Lysimeter trials to assess the impact of different flood–dry-cycles on the dynamics of pore water concentrations of As, Cr, Mo and V in a contaminated floodplain soil

Geoderma ◽  
2014 ◽  
Vol 228-229 ◽  
pp. 5-13 ◽  
Author(s):  
Sabry M. Shaheen ◽  
Jörg Rinklebe ◽  
Holger Rupp ◽  
Ralph Meissner
Keyword(s):  
Pore Water ◽  
Floodplain Soil ◽  
The Impact

scholarly journals Desiccation-crack-induced salinization in deep clay sediment

2012 ◽  
Vol 9 (11) ◽  
pp. 13155-13189
Author(s):  
S. Baram ◽  
Z. Ronen ◽  
D. Kurtzman ◽  
C. Küells ◽  
O. Dahan
Keyword(s):  
Isotopic Composition ◽  
Conceptual Model ◽  
Pore Water ◽  
Vadose Zone ◽  
Land Surface ◽  
Water Infiltration ◽  
Arid Environments ◽  
Desiccation Cracks ◽  
The Impact ◽  
Desiccation Crack

Abstract. A study on water infiltration and solute transport in a clayey vadose zone underlying a dairy farm waste source was conducted to assess the impact of desiccation cracks on subsurface evaporation and salinization. The study is based on five years of continuous measurements of the temporal variation in the vadose zone water-content and on the chemical and isotopic composition of the sediment and pore-water in it. The isotopic composition of water stable isotopes (δ18O and δ2H) in water and sediment samples, from the area where desiccation crack networks prevail, indicated subsurface evaporation down to ∼3.5 m below land surface, and vertical and lateral preferential transport of water, following erratic preferential infiltration events. Chloride (Cl-) concentrations in the vadose zone pore water substantially increased with depth, evidence of deep subsurface evaporation and down flushing of concentrated solutions from the evaporation zones during preferential infiltration events. These observations led to development of a Desiccation-Crack-Induced Salinization (DCIS) conceptual model. DCIS suggests that thermally driven convective air flow in the desiccation cracks induces evaporation and salinization in relatively deep sections of the subsurface. This conceptual model supports previous conceptual models on vadose zone and groundwater salinization in fractured rock in arid environments and extends its validity to clayey soils in semi-arid environments.

Nitrogen process in stormwater bioretention: The impact of alternate drying and rewetting on nitrogen migration and transformation

2021 ◽  
Author(s):  
Yao Chen ◽  
Renyu Chen ◽  
Zhen Liu ◽  
Xuehua Yu ◽  
Shuang Zheng ◽  
...  
Keyword(s):  
Pore Water ◽  
Laboratory Experiments ◽  
Reductase Activity ◽  
Nitrogen Transformation ◽  
Transformation Mechanism ◽  
Dry Period ◽  
Bioretention System ◽  
Plant Organ ◽  
Drying And Rewetting ◽  
The Impact

Abstract Abstract Nitrogen migration and transformation in the stormwater bioretention system were studied in laboratory experiments, in which the effects of drying-rewetting were particularly investigated. The occurrence and distribution of nitrogen in the plants, the soil, and the pore water were explored under different drying-rewetting cycles. The results clearly showed that bioretention system could remove nitrogen efficiently in all drying-rewetting cycles. The incoming nitrogen could be retained in the topsoil (0–10 cm) and accumulated in the planted layer. However, the overlong dry periods (12 and 22 days) cause an increase in nitrate in the pore water. In addition, nitrogen is mostly stored in the plants’ stem tissues. Up to 23.26% of the inflowing nitrogen can be immobilized in plant organ after a dry period of 22 days. In addition, the relationships between nitrogen reductase activity in the soil and soil nitrogen content were explored. The increase of soil TN content could enhance the activity of nitrate reductase. Meanwhile, the activity of hydroxylamine reductase (HyR) could be enhanced with the increase of soil NO3− content. These results provide a reference for the future development of nitrogen transformation mechanism and the construction of stormwater bioretention systems.

scholarly journals Desiccation-crack-induced salinization in deep clay sediment

2013 ◽  
Vol 17 (4) ◽  
pp. 1533-1545 ◽  
Author(s):  
S. Baram ◽  
Z. Ronen ◽  
D. Kurtzman ◽  
C. Külls ◽  
O. Dahan
Keyword(s):  
Isotopic Composition ◽  
Conceptual Model ◽  
Pore Water ◽  
Vadose Zone ◽  
Land Surface ◽  
Water Infiltration ◽  
Arid Environments ◽  
Desiccation Cracks ◽  
The Impact ◽  
Desiccation Crack

Abstract. A study on water infiltration and solute transport in a clayey vadose zone underlying a dairy farm waste source was conducted to assess the impact of desiccation cracks on subsurface evaporation and salinization. The study is based on five years of continuous measurements of the temporal variation in the vadose zone water content and on the chemical and isotopic composition of the sediment and pore water in it. The isotopic composition of water stable isotopes (δ18O and δ2H) in water and sediment samples, from the area where desiccation crack networks prevail, indicated subsurface evaporation down to ~ 3.5 m below land surface, and vertical and lateral preferential transport of water, following erratic preferential infiltration events. Chloride (Cl−) concentrations in the vadose zone pore water substantially increased with depth, evidence of deep subsurface evaporation and down flushing of concentrated solutions from the evaporation zones during preferential infiltration events. These observations led to development of a desiccation-crack-induced salinization (DCIS) conceptual model. DCIS suggests that thermally driven convective air flow in the desiccation cracks induces evaporation and salinization in relatively deep sections of the subsurface. This conceptual model supports previous conceptual models on vadose zone and groundwater salinization in fractured rock in arid environments and extends its validity to clayey soils in semi-arid environments.

scholarly journals Thermokarst Lagoons: A Core-Based Assessment of Depositional Characteristics and an Estimate of Carbon Pools on the Bykovsky Peninsula

2021 ◽  
Vol 9 ◽  
Author(s):  
Maren Jenrich ◽  
Michael Angelopoulos ◽  
Guido Grosse ◽  
Pier Paul Overduin ◽  
Lutz Schirrmeister ◽  
...  
Keyword(s):  
Pore Water ◽  
Sediment Cores ◽  
The Arctic ◽  
Middle Pleistocene ◽  
Carbon Pools ◽  
Permafrost Region ◽  
Depositional History ◽  
Terrestrial Carbon Cycle ◽  
Lake Drainage ◽  
The Impact

Permafrost region subsurface organic carbon (OC) pools are a major component of the terrestrial carbon cycle and vulnerable to a warming climate. Thermokarst lagoons are an important transition stage with complex depositional histories during which permafrost and lacustrine carbon pools are transformed along eroding Arctic coasts. The effects of temperature and salinity changes during thermokarst lake to lagoon transitions on thaw history and lagoon deposits are understudied. We analyzed two 30-m-long sediment cores from two thermokarst lagoons on the Bykovsky Peninsula, Northeast Siberia, using sedimentological, geochronological, hydrochemical, and biogeochemical techniques. Using remote sensing we distinguished between a semi-closed and a nearly closed lagoon. We (1) characterized the depositional history, (2) studied the impact of marine inundation on ice-bearing permafrost and taliks, and (3) quantified the OC pools for different stages of thermokarst lagoons. Fluvial and former Yedoma deposits were found at depth between 30 and 8.5 m, while lake and lagoon deposits formed the upper layers. The electrical conductivity of the pore water indicated hypersaline conditions for the semi-closed lagoon (max: 108 mS/cm), while fresh to brackish conditions were observed beneath a 5 m-thick surface saline layer at the nearly closed lagoon. The deposits had a mean OC content of 15 ± 2 kg/m3, with higher values in the semi-closed lagoon. Based on the cores we estimated a total OC pool of 5.7 Mt-C for the first 30 m of sediment below five mapped lagoons on the Bykovsky Peninsula. Our results suggest that paleo river branches shaped the middle Pleistocene landscape followed by late Pleistocene Yedoma permafrost accumulation and early Holocene lake development. Afterward, lake drainage, marine flooding, and bedfast ice formation caused the saline enrichment of pore water, which led to cryotic talik development. We find that the OC-pool of Arctic lagoons may comprise a substantial inventory of partially thawed and partially refrozen OC, which is available for microbial degradation processes at the Arctic terrestrial-marine interface. Climate change in the Arctic leading to sea level rise, permafrost thaw, coastal erosion, and sea ice loss may increase the rate of thermokarst lagoon formation and thus increase the importance of lagoons as biogeochemical processors of former permafrost OC.

scholarly journals Carbon and Nitrogen Mineralization in Dark Grey Calcareous Floodplain Soil Is Influenced by Tillage Practices and Residue Retention

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1650
Author(s):  
Nazmus Salahin ◽  
Md. Khairul Alam ◽  
Sharif Ahmed ◽  
Mohammad Jahiruddin ◽  
Ahmed Gaber ◽  
...  
Keyword(s):  
Crop Residue ◽  
Soil Depth ◽  
Decay Rates ◽  
N Cycling ◽  
Growth Stages ◽  
Floodplain Soil ◽  
Tillage Practices ◽  
C And N ◽  
The Impact ◽  
Residue Retention

Very little is known about the changes that occur in soil organic carbon (SOC) and total nitrogen (TN) under an intensive rice-based cropping system following the change to minimal tillage and increased crop residue retention in the Gangetic Plains of South Asia. The field experiment was conducted for 3 years at Rajbari, Bangladesh to examine the impact of tillage practices and crop residue retention on carbon (C) and nitrogen (N) cycling. The experiment comprised four tillage practices—conventional tillage (CT), zero tillage (ZT), strip-tillage (ST), and bed planting (BP) in combination with two residue retention levels—increased residue (R50%) and low residue (R20%—the current practice). The TN, SOC, and mineral N (NH4+-N and NO3−-N) were measured in the soil at different crop growth stages. After 3 years, ZT, ST, and BP sequestered 12, 11, and 6% more SOC, and 18, 13, and 10% more TN, respectively than the conventional crop establishment practice at 0–5 cm soil depth. The accumulation of SOC and TN was also higher compared to the initial SOC and TN in soil. Among the tillage practices, the maximum SOC and TN sequestration were recorded with ST and with R50% that might be attributed to reduced mineralization of C and N in soil particularly with increased residue retention, since decay rates of potentially mineralizable C was lower in the ST with both the residue retention practices. Increased residue retention and minimum tillage practices after nine consecutive crops has altered the C and N cycling by slowing the in-season turnover of C and N, reducing the level of nitrate-N available to plants in the growing season and increasing retained soil levels of SOC and TN.

scholarly journals Ecotoxicity of Pore Water in Meadow Soils Affected by Historical Spills of Arsenic-Rich Tailings

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 751 ◽  
Author(s):  
Agnieszka Dradrach ◽  
Katarzyna Szopka ◽  
Anna Karczewska
Keyword(s):  
Pore Water ◽  
Mineral Fertilizers ◽  
Test Plant ◽  
Mineral Fertilization ◽  
Floodplain Soil ◽  
Soil Material ◽  
The Past ◽  
Floodplain Meadow ◽  
Microbial Assay ◽  
Very High

This study was carried out in Złoty Stok, a historical centre of gold and arsenic mining. Two kinds of soil material, containing 5020 and 8000 mg/kg As, represented a floodplain meadow flooded in the past by tailings spills and a dry meadow developed on the plateau built of pure tailings, respectively. The effects of soil treatment with a cattle manure and mineral fertilizers were examined in an incubation experiment. Soil pore water was collected after 2, 7, 21, 90, and 270 days, using MacroRhizon samplers and analyzed on As concentrations and toxicity, and assessed in three bioassays: Microtox, the Microbial Assay for Risk Assessment (MARA), and Phytotox, with Sinapis alba as a test plant. In all samples, As concentrations were above 4.5 mg/L. Fertilization with manure caused an intensive release of As, and its concentration in pore water of floodplain soil reached 81.8 mg/L. Mineral fertilization caused a release of As only from the pure tailings soil. The results of bioassays, particularly of Phytotox and MARA, correlated well with As concentrations, while Microtox indices depended additionally on other factors. Very high toxicity was associated with As > 20 mg/L. Despite an effect of “aging”, pore water As remained at the level of several mg/L, causing a potential environmental risk.

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