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Impact of long-term water level fluctuation on the distribution, transport, and fate of phosphorus in reservoir sediment Full text
2019
Yu, Huijuan | Xu, Shiguo | Tian, Wen | Zhu, Lin | Sun, Ya
Water level fluctuation zone (WLFZ) with changeable environmental conditions would affect the transport and release of nutrients in the sediment. To investigate the influence of long-term water level fluctuations on sediment phosphorus (P), a reservoir sediment partitioning method based on historical water level was developed and applied in the Biliuhe Reservoir. The reservoir sediment was divided into frequent fluctuation zone (FFZ), fluctuation zone of continuous droughts (DFZ), and continuously submerged zone (CSZ). Sediment cores in different zones were collected and P was analyzed. TP content in the surface sediment progressively increased from FFZ, DFZ, to CSZ except the 0–10-cm samples of D1, and TP content of sediment cores increased gradually with decreasing depth except D1 core. Ferric iron-bound P (Fe-P) and organic P (OP) exhibited uniform spatial variation with TP, while no clear patterns were found with regard to the other forms. Fe-P composed most of TP (54.67 ± 10.15%) and had a significant positive correlation with stable OP (5.55 ± 2.07%). The contributions of Fe-P, detrital apatite P (Det-P), and OP are stable among the four cores, indicating that the relationship between the various P forms is relatively stable despite variations in environmental conditions of WLFZ. The alternation of deposition and erosion under long-term water level fluctuation can promote P transport down-flow, which can be prevented by the continuous growth of plants in WLFZ. Thus, the reasonable use of the plant growth in WLFZ can control the P load of the reservoir.
Show more [+] Less [-]Introduction of hydrogen fuel cell vehicles: prospects and challenges for Malaysia’s transition to a low-carbon economy Full text
2019
Al-Amin, Abul Quasem | Doberstein, Brent
Alternative energy policies targeting the adoption of hydrogen fuel cell vehicles (HFCVs) could have significant positive impacts on Malaysia’s ability to meet both its carbon reduction goal and its energy security needs. The transport sector generally contributes heavily to carbon emissions, and is also difficult to decarbonize because of the costs associated with many greener options. This study explores the possibility of decarbonizing the Malaysian transport sector by promoting the use of hydrogen vehicles, and analyzes the adoption challenges and economic obstacles (especially public acceptance) associated with introducing HFCVs. This study contends that the adoption challenges of this new technology can be overcome through the use of development strategies outlined. This study also addresses the regulatory framework that Malaysia (and other countries) might use to overcome common policy adoption challenges of HFCVs.
Show more [+] Less [-]Solubility, uptake, and translocation of BDE 47 as affected by DOM extracted from agricultural wastes Full text
2019
Li, Helian | Shao, Fengluan | Qiu, Yanhua | Ma, Yibing
Dissolved organic matter (DOM) extracted from wheat straw (SDOM) and cow manure (MDOM) were used to investigate their effects on the solubilization, uptake, and translocation of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47). Partition coefficients (KDOC) of BDE 47 between water and the two types of DOM were measured by the solubility enhancement method. The uptake and translocation of BDE 47 by wheat plants were explored by hydroponic exposure experiments. In the range of 0 to 100 mg/L of DOM, the solubility of BDE 47 increased with increasing concentrations of DOM. The log [KDOC] values of BDE 47 in SDOM and MDOM solutions were 5.77 and 5.31, respectively. The log [KDOC] values of BDE 47 in SDOM solutions were higher than those in MDOM solutions, which might be ascribed to the higher content of aliphatic carbon and lower molecular weight of SDOM. The addition of DOM (50 mg/L) significantly increased the accumulation of BDE 47 in the shoots of wheat plants. Wheat straw DOM had greater effect than MDOM in enhancing the accumulation of BDE 47. This study demonstrated the potential risk of BDE 47 to plants resulting from DOM-facilitated transport or the changes in metabolic properties.
Show more [+] Less [-]Protective effects of quercetin supplementation against short-term toxicity of cadmium-induced hematological impairment, hypothyroidism, and testicular disturbances in albino rats Full text
2019
Badr, Gehan M. | Elsawy, Hany | Sedky, Azza | Eid, Rania | Ali, Awatef | Abdallah, Basem M. | Alzahrani, Abdullah M. | Abdel-Moneim, Ashraf M.
The aim of this study was to evaluate the probable protective effect of quercetin (QUE) against cadmium (Cd)-induced sub-chronic toxicity in rats. Adult male rats were given either Cd (as cadmium chloride; 5 mg/kg) alone or in combination with QUE (50 mg/kg) daily for 4 weeks by oral gavage. At the end of the experimental period, Cd accumulation, and selected hematological, thyroid, and reproductive markers were assessed. Results revealed that Cd treatment significantly increased Cd concentrations in blood, thyroid gland, and testicular tissue of rats. Cd also caused a decline in hemoglobin content, hematocrit value, and total erythrocyte and leucocyte counts. Further, significant suppressions in the blood levels of hormones related to thyroid gland function, and male reproductive hormones (i.e., testosterone, luteinizing hormone and follicle-stimulating hormone), were observed in Cd-treated rats compared to the control. In parallel, low sperm count and sperm motility, increased sperm abnormalities, and marked pathology occurred in testis. Combination with QUE recorded amelioration of the deleterious effects of Cd, involving regulation of hematological toxicity and thyroid hormonal levels and subsequently modulation of testicular function. In conclusion, it appears that dietary QUE can rescue from Cd-induced hematological dysfunctions and testicular damage by reversing the hypothyroid state.
Show more [+] Less [-]Ingestion of plastic fragments by the Guri sea catfish Genidens genidens (Cuvier, 1829) in a subtropical coastal estuarine system Full text
2019
Dantas, David V. | Ribeiro, Cristian I. R. | Frischknecht, Catarina de C. A. | Machado González Prada, Rodrigo | Farias, Eduardo G. G.
One of the most recognized anthropogenic impacts in marine environments is solid waste pollution, especially plastic, which can be ingested by fish, thus interfering with their health. In this context, the aim of this study is to describe the ingestion of plastic fragments and to identify the possible effect of this contamination in the condition factor of Genidens genidens in the Laguna Estuarine System. The stomach contents of 92 G. genidens (26 juveniles and 66 adults) were analyzed. The Index of Relative Importance was performed to identify the contribution of each prey item. Condition factor (CF) was used to analyze the effect of plastic ingestion on the fish’s body condition (by comparing individuals in the same ontogenetic phase). For the juveniles, eight items were observed, the most important of which were Penaeidae, followed by Portunidae and plastic. For the adults, 12 items were observed, the most important of which were Penaeidae, Portunidae, Polychaeta, and plastic. The analysis of CF demonstrated higher values for individuals without plastic in the stomach, which indicated a better health condition. The CF of a fish may be affected by variations in the physiological condition, environmental stresses, and nutritional and biological variations, and could be used to compare the body condition or health of a fish species. The ingestion of plastic could significantly influence the worst body condition of the individuals that were analyzed in the present study. The plastic pollution in marine coastal waters is associated with the appropriate waste management levels.
Show more [+] Less [-]Anthropogenically driven differences in n-alkane distributions of surface sediments from 19 lakes along the middle Yangtze River, Eastern China Full text
2019
Zhang, Yongdong | Su, Yaling | Yu, Jinlei | Liu, Zhengwen | Du, Yingxun | Jin, Miao
During the past few decades, the Yangtze River basin has undergone massive anthropogenic change. In order to evaluate the impacts of human interventions on sediment n-alkanes of lakes across this region, the aliphatic hydrocarbon fractions of 19 surface sediment samples collected from lakes along the middle reaches of the Yangtze River (MYR) were analyzed using gas chromatography–mass spectrometry. The n-alkanes extracted from the sediments contained a homologous series from C15 to C34, with a notable predominance of odd carbon compounds except for sediments from the more intensively industrialized Lake Daye, in which > C21 n-alkanes showed no odd/even predominance, and carbon preference index (CPI) approached unity. Abundance values of middle-chain (C21, C23, and C25) and long-chain (C27, C29, C31, and C33) n-alkanes in Lake Daye were approximately 4 to 3 times greater than the average for other lakes, reaching 272.4 and 486.3 μg/g TOC, respectively, in the study. Short-chain n-alkanes (C15, C17, and C19) in the sediments varied in abundance from 10.0 to 76.2 μg/g TOC across the study and showed a moderate correlation with total phosphorus (TP) concentrations in the overlying water. The results indicated anthropogenic eutrophication enhanced the accumulation of short-chain n-alkanes in sediments because the primary producers in which they are synthesized are highly susceptible to nutrient forcing. Middle-chain n-alkane abundances were less affected by eutrophication and generally enriched in macrophyte lakes, while long-chain n-alkanes tend to be low in sediments from more eutrophic water. In the case of Lake Daye, direct discharges of petroleum products from heavy industry have introduced quantities of petroleum n-alkanes (> C21), far exceeding the amounts of biogenic input, and the sediment > C21 n-alkanes detected in this study showed typical characteristics of petroleum source. In other lakes, inputs of petroleum products from surface runoff of vehicle/traffic emissions associated with urbanization and economic growth contributed comparatively few n-alkanes to sediments, resulting in declines in CPI for > C21 n-alkanes, most obviously in Lakes Huanggai, Donghu, and Futou. Calculated CPI values suggest that a major proportion of the n-alkanes present in these lakes are derived from biogenic input. The results of this study provided evidences that n-alkane profiles of lake sediments respond sensitively to human-induced eutrophication and different sources of petroleum pollution.
Show more [+] Less [-]The impact of electric generation capacity by renewable and non-renewable energy in Brazilian economic growth Full text
2019
de Oliveira Noronha, Maiara | Zanini, Roselaine Ruviaro | Souza, Adriano Mendonça
Renewable sources are relevant in a country’s energy planning because they are linked to the creation of opportunities for technological, economic, and productive development guided by the principles of sustainability. Thus, the aim of this study was to investigate the relation between electric generation capacity by renewable and non-renewable energies and Brazilian socioeconomic variables. The analysis of the interrelationships between electricity generation capacity and economic growth in Brazil, from April 2009 to March 2017, was carried out by the vector autoregressive and autoregressive distributed lag methodologies. It was verified that the variance of employment is explained by renewable sources: hydroelectric in 7.71%, biomass in 1.99%, wind energy in 3.13%, and solar energy in 10.58%. While, the GDP variance is explained in 3.15% by hydroelectric energy, 0.06% by biomass, 1.70% by wind energy, and 17.38% by solar energy. The export variance is explained by renewable sources: hydroelectric 2.48%, biomass 0.39%, wind energy 2.34%, and solar energy 17.58%. Finally, the variance of the minimum wage is explained by hydroelectric energy in 1.48%, biomass in 5.09%, wind energy in 9.09%, and solar energy in 10.67%. An ARDL (1, 1, 2, 0, 0, 0, 3, 2, 0, 2, 0, 2) model was also adjusted for natural gas, with AIC (13.082) and BIC (13.739), and the ARDL (1, 0, 1, 0, 0, 0, 0, 0, 3, 0, 0, 4) model adjusted for hydroelectric power, with AIC (13.633) and BIC (14.189), considering the variables’ order cited above. Through the adjustment of the ARDL model, it was verified that there is a long-term influence of socioeconomic variables on electricity production variables, both renewable and non-renewable ones. The analysis of the impulse response function and the variance decomposition allowed us to verify that the installed capacity for production of electric energy exerts influence on Brazilian socioeconomic variables considered in this study.
Show more [+] Less [-]Neutral polyfluoroalkyl and perfluoroalkyl substances in surface water and sediment from the Haihe River and Dagu Drainage Canal deserve more attention Full text
2019
Hua, Xia | Luo, Jianbo | Zhao, Zhen | Wang, Qi | Sun, Hongwen
Neutral polyfluoroalkyl and perfluoroalkyl substances (nPFASs) were detected in the surface water and sediment from the Haihe River (HR) and Dagu Drainage Canal (DDC), Tianjin, China. N-methyl perfluorooctane sulfonamide ethanol (MeFOSE) and N-ethyl perfluorooctane sulfonamide ethanol (EtFOSE) were the predominant nPFASs in surface water and sediment, which was different from the composition in air. The concentrations of ΣnPFASs in water from the HR (1.88–8.21 ng/L) were lower than those from the DDC (3.72–11.32 ng/L). Concentrations of ΣnPFASs were higher in the middle of the HR in the Dongli District due to industrial activity, whereas at lower reaches of the DDC, high ΣnPFAS concentrations might be due to effluent from wastewater treatment plants (WWTPs). The detection frequency in sediment (13.5%) was less than that in water (83%). The concentrations in sediment from the DDC (below limit of qualification (LOQ) to 5.58 ng/g) were higher than those from the HR (below LOQ to 2.46 ng/g). The distribution coefficient (log KD) between water and sediment was calculated, and they were highly related to the compound structures. The contribution of nPFASs to nPFASs+PFAAs was up to 52% in sediment in the DDC, suggesting the importance of nPFASs in aquatic systems.
Show more [+] Less [-]Synthesis and characterization of Ag2O/B2O3/TiO2 ternary nanocomposites for photocatalytic mineralization of local dyeing wastewater under artificial and natural sunlight irradiation Full text
2019
Tijani, Jimoh Oladejo | Momoh, Ufon Ojogbane | Salau, Rasaq Bolakale | Bankole, Mercy Temitope | Abdulkareem, Ambali Saka | Roos, Wiets Dániel
In this work, Ag₂O/B₂O₃/TiO₂ ternary nanocomposite was synthesized by a combination of green and precipitation method involving mixing of different concentrations of silver nitrate, boric acid, and titanium (IV) isopropoxide precursor with Plumeria acuminate leaf extract. The extract was obtained by boiling the mixture of distilled water and the powdered leaves in a beaker for few minutes followed by filtration. The microstructure, morphology, chemical composition, surface area, phase structure, and optical properties of the various prepared nanomaterials were determined by HRTEM, HRSEM, UV-Vis/DRS, BET, XRD, and XPS. The photocatalytic potential of TiO₂ nanoparticles and Ag₂O/B₂O₃/TiO₂ nanocomposites to degrade local dyeing wastewater under artificial and natural sunlight irradiation was investigated. The extent of degradation of the organic pollutants was measured using chemical oxygen demand (COD) and total organic carbon (TOC) as indicator parameters. The XRD pattern of Ag₂O/B₂O₃/TiO₂ nanocomposites revealed that the formation of pure anatase TiO₂ phase and the addition of both silver and boron precursors did not influenced the phase structure of the nanocomposites. The oxidation states of +1 and +3 for both Ag and B on the surface of Ag₂O/B₂O₃/TiO₂ nanocomposites were confirmed by XPS. Optical characterization of the sample revealed reduction of band gap energy from 2.6 to 2.0 eV for TiO₂ and Ag₂O/B₂O₃/TiO₂, respectively. The Ag₂O/B₂O₃/TiO₂ nanocomposites demonstrated excellent photocatalytic activity under natural sunlight and artificial light than mono and binary oxide systems with TOC and COD degradation efficiencies of 86.11% and 75.69%, respectively. The kinetics of degradation of organic dyes in the wastewater followed the order of Langmuir–Hinshelwood pseudo-first-order > Freundlich > Zero > Parabolic diffusion model. The coupling effect of Ag₂O and B₂O₃ onto TiO₂ framework was responsible for the enhanced photochemical stability of the nanocomposites even after five repeated cycles.
Show more [+] Less [-]Evaluation of the environmental noise problems in holiday villages: a case study from Antalya, Turkey Full text
2019
Gürsoy, Özge | Yüğrük Akdağ, Neşe
Not only the appeal of the sun, natural, and historical beauties but also architectural features and business advantages of the accommodation facilities emerge as important factors in tourism development. Holiday villages differ from other types of accommodation facilities in terms of their functions and services. It is important to provide tourists acceptable levels of comfort in holiday villages offering various functions. One of these comfort conditions is acoustic comfort, which involves noise control. Noise emitted from various indoor and outdoor facilities is the main component impacting acoustic comfort in holiday villages. In this study, a holiday village in Antalya, Turkey with an open area of 120,000 m² was examined to identify noise exposure conditions of outdoor areas. Pools, restaurants, animation areas, playgrounds, and courts are the main outdoor noise sources in this holiday village. The noise emitted by these sources during daytime (Ld) and evening time (Le) are shown in noise maps. The open areas affected by 65 LAₑq noise level extend to an area of 55,500 and 21,000 m² during Ld and Le, respectively. With the noise barriers around the main noise sources, impacted open areas are reduced by 13% in Ld and 12% in Le. The results of this study clearly reveals the importance of resolving the issue of environmental noise in the most efficient and cost-effective way in terms of settlement and planning, especially in areas with dominant noise sources like holiday villages.
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