Black carbon (**) is a substance that significantly affects the migration and transformation of hydrophobic organic compounds (HOCs) in soil/sediment. https://www.selleckchem.com/products/TW-37.html High-temperature ** is an important form of ** in the environment, and, currently, there is relatively little research on the influence of high-temperature ** on the sorption and the desorption behavior of HOCs and its mechanism. In this study, the sorption isotherms and TENAX-aided desorption kinetics of PCB1 by three typical high-temperature BCs (fly ash (FC), soot (SC), and high-temperature biochar (** 900)) and a low-temperature biochar (** 400) were compared. In addition, the sorption-desorption mechanism was clarified through its correlation with the physicochemical properties of **. The results indicated that the Freundlich sorption parameters of FC, SC, ** 900, and ** 400 were 9947.90, 5417.57, 77690.16, and 2804.54 (mg kg-1)/(mg L-1), respectively, indicating that these high-temperature BCs had stronger sorption capacity. The desorption rate of PCB1 on ** 900 was slow, and the ratio of the difficult desorption fraction (Fr) was as high as 96.2%, while those of FC, SC, and ** 400 were only 35.3%, 19.1%, and 54.7%, respectively. The sorption and desorption mechanisms of the three high-temperature BCs were similar to those of ** 400. They exhibited nonlinear adsorption at low PCB1 concentrations and linear partition at high PCB1 concentrations. Moreover, the results demonstrated that different types of high-temperature BCs in the environment have different sequestration effects on HOCs. Frap, the part that can be quickly desorbed, was predominantly PCB1 sorbed onto ** through a linear partition mechanism, but the surface acidic functional groups and larger pores would also increase the Frap. Meanwhile, the slow desorption ratio (Fslow) was mainly affected by the degree of surface aromatization; the difficult-to-desorb PCB1 (Fr) was combined with ** through a nonlinear adsorption mechanism and was mainly related to the micropore volume. Graphical abstract.In the context of the continued increased global uptake of fingerprinting procedures to explore fluvial sediment sources, far less attention has been paid to dust source tracing and especially using different particle size fractions and low-cost tracers such as colour and magnetic susceptibility. The objective of this study, therefore, was to apportion local dust storm source contributions for the less then 63-μm and 63-125-μm fractions of dust samples in a case study in central Iran. Colour and magnetic susceptibility properties were measured on 62 source samples and six dust storm samples. Statistical methods were used to select four different composite fingerprints for discriminating the dust sediment sources. These statistical approaches comprised (1) the Kruskal-Wallis H test (KW-H), (2) a combination of KW-H and discriminant function analysis (DFA), (3) a combination of KW-H and principal components and classification analysis (PCCA), and (4) a combination of KW-H and a general classification and regrwith a corresponding mean value of 9.4%). The equivalent estimates for the 63-125-μm fraction were 1.2-20.1% (8.3%). The findings clearly demonstrate that colour and magnetic susceptibility tracers offer low-cost options for apportioning dust sources.In this study, we evaluated the possible effects of sequenced pulsed magnetic fields (PMF) of 1-mT treatments with designed different frequencies (PMF-1-1, 3, 5, 7 Hz or PMF-2-7, 9, 12, 14 Hz) on the inflammatory signs such as abnormal pain behaviors, hyperalgesia and allodynia, edema, and fever in carrageenan (CG)-induced hind paw inflammation model in rats. Paw tissues were also histologically examined. PMF exposure was applied 3 times in 24 h. CG injection gradually decreased the thermal latencies and mechanical threshold and caused significant increases in temperature and mass of paw. PMF treatments significantly reduced the temperature and mass in the paw of rats with inflammation. PMF-1 treatments caused significant increases in the latencies and thresholds. However, administration of PMF-2 treatment was significantly decreased the latency and threshold. Furthermore, the histological pieces of evidence also suggested the anti-inflammatory effects of PMF-1 treatments or inflammatory actions of PMF-2 treatments. Findings presented in this paper suggest that 1-mT PMF treatments may have anti-edematous and antipyretics activities in inflamed rats. However, the effects of PMF treatments on abnormal pain hypersensitivities may be different. PMF treatments may make inflammatory pain relief or worse in inflamed rats depending on the PMF frequencies in sequence.Heavy metal contamination of river water has become a major issue affecting environmental and human health worldwide. This study makes an effort to observe the heavy metal incidence of River Brahmaputra, India, and its river restoration assessment for 2 years, 2017-2018 and 2018-2019. River Brahmaputra is the second longest and a major transboundary river of the South Asian region, which transcends the political boundaries of China, India and Bangladesh. The Pearson correlation analysis was used to analyse the interrelationships between physico-chemical parameters (which was also analysed during our study) and heavy metals. Heavy metal pollution index and multivariate analyses such as hierarchical cluster analysis and principal component analysis were used to establish our scientific observations. An assessment involving people's willingness to pay for river restoration was also done. Arsenic (As), lead (Pb), antimony (Sb), nickel (Ni), chromium (Cr), mercury (Hg) and cadmium (Cd) were monitored in three state Brahmaputra river and citizens willingness to contribute towards restoring its water quality, the need for an appropriate river restoration strategy and water policy is strongly felt as an outcome of this study.In practical conditions, the remediation efficiency is always very limited due to the rapid aggregation and deactivation of nanoscale zero-valent iron (nZVI). Porous SiO2-coated technology can effectively suppress the agglomeration and oxidation of nZVI particle, resulting in the excellent dispersion and stability in water. A series of characterization results show that the porous SiO2-coated Fe0 (Fe0@p-SiO2) was a core-shell structure composite, with Fe0 as the core and the porous SiO2 as the shell. Moreover, the prepared composite material has a large specific surface area (244.04 m2/g). The experiments of nitrobenzene (NB) reduction and one-dimensional simulation column indicated that the different amounts of NaOH in the preparation process lead to the different structures, shapes, and particle sizes of prepared composite materials, which have significant effects on its activity and transportability. Under the conditions investigated, the optimum ratio of Fe0@p-SiO2 synthesis was nFe3+n(Tetraethoxy silane, TEOS)nNaOH = 11.
Black carbon (BC) is a substance that significantly affects the migration and transformation of hydrophobic organic compounds (HOCs) in soil/sediment. https://www.selleckchem.com/products/TW-37.html High-temperature BC is an important form of BC in the environment, and, currently, there is relatively little research on the influence of high-temperature BC on the sorption and the desorption behavior of HOCs and its mechanism. In this study, the sorption isotherms and TENAX-aided desorption kinetics of PCB1 by three typical high-temperature BCs (fly ash (FC), soot (SC), and high-temperature biochar (BC 900)) and a low-temperature biochar (BC 400) were compared. In addition, the sorption-desorption mechanism was clarified through its correlation with the physicochemical properties of BC. The results indicated that the Freundlich sorption parameters of FC, SC, BC 900, and BC 400 were 9947.90, 5417.57, 77690.16, and 2804.54 (mg kg-1)/(mg L-1), respectively, indicating that these high-temperature BCs had stronger sorption capacity. The desorption rate of PCB1 on BC 900 was slow, and the ratio of the difficult desorption fraction (Fr) was as high as 96.2%, while those of FC, SC, and BC 400 were only 35.3%, 19.1%, and 54.7%, respectively. The sorption and desorption mechanisms of the three high-temperature BCs were similar to those of BC 400. They exhibited nonlinear adsorption at low PCB1 concentrations and linear partition at high PCB1 concentrations. Moreover, the results demonstrated that different types of high-temperature BCs in the environment have different sequestration effects on HOCs. Frap, the part that can be quickly desorbed, was predominantly PCB1 sorbed onto BC through a linear partition mechanism, but the surface acidic functional groups and larger pores would also increase the Frap. Meanwhile, the slow desorption ratio (Fslow) was mainly affected by the degree of surface aromatization; the difficult-to-desorb PCB1 (Fr) was combined with BC through a nonlinear adsorption mechanism and was mainly related to the micropore volume. Graphical abstract.In the context of the continued increased global uptake of fingerprinting procedures to explore fluvial sediment sources, far less attention has been paid to dust source tracing and especially using different particle size fractions and low-cost tracers such as colour and magnetic susceptibility. The objective of this study, therefore, was to apportion local dust storm source contributions for the less then 63-μm and 63-125-μm fractions of dust samples in a case study in central Iran. Colour and magnetic susceptibility properties were measured on 62 source samples and six dust storm samples. Statistical methods were used to select four different composite fingerprints for discriminating the dust sediment sources. These statistical approaches comprised (1) the Kruskal-Wallis H test (KW-H), (2) a combination of KW-H and discriminant function analysis (DFA), (3) a combination of KW-H and principal components and classification analysis (PCCA), and (4) a combination of KW-H and a general classification and regrwith a corresponding mean value of 9.4%). The equivalent estimates for the 63-125-μm fraction were 1.2-20.1% (8.3%). The findings clearly demonstrate that colour and magnetic susceptibility tracers offer low-cost options for apportioning dust sources.In this study, we evaluated the possible effects of sequenced pulsed magnetic fields (PMF) of 1-mT treatments with designed different frequencies (PMF-1-1, 3, 5, 7 Hz or PMF-2-7, 9, 12, 14 Hz) on the inflammatory signs such as abnormal pain behaviors, hyperalgesia and allodynia, edema, and fever in carrageenan (CG)-induced hind paw inflammation model in rats. Paw tissues were also histologically examined. PMF exposure was applied 3 times in 24 h. CG injection gradually decreased the thermal latencies and mechanical threshold and caused significant increases in temperature and mass of paw. PMF treatments significantly reduced the temperature and mass in the paw of rats with inflammation. PMF-1 treatments caused significant increases in the latencies and thresholds. However, administration of PMF-2 treatment was significantly decreased the latency and threshold. Furthermore, the histological pieces of evidence also suggested the anti-inflammatory effects of PMF-1 treatments or inflammatory actions of PMF-2 treatments. Findings presented in this paper suggest that 1-mT PMF treatments may have anti-edematous and antipyretics activities in inflamed rats. However, the effects of PMF treatments on abnormal pain hypersensitivities may be different. PMF treatments may make inflammatory pain relief or worse in inflamed rats depending on the PMF frequencies in sequence.Heavy metal contamination of river water has become a major issue affecting environmental and human health worldwide. This study makes an effort to observe the heavy metal incidence of River Brahmaputra, India, and its river restoration assessment for 2 years, 2017-2018 and 2018-2019. River Brahmaputra is the second longest and a major transboundary river of the South Asian region, which transcends the political boundaries of China, India and Bangladesh. The Pearson correlation analysis was used to analyse the interrelationships between physico-chemical parameters (which was also analysed during our study) and heavy metals. Heavy metal pollution index and multivariate analyses such as hierarchical cluster analysis and principal component analysis were used to establish our scientific observations. An assessment involving people's willingness to pay for river restoration was also done. Arsenic (As), lead (Pb), antimony (Sb), nickel (Ni), chromium (Cr), mercury (Hg) and cadmium (Cd) were monitored in three state Brahmaputra river and citizens willingness to contribute towards restoring its water quality, the need for an appropriate river restoration strategy and water policy is strongly felt as an outcome of this study.In practical conditions, the remediation efficiency is always very limited due to the rapid aggregation and deactivation of nanoscale zero-valent iron (nZVI). Porous SiO2-coated technology can effectively suppress the agglomeration and oxidation of nZVI particle, resulting in the excellent dispersion and stability in water. A series of characterization results show that the porous SiO2-coated Fe0 (Fe0@p-SiO2) was a core-shell structure composite, with Fe0 as the core and the porous SiO2 as the shell. Moreover, the prepared composite material has a large specific surface area (244.04 m2/g). The experiments of nitrobenzene (NB) reduction and one-dimensional simulation column indicated that the different amounts of NaOH in the preparation process lead to the different structures, shapes, and particle sizes of prepared composite materials, which have significant effects on its activity and transportability. Under the conditions investigated, the optimum ratio of Fe0@p-SiO2 synthesis was nFe3+n(Tetraethoxy silane, TEOS)nNaOH = 11.
0 Commentarii
0 Distribuiri
44 Views
0 previzualizare
