scholarly journals Influence of Saltwater Submergence on Geohydraulic Properties of Sand: A Laboratory Investigation

Hydrology ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 181
Author(s):  
Sudip Basack ◽  
Ghritartha Goswami ◽  
Sumanpran Sonowal ◽  
Moses Karakouzian
Keyword(s):  
Specific Gravity ◽  
Laboratory Investigation ◽  
Saline Water ◽  
Groundwater Resources ◽  
Resource Planning ◽  
Fine Sand ◽  
Engineering Properties ◽  
Dry Density ◽  
Sand Sample ◽  
Fresh Groundwater

Saline water intrusion into freshwater aquifers is a major geohydraulic problem relevant to coastal environment. Apart from contaminating the fresh groundwater resources, the saltwater intrusion alters the geotechnical properties of the aquifer materials, affecting the coastal water resource planning and management. The present study focuses on an in-depth laboratory investigation of the influence of saltwater submergence on the geohydraulic properties of sand. The fine sand sample was submerged under saline water of specified concentrations for specific periods, and the alteration in their engineering properties has been studied. It is observed that the specific gravity, dry density, and permeability of fine sand is significantly affected by the period of submergence and saline concentration. The specific gravity of sand particles was observed to increase almost linearly with period of submergence and saline concentration. While the sand dry density decreased fairly linearly with the period of submergence, the same is not being affected significantly by saline concentration. The permeability of sand increased nonlinearly with both period of submergence and saline concentration; for a submergence period of 14 days and saline concentration of 30,000 ppm, the permeability increased to a maximum value.

scholarly journals Advances in the Coastal and Submarine Groundwater Processes: Controls and Environmental Impact on the Thriassion Plain and Eleusis Gulf (Attica, Greece)

2020 ◽  
Vol 8 (11) ◽  
pp. 944
Author(s):  
Demetrios Hermides ◽  
Panayota Makri ◽  
George Kontakiotis ◽  
Assimina Antonarakou
Keyword(s):  
Coastal Plain ◽  
Water Resource Management ◽  
Saline Water ◽  
Groundwater Resources ◽  
Quaternary Sediments ◽  
Major Goal ◽  
Fresh Groundwater ◽  
Sea Floor ◽  
Actual Mechanism ◽  
New Perspective

This study focuses on the hydrogeological conditions in the coastal (Thriassion plain) and submarine (Eleusis Gulf) environment of West Attica, Greece. Up to now, the predominant aspect for the Thriassion plain groundwater—hosted within the Neogene-Quaternary sediments—was its direct hydraulic contact with the seawater. Due to that, the coastal plain groundwater is strongly believed to be of brackish quality irrespective of the local hydrodynamic conditions. Our major goal is to evaluate the actual mechanism controlling the groundwater flow, the origin and distribution of saline water, and the existence of fresh groundwater in the submarine environment. We summarize the following: (1) groundwater of the Thriassion plain is partly discharged as an upwards leakage from deeper aquifers, (2) modern direct seawater intrusion is not possible in the Neogene-Quaternary sediments, and (3) fresh groundwater possibly exists below the sea floor of the Eleusis Gulf. The results may serve as hint of further research in groundwater resources below the Mediterranean Sea floor, and, consequently, a new perspective on water resource management could emerge.

scholarly journals Impacts of Sea Level Rise and Groundwater Extraction Scenarios on Fresh Groundwater Resources in the Nile Delta Governorates, Egypt

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1690 ◽  
Author(s):  
Marmar Mabrouk ◽  
Andreja Jonoski ◽  
Gualbert H. P. Oude Essink ◽  
Stefan Uhlenbrook
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Driving Forces ◽  
Nile Delta ◽  
Saline Water ◽  
Groundwater Resources ◽  
Salt Transport ◽  
Groundwater Extraction ◽  
Fresh Groundwater ◽  
The Impact

As Egypt’s population increases, the demand for fresh groundwater extraction will intensify. Consequently, the groundwater quality will deteriorate, including an increase in salinization. On the other hand, salinization caused by saltwater intrusion in the coastal Nile Delta Aquifer (NDA) is also threatening the groundwater resources. The aim of this article is to assess the situation in 2010 (since this is when most data is sufficiently available) regarding the available fresh groundwater resources and to evaluate future salinization in the NDA using a 3D variable-density groundwater flow model coupled with salt transport that was developed with SEAWAT. This is achieved by examining six future scenarios that combine two driving forces: increased extraction and sea level rise (SLR). Given the prognosis of the intergovernmental panel on climate change (IPCC), the scenarios are used to assess the impact of groundwater extraction versus SLR on the seawater intrusion in the Delta and evaluate their contributions to increased groundwater salinization. The results show that groundwater extraction has a greater impact on salinization of the NDA than SLR, while the two factors combined cause the largest reduction of available fresh groundwater resources. The significant findings of this research are the determination of the groundwater volumes of fresh water, brackish, light brackish and saline water in the NDA as a whole and in each governorate and the identification of the governorates that are most vulnerable to salinization. It is highly recommended that the results of this analysis are considered in future mitigation and/or adaptation plans.

Density-dependent 3D FE modelling of a recharge drain to mitigate saltwater contamination at the Venice farmland

2021 ◽  
Author(s):  
Maria Elisa Travaglino ◽  
Pietro Teatini
Keyword(s):  
Coastal Aquifers ◽  
Saltwater Intrusion ◽  
Sea Water ◽  
Transport Model ◽  
Saline Water ◽  
Numerical Models ◽  
Groundwater Resources ◽  
Fe Modelling ◽  
Fresh Groundwater ◽  
Density Dependent

<p>Saltwater intrusion in coastal aquifers is one of the most challenging and worldwide environmental problems, severely affected by human activities and climate change. It represents a threat to the quality and sustainability of fresh groundwater resources in coastal aquifers. Saline water is the most common pollutant in fresh groundwater which can also compromise the agriculture and the economy of the affected regions. Therefore, it is necessary to develop engineering solutions to restore groundwater quality or at least to prevent further degradation of its quality.</p><p>For this purpose, the goal of the Interreg Italy – Croatia MoST (MOnitoring Sea-water intrusion in coastal aquifers and Testing pilot projects for its mitigation) project is to test possible solutions (such as underground barriers, cut-off walls, recharge wells and recharge drains) against saltwater intrusion properly supported by field characterization, laboratory experiments, monitoring of hydrological parameters, and numerical models.</p><p>This works shows the preliminary results of an ongoing modelling study carried out for a coastal farmland at Ca’ Pasqua, in the southern part of the Venice lagoon, in Italy. A three-dimensional finite-element density-dependent groundwater flow and transport model is developed to simulate the dynamics of saltwater intrusion in this lowlying area. The model is used to assess the potential effects of a recharge drain recently established at 1.5 m depth along a sandy paleochannel crossing the organic-silty area. The goal of the intervention is to mitigate the soil and groundwater salinization by spreading freshwater supplied by a nearby canal. The beneficial consequences of the recharge drain should be enhanced by the higher permeability of the paleochannel.</p>

scholarly journals Management of Seawater Intrusion in Coastal Aquifers: A Review

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2467 ◽  
Author(s):  
Mohammed S. Hussain ◽  
Hany F. Abd-Elhamid ◽  
Akbar A. Javadi ◽  
Mohsen M. Sherif
Keyword(s):  
Seawater Intrusion ◽  
Coastal Aquifers ◽  
Arid Regions ◽  
Saline Water ◽  
Groundwater Resources ◽  
Management Strategies ◽  
Environmental Costs ◽  
Fresh Groundwater ◽  
Advantages And Disadvantages ◽  
And Control

Seawater intrusion (SWI) is one of the most challenging and widespread environmental problems that threaten the quality and sustainability of fresh groundwater resources in coastal aquifers. The excessive pumping of groundwater, associated with the lack of natural recharge, has exacerbated the SWI problem in arid and semi-arid regions. Therefore, appropriate management strategies should be implemented in coastal aquifers to control the impacts of SWI problems, considering acceptable limits of economic and environmental costs. The management of coastal aquifers involves the identification of an acceptable ultimate landward extent of the saline water body and the calculation of the amount of seaward discharge of freshwater that is necessary to keep the saline–freshwater interface in a seacoast position. This paper presents a comprehensive review of available hydraulic and physical management strategies that can be used to reduce and control SWI in coastal aquifers. Advantages and disadvantages of the different approaches are presented and discussed.

scholarly journals Modeling Seawater Intrusion to Coastal Aquifers in South Coast of Laizhou Bay, China

2018 ◽  
Vol 54 ◽  
pp. 00004
Author(s):  
Yawen Chang ◽  
Bill X. Hu ◽  
Xue Li
Keyword(s):  
Seawater Intrusion ◽  
Coastal Aquifers ◽  
Saline Water ◽  
Groundwater Resources ◽  
Water Area ◽  
Laizhou Bay ◽  
Precipitation Condition ◽  
Fresh Groundwater ◽  
Depression Cone ◽  
Error Method

In this study, a two-dimensional SEAWAT 2000 model is developed to simulate the seawater intrusion to coastal aquifers and brine water/fresh water interaction in the south of Laizhou Bay, Shandong Province, China and forecast the seawater intrusion and brine water/freshwater interface development in the coming years. The model profile is perpendicular to the coastal line, about 40 km long and 110 m in depth, and consists of two interfaces, freshwater-saline water interface and brine water-saline water-seawater interface. The parameters of aquifers in the SEAWAT-2000 model are calibrated by trial-error method repeatedly to fit the head and salinity measurements. Based on the historical groundwater and brine water exploration and natural precipitation condition, the prediction results indicate that equivalent freshwater head in shallow freshwater-saline water area will decrease year by year and decline 2.0 m in the forecasting period, caused by groundwater over-pumping for irrigating farmlands. The groundwater head in the brine-saline water area will also decrease about 1.8 m in forecasting period. A larger depression cone appears in the brine area, with smaller funnels in other areas. The salinity in the brine area finally drops below 105g/l. In the meanwhile, the salinity increases in other areas, damage fresh groundwater resources.

scholarly journals Coastal Ground Water Flow and Management: A State-of-the-Art Review

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Water Supply ◽  
Saline Water ◽  
Groundwater Resources ◽  
Industrial Effluents ◽  
Cost Effective ◽  
Fresh Groundwater ◽  
Local Climate ◽  
Indiscriminate Disposal ◽  
Groundwater Reserves ◽  
Anthropogenic Intervention

Seawater intrusion has led to salinization of fresh groundwater reserves in coastal areas worldwide and has forced the closure of water supply wells. There is a paucity of well-documented studies that report on the reversal of SWI after the closure of a well field. Saline water from a storm surge can flow down storm-damaged submerged water supply wells and contaminate boreholes and surrounding aquifers. Water is an invaluable commodity in nature and can be a limiting resource to man and other living beings. Water quality is influenced by both natural and anthropogenic intervention where the former includes local climate, geology etc., and the latter covers the construction of dams and embankments, irrigation practices, indiscriminate disposal of industrial effluents etc. Therefore, it is highly desirable to properly manage groundwater resources for drinking-water supply by controlling saltwater intrusion. A cost effective method Abstraction, Desalinization and Recharge was found to be efficient.

scholarly journals Engineering Properties of Volcanic Tuff from the Western Part of Yemen

2018 ◽  
Vol 22 (2) ◽  
pp. 81
Author(s):  
Adnan A. Barahim ◽  
Ibrahim A. Al-Akhaly ◽  
Is'haq R. Shamsan
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Specific Gravity ◽  
Water Absorption ◽  
Uniaxial Compressive Strength ◽  
Void Ratio ◽  
Engineering Properties ◽  
Dry Density ◽  
Dimension Stone ◽  
Volcanic Tuff

This paper deals with a study of the physical and mechanical characteristics of volcanic tuff and ignimbrite from six quarries located at different areas in the western part of Yemen (Manakha, Jahran, Bakhran, Dar Al-Hanash, Abaser and Soraifa). In the region, volcanic tuffs and ignimbrite are locally known by their location names and have been used as solid masonry and cladding stones. All the investigated pyroclastic rocks belong to the Tertiary volcanic. The standard physical and mechanical tests (void ratio, porosity, density, specific gravity, water absorption, uniaxial compressive strength and tensile strength) were carried out on the tuff and ignimbrite samples collected from different parts of the region. Laboratory tests revealed that the void ratio average values range between 0.12 and 0.37, the porosity ranges between 10.57 and 27.12%, the dry density ranges between 1.66 and 2.25 gm/cm3, specific gravity ranges from 1.45 to 1.94, and water absorption ranges from 4.69 to 16.39%. The measured uniaxial compressive strength values range from 24 to 68 MPa, and the tensile strength values range between 4 and 10 MPa. These tuffs and ignimbrites generally are light green, gray, beige, or yellowish in color. With these colors they are favoured for building, coating and decorative stone. This paper concludes that the studied stones have acceptable to good properties as dimension stone. Jahrani and Manakhi tuffs are the best quality, whereas Hanashi ignimbrite is of poorer quality.

scholarly journals EVALUATION OF ENGINEERING PROPERTIES OF THERMAL POWER PLANT WASTE FOR SUBGRADE TREATMENT

2021 ◽  
Vol 12 (2) ◽  
pp. 112-123
Author(s):  
Md. Belal Hossain ◽  
Md. Roknuzzaman ◽  
Md. Asib Biswas ◽  
Motaharul Islam
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Specific Gravity ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Engineering Properties ◽  
Dry Density ◽  
Cohesive Soils ◽  
Plant Waste ◽  
Class F

Soft cohesive soils have low strength, high plasticity, and a large expansion ratio making them unsuitable as a road subgrade. This study aims to evaluate the potential of power plant waste (fly ash) from the Barapukuria Thermal Power Plant, Dinajpur, Bangladesh to improve the characteristics of such soft cohesive soil. X-ray fluorescence test conducted to classify the power plant fly ash and the type was identified as “Class F” according to “American Association of State Highway and Transportation Officials” and "American Society for Testing and Materials". Laboratory tests were conducted on clay soil obtained from Dinajpur region modified by the collected power plant waste. As the Class F fly ash has low cementing property, 3% cement was added with it. Cement mixed soil was modified with 5%, 10%, 15%, and 20% fly ash respectively. Specific Gravity, Atterberg limits, Modified Proctor Compaction, Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) tests were conducted. The study reveals that there is a decrease in specific gravity, dry density, and plasticity index with the addition of power plant waste. On the other hand, there is an increase in optimum moisture content, UCS, and CBR value. UCS and CBR values were found to be improved remarkably. Soaked CBR value of soil is found to be improved from 2.79% to 92.59% when treated with 5% fly ash and 3% cement. The UCS value of this modified soil was 560.36 kPa. The stabilized soil thus obtained meets the requirements for subgrade as specified by the Local Government Engineering Department (LGED)’s design manual (2005), Bangladesh. Since there is a possibility of leaching by dumping a large quantity of fly ash in the pond, the use of fly ash from the power plants to improve soft cohesive soils for road subgrade may be an environment-friendly alternative to its disposal in the ponds.

scholarly journals Characterization of Fly and Bottom Ashes Mixtures Treated using Sodium Lauryl Sulphate and Polyvinyl Alcohol

2018 ◽  
Vol 34 ◽  
pp. 01018
Author(s):  
C.G. Robert ◽  
A. Ayob ◽  
M.F. Muhammad Zaki ◽  
M.E. Razali ◽  
E.V. Lew ◽  
...  
Keyword(s):  
Power Generation ◽  
Specific Gravity ◽  
Polyvinyl Alcohol ◽  
Sodium Lauryl Sulphate ◽  
Engineering Properties ◽  
Coal Waste ◽  
Dry Density ◽  
Main Concern ◽  
Maximum Dry Density ◽  
Waste Products

Malaysia promotes coal as an option for solid fuel in electric power generation. Demanding of electricity needs, therefore, has led to increase the coal consumption and thus producing more coal waste products. The disposal of coal waste ashes has been a main concern to power generation station due to the need of disposal sites and operational costs. This study investigates the composition of fly ash (FA) and bottom ash (BA) mixtures with difference component percentage treated with sodium lauryl sulphate (SLS) and polyvinyl alcohol (PVA) at 1.5 and 2.5 wt% solutions and examined in terms of specific gravity, pH, maximum dry density properties, and its surface morphology. Although the chemical composition of the SLS and PVA treated fly and bottom ashes studied in this current work is not altered extensively, significant changes could be observed in its physicochemical properties. Chemically treated fly and bottom ashes mixtures with SLS and PVA at 1.5 wt% solution exhibited specific gravity of 1.97 to 2.92 and high pH values within range of 9.28 to 10.52. The mixture of BA:FA=0:1 ratio depicting high maximum dry density of 1.35 to 1.56 g/cm3 in both SLS and PVA solutions at 1.5 and 2.5 wt%. Scanning electron microscopy image shows distinct surface morphologies of SLS-treated fly and bottom ashes mixture that the particles are packed closely, strongly bonded similar to popcorn shape due to the effect of active silanol groups acted on coal ashes surface with the presence of Al-O/Si-O/other oxides. These findings suggest that higher level of chemical interaction between the fly and bottom ashes particles, significantly enhances pozzolanic reactions such as shear strength, plasticity, cementing properties, and thus other engineering properties.

Effect of Humic Acid on Geochemistry Properties of Kaolin

2013 ◽  
Vol 701 ◽  
pp. 310-313 ◽  
Author(s):  
Faizal Bin Pakir ◽  
Ahmad Tarmizi Bin Abdul Karim ◽  
Felix N.L. Ling ◽  
Khairul Anuar Kassim
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Specific Gravity ◽  
Peat Soil ◽  
Atterberg Limits ◽  
Engineering Properties ◽  
Organic Soils ◽  
Dry Density ◽  
Loss On Ignition ◽  
Maximum Dry Density

Organic soil is always known as problematic soil because of its engineering properties are inferior from other soft soils and/or because its behaviour may deviate from traditional rules of soil behaviour which makes it difficult to predict and design. Considerable research has been carried out over the years on organic soils, particularly peat soil which consists of various components of organic matter but the effect of particular organic matter is less reported. Hence, this study is carried out to determine the effect of humic acid (a kind of humified organic matter) on kaolin (which is widely studied). This paper addresses the influence of humic acid (30% and 50% of dry mass) on kaolins geochemistry properties namely Atterberg limits, compaction, specific gravity and Loss on Ignition (LOI). The findings of the study showed that the contents of humic acid had altered the behaviour of kaolin. The loss on ignition increased linearly with the increment of humic acid. However, the specific gravity, maximum dry density and Atterberg limits decreased with addition of humic acid. Atterberg limits decreased as the humic acid increased is believed to be due to the nature of humic acid which precipitated under acidic environment.

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