scholarly journals Assessment of Mercury-Polluted Soils Adjacent to an Old Mercury-Fulminate Production Plant

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
M. Camps Arbestain ◽  
L. Rodríguez-Lado ◽  
M. Bao ◽  
F. Macías
Keyword(s):  
Surface Waters ◽  
Contaminated Soils ◽  
Flow Direction ◽  
Surface Flow ◽  
Mercury Contamination ◽  
Production Plant ◽  
Polluted Soils ◽  
Flow Through ◽  
Contamination Of Soils ◽  
Surrounding Soil

Mercury contamination of soils and vegetation close to an abandoned Hg-fulminate production plant was investigated. Maximum concentrations of Hg (>6.5 gkg−1soil) were found in the soils located in the area where the wastewater produced during the washing procedures carried out at the production plant used to be discharged. A few meters away from the discharge area, Hg concentrations decreased to levels ranging between 1 and 5 gkg−1, whereas about 0.5 ha of the surrounding soil to the NE (following the dominant surface flow direction) contained between 0.1 and 1 gkg−1. Mercury contamination of soils was attributed (in addition to spills from Hg containers) to (i) Hg volatilization with subsequent condensation in cooler areas of the production plant and in the surrounding forest stands, and (ii) movement of water either by lateral subsurface flow through the contaminated soils or by heavy runoff to surface waters.

scholarly journals Denitrifying bacterial communities in surface-flow constructed wetlands during different seasons: characteristics and relationships with environment factors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jia-ming Wei ◽  
Li-juan Cui ◽  
Wei Li ◽  
Yun-mei Ping ◽  
Wan Li
Keyword(s):  
Environmental Factors ◽  
High Throughput Sequencing ◽  
Bacterial Abundance ◽  
Flow Direction ◽  
Denitrifying Bacteria ◽  
Surface Flow ◽  
Strongly Correlated ◽  
Community Structures ◽  
Oxidation Reduction ◽  
Different Seasons

AbstractDenitrification is an important part of the nitrogen cycle and the key step to removal of nitrogen in surface-flow wetlands. In this study, we explored space–time analysis with high-throughput sequencing to elucidate the relationships between denitrifying bacteria community structures and environmental factors during different seasons. Our results showed that along the flow direction of different processing units, there were dynamic changes in physical and chemical indicators. The bacterial abundance indexes (ACEs) in May, August, and October were 686.8, 686.8, and 996.2, respectively, whereas the Shannon-Weiner indexes were 3.718, 4.303, and 4.432, respectively. Along the flow direction, the denitrifying bacterial abundance initially increased and then decreased subsequently during the same months, although diversity tended to increase. The abundance showed similar changes during the different months. Surface flow wetlands mainly contained the following denitrifying bacteria genus: unclassified Bacteria (37.12%), unclassified Proteobacteria (18.16%), Dechloromonas (16.21%), unranked environmental samples (12.51%), unclassified Betaproteobacteria (9.73%), unclassified Rhodocyclaceae (2.14%), and Rhodanobacter (1.51%). During different seasons, the same unit showed alternating changes, and during the same season, bacterial community structures were influenced by the second genus proportion in different processing units. ACEs were strongly correlated with temperature, dissolved oxygen, and pH. Bacterial diversity was strongly correlated with temperature, electrical conductivity, pH, and oxidation reduction potential. Denitrifying bacteria are greatly affected by environmental factors such as temperature and pH.

An approach to simulation of dual drainage

1999 ◽  
Vol 39 (9) ◽  
pp. 95-103 ◽  
Author(s):  
S. Djordjević ◽  
D. Prodanović ◽  
Č. Maksimović
Keyword(s):  
Numerical Model ◽  
Model Development ◽  
Ground Level ◽  
Surface Flow ◽  
Surface Excess ◽  
Runoff Simulation ◽  
Sewer System ◽  
Excess Water ◽  
Flow Through ◽  
The One

The paper presents the development of the field of urban drainage modelling known as dual drainage - an approach to rainfaill runoff simulation in which the numerical model takes into account not only the flow through the sewer system, but also the flow on the surface. The steps in model development are described, and necessary data, assumptions used and operations to be performed using GIS are discussed. The numerical model simultaneously handles the full dynamic equations of flow through the sewer system and simplified equations of the surface flow. The surface excess water (due to the limited capacity of inlets or to the hydraulic head in the sewer system reaching the ground level) is routed to the neighbour subcatchment (not necessarily the one attached to the downstream network node), using surface retentions, if any.

Doppler Profiler and Radar Observations of Boundary Layer Variability during the Landfall of Tropical Storm Gabrielle

2006 ◽  
Vol 63 (1) ◽  
pp. 234-251 ◽  
Author(s):  
Kevin R. Knupp ◽  
Justin Walters ◽  
Michael Biggerstaff
Keyword(s):  
Boundary Layer ◽  
Doppler Radar ◽  
Layer Structure ◽  
Flow Direction ◽  
Surface Flow ◽  
Tropical Storm ◽  
Mean Flow ◽  
Boundary Layer Structure ◽  
Stratiform Precipitation ◽  
Wind Profiles

Abstract Detailed observations of boundary layer structure were acquired on 14 September 2001, prior to and during the landfall of Tropical Storm Gabrielle. The Mobile Integrated Profiling System (MIPS) and the Shared Mobile Atmospheric Research and Teaching Radar (SMART-R) were collocated at the western Florida coastline near Venice, very close to the wind center at landfall. Prior to landfall, the boundary layer was rendered weakly stable by a long period of evaporational cooling and mesoscale downdrafts within extensive stratiform precipitation that started 18 h before landfall. The cool air mass was expansive, with an area within the 23°C surface isotherm of about 50 000 km2. East-northeasterly surface flow transported this cool air off the west coast of Florida, toward the convergent warm core of the Gabrielle, and promoted the development of shallow warm and cold fronts that were prominent during the landfall phase. Airflow properties of the boundary layer around the coastal zone are examined using the MIPS and SMART-R data. Wind profiles exhibited considerable temporal variability throughout the period of observations. The stable offshore flow within stratiform precipitation exhibited a modest jet that descended from about 600 to 300 m within the 20-km zone centered on the coastline. In contrast, the onshore flow on the western side of the wind center produced a more turbulent boundary layer that exhibited a well-defined top varying between 400 and 1000 m MSL. The horizontal variability of each boundary layer is examined using high-resolution Doppler radar scans at locations up to 15 km on either side of the coastline, along the mean flow direction of the boundary layer. These analyses reveal that transitions in boundary layer structure for both the stable and unstable regimes were most substantial within 5 km of the coastline.

scholarly journals A computational investigation of the hydrodynamics of the Badush dam in northern Iraq

2018 ◽  
Vol 240 ◽  
pp. 04009
Author(s):  
Younis Saida Saeedrashed ◽  
Ali Cemal Benim
Keyword(s):  
Three Dimensional ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Dam Failure ◽  
Northern Iraq ◽  
Digital Elevation ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Elevation Model ◽  
Bottom Outlets

A computational analysis of the hydrodynamics of the Badush dam in Iraq is presented, which is planned to be reconstructed as a repulse dam, to prevent the Mosul city, in case of a failure of the Mosul dam. Computational Fluid Dynamics (CFD) is applied in combination with Geometric Information System (GIS) and Digital Elevation Model (DEM). In the first part of the study, a hydrologic study of a possible Mosul dam failure is performed, predicting the important parameters for a possible flooding of Mosul city. Here, a two-dimensional, depth-averaged shallow water equations are used to formulate the flow. Based on GIS and DEM, the required reservoir size and the water level of the Badush dam are predicted, for its acting as a repulse dam. Subsequently, a computational model of the reconstructed Badush dam is developed, combining the proposed construction with the local geographic topology to achieve a perfect fit. Finally, the water flow through the bottom outlets and stilling basin of the proposed dam is calculated by an unsteady, three-dimensional CFD analysis of the turbulent, free-surface flow. The CFD model is validated by comparing the predictions with measurements obtained on a physical model, where a quite satisfactory agreement is observed.

The influence of hydrological pathways on the transport of the herbicide, isoproturon, through an underdrained clay soil

1999 ◽  
Vol 39 (12) ◽  
pp. 77-84 ◽  
Author(s):  
C. M. Heppell ◽  
T. P. Burt ◽  
R. J. Williams ◽  
A. H. Haria
Keyword(s):  
Surface Waters ◽  
Clay Soil ◽  
Quality Standard ◽  
Early Spring ◽  
Hydrological Response ◽  
Macropore Flow ◽  
Ephemeral Stream ◽  
Low Intensity ◽  
Flow Through ◽  
High Concentrations

This paper reports the findings of a 12 month field monitoring programme at Wytham (Oxfordshire, UK), which examined the leaching of the phenylurea herbicide, isoproturon, from an agricultural clay hillslope to the adjacent ephemeral stream. Isoproturon was shown to reach the drains (at 50 cm depth) through a combination of vertical and lateral macropore flow through wormholes and inter-pedal cracks. Seasonal changes in hydrological response were also observed at the site, with lateral flow through inter-pedal cracks providing an important route by which herbicide was transported during autumn and early spring when the clay soils were wetting up. Concentrations of isoproturon in drainflow frequently exceeded the Environment Agency's (EA) non-statutory Environmental Quality Standard (EQS) of 20 μg/l for isoproturon in surface waters. Even under low intensity rainfall (< 1 mm/hr) the saturated region at the base of the hillslope was shown to conduct macropore flow containing significantly high concentrations of herbicide to the drain. The results of this study suggest that those regions close to surface waters which are areas of converging hydrological flow may be key contributors to the problem of isoproturon contamination of surface waters.

scholarly journals Heavy Metals Concentration in Contaminated Soils from Southern Part of Romania

2011 ◽  
Vol 68 (2) ◽  
Author(s):  
Diana FLORESCU ◽  
Andreea IORDACHE ◽  
Claudia SANDRU ◽  
Elena HORJ ◽  
Roxana IONETE ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soils ◽  
Metal Contamination ◽  
Industrial Waste ◽  
Heavy Metal Contamination ◽  
Land Application ◽  
Industrial Wastes ◽  
Treatment Processes ◽  
Contamination Of Soils

As a result of accidental spills or leaks, industrial wastes may enter in soil and in streams. Some of the contaminants may not be completely removed by treatment processes; therefore, they could become a problem for these sources. The use of synthetic products (e.g. pesticides, paints, batteries, industrial waste, and land application of industrial or domestic sludge) can result in heavy metal contamination of soils.

Phytoremediation of contaminated soil Lead and Cadmium by Brassica júncea (L.) Czern plant

2020 ◽  
Vol 5 (4) ◽  
pp. 110-120
Author(s):  
Qunshan Wei ◽  
◽  
Bilal . ◽  
Muhammad Noman ◽  
Zhemin Shen ◽  
...  
Keyword(s):  
Brassica Juncea ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Plant Biomass ◽  
Research Work ◽  
Alluvial Soil ◽  
Body Parts ◽  
Polluted Soils ◽  
Lead And Cadmium ◽  
Allowable Range

Many remediating strategies are used for polluted soils, however, but mostly the essential phytoremediation is a less expensive, organically satisfying technique that is generally reasonable for various countries. Pot tests were managed to dissect the Brassica júncea plant biomass cultivated on Pb as well as Cd polluted soils as well to survey its ampleness for the evacuation of Pb and Cd. Samples of picked plants developed at a blend of alluvial soil and sand were moved with vessel of pots the earth finishing extents as well allowed make with time regenerative development. Through acid digestion, Pb and Cd extraction was settled from the plant. Consequently, they were collected and afterwards examined for chosen metals through utilizing Atomic Absorption Spectrometry (AAS). Generally, the current examination results demonstrated that no hyperaccumulators of Pb as well Cd were recognized in the region. Body parts of the plant were categorized as Pb low accumulators, moderate accumulators and excluder, as well as Cd low accumulator, excluder. Additionally, Cd concentration was high up than the allowable range in species of plant. In plants, allowable range of Pb and Cd is 0.2 - 20 and 0.1 -2.4 mg kg – 1. In Brassica júncea plant the Pb as well Cd both were no hyperaccumulators. Hence, this local plant had the suitable ability to use for phytoremediation of contaminated soils around the Hayatabad Industrial area, Peshawar. All experimental Results demonstrated that from the medium of soil by Brassica júncea (L.) Czern plant the maximum lead and cadmium removals were 94 % and 94.26 %, respectively in the open environment, while in the control environment this removal was 82 % for Pb and 93.16 % for Cd .The present research work observes that brassica júncea (L.) Czern plant was more helpful for Cd take-up contrasted with Pb, and thus it is capacity we suggest Pb as well Cd for remediation from polluted soils. Keywords: Lead, Cadmium, Contaminated soil, Removal

scholarly journals Three-dimensional hydrodynamics numerical of wind-driven circulations in Danjiangkou Reservoir

2018 ◽  
Vol 246 ◽  
pp. 02021
Author(s):  
Jie Zhu ◽  
Jin Quan ◽  
Xiaohui Lei ◽  
Xia Yue ◽  
Yang Duan
Keyword(s):  
Wind Speed ◽  
Flow Field ◽  
Potential Flow ◽  
Flow Direction ◽  
Three Dimensional ◽  
Surface Flow ◽  
Surface Velocity ◽  
Wind Condition ◽  
Reservoir Area ◽  
Danjiangkou Reservoir

This paper focuses on the analysis of the flow field of Danjiangkou Reservoir under the action of wind stress. Based on the analysis of the annual wind field data of Danjiangkou Reservoir, the three-dimensional hydrodynamic model of Danjiangkou Reservoir was established. The distribution of water flow field in the reservoir area under five different wind directions and two different wind speeds was studied. The simulation results were compared with the flow field without wind. The results show that when the wind speed in the reservoir area is 3.3m/s, the surface velocity and flow direction change less under the same wind conditions as the potential flow direction. Under the wind condition opposite to the potential flow direction, the reservoir area is locally generated. The small circulation and surface flow are more disordered; when the wind speed reaches 10.0m/s, under the same wind condition as the potential flow direction, the surface velocity of the reservoir area increases significantly. Under the wind condition opposite to the direction of the potential flow, a stable counterclockwise circulation is generated, and the wind direction dominates the surface layer. seriously affecting the flow field distribution in the reservoir area. The research results in this paper can provide support for the reservoir in the formulation of emergency water pollution emergency strategy and the formulation of real-time scheduling plan.

A critical evaluation of a pilot scale subsurface flow wetland: 10 years after commissioning

1997 ◽  
Vol 35 (5) ◽  
pp. 337-343 ◽  
Author(s):  
Allan Batchelor ◽  
Pierre Loots
Keyword(s):  
Critical Evaluation ◽  
Subsurface Flow ◽  
Plug Flow ◽  
Pilot Scale ◽  
Preliminary Evidence ◽  
Surface Flow ◽  
Organic Load ◽  
Hydraulic Load ◽  
Flow Through ◽  
Back Mixing

A pilot scale subsurface flow wetland, commissioned in 1986, has been continuously operated since 1990 at a hydraulic load of 330 mm/day and a corresponding organic load of 1200 kg/ha·day. At these loading rates preliminary evidence suggests that the microbial biomass in the wetland was dominated by anaerobes. Attempts to increase the hydraulic load resulted in surface flooding which was attributed to suspended solids clogging the surface. Despite short circuiting, revealed by tracer studies, COD removal exceeded 70%. The hydraulic flow through the wetland was modelled and was described as modified plug flow with a degree of back mixing. A comparative costing exercise revealed that the unit treatment cost of a combination of a subsurface flow wetland/nitrification column, surface flow wetland was lower than that of an activated sludge system treating the same volume of effluent.

Computational Study of the Downpull Force on High-Head Slide Gates

2019 ◽  
Author(s):  
Juan C. Arango Escobar ◽  
David Calderon Villegas ◽  
Aldo Benavides Moran ◽  
Alejandro Molina Ochoa
Keyword(s):  
Computational Study ◽  
Maximum Flow ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Cfd Simulations ◽  
Ansys Fluent ◽  
Flow Through ◽  
High Head ◽  
The One ◽  
Bottom Outlet

Abstract This paper presents CFD simulations of the flow through a real bottom outlet equipped with high-head slide gates. The operating head of the gates and the maximum flow rate are 70 m and 650 m3/s, respectively. The numerical simulations were performed in ANSYS-FLUENT version 19.2. VOF method was used to model the free surface flow downstream the slide gates. Hydrodynamic forces were calculated at nine gate openings for a standard 45° lip gate; the downpull coefficients obtained from the simulations were compared with estimates from Naudascher’s analytical method. According to the CFD results, the downpull force acting on the 45° lip gate is 5%–10% lower than the one estimated analytically for the analyzed gate positions. Additionally, the flow through an inverted 30° lip gate was simulated to estimate the downpull coefficient at various gate openings. These coefficients cannot be determined analytically. The methodology here described can easily be applied to different gate geometries for which design coefficients are not available.

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