Kinetics of DTPA extraction of Zn,Pb, and Cd from contaminated calcareous soils amended with sewage sludge     

Amir Mohseni  Adel Reyhanitabar  Nosratollah Najafi  Shahin Oustan  Kambiz Bazargan 《Arabian Journal of Geosciences》2018,11(14):384

The aim of this study was to determine the influence of sewage sludge (SLU) amendment on the desorption characteristics of zinc (Zn), lead (Pb), and cadmium (Cd) in contaminated calcareous soils. Three levels of SLU (0, 1, and 3% w/w) were added to the two calcareous contaminated soils. Samples were incubated for 30 days and equilibrated with 0.005 M DTPA for 0.25 to 240 h. The addition of SLU significantly increased the amount of DTPA-extractable Zn in soils. While the amounts of Cd, Pb, dissolved organic carbon (DOC), and pH showed a significant increase only in 3% w/w of SLU, with the exception of Cd desorption in 1% w/w of SLU, kinetics of Zn, Pb, and Cd extraction increased together with an increase in the level of applied SLU. The best models for describing desorption data were explicitly power function and Elovich. The rate constants of Zn and Pb had significant correlations with DTPA-extractable Zn and Pb, DOC and pH, which affect Zn and Pb desorption. Also, the rate constants of Cd had significant correlations with CEC that can be deemed as equivalent to the fact that Cd desorption is controlled by surface adsorption, particularly in the lower sludge application amount. These results can be used for management of sewage sludge application in contaminated calcareous soils.  相似文献   

A new insight into onset of inertial flow in porous media using network modeling with converging/diverging pores     

Maziar Veyskarami  Amir Hossein Hassani  Mohammad Hossein Ghazanfari 《Computational Geosciences》2018,22(1):329-346

The network modeling approach is applied to provide a new insight into the onset of non-Darcy flow through porous media. The analytical solutions of one-dimensional Navier-Stokes equation in sinusoidal and conical converging/diverging throats are used to calculate the pressure drop/flow rate responses in the capillaries of the network. The analysis of flow in a single pore revealed that there are two different regions for the flow coefficient ratio as a function of the aspect ratio. It is found that the critical Reynolds number strongly depends on the pore geometrical properties including throat length, average aspect ratio, and average coordination number of the porous media, and an estimation of such properties is required to achieve more reliable predictions. New criteria for the onset of non-Darcy flow are also proposed to overcome the lack of geometrical data. Although the average aspect ratio is the main parameter which controls the inertia effects, the effect of tortuosity on the onset of non-Darcy flow increases when the coordination number of media decreases. In addition, the higher non-Darcy coefficient does not essentially accelerate the onset of inertial flow. The results of this work can help to better understand how the onset of inertial flow may be controlled/changed by the pore architecture of porous media.  相似文献   

Sphere-boundary edge and sphere-boundary corner contacts model in DDA for simulating particulate media in 3-D     

S. Amir Reza Beyabanaki  Amvrossios C. Bagtzoglou 《Geomechanics and Geoengineering》2015,10(2):83-94

In modelling particulate media, such as soils, using 3-D DDA, there are four types of contacts: sphere to sphere, sphere to boundary face, sphere to boundary edge, and sphere to boundary corner contacts. The first two were studied by the authors in a previous work (Beyabanaki and Bagtzoglou 2012). In this paper, we present a new contact model for sphere-boundary edge and sphere-boundary corner contacts in sphere-based 3-D DDA. The model includes a new algorithm to search for contacts, detect the contact types and calculate contact points. Moreover, formulas for contact sub-matrices are derived. The proposed contact model has been implemented into a sphere-based 3-D DDA program and three test cases are studied in order to verify the workability of the new contact model. The numerical results obtained demonstrate the capability of the model to deal with sphere-boundary interaction in particulate media.  相似文献   

Using of hybrid fuzzy models to predict spatiotemporal groundwater quality parameters     

Amir Jalalkamali 《Earth Science Informatics》2015,8(4):885-894

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Groundwater qanat potential mapping using frequency ratio and Shannon’s entropy models in the Moghan watershed,Iran   总被引：6，自引：0，他引：6  

Seyed?Amir?Naghibi  Hamid?Reza?PourghasemiEmail author  Zohre?Sadat?Pourtaghi  Ashkan?Rezaei 《Earth Science Informatics》2015,8(1):171-186

The purpose of current study is to produce groundwater qanat potential map using frequency ratio (FR) and Shannon's entropy (SE) models in the Moghan watershed, Khorasan Razavi Province, Iran. The qanat is basically a horizontal, interconnected series of underground tunnels that accumulate and deliver groundwater from a mountainous source district, along a water- bearing formation (aquifer), and to a settlement. A qanat locations map was prepared for study area in 2013 based on a topographical map at a 1:50,000-scale and extensive field surveys. 53 qanat locations were detected in the field surveys. 70 % (38 locations) of the qanat locations were used for groundwater potential mapping and 30 % (15 locations) were used for validation. Fourteen effective factors were considered in this investigation such as slope degree, slope aspect, altitude, topographic wetness index (TWI), stream power index (SPI), slope length (LS), plan curvature, profile curvature, distance to rivers, distance to faults, lithology, land use, drainage density, and fault density. Using the above conditioning factors, groundwater qanat potential map was generated implementing FR and SE models, and the results were plotted in ArcGIS. The predictive capability of frequency ratio and Shannon's entropy models were determined by the area under the relative operating characteristic curve. The area under the curve (AUC) for frequency ratio model was calculated as 0.8848. Also AUC for Shannon's entropy model was 0.9121, which depicts the excellence of this model in qanat occurrence potential estimation in the study area. So the Shannon's entropy model has higher AUC than the frequency ratio model. The produced groundwater qanat potential maps can assist planners and engineers in groundwater development plans and land use planning.  相似文献   

Determination of Key Beds from the Cap Rocks of Oil Reservoirs Using a Novel Method,Case Study: The Gachsaran Formation,Southwest Iran     

Pourmorad  Saeid  Jokar  Amir  Jahan  Shakura 《Lithology and Mineral Resources》2021,56(6):559-578

Lithology and Mineral Resources - The use of key beds in the cap rocks of the oil reservoirs is crucial. Lack of awareness of these key beds will have serious risks and damages. The Gachsaran oil...  相似文献   

Determination of Two-phase Relative Permeability from a Displacement with Safman-Rayleigh Instability Using a Coarse-Scale Model History Matching Approach     

Taura  Usman H.  Mahzari  Pedram  Sohrabi  Mehran  Al-Wahaibi  Yahya  Farzaneh  Sayyed Amir 《Computational Geosciences》2022,26(5):1207-1222

Computational Geosciences - In heavy oil displacement by fluid injection, severe instability can occur due to the adverse mobility ratio, gravity segregation or compositional effects. However, when...  相似文献   

Effects of Roof-Edge Roughness on Air Temperature and Pollutant Concentration in Urban Canyons     

Amir A. Aliabadi  E. Scott Krayenhoff  Negin Nazarian  Lup Wai Chew  Peter R. Armstrong  Afshin Afshari  Leslie K. Norford 《Boundary-Layer Meteorology》2017,164(2):249-279

The influence of roof-edge roughness elements on airflow, heat transfer, and street-level pollutant transport inside and above a two-dimensional urban canyon is analyzed using an urban energy balance model coupled to a large-eddy simulation model. Simulations are performed for cold (early morning) and hot (mid afternoon) periods during the hottest month of the year (August) for the climate of Abu Dhabi, United Arab Emirates. The analysis suggests that early in the morning, and when the tallest roughness elements are implemented, the temperature above the street level increases on average by 0.5 K, while the pollutant concentration decreases by 2% of the street-level concentration. For the same conditions in mid afternoon, the temperature decreases conservatively by 1 K, while the pollutant concentration increases by 7% of the street-level concentration. As a passive or active architectural solution, the roof roughness element shows promise for improving thermal comfort and air quality in the canyon for specific times, but this should be further verified experimentally. The results also warrant a closer look at the effects of mid-range roughness elements in the urban morphology on atmospheric dynamics so as to improve parametrizations in mesoscale modelling.  相似文献   

Assessment of Inherent Anisotropy and Confining Pressure Influences on Mechanical Behavior of Anisotropic Foliated Rocks Under Triaxial Compression     

Davood Fereidooni  Gholam Reza Khanlari  Mojtaba Heidari  Ali Asghar Sepahigero  Amir Pirooz Kolahi-Azar 《Rock Mechanics and Rock Engineering》2016,49(6):2155-2163

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Design of a support vector machine with different kernel functions to predict scour depth around bridge piers     

Hassan Sharafi  Isa Ebtehaj  Hossein Bonakdari  Amir Hossein Zaji 《Natural Hazards》2016,84(3):2145-2162

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