Efficacy Assessment of Silty–Sandy Soil as Bed Material in Constructed Wetland to Treat Naphthalene-Laden Wastewater: Physical and Numerical Modeling

2022 ◽  
Vol 26 (2) ◽  
Author(s):  
Avishek Adhikary ◽  
Pradyumna Konar ◽  
Tapabrata Chakraborty ◽  
Supriya Pal ◽  
Sudipta Ghosh
Keyword(s):  
Numerical Modeling ◽  
Sandy Soil ◽  
Constructed Wetland ◽  
Efficacy Assessment ◽  
Bed Material

scholarly journals Grain sorting in the morphological active layer of a braided river physical model

2015 ◽  
Vol 3 (4) ◽  
pp. 577-585 ◽  
Author(s):  
P. Leduc ◽  
P. Ashmore ◽  
J. T. Gardner
Keyword(s):  
Grain Size ◽  
Numerical Modeling ◽  
Active Layer ◽  
Bedload Transport ◽  
Scale Model ◽  
Active Layer Thickness ◽  
Braided River ◽  
River Bed ◽  
Physical Scale ◽  
Bed Material

Abstract. A physical scale model of a gravel-bed braided river was used to measure vertical grain size sorting in the morphological active layer aggregated over the width of the river. This vertical sorting is important for analyzing braided river sedimentology, for numerical modeling of braided river morphodynamics, and for measuring and predicting bedload transport rate. We define the morphological active layer as the bed material between the maximum and minimum bed elevations at a point over extended time periods sufficient for braiding processes to rework the river bed. The vertical extent of the active layer was measured using 40 hourly high-resolution DEMs (digital elevation models) of the model river bed. An image texture algorithm was used to map bed material grain size of each DEM. Analysis of the 40 DEMs and texture maps provides data on the geometry of the morphological active layer and variation in grain size in three dimensions. By normalizing active layer thickness and dividing into 10 sublayers, we show that all grain sizes occur with almost equal frequency in all sublayers. Occurrence of patches and strings of coarser (or finer) material relates to preservation of particular morpho-textural features within the active layer. For numerical modeling and bedload prediction, a morphological active layer that is fully mixed with respect to grain size is a reliable approximation.

NUMERICAL MODELING OF HORIZONTAL SUBSURFACE FLOW CONSTRUCTED WETLAND SYSTEM

2021 ◽  
Vol 12 (2) ◽  
pp. 13-27
Author(s):  
Zuhal A. Hamza ◽  
◽  
Wisam S. Al-Rekabi ◽  
Azraa M. Ajell ◽  
◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Constructed Wetland ◽  
Subsurface Flow ◽  
Subsurface Flow Constructed Wetland ◽  
Wetland System ◽  
Horizontal Subsurface Flow

scholarly journals Grain sorting in the morphological active layer of a braided river physical model

2015 ◽  
Vol 3 (3) ◽  
pp. 577-600
Author(s):  
P. Leduc ◽  
P. Ashmore ◽  
J. T. Gardner
Keyword(s):  
Grain Size ◽  
Numerical Modeling ◽  
Active Layer ◽  
Scale Model ◽  
Bed Load ◽  
Active Layer Thickness ◽  
Braided River ◽  
River Bed ◽  
Physical Scale ◽  
Bed Material

Abstract. A physical scale model of a gravel-bed braided river was used to measure vertical grain size sorting in the morphological active layer aggregated over the width of the river. This vertical sorting is important for analyzing braided river sedimentology, for numerical modeling of braided river morpho-dynamics and for measuring and predicting bed load transport rate. We define the morphological active layer as the bed material between the maximum and minimum bed elevations at a point over extended time periods sufficient for braiding processes to re-work the river bed. The vertical extent of the active layer was measured using 40 hourly high-resolution DEMs of the model river bed. An image texture algorithm was used to map bed material grain size of each DEM. Analysis of the 40 DEMs and texture maps provides data on the geometry of the morphological active layer and variation in grain size in three-dimensions. Normalizing active layer thickness and dividing into 10 sub-layers we show that all grain sizes occur with almost equal frequency in all sub-layers. Occurrence of patches and strings of coarser (or finer) material relates to preservation of particular morpho-textural features within the active layer. For numerical modeling and bed load prediction a morphological active layer that is fully mixed with respect to grain size is a reliable approximation.

A Crystal Arrow Point

1944 ◽  
Vol 10 (2) ◽  
pp. 205-206
Author(s):  
J. Henry Ray
Keyword(s):  
Sandy Soil ◽  
West Bank ◽  
Water Erosion ◽  
Red River ◽  
The West ◽  
The Face ◽  
Bed Material ◽  
Horizontal Layers ◽  
Red Bed

Approximately eighteen miles north of Vernon, Wilbarger County, Texas, is Cedar Bluff. It is not as imposing as the word “bluff” may imply, but, in comparison with the low hills and level farm lands of this area, it deserves the name. It is a terrace, about two miles in length, which forms the west bank of Red River at a bend in that stream. The approach to Cedar Bluff is of sandy soil which is of good quality for farming and is mostly under cultivation. Crops are grown in most places to the very edge of the bluff. The face of the cliff shows some water erosion. The general formation consists of an upper layer of sand on gravel; underneath this are horizontal layers of limestone bedded in shale which are underlain in turn by a deep formation of sandstone and red bed material of Wichita Permian.

Numerical Modeling of Earth Structures: Frictional Anchors in Sand

2012 ◽  
Vol 486 ◽  
pp. 214-220 ◽  
Author(s):  
Wen Chi Hu ◽  
Shih Tsung Hsu
Keyword(s):  
Numerical Modeling ◽  
Constitutive Model ◽  
Strain Hardening ◽  
Sandy Soil ◽  
Soil Analysis ◽  
Friction Stress ◽  
Triaxial Tests ◽  
Yielding Behavior ◽  
Earth Structures ◽  
Fixed End

This research performed a series of triaxial tests on sandy specimens to obtain the parameters needed for a constitutive model. The model is capable to simulate the strain hardening/softening and the volumetric dilation of sandy soil during stressing. The model and the related parameters were then employed in the commercial software FLAC2D to analyze the uplift behavior of various frictional anchors in sandy soil. Analysis results indicate that the friction stress along the fixed end of the anchor with a long fixed length exhibits progressive yielding under not only for a tension but also for a compression anchor. The progressive yielding behavior could be eliminated using a compound anchor because of the upward and downward transfer of load within the anchor shaft from the anchorage body. Therefore, a compound anchor can generate a higher anchorage capacity of all frictional anchors.

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