Journal of Polymers and the Environment - Novel sorbent named “coated filter cake by hydroxyapatite (CFCHAP)” that prepared from precipitation of hydroxyapatite nanoparticles on the... 相似文献
Sedimentation in artificial ports and harbors is a common issue throughout the world. Based on an assessment of the coastal fishing harbors in Egypt, the El-Burullus fishing harbor has been found to suffer severely from siltation. Sediment deposits are concentrated at the harbor entrance, which threatens navigation through this area. Although the harbor authority has constructed a perpendicular extension on the main breakwater to mitigate these siltation issues, fishing boats are still suffering from the siltation at the harbor entrance. Dredging is required every year to maintain continuity of navigation through the harbor; the cost of dredging is a critical element which impacts the economic feasibility of the harbor. Therefore, the need to investigate new solutions for the siltation issue is critical. In this study, a two-dimensional calibrated and validated model using the Coastal Modeling System package is used to understand the coastal processes within the study area. It is also used to investigate the effects of the proposed breakwater extension on the siltation at the harbor outlet. Field data such as hydrographic surveys, waves, tides, and lake outlet discharge data were collected and included in the model. The results obtained for the current breakwater conditions confirmed the claims of the fishermen that the sedimentation problem still occurs at the entrance. Thus, five possible solutions to mitigate the problem were proposed and simulated considering the following parameters: sediment deposition rate to the west of the main breakwater, the erosion rate in front of the seawall in the eastern part of the harbor, and the morphological changes within the El-Burullus lake outlet. According to the simulation results, reducing the length of the upper edge of the middle jetty by 90 m improves the stability of the harbor entrance. Alternatively, replacing the perpendicular extension by an inclined extension of 60 m in length and shortening the middle jetty by 60 m reduces the accretion and erosion rates around the harbor which promotes the long-term stability for the coastal area in addition to favorable conditions to the El-Burullus harbor entrance. 相似文献
The River Nile is the primary source of freshwater for drinking, irrigation, and industrial purposes in Egypt. Thus, the water quality in this river concerns the health of local inhabitants. The present study reveals seasonal variations of various physicochemical and heavy metals parameters and microbial load of water at 15 sites from Qena to Sohag cities, Egypt. The water is fresh with TDS?≤?270 and 410 mg L?1 in summer and winter, respectively. Fe, Mn, Cd, Cr, Cu, Ni, and Zn concentrations were within drinking water specification in both seasons except Cr and Cd in summer. Viable numbers of total coliform, fecal coliform, and fecal streptococci were recorded in both seasons with fecal streptococci's disappearing in winter. The concentrations of salts and ions in winter were higher than summer due to decreased water quantity and flow rate in this season. On the other hand, heavy metals and bacteria were higher in summer owing to the rain and weathering of upstream rocks and increasing of human activities during the summer. The calculated water quality index (WQI) depicted that the chemical quality of water was poor for drinking and treatment, especially biological treatment, which is required before the water is supplied for drinking. Human health risk assessment factors such as probable daily intake, hazard quotient, and carcinogenic risk indicated high risks of Cr, Cd, and Ni for adults and children in both seasons. The non-carcinogenic and carcinogenic risks are mainly posed by Cr. The WQI values for the other water uses indicated the marginal quality for aquatic life, fair for irrigation, and fair in summer to good in winter for livestock consumption. The irrigation water quality parameters indicated that the water could be used to irrigate all soils and crops except the hazard of biological contamination. The water–rock interaction controls water chemistry besides the contribution of human activities. The agricultural, industrial, and municipal wastewaters were the main contributors to water pollution and should be treated before discharge into the Nile River. Source and drinking water should be monitored continuously to prevent related human waterborne diseases.
Environmental Modeling & Assessment - Calibration of the rating curve is a challenge due to uncertainty in the parameters. This problem increases in an area with considerable seasonal... 相似文献
Fine particles in the atmosphere from soil and sand resuspension contain a variety of organic compounds from natural biogenic and anthropogenic matter. Soil and sand samples from various sites near Kuwait city were collected, sieved to retain the fine particles, and extracted with a mixture of dichloromethane and methanol. The extracts were derivatized and analyzed by gas chromatography-mass spectrometry in order to characterize the chemical compositions and sources of the organic components. The major inputs of organic compounds were from both natural biogenic and anthropogenic sources in these samples. Vegetation was the major natural source of organic compounds and included n-alkanols, n-alkanoic acids, n-alkanes, sterols and triterpenoids. Saccharides had high concentrations (31–43%) in the sand dune and seafront samples, indicating sources from decomposed vegation materials and/or the presence of viable microbiota such as bacteria and fungi. Vehicular emission products, leakage of lubricating oils, discarded plastics and emissions from cooking operations were the major anthropogenic inputs in the samples from the urban areas. This input was mainly UCM, n-alkanes, hopanes, plasticizers and cholesterol, respectively. 相似文献
The coal mining industries influence hydro-geological parameters, which affect the aquifer recharge in the coal mining areas. This research aimed to evaluate the impact of various hydro-geological parameters on fluctuation of groundwater level in the study area. The various hydro-geological parameters such as soil, geology, drainage pattern, elevation and slope have been considered to accomplish the objective. A comparative analysis was performed by comparing the groundwater level fluctuation (WLF) map with the GIS-based various hydro-geological parameter maps to assess the combined influence of different hydro-geological parameters on groundwater level fluctuation. A total of eighty-six (86) dug-wells were chosen to monitor the level of the groundwater for around ten blocks of Singrauli coalfield, and these wells were examined during the months of dry and wet seasons for 2016. Based on the comparative analysis between the WLF map and thematic maps of various hydro-geological parameters, it has been found that WLF in the south-western and some portions of the north-eastern showed moderate to a higher value. This may be because most of the non-hilly areas come under gentle to moderate slope category, with lower elevation in the area forming the suitable hydro-geological condition for recharging groundwater. It was observed that the northwest, south-east and central part of the study area showed lower WLF, which may be due to the presence of overburden dump, presence of higher elevation and steep slope. Thus, the combined effect of slope, elevation, geology, drainage and mining activities on the WLF in the study region is moderate. 相似文献
Environmental Science and Pollution Research - Senna alexandrina is traditionally used for its antioxidant and anti-inflammatory properties, but little information is available concerning its... 相似文献
Environmental Science and Pollution Research - Tramadol abuse is an increasingly alarming phenomenon among Egyptian Community especially among workers and drivers. Study profile and factors... 相似文献
Environmental Science and Pollution Research - This study investigates the heterogeneous causal linkages between urbanization, the intensity of electric power consumption, water-based pollutant... 相似文献
Fisheries bycatch is a critical threat to sea turtle populations worldwide, particularly because turtles are vulnerable to multiple gear types. The Canary Current is an intensely fished region, yet there has been no demographic assessment integrating bycatch and population management information of the globally significant Cabo Verde loggerhead turtle (Caretta caretta) population. Using Boa Vista island (Eastern Cabo Verde) subpopulation data from capture–recapture and nest monitoring (2013–2019), we evaluated population viability and estimated regional bycatch rates (2016–2020) in longline, trawl, purse-seine, and artisanal fisheries. We further evaluated current nesting trends in the context of bycatch estimates, existing hatchery conservation measures, and environmental (net primary productivity) variability in turtle foraging grounds. We projected that current bycatch mortality rates would lead to the near extinction of the Boa Vista subpopulation. Bycatch reduction in longline fisheries and all fisheries combined would increase finite population growth rate by 1.76% and 1.95%, respectively. Hatchery conservation increased hatchling production and reduced extinction risk, but alone it could not achieve population growth. Short-term increases in nest counts (2013–2021), putatively driven by temporary increases in net primary productivity, may be masking ongoing long-term population declines. When fecundity was linked to net primary productivity, our hindcast models simultaneously predicted these opposing long-term and short-term trends. Consequently, our results showed conservation management must diversify from land-based management. The masking effect we found has broad-reaching implications for monitoring sea turtle populations worldwide, demonstrating the importance of directly estimating adult survival and that nest counts might inadequately reflect underlying population trends. 相似文献