in different seasons. Compared with biogenic emissions, anthropogenic precursors play a dominant role in O₃ production. In Guangzhou city, among different source categories, mobile emission is the largest contributor (accounting for approximately 40%), followed by industry emissions (20%–24%). Regional control measures for solvent use and mobile emissions are effective for reducing O₃ concentration. In the PRD region, self-contribution is more significant in daytime (∼40%) than in nighttime (∼10%) on average. Among the source regions outside PRD, the northern part of Guangdong province, Jiangxi province, and Fujian province are important contributors. Within the PRD region, the self-contribution of each city increases by 12%–32% during O₃ episodes (>80 ppbv) compared with the annual mean contribution. The contribution of the entire PRD region and the entire Guangdong province is 46%–63% and 63%–74% in PRD cities during O₃ episodes. These results indicate that regional collaboration on emission control within PRD or Guangdong province is effective for reducing O₃ episodes in the PRD region. In addition, because long-range transport from regions outside Guangdong province played an important role in the O₃ concentration in the PRD region, long-term emission control measures throughout China in subsequent years should be propitious to further reduce the annual O₃ level and improve air quality in the PRD region.
Show more [+] Less [-]A review of graphene-based nanomaterials for removal of antibiotics from aqueous environments Full text
2019
Wang, Xuandong | Yin, Renli | Zeng, Lixi | Zhu, Mingshan
Antibiotics as emerging pharmaceutical pollutants have seriously not only threatened human life and animal health security, but also caused environmental pollution. It has drawn enormous attention and research interests in the study of antibiotics removal from aqueous environments. Graphene, an interesting one-atom-thick, 2D single-layer carbon sheet with sp² hybridized carbon atoms, has become an important agent for removal of antibiotic, owing to its unique physiochemical properties. Recently, a variety of graphene-based nanomaterials (GNMs) are reported to efficiently remove antibiotics from aqueous solutions by different technologies. In this review, we summarize different structure and properties of GNMs for the removal of antibiotics by adsorption. Meanwhile, advanced oxidation processes (AOPs), such as photocatalysis, Fenton process, ozonation, sulfate radical and combined AOPs by the aid of GNMs are summarized. Finally, the opportunities and challenges on the future scope of GNMs for removal of antibiotics from aqueous environments are proposed.
Show more [+] Less [-]Synergistic effects of glyphosate formulation herbicide and tank-mixing adjuvants on Pardosa spiders Full text
2019
Niedobová, Jana | Skalský, Michal | Ouředníčková, Jana | Michalko, Radek | Bartošková, Adéla
Glyphosate-based herbicides are the world’s most consumed agrochemicals, and they are commonly used in various agroecosystems, including forests, as well as in urban zones and gardens. These herbicides are sold as formulations containing adjuvants. Other tank-mixing adjuvants (most often surfactants) are commonly added to these formulations prior to application. According to the manufacturers of agrochemicals, such tank mixes (as these are known in agronomic and horticultural practice) have modified properties and perform better than do the herbicides as used alone. The effects of these tank mixes on the environment and on beneficial arthropods are almost unknown. Therefore, we studied whether a herbicide formulation mixed with adjuvant has modified effects on one of the most common genera of ground-dwelling wolf spiders vis-à-vis the herbicide formulation and adjuvants themselves. Specifically, we studied the synergistic effect in the laboratory on the predatory activity (represented by the number of killed flies) of wolf spiders in the genus Pardosa after direct treatment using the glyphosate-based herbicide formulation Roundup klasik Pro®, Roundup klasik Pro® in a mixture with the surfactant Wetcit®, Roundup klasik Pro® in a mixture with the surfactant Agrovital®, and the surfactants alone. We found that pure surfactants as well as herbicide-and-surfactants tank mixes significantly decrease the predatory activity of Pardosa spiders in the short term even as Roundup klasik Pro® did not itself have any such effect. Our results support the hypothesis that plant protection tank mixes may have modified effect on beneficial arthropods as compared to herbicide formulations alone. Therefore, testing of pesticide tank mixes is highly important, because it is these tank mixes that are actually applied to the environment.
Show more [+] Less [-]Azo dye biotransformation mediated by AQS immobilized on activated carbon cloth in the presence of microbial inhibitors Full text
2019
Castañon, Daniel | Alvarez, Luis H. | Peña, Karen | García-Reyes, Refugio B. | Martinez, Claudia M. | Pat-Espadas, Aurora
In this work, anthraquinone-2-sulfonate (AQS) was covalently immobilized onto activated carbon cloth (ACC), to be used as redox mediator for the reductive decolorization of reactive red 2 (RR2) by an anaerobic consortium. The immobilization of AQS improved the capacity of ACC to transfer electrons, evidenced by an increment of 3.29-fold in the extent of RR2 decolorization in absence of inhibitors, compared to incubations lacking AQS. Experiments conducted in the presence of vancomycin, an inhibitor of acidogenic bacteria, and with 2-bromoethane sulfonic acid (BES), an inhibitor of methanogenic archaea, revealed that acidogenic bacteria are the main responsible for RR2 biotransformation mediated by immobilized AQS. Nonetheless, the results also suggest that some methanogens are able to maintain their capacity to use immobilized AQS as an electron acceptor to sustain the decolorization process, even in the presence of BES.
Show more [+] Less [-]Simultaneous Cr(VI) reduction and electricity generation in Plant-Sediment Microbial Fuel Cells (P-SMFCs): Synthesis of non-bonding Co3O4 nanowires onto cathodes Full text
2019
Cheng, Ce | Hu, Yongyou | Shao, Sicheng | Yu, Jiayuan | Zhou, Weijia | Cheng, Jianhua | Chen, Yuancai | Chen, Shengnan | Chen, Junfeng | Zhang, Lihua
Development of low-cost cathode materials for Plant-Sediment Microbial Fuel Cells (P-SMFCs) has gained increasing interest, due to improved performance levels in terms of power and pollutant removal. A novel low cost three-dimensional cathode prepared by simple three-step strategy with growth of Co₃O₄ in-situ biofilm was successfully prepared. Different cathodes were applied to the six parallel P-SMFCs systems (reactor: R1-R6), such as graphite felt (GF), Pt/C, GF@Co₃O₄ (non-bonding Co₃O₄ nanowires on GF), GF@SG-Co₃O₄ (using argon as shielding gas (SG)). Its performances (R1, R2: control groups) were evaluated by electricity generation and Cr(VI) reduction at initial cadmium concentrations (4.97, 10.29 and 21.16 mg L⁻¹). A significant Cr(VI) removal efficiency of 99.76%, maximum power density of 75.12 ± 2.90 mW m⁻² and Cr(VI) adsorption capacity of 1.67 mg g⁻¹ were obtained at initial Cr(VI) concentration of 21.16 mg L⁻¹ with non-bonding GF@Co₃O₄ and bio-GF@SG-Co₃O₄ as cathodes. This indicated that these two materials were better than others (GF, Pt/C and GF@Co₃O₄) as cathodes. Characterization analysis including scanning electron microscope (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Polarization curve, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) showed that high current generation Cr(VI) removal mainly attributed to transportation of plants, adsorption of bio-cathode, formation of a relatively high concentration region and abundant oxygen vacancies of GF@SG-Co₃O₄. The results show that P-SMFCs with GF@SG-Co₃O₄ cathode may be a potentially novel approach for remediating Cr(VI) contaminated waster or soil.
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