scholarly journals Estimation of Iodine Leaching in Soil Amended with Organic and Inorganic Materials Using HYDRUS 1-D Model

2021 ◽  
Vol 13 (19) ◽  
pp. 10967
Author(s):  
Muhammad Mohiuddin ◽  
Jawad Ali ◽  
Megersa Kebede Leta ◽  
Muhammad Waseem ◽  
Muhammad Irshad ◽  
...  
Keyword(s):  
Preferential Flow ◽  
Soil Depth ◽  
Soil Column ◽  
Freundlich Isotherm ◽  
Iodine Content ◽  
Inorganic Materials ◽  
Soil Columns ◽  
Column Studies ◽  
1D Model ◽  
Hydrus 1D

This study investigated the ability of a HYDRUS 1D model for predicting the vertical distribution of potassium iodine (200 ppm) in soil columns after amendment with five different common remediation materials (gypsum, lime, fly ash, charcoal, and sawdust) at a rate of 2.5% (w/w), relative to an unamended control soil. Results showed that relative to the unamended soil, iodine leaching was decreased by all amendments but that the magnitude of the decreases varied with the soil amendment applied. Iodine content was highest in the upper layer of the soil columns and decreased progressively with soil depth. The model was evaluated via comparison of the model simulated values with measured values from the soil column studies. The results showed that the HYDRUS 1D model efficiency was near to 1, indicating the stimulated results near to the measured values. Therefore, this study showed that iodine leaching through a soil could be ascertained well using a HYDRUS 1D model. The model over predicted iodine leaching, results in a weak correspondence between the simulated and the measured results for iodine leaching. This suggests that the HYDRUS-1D model does not explain accurately different organic and inorganic amended soil and the preferential flow that occurs in these columns. This may be due to the fact that Freundlich isotherm, which is part of the transport equations, does not sufficiently describe the mechanism of iodine adsorption onto the soil particles. This study would help to select an amendment for an effective management strategy to reduce exogenous iodine losses from agro-ecosystems. This would also improve scientific understanding of iodine transport in soil profile.

scholarly journals Estimation of Iodine Leaching in Soil Amended with Organic and Inorganic Materials Using Hydrus 1-D Model

2021 ◽  
Author(s):  
Muhammad Mohiuddin ◽  
Jawad Ali ◽  
Megersa Kebede Leta ◽  
Muhammad Waseem ◽  
Muhammad Irshad ◽  
...  
Keyword(s):  
Preferential Flow ◽  
Soil Depth ◽  
Soil Column ◽  
Freundlich Isotherm ◽  
Iodine Content ◽  
Inorganic Materials ◽  
Soil Columns ◽  
Column Studies ◽  
1D Model ◽  
Hydrus 1D

This study investigated the ability of a HYDRUS 1D model for predicting the vertical distribution of potassium iodine (200 ppm) in soil columns after amendment with five different common remediation materials (gypsum, lime, fly ash, charcoal and sawdust) at a rate of 2.5% (w/w), relative to an unamended control soil. Results shows that relative to the unamended soil, iodine leaching was decreased by all amendments but that the magnitude of the decreases varied with the soil amendment applied. Iodine content was highest in the upper layer of the soil columns and decreased progressively with soil depth. The model was evaluated via comparison of the model simulated values with measured values from the soil column studies. The results showed that the HYDRUS 1D model efficiency was near to 1, indicating that the stimulated results were near to the measured values. Therefore, this study showed that iodine leaching through a soil could be ascertained well using a HYDRUS 1D model. The model over predicted iodine leaching, resulting to a weak correspondence between the simulated and the measured results for iodine leaching. This suggests that the HYDRUS-1D model does not explain accurately different organic and inorganic amended soil and the preferential flow that occurs in these columns. This may be due to the fact that Freundlich isotherm, which is part of the transport equations, does not sufficiently describe the mechanism of iodine adsorption onto the soil particles. This study would help to select amendments for an effective management strategy to reduce exogenous iodine losses from agro-ecosystems. This would also improve understanding of iodine transport in soil profile.

scholarly journals Leaching of microplastics by preferential flow in earthworm (Lumbricus terrestris) burrows

2019 ◽  
Vol 16 (1) ◽  
pp. 31 ◽  
Author(s):  
Miao Yu ◽  
Martine van der Ploeg ◽  
Esperanza Huerta Lwanga ◽  
Xiaomei Yang ◽  
Shaoliang Zhang ◽  
...  
Keyword(s):  
Preferential Flow ◽  
Soil Depth ◽  
Soil Column ◽  
Soil Surface ◽  
Lumbricus Terrestris ◽  
Soil Samples ◽  
Average Weight ◽  
Soil Layers ◽  
Groundwater Systems ◽  
Set Up

Environmental contextMicroplastics found in soil pose several potential environmental risks. This study shows that microplastics on the soil surface can be ingested by earthworms and transported to the lower soil layers. In this way, microplastics may enter the food chain and find their way into groundwater systems, especially in cases where the water table is shallow. AbstractIn the current study, we examine how the activities of earthworms (Lumbricus terrestris) affect microplastic (MP) distribution and concentration in soil, with a focus on low density polyethylene (LDPE). We also want to determine if MPs can be flushed out with water. We used a laboratory sandy soil column (polyvinyl chloride tube) experimental set-up and tested five different treatments: (1) treatment with just soil (control) to check if the saturated conductivity (Ksat) could be impacted by MP, (2) treatment with MP, (3) treatment with MP and litter, (4) treatment with earthworms and litter as a second control for treatment 5 and (5) treatment with MPs, earthworms and litter. Each treatment consisted of eight replicates. For the treatments with MP, the concentration of MP added at the start of the experiment was 7% by weight (3.97g, polyethylene, 50% 1mm–250µm, 30% 250µm–150µm and 20% <150µm) based on 52.78g of dry litter from Populus nigra. In the treatments using earthworms, two adult earthworms, with an initial average weight of (7.14±0.26) g, were placed in each column. Results showed that LDPE particles could be introduced into the soil by the earthworms. MP particles were detected in each soil sample and within different soil layers for the earthworm treatments. Earthworms showed a tendency to transport the smaller MP particles and that the amount of MPs in size class <250μm increased in soil samples with increasing soil depth in comparison to the other size classes. After leaching, MPs were only detected in the leachate from the treatments with the earthworms, and the MP had similar size distributions as the soil samples in the 40–50cm layer of the treatment with MP, earthworms and litter. The results of this study clearly show that biogenic activities can mobilise MP transport from the surface into the soil and even be leached into drainage. It is highly likely that biogenic activities constitute a potential pathway for MPs to be transported into soil and groundwater.

Risk evaluation of radionuclides contamination on soil and groundwater under different scenarios simulating by HYDRUS-1D

2021 ◽  
Author(s):  
Liu Wenxiang ◽  
Yu Hanqing ◽  
Lu Yang
Keyword(s):  
Water Content ◽  
Radioactive Contamination ◽  
Soil Depth ◽  
Residual Water ◽  
High Concentration ◽  
Predictive Values ◽  
Lysimeter Experiment ◽  
Farmland Soil ◽  
1D Model ◽  
Hydrus 1D

<p>A large number of radionuclides, produced by nuclear accidents or nuclear waste, may cause radioactive contamination in the agricultural and aquatic ecosystems. Under these circumstances, it is necessary to optimize the remediation of agricultural areas polluted by radionuclides using innovative monitoring and prediction techniques. To mitigate radioactive contamination in farmland soil and effectively protect groundwater, some measures should be taken against on field investigation, laboratory experiment and model prediction. In this study, the HYDRUS-1D model was used to simulate the vertical migration of <sup>137</sup>Cs and <sup>60</sup>Co in farmland soil in northern China calibrating by the soil lysimeter experiment, and the scenario simulations of <sup>137</sup>Cs and <sup>60</sup>Co migration were conducted under different radioactive levels. Results showed that the order of sensitivity in saturated water content (θ<sub>s</sub>), residual water content(θ<sub>r</sub>), saturated hydraulic conductivity(K<sub>s</sub>) and distribution coefficient (K<sub>d</sub>) applied in HYDRUS 1D model was K<sub>d</sub> > θ<sub>s</sub> > θ<sub>r</sub> >K<sub>s</sub>. The simulated concentrations ​​of <sup>137</sup>Cs and <sup>60</sup>Co in Brown soil and Aeolian sandy soil on day 175 and 355 were significantly positively correlated with the measured values​​ (r>0.90, p<0.01). The verification results showed that the predictive values on the 577<sup>th </sup>day were also significant positive correlated with the measured values ​​(r>0.90, p<0.01). The RMSE, CRM and NRMSE calculating by simulated and measured values ​​of <sup>137</sup>Cs and <sup>60</sup>Co in soil were very small, indicating that HYDRUS 1D can be used to simulate the migration of radionuclides in farmland soil. Scenarios simulation results revealed that radionuclides were concentrated in the surface layer within 5 cm, but the migration depth has exceed 10 cm soil depth, and even reaches up to 23.5 cm depth at high concentration level. The surface soil should be cleaned timely to protect groundwater with high level from radioactive contamination and further study should be done about horizontal transport and numerical simulation.</p>

MOBILITY AND DISSIPATION OF METALAXYL IN TOBACCO SOILS

1986 ◽  
Vol 66 (3) ◽  
pp. 761-771 ◽  
Author(s):  
M. S. SHAROM ◽  
L. V. EDGINGTON
Keyword(s):  
Thin Layer ◽  
Soil Column ◽  
Soil Samples ◽  
Simulated Rainfall ◽  
Soil Columns ◽  
Field Plot ◽  
Column Studies ◽  
Dry Spells ◽  
Field Plots ◽  
Layer Chromatography

Soil thin layer chromatography studies showed that metalaxyl (methyl-N-(2,6-dimethylphenyl)-N-(2-methoxyacetyl)alaninate) was similar to 2,4-D and more mobile than pyrazone > permethrin. Soil column studies indicated that approximately 0, 9, 73 and 83% of the applied fungicide leached through a 25-cm soil column after being subjected to 5, 10, 15 and 20 cm of simulated rainfall, respectively. A study on the effects of sequential periods of rain and dry spells on movement of metalaxyl showed that the fungicide was leached with each 5 cm simulated rainfall but moved upward during the dry cycle. There was no leachate from soil columns that received four increments of 5 cm of simulated rainfall alternated with a 48-h drying cycle. However, approximately 32% of the applied metalaxyl was leached through soil columns that received similar rainfall treatment alternated with a 24-h drying cycle. Field plot studies indicated that most of the soil-incorporated metalaxyl remained in the upper 0–30 cm, with approximately 10% being leached into the 30- to 45-cm zone. The half-life of metalaxyl in soil from field plots and six growers’ farms ranged from 3 to 5 wk. Metalaxyl acid, a possible metabolite, was not detected in any of the soil samples. Metalaxyl and its acid were not detected in either the water or sediment of Big Creek which drains the tobacco region.Key words: Metalaxyl, mobility, persistence, environmental contamination

Estimating phosphorus leachability in reconstructed soil columns using HYDRUS-1D model

2011 ◽  
Vol 65 (6) ◽  
pp. 1751-1758 ◽  
Author(s):  
Abdirashid Elmi ◽  
Joumana S. Abou Nohra ◽  
Chandra A. Madramootoo ◽  
William Hendershot
Keyword(s):  
Soil Columns ◽  
1D Model ◽  
Reconstructed Soil ◽  
Hydrus 1D

Flurtamone Adsorption and Mobility in Three Georgia Soils

Weed Science ◽  
1991 ◽  
Vol 39 (2) ◽  
pp. 275-279 ◽  
Author(s):  
Thomas C. Mueller ◽  
Philip A. Banks
Keyword(s):  
Soil Depth ◽  
Soil Column ◽  
Clay Content ◽  
Loamy Sand ◽  
Clay Loam ◽  
Flow Conditions ◽  
Soil Columns ◽  
Saturated Flow ◽  
Sandy Clay Loam ◽  
Sandy Clay

Flurtamone and atrazine adsorption to soil was examined using a batch equilibrium method. Flurtamone mobility in packed soil columns under saturated flow conditions was also evaluated. Adsorption was greater for flurtamone than atrazine in the three soils, and the order of adsorption to soil for both herbicides was Greenville sandy clay loam > Cecil loam > Dothan loamy sand. Greater adsorption of each herbicide corresponded to soils with greater organic matter and clay content. The14C–flurtamone movement under saturated flow conditions in 28–cm soil–packed columns was limited to 16 cm, with no flurtamone leaching from any soil column after the addition of two pore volumes of water. Seventy–five percent of the applied14C–flurtamone remained in the 0– to 4–cm soil depth in the Greenville sandy clay loam, with less than 5 percent moving to a depth > 4 cm. Flurtamone movement was greater in the Cecil loam and the Dothan loamy sand, with movement in each soil to a depth of 16 and 12 cm, respectively.

scholarly journals Prediction of leaching and groundwater contamination by pesticides

2006 ◽  
Vol 78 (5) ◽  
pp. 1081-1090 ◽  
Author(s):  
Werner Kördel ◽  
Michael Klein
Keyword(s):  
Maximum Concentration ◽  
Management Practices ◽  
Preferential Flow ◽  
Soil Depth ◽  
Sandy Soils ◽  
Field Studies ◽  
Macropore Flow ◽  
Eu Directive ◽  
Present Information ◽  
Silty Soils

Herein, we describe how pesticide leaching is assessed in Europe in order to fulfill EU Directive 91/414. The assessment schemes were developed to protect groundwater from unacceptable effects caused by pesticide use. They presently focus on chromatographic flow processes, which are dominant in sandy soils. Nevertheless, important regions in Europe are characterized by structured soils where transport through macropores is most relevant.Comparison of parallel field studies with isoproturon performed in sandy and silty soils showed that maximum concentration in the structured soil at a soil depth of 1 m may exceed respective concentrations in sandy soils by a factor of 60. Similar results were obtained by lysimeter studies using silty soil cores with maximum concentration of 40 μg/l at the soil bottom. These results demonstrate that preferential flow is more the rule than the exception in well-structured fine-textured soils, and pesticide losses via macropore flow may exceed losses via matrix transport considerably. All present information available for macropore flow suggest the need for greater regional assessments. Other recommendations include analysis of the influence of different soil management practices on the formation of macropores.

Development of a soil water dispersion index (SOWADIN) for testing the effectiveness of soil-wetting agents

Soil Research ◽  
1989 ◽  
Vol 27 (1) ◽  
pp. 17 ◽  
Author(s):  
Y Sawada ◽  
LAG Aylmore ◽  
JM Hainsworth
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Distribution ◽  
Soil Column ◽  
Water Repellent ◽  
Computer Assisted ◽  
Dispersion Index ◽  
Soil Columns ◽  
Water Dispersion ◽  
Soil Wetting

Computer-assisted tomography (CAT) applied to gamma-ray attenuation measurements has been used to develop an index termed the soil water dispersion index (SOWADIN), which describes quantitatively the amount and distribution of water in soil columns. The index, which is determined by classifying pixels in a scanned slice into three categories according to their attenuation coefficients, contains two numerical values. The first value corresponds to the water content of the scanned slice and the second value is a measure of the dispersion of the water throughout the slice. Artificially wetted zones were created in soil columns to give one-third of the scanned layer wetted with various patterns of wetted-area distribution. The SOWADIN values obtained accurately reflected the differences in water distribution associated with the different patterns. Application of SOWADIN to columns of a water-repellent sand before and after treatment with a soil-wetting agent clearly illustrates both the increase in water content and improvement in water distribution in the soil column following treatment.

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