scholarly journals Water Distribution and Silt Clogging in the Strong-Seepage Zone Infiltration Process of Yufuhe River from Yellow River Water Based on the Two-Dimensional Sand Tank Model

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1200
Author(s):  
Weidong Zhao ◽  
Weiping Wang ◽  
Shuai Liu ◽  
Shisong Qu ◽  
Xiuxiu Sun ◽  
...  
Keyword(s):  
River Water ◽  
Water Distribution ◽  
Yellow River ◽  
Removal Rate ◽  
Suspended Particles ◽  
Suspended Solid ◽  
Karst Water ◽  
Two Dimensional ◽  
Infiltration Process ◽  
Tank Model

A two-dimensional sand tank experiment was designed to explore the mechanism of water distribution and silt clogging of Yellow River water whilst replenishing groundwater in ‘open window’ reach of the piedmont river and strong seepage area consisting of a gravel and karst layer from top to bottom. Water released through the reach was divided into surface, pore and fracture karst water, of which karst water was an effective recharge from the surface water. A reasonable released water plan is necessary in recharging to avoid invalid recharge. The karst water accounted for 60–70% of the amount of water released before clogging, and this value was reduced to approximately 10–20% whilst a thin clay layer formed from suspended particles on the surface layer of the medium after clogging. The removal rate of suspended solids along vertical and lateral directions in the medium can reach over 96%. The retained amount of suspended particles was mainly distributed on the surface and upper layer region of the medium. A rubber dam can improve effective infiltration whilst promoting suspended solid deposition in the medium. The fitting degree of the numerical simulation and measured results was above 0.9, which proves the reliability of the sand tank model results.

scholarly journals Influence of the North Branch of the Qingshuigou River on the Lower Reaches of Yellow River Based on Two-dimensional Numerical Model

2021 ◽  
Vol 1885 (2) ◽  
pp. 022043
Author(s):  
Caodong Jiang ◽  
Liangchao Ma ◽  
Dongfeng Li ◽  
Hongwu Zhang ◽  
Zihao Li
Keyword(s):  
Numerical Model ◽  
Yellow River ◽  
Two Dimensional ◽  
The North

A generalized settling approach in the numerical modeling of sedimentation tanks

1998 ◽  
Vol 38 (3) ◽  
pp. 95-102 ◽  
Author(s):  
G. Mazzolani ◽  
F. Pirozzi ◽  
G. d'Antonoi
Keyword(s):  
Transport Model ◽  
Numerical Models ◽  
Removal Rate ◽  
Total Concentration ◽  
Suspended Solid ◽  
Primary Concern ◽  
High Concentration ◽  
Hindered Settling ◽  
Low Concentration ◽  
Solid Distribution

Numerical models for the prediction of turbulent flow field and suspended solid distribution in sedimentation tanks are characterized by refined modeling of hydrodynamics, but apparently weak modeling of settling properties of suspensions. It is known that sedimentation tanks typically treat highly heterodisperse suspensions, whose concentrations range from relatively high to low values. However, settling is modeled either by considering one or more particle classes of different settling velocity, without accounting for hindered settling conditions, or by treating the suspension as monodisperse, even in regions of low concentration. A new generalized settling model is proposed to account for both discrete settling conditions in low concentration regions of the tanks and hindered settling conditions in high concentration regions. Settling velocities of heterodisperse suspensions are then determined as a function of particle velocities in isolation and their total concentration. The settling model is used in the framework of a transport model for the simulation of hydrodynamics and solid distribution in a rectangular sedimentation tank. Results show that solid distribution is mainly affected by particle interactions in the inlet region and by settling properties of individual particles in the outlet region. Comparison of the proposed settling model with other settling models suggests that a generalized approach of the modeling of settling properties of suspensions is a primary concern to obtain reliable predictions of the removal rate.

Selective desorption and analysis of humic substances on suspended particles in river water

1988 ◽  
Vol 96 (1-6) ◽  
pp. 231-238 ◽  
Author(s):  
Masataka Hiraide ◽  
Yoshio Arima ◽  
Atsushi Mizuike
Keyword(s):  
Humic Substances ◽  
River Water ◽  
Suspended Particles

Nutrient Removal from Polluted River Water by Combining Vertical and Horizontal Subsurface Flow Constructed Wetlands

2013 ◽  
Vol 663 ◽  
pp. 1029-1032 ◽  
Author(s):  
Cheng Xin Qin ◽  
Gang He ◽  
Yu Huan Duan ◽  
Xiao Ping Pang ◽  
Zong Lian She
Keyword(s):  
River Water ◽  
Removal Rate ◽  
Subsurface Flow ◽  
Ammonia Removal ◽  
Polluted River ◽  
Main Layer ◽  
Second Stage ◽  
N Removal ◽  
Different Depths ◽  
Horizontal Subsurface Flow

A lab-scale hybrid constructed wetland system was constructed to purify polluted river water. The system was composed of a first stage of the vertical subsurface flow filter, followed by a second stage of horizontal subsurface flow bed. Both beds used furnace slag with a size of 4-60 mm for the main layer. The system was continuously fed. Different depths of unsaturated layer (0 cm, 15 cm and 30 cm) in vertical filter were tested. The unsaturated layer of 30 cm in vertical filter presented the most effective ammonia removal of 89.1%, while lowest NO3--N removal rate of 74.1% for the system. High TN removal efficiencies (77.3%-81.0%) could be observed during operation of three depths. The removals of COD and TP were in the range of 97.1%-98.4% and 76.4%-88.9%, respectively.

scholarly journals Study on the hydro-chemistry process after mixing between water and rocks

2018 ◽  
Vol 54 (2) ◽  
pp. 104-114
Author(s):  
Xiuyan Jing ◽  
Hongbin Yang ◽  
Na Wang
Keyword(s):  
River Water ◽  
Arid Regions ◽  
Yellow River ◽  
Dilution Effect ◽  
Northwest China ◽  
Experimental Simulation ◽  
The Yellow River ◽  
Mixing Ratio ◽  
Close Attention ◽  
Semi Arid

Abstract The chemical evolution of groundwater has received close attention from hydro-geologists. Northwest China largely consists of arid and semi-arid regions, where surface water and groundwater frequently exchange with each other, and where the mixing and water–rock interactions significantly affect the direction of water quality evolution. Based on experimental simulation, this paper investigates the interactions among the Yellow River water, groundwater and rocks in Yinchuan. The study found that when groundwater is mixed with the Yellow River water, the Yellow River water has a certain dilution effect on the hydro-chemical composition of groundwater; however, this effect is not simply diluted by proportion for no reaction between irons, but a portion of calcium, sulfur, and carbonate form precipitates. After mixing of the Yellow River water, groundwater and rocks, the pH increased, and the carbon dioxide system reached equilibrium again. In addition, CO32− was produced. While Na+ increase was mainly due to dissolution, SO42− decrease was because of precipitation. The precipitation or dissolution of Ca2+, Mg2+, and CO32− mainly depended on the mixing ratio between groundwater and river water, which suggested the reversible behavior of the dissolution-precipitation of carbonate minerals.

scholarly journals Bio-Capture of Solid Pollutants by Vegetation Canopy Cave in Shallow Water Flow

2019 ◽  
Vol 16 (23) ◽  
pp. 4846 ◽  
Author(s):  
Yanhong Li ◽  
Liquan Xie ◽  
Tsung-chow Su
Keyword(s):  
Shallow Water ◽  
Water Flow ◽  
Removal Rate ◽  
Suspended Solid ◽  
Solid Particles ◽  
Capture Efficiency ◽  
Vegetation Canopy ◽  
Shallow Water Flow ◽  
Flume Experiments ◽  
Aspect Ratios

Vegetation has already been acknowledged to have the ability to remove fine solid pollutants by retention and absorption, and is widely used in the biorestoration engineering of natural shallow water flow. Vegetation usually takes a long time to obtain the expected removal rate. Therefore, vegetation is not applicable for some urgent or pressing situations. In addition, in traditional biorestoration engineering, solid pollutants usually deposit in the soil of flow bed, which infiltrates into the far-field and accumulates in crops to threaten human health. Herein, we propose a new biotechnique of foliage capture by designing a cave on the top of a vegetation canopy, which is aimed to enhance the removal efficiency (i.e., achieve quick removal) and avoid the soil deposition of pollutants. The effectiveness and efficiency of this new design were validated by a set of indoor water flume experiments, with one flat canopy top configuration serving as the model of a traditional bioretention system and three cave configurations of differing aspect ratios. The results showed that compared with that of the flat canopy top, the total amount of foliage-captured solid particles for the three caved canopies increased by 3.8, 7.3, and 12.2 times. Further, we found that the foliage-capture efficiency depended on the aspect ratio of the canopy cave. The results revealed that the effectiveness of foliage capture and the enhanced efficiency were mainly from three hydrodynamic mechanisms: (i) as flow penetrated the cave boundary from the above-canopy region to the within-canopy region, it entrained solid pollutants to collide with the foliage and increased their fate of capture; (ii) the large eddy vortices of turbulence broke due to the increasing canopy resistance, which resulted in enhanced mixing dynamics for fine, suspended, solid pollutants to collide into foliage; and (iii) the flow shear along the cave boundary decreased, which provided a reduced lift force for solid pollutants to suspend or resuspend. Comparisons between the flat canopy and caved canopies of three aspect ratios showed that the design of the canopy cave is highly significant for capture efficiency.

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