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Water used for electric power production and different purposes nowadays in Egypt is from traditional sources like the Nile River and non-traditional sources such as seawater, excessively hard or brackish groundwater, poor quality surface waters, and wastewater. All these sources commonly require treatment with high-quality technologies before use. In the area of the West-Assiut Combined Cycle Power Plant (WACCPP), in Upper Egypt, groundwater is used as the source for demineralized water production for this power plant and it is used in other applications as well. In this paper, the quality of this groundwater and its suitability for different purposes are examined. Many chemical properties were examined such as corrosive ratio, water action according to the relation between pH and alkalinity, Kelly’s ratio, sodium absorption ratio, soluble sodium percent, the relation between EC and Na %, residual sodium carbonate, permeability index, potential salinity, magnesium adsorption ratio. The water pollution index rating scale was calculated for evaluating the water suitability for different purposes. Results showed that water is unsuitable for most purposes, and hence, polluted water is used in WACCPP.

This research work aimed to investigate the degree of quality of tap and bottled waters available in Al-Madinah city through an experimental program comprising chemical, physical and biological tests. The study included examining the quality of the water supply network components such as taps, underground storage tanks and feeding pipes of the network. Filtration influence on the tap water was investigated by testing different water samples before and after the filtration process at different locations. The experiments also examined various bottled water brands sold in Al-Madinah. In addition, the impact of using the dispenser on the water quality of large bottled waters was studied. The water quality of two types of waters was compared by estimating water quality index (WQI). Results of this study revealed that the overall quality of the tap water is within standard values; however, deterioration occurs for the water through its journey in the water supply system. Results revealed that hardness and fluoride concentrations in bottled waters exhibited high values close to or more than allowable values of the standards. Furthermore, results confirmed that using the filter and dispenser decreased the water quality degree in the long run. Bottled waters showed a higher grade of WQI than tap water.

Dissolved organic matter (DOM) has been recognized as a serious water quality problem in natural water bodies receiving pollution loads from point and nonpoint sources. The present study investigates the spatiotemporal variability of DOM composition in the Kushiro River and its tributaries (Eastern Hokkaido, Japan) impacted by the Kushiro wetland. Water samples were collected in the wet and dry seasons from several locations of the river and analyzed for DOM characteristics by UV–visible and excitation–emission matrix fluorescence spectroscopy techniques and by developing water quality index. Rather than the spatial effect, significant seasonal impacts on DOM pollution in the Kushiro River were observed. Overall concentrations of DOM decreased during the dry season. The increase of specific ultraviolet absorbance in the dry season indicated an increasing trend of humification, aromaticity and molecular weight of DOM. Five fluorescent peaks, including peaks A, C, M, B, and T were predicted by EEM spectra. Peaks A and C were found to be the most dominating peaks in both the seasons and indicated enrichment of humic-like matters in river water. The intensities of poly-aromatic humic substances as well as DOM components of microbial origin increase in the wet season and proteins like autochthonous DOM increase during the dry season. The study recognized the contribution of freshly produced DOM component by the decomposition of wetland plants in wet season and effect of snowfall in the dry season. Analysis of three fluorescence indices revealed that the river water primarily contains terrestrially dominated DOM. A significant impact of the adjacent WWTPs and wetland to the river water DOM were also observed. The water quality index of river water DOM showed low to medium levels of DOM pollution in the Kushiro River.

Water is life, and without water, there would be no civilizations and a vacant Earth. Water is considered an abundant natural resource on the earth. Water covers 3/4 of the surface. However, 97% of the available water on the earth is salty oceanic water, and only a tiny fraction (3%) is freshwater. This small portion of the available water supplies the needs of humans and animals. However, freshwater exists in underground, rivers, and lakes and is insufficient to cover all the world’s water demands. Thus, water saving, water reuse, rainwater harvesting, stormwater utilization, and desalination are critical for maintaining water supplies for the future of humanity. Desalination has a long history spanning centuries from ancient times to the present. In the last two decades, desalination has been rapidly expanding to meet water needs in stressed water regions of the world. Yet, there are still some problems with its implementation in several areas of the world. This review provides a comprehensive assessment of the history of desalination for wiser and smarter water extraction and uses to sustain and support the water needs of the earth’s inhabitants.

The new coronavirus, COVID-19, spread quickly and causes the death for thousands of people, and a major freeze for the economy and people activities worldwide. This study made statistical analysis for the influences of the environmental conditions such as temperature, humidity, precipitation, wind, and air pollution, which may aid in spreading this virus very fast. The study also investigated statistically the impact of people customs such as smoking, drinking wine, and eating pig meat on the number of deaths among infected people. The study depicted reasons for spreading it in some places much more than others over the world. A statistical software SPSS was adopted to find a correlation among the different variables affecting the virus spread. The results exhibited a significant relationship between the suggested conditions and the virus spread. The study introduced two regression equations for expecting infected people and deaths based on the examined conditions for any region.

Wastewater generated from industrial activities has delivered elevated heavy metal concentrations into fresh and salted aqueous systems. Herein, the migrated trace metals were studied from their initial location through a coastal aquifer up to the seawater. The experiments were carried out at lab scale using a sandbox with glass beads and two attached chambers containing natural groundwater and seawater. The study focused on the transport behaviour of heavy metals such as copper, zinc and lead into freshwater and seawater. Plasma optical emission spectrometry (ICP-OES) analysis was performed to detect the heavy metal concentrations from the water samples taken with time from the experiments. The simulation work adopted Groundwater Modelling System (GMS) codes were used for validation of the experimental outcomes. Results showed that the heavy metals concentrations in wastewater effluents affect the water quality of the aquifer. The water quality and resistance of the aquifer to heavy metals pollution increased with the presence of a renewable recharging of freshwater along with the contamination source. Heavy metal ions in seawater exhibited a gradual increase in their concentrations with time in all studied cases.

Arid countries such as Arabian Gulf countries are suffering from a water shortage, especially with the recent high-water demand. The best solution for this shortage is the management of currently available water resources, through the reuse of treated wastewater for irrigation purposes. This solution also solves the problem of regularization of wastewater discharge, with positive impacts on the environment. This study aimed to apply an innovative, advanced method for treating wastewater with a favorable environment, low economic cost, and less energy consumption. The research investigated the possibility of using natural rocks such as volcanic and zeolite for advanced treatment of wastewater effluent. The research methodology relied on an experimental work in the lab scales and applied on materials available in Saudi Arabia. The experiments included a leaching batch test to first examine what leaches out from these rocks into water. Then, the materials were tested with wastewater effluent. The main mechanism of treatment was based on the absorption process. The results exhibited significant improvement in the water quality of treated wastewater. On the other hand, the results of the leaching tests showed many ions being dissolved from both rocks into water; thus, it is recommended to soak and flush these solid materials with clean water before using them for the treatment process. Further research is required to determine the best pretreated methods to be applied on these rocks to improve their performance as absorbents.

Control and management of landfill leachate are the most important concerns to protect the surrounding environment, especially the groundwater. In this study, an attempt was carried out to design an approximate tool for finding the safe groundwater withdrawal away from the pollution sources. A case study was applied to a landfill site in a desert climate region, at Mufrihat, the south western region of the Madinah City, KSA. Three boreholes were adopted to monitor the groundwater quality close to leachate collection lake of the landfill site. A 3D simulation model, combining modular finite-difference flow model and the modular three-dimensional transport model, was applied to the leachate collection site to understand the fate and migration of the leachate from collection site bed into the groundwater. The focus of this work was to predict the distribution of heavy metal concentration with both time and distance and to determine the safe location for water extraction from this aquifer. Results showed a good match between numerical model results and experimental measurements. Based on this math and sensitivity analyses performed by the computer model, an empirical mobility model was generated to support the decision makers of this area and similar regions to estimate the safe location for water withdrawal according to the initial concentration of the element, pumping rate and contact time. The mobility model showed that the well located at a minimum of 113 m away from the leachate collection lake would be safe from all studied pollutants.

Miscanthus species originated in Asia and were imported into Europe and North America as ornamental plants. They are perennial rhizomatous grasses with lignified stems and present very high growth rates, even in more temperate maritime climates. This potentially abundant biomass offers benefits to many sectors and is used to an extent in energy generation applications, however, issues with regards to its physicochemical combustion characteristics currently hinder this uptake. In this work, a novel alternative application, namely its direct use of dry miscanthus (DM) plant as an adsorbent for heavy metals removal (HMR) from wastewaters, was investigated. The physical, chemical, and leaching properties of DM were analyzed using XRD, SBET, TGA, DSC, SEM-EDX, elemental analysis, halogen, and ICP techniques. Subsequently, the HMR capacity of miscanthus was studied for lead, copper, and zinc from aqueous solutions. Results showed a high percentage removal of 66%, 83%, and 88%, respectively, with the majority being removed during the first hour of the test. Overall the results show that DM plant can be effectively utilized in wastewater treatment. © 2017 American Institute of Chemical Engineers Environ Prog, 2017

The contamination of fresh groundwater by saltwater intrusion (SWI) becomes a worldwide alarming problem, which threatens all countries depending on groundwater abstraction from coastal areas. Various control and treatment strategies have been suggested to prevent SWI. The construction of subsurface physical barriers is one of the most practical implementation methods to prevent SWI. In this work, the use of subsurface dam as a remediation and protection tool was investigated in a heterogeneous aquifer via lab scale experiments and numerical simulation. The experiments depended on a novel automated imaged analysis method for SWI measurements. Glass beads of different grain sizes were used in sandbox experiments. The simulation works adopted the SEAWAT code for validation of the experimental results and making numerical sensitivity analyses for affecting parameters. Results proved the significant impact of using sub water dams with heterogonous aquifers. The remediation impacts of the dam was captured clearly in preventing and backwashing of the existed SWI. The results revealed also that the heterogeneous aquifers with high permeability in the bottom boundary behave closer to the homogenous aquifers in SWI than those having low hydraulic conductivity in the bottom. Sensitivity analyses results showed that the closer dam to seawater boundary led to the quicker and more effective backwashing process. Results exhibited also that the dam height with 50% of the aquifer dam has the ability to hold the seawater so long as the hydraulic gradient is high and dams with 67% of aquifer height prevent the saltwater intrusion completely.

An underground aqueduct is usually a canal built in the subsurface to transfer water from a starting point to a distant location. Systems of underground aqueducts have been applied by ancient civilizations to manage different aspects of water supply. This research reviews underground aqueducts from the prehistoric period to modern times to assess the potential of achieving sustainable development of water distribution in the sectors of agriculture and urban management, and provides valuable insights into various types of ancient underground systems and tunnels. The review illustrates how these old structures are a testament of ancient people’s ability to manage water resources using sustainable tools such as aqueducts, where the functionality works by using, besides gravity, only “natural” engineering tools like inverted siphons. The study sheds new light on human’s capability to collect and use water in the past. In addition, it critically analyzes numerous examples of ancient/historic/pre-industrial underground water supply systems that appear to have remained sustainable up until recent times. The sustainability of several underground structures is examined, correlated to their sound construction and regular maintenance. Moreover, several lessons can be learned from the analysis of ancient hydraulic works, particularly now, as many periodically hydrologic crises have occurred recently, overwhelmingly impacted by climate change and/or over-exploitation and degradation of available water resources.

A detail investigation was carried out to improve the current knowledge of groundwater salinisation processes in coastal aquifers using hydrochemical and isotopic parameters. Data of major ions for 40 wells located in the Salalah plain aquifer, Sultanate of Oman, were collected during pre-monsoon 2004 and analysed. The groundwater changes along the general flow path towards the coast from fresh (EC 3000 μS/cm). Results of inverse modeling simulations using PHREEQC show that dissolution of halite may be the main source of Cl and Na in the study area. Ionic delta calculation indicates that the depletion of Na and K and enrichment of Ca and Mg in groundwater were probably attributed to reverse ion exchange reactions. During a sampling campaign conducted in October 2015, 11 groundwater samples were collected for Cl, Br and isotopic analysis ( 2 H/ 18 O). Molar Cl/Br ratios in fresh groundwater were higher than those of seawater, indicating the impact of halite dissolution on the groundwater quality. For saline groundwater, these ratios were less than those of seawater, showing the influence of anthropogenic input from agriculture on the same. Relatively depleted isotopic signature of all groundwater samples show that the monsoon precipitation is the main source of groundwater recharge in the study area.

International audience

The use of water for domestic and agricultural purpose is not a new phenomenon. It has been used throughout centuries all over the world. After food, water is the basic component of human life and their settlement. This paper considers developments in water dams and water harvesting systems throughout history in different civilisations. The major component of this review consists of hydraulic dams during Pre-Historical Time, Bronze Ages (Minoan Era, Indus Valley Civilization, Early Ancient Egyptian Era, Hittites in Anatolia, and Mycenaean Civilization), Historical Period, (Pre-Columbian, Archaic Period, Classical Greek and Hellenistic Civilizations, Gandahara and Mauryan Empire, Roman Period, and early Chinese dynasties), Medieval times (Byzantine Period, Sui, Tang and Song Dynasties in China, Venetian Period, Aztec Civilization, and Incas) and Modern Time (Ottoman Period and Present Time). The main aim of the review is to present advances in design and construction of water dams and water harvesting systems of the past civilizations with reference to its use for domestic as well as agricultural purposes, its impact on different civilizations and its comparison to the modern technological era. In addition, emerging trends and perspectives are discussed.

The Nile River (NR) is the primary water resource and the life artery for its downstream countries such as Egypt and Sudan. This chapter focuses on the impacts of constructing the Grand Ethiopian Renaissance Dam (GERD) on three main parts of the NR: close to Sudan-Ethiopia border; near Khartoum, Sudan; and the main Nile at the entrance of Lake Nasser, Egypt. The dam is designed to create a storage reservoir that will maintain a holding capacity of about 74 billion cubic meters of water at the full supply level. The impacts are divided into two main categories which are hydrological and environmental impacts. By studying the hydrological impacts, the study delineated the reservoir area to estimate the reservoir volume and its geometrical dimensions for all possible scenarios from starting the dam construction up to reaching the full operation and storage capacity. Results show that the best-accepted scenario for constructing the dam is by filling the dam reservoir with 10 BCM/year or less in 3.8 years. Furthermore, the impacts of the dam breach on Ethiopia and the downstream countries are studied via simulations from HEC-RAS model. In case of dam breach, a severe flood will result in inundation of the Sennar Dam, Sudan, 15 km wide and 200 km long, and the areas in between, until it reaches Khartoum, Sudan. Also, excessive water level with 3 m rise is expected from the dam until it reaches Nasser Lake. By studying the environmental impacts, particularly those of the population displacement, carbon dioxide emissions, agricultural lands, animals, and aquatic life, we will gain a better understanding of potential risks. This chapter discusses successes and many drawbacks of the GERD construction and its hydrological and environmental impacts on the Nile River downstream countries.

The Sultanate of Oman is an arid country with scarce water resources mainly consisting of groundwater. Aflaj are artificial canals constructed centuries ago to transfer horizontally the groundwater to a location at the surface. The water quality of these Aflaj is a very important factor to be considered for healthy and safe use of this water. This paper aimed to study the characteristics of the groundwater through its journey in Aflaj from source point up to its usage point. An experimental programme was adopted to investigate the water quality of Al Hammam Aflaj in Muscat, Sultanate of Oman. The results showed that some positions of the Falaj have high content of some elements, such as Ca, above the allowable values of drinking water standards. Results proved that the water of Al Hammam Falaj in general can be used with caution as a drinking water; however, some care and monitoring should be applied regularly. Results of sodium adsorption ratio (SAR) and soluble sodium percentage (SSP) equations revealed that the water Falaj can be used for irrigation for all soil types but cannot be used on soils with restricted drainage due to its relatively high salinity.

The characterization of dissolved organic matter (DOM) is an important parameter for the management of water resources. In this study, physical and chemical characteristics of DOM in Kushiro river, and its territory (Eastern Hokkaido, Japan) were analyzed using multiple analytical tools. Multiple samples were collected from diverse locations (Kushiro river, Kushiro wetland, compost fertilizer, forest and treated sewage) and compared them against their DOM characteristics. Among the samples, Kushiro wetland samples presented higher specific ultraviolet absorbance (SUVA) values demonstrating DOM derived from vascular plants which are rich in aromatic-components. The SUVA values of the two samples of the Kushiro river were relatively close to those of the wetland samples implying the fact that the river contains high amount of plant derived aromatic DOM compounds, originating from the wetland. The excitation–emission matrix (EEM) fluorescence results showed that generally all water samples have two peaks namely, A and C. These two peaks are related to humic-like substance typically derived from the breakdown of organic matters. The excitation–emission matrix (EEM) fluorescence results of the river samples were also similar to those of the wetland samples, characterized by no appearance of protein, amino acid, polysaccharide, and fluvic like matter, but more pronounced to the aromatic component rich humic acid. Principal component analysis revealed that approximately 88% of the variance in the DOM characteristics might be explained by the type of different sources. From the loadings on PC1 and PC2 in the scores plot, the properties of the DOM of the wetland appeared to be similar to those of the river DOM. Combined results exhibited that the quality of the Kushiro river water is fundamentally inherited from the Kushiro wetland, and the main structure of the river water is characterized by poly-aromatic humic like matter and higher molecular weight.

In southern Tunisia oases, waterlogging, salinity, and water shortage represent serious threats to the sustainability of irrigated agriculture. Understanding the interaction between these problems and their effects on root water uptake is fundamental for suggesting possible options of improving land and water productivity. In this study, HYDRUS-1D model was used in a plot of farmland located in the Fatnassa oasis to investigate the effects of waterlogging, salinity, and water shortage on the date palm water use. The model was calibrated and validated using experimental data of sap flow density of a date palm, soil hydraulic properties, water table depth, and amount of irrigation water. The comparison between predicted and observed data for date palm transpiration rates was acceptable indicating that the model could well estimate water consumption of this tree crop. Scenario simulations were performed with different water table depths, and salinities and frequencies of irrigation water. The results show that the impacts of water table depth and irrigation frequency vary according to the season. In summer, high irrigation frequency and shallow groundwater are needed to maintain high water content and low salinity of the root-zone and therefore to increase the date palm transpiration rates. However, these factors have no significant effect in winter. The results also reveal that irrigation water salinity has no significant effect under shallow saline groundwater.

This study aims to investigate the ability of low cost ceramic membrane filtration in removing three common heavy metals namely; Pb2+, Cu2+, and Cd2+ from water media. The work includes manufacturing ceramic membranes with dimensions of 15 by 15 cm and 2 cm thickness. The membranes were made from low cost materials of local clay mixed with different sawdust percentages of 0.5%, 2.0%, and 5.0%. The used clay was characterized by X-ray diffraction (XRD) and X-ray fluorescence analysis. Aqueous solutions of heavy metals were prepared in the laboratory and filtered through the ceramic membranes. The influence of the main parameters such as pH, initial driving pressure head, and concentration of heavy metals on their removal efficiency by ceramic membranes was investigated. Water samples were collected before and after the filtration process and their heavy metal concentrations were determined by chemical analysis. Moreover, a microstructural analysis using scanning electronic microscope (SEM) was performed on ceramic membranes before and after the filtration process. The chemical analysis results showed high removal efficiency up to 99% for the concerned heavy metals. SEM images approved these results by showing adsorbed metal ions on sides of the internal pores of the ceramic membranes.

Many granular waste and recycling materials are being considered as substitutes for natural aggregates in construction applications. Incinerator bottom ash waste (IBAW), a residue from burning household waste, was previously landfilled, but now two-thirds of this ash is recycled, primarily in road construction. In this study, IBAW was mixed with limestone to produce a blend with acceptable properties for use as a road foundation layer. Cement was added to the blends to improve their mechanical characteristics. Scanning electron microscopy (SEM) was used to study the physical and chemical features of untreated and cement-treated IBAW blends and to identify the nature of the materials and any secondary reaction elements, especially after mixing with water. The micromechanical behavior of limestone–IBAW blends under uniaxial compression stresses was modeled on the basis of SEM images of the blends' microstructures. The results of micromodeling in general matched the experimental data very well. Microstructure modeling proved the high stiffness of the cement-treated blends. The material behavior in the plastic stage changed significantly with a change in the geometry and stiffness of the inclusions. Experimental and modeling results also showed that IBAW material behaved as a conventional aggregate. Results demonstrated in general that microstructural analysis was quite useful in describing the mechanical behavior of IBAW and could be applied to all granular waste materials.

The groundwater aquifer in the coastal region of the northwest of Oman has been used extensively since the early 1980s for agricultural, industrial and municipal purposes. The over pumping of this reservoir has led to the intrusion of seawater and therefore to the deterioration of the groundwater quality. In this study, an investigation was carried out in the southern part of this region to identify the quality of groundwater, to understand the main sources of groundwater mineralisation, and to check the suitability of groundwater for drinking and irrigation. The spatial distributions and temporal variations of groundwater level and electrical conductivity were studied for the period from 1982 to 2005 using data collected from 225 wells. In addition, groundwater samples were collected recently in 2012 from eight wells and analysed for pH, EC, and major ions to understand the sources of dissolved ions and assess the chemical quality of the groundwater. The study area was divided into two strips parallel to the coastline, A and B, located in the discharge and recharge parts of the aquifer, respectively. Results showed a significant increase in the degree of water mineralisation in the direction of south to north following the regional flow direction. Results showed also that the groundwater in the last area could be used for irrigation with little danger of exchangeable sodium while this aquifer is unsuitable for irrigation in the discharge area because it presents a very high salinity hazard.

International audience; An environmentally acceptable disposal of sewage sludge and agro-wastes presents an urgent problem facing many countries. Anaerobic digestion (AD) is a robust and suitable technique for producing renewable energy from wastes. This study aims to improve methane production from anaerobic co-digestion of primary sludge (PS) and wheat straw (WS) depending on their volatile solids (VS) organic load and by adding a proposed waste material of buckwheat husk (BH) based on their carbon to nitrogen (C/N) ratio. Mesophilic anaerobic batch tests were carried out in 500-mL digesters. Individual and six mixtures of PS and WS at different VS organic loads were anaerobically digested to optimize VS load for the greatest gas production. The highest cumulative methane yield (CMYs) occurred with combined substrates at a VS load of 7.50 gVS/L. In general, the optimized organic loads that gave the highest cumulative biogas yield (CBYs) and CMYs were in the range of 6-8 gVS/L. In addition, AD of individual substrates of PS, WS, and BH and of their mixture at different C/N ratios was investigated regarding to the methane yields. Multi-component substrates produced the greatest CMY at a C/N ratio of 10.07. The CMYs was increased by 39.26% when the proposed waste material of buckwheat husk (BH) was added to the different mixtures of PS and WS compared to the co-digestion of PS and WS. Experimental results were approved using statistical analysis by ANOVA test at P-value less than 0.05. Purification of methane and biodegradation of VS were evaluated. The results emphasized positive synergy of anaerobic co-digestion for improving CMY and best feedstock utilization. (C) 2016 Elsevier Ltd. All rights reserved.

This paper suggests an approximate model to estimate the total plastic deformation of layers made of granular materials. In this work, the model was designed to calculate the plastic deformations of the cylindrical specimen of monotonic triaxial tests. The model concept is based on the deformation mechanisms of granular material presented in the literature review. These mechanisms assumed that the volume of the whole granular material structure decreases because of particle rearrangements and compressibility of the materials. In triaxial tests, there are three main stages of loading and deformations. A plastic deformation begins in the material due to the post-compaction and tamping effects of the initial loading. This deformation results from compression of the fine material coating between the particles completely or partially depending on its degree of compressibility expressed, herein, by a hardness coefficient. At further loads, the particles contact directly each other and the sample behaves elasticity. When resultant forces on the particle at high levels of loading are more than the confining pressure and shear strength of the material, the particles move or slip laterally causing damage and buckling. The model estimates the total vertical deformations of the material as the sum of the deformation resulting from the post-compaction process and those generated from the re-orientation and horizontal movement of the particles. The model was validated with the results of monotonic triaxial tests of untreated and treated blends made of limestone and Incinerator Bottom Ash Waste (IBAW) to examine the effect of various material properties on the model calculation accuracy. The model results showed that the approximation model depicted the experimental value of the plastic deformations fairly well as the error parentage ranged between 12% and −15% for treated and untreated blends.

A substantial amount of incinerator bottom ash (IBA) waste is generated annually from burning municipal solid waste. IBA is similar to aggregate consisting of ferric metals, non-ferrous metals, brick and tile fragments, ceramic, glass, stone, dirt, etc. In this work, IBA waste was mixed with conventional limestone aggregate in an attempt to achieve a blend with acceptable mechanical properties and minimum environmental risks for use in road foundation layers. Enzyme treatment was applied in order to improve the behaviour of IBA–limestone blends. A series of laboratory tests, such as cyclic triaxial compression tests, pH monitoring and scanning electron microscope, were adopted to determine the materials' mechanistic behaviour and microstructure characteristics. Emphasis was on examining the effect of various parameters, such as IBA content, enzyme content, moisture content and curing time. Results of this study showed that IBA blends gave a favourable performance as road foundation layers in comparison wi...

Incinerator bottom ash (IBA) is a residue from burning household waste that once was put into landfills. Nearly two-thirds of this ash is reused, primarily in road construction. In this study, IBA was mixed with limestone to produce a blend with acceptable properties for use as a road foundation layer. In situ simulative testing with a light falling weight deflectometer (LFWD) and subsequent interpretation of the surface deflection data have enabled evaluation of the mechanical properties of the foundation and subgrade layers. An experimental and modeling study of the elastic dynamic response of a foundation layer of IBA waste and limestone that was subjected to LFWD impact loading is presented. Several parameters—such as IBA content, water content, and curing time—were studied. Regression, mathematical, and three-dimensional finite element models were developed to backcalculate the LFWD moduli of the foundation layers. The modeling approach accounted for the static and impact nature of the LFWD load. Results showed that IBA blends underwent less deflection, as a foundation layer, than the control limestone blend. Backcalculated modulus results based on the dynamic effect of the LFWD load produced different values from those calculated by Boussinesq's equation, which is adopted by the LFWD manufacturer.

Incinerator bottom ash (IBA) is a residual produced from incinerating municipal solid waste. In the past, IBA presented a big waste disposal problem; however, various recycling approaches have been adopted in recent years to mitigate this problem, as well as to provide a useful alternative to using primary aggregate resources. The use of IBA as an alternative to conventional aggregates in different civil engineering construction applications helps to conserve premium grade aggregate supplies; however, when IBA is in contact with water in the field, as a consequence of precipitation events or changes in water table, elements, such as salts and heavy metals, may be released to the soil and ground water. In this work, IBA waste was mixed with limestone aggregate to produce a blend with acceptable mechanical properties and minimum environmental risks for use as road foundation. The study focused on evaluating potential environmental impacts of some constituents, including sulphate, chloride, sodium, copper, zinc and lead in IBA blends using a lysimeter as a large scale leaching tool. Moreover, a specific scenario simulating field conditions was adopted in the lysimeter to assess the potential impact of changing conditions, such as IBA content in the blend, liquid to solid ratio (L/S) and pH value, on long-term release of heavy metals and salts. Then, numerical modelling was used to predict the release of the aforementioned constituents from IBA based on initial measurement of intrinsic material properties and the kinetic desorption process concept. Experimental results showed that zinc and lead were released in very low concentrations but sodium and sulphate were in high concentrations. The control limestone only blend also demonstrated low release concentrations of constituents in comparison to IBA blends, where constituent concentrations increased with increase in IBA content. Experimental results were compared with numerical results obtained using a non-equilibrium desorption model. Good agreement was found between the two sets of data.

The use of waste and recycled materials in different construction applications is a widespread approach. In this work, incinerator bottom ash (IBA) waste was mixed with limestone at different levels, namely, 0%, 30%, 50%, and 80%, to produce blends for use as pavement foundation layers. The study focused on evaluating the resistance to permanent deformation of IBA–limestone blends, which is vital to prevent or minimize pavement rutting. An experimental program was undertaken to investigate the influence of plant-based enzyme treatment on the behavior of these blends. Cyclic and static triaxial compression tests were adopted to determine the materials’ mechanical characteristics. Emphasis was on examining the effect of various parameters, such as IBA content, enzyme content, moisture content, curing time, stress level, and number of load applications, on the behavior of the investigated blends. The accumulated permanent strain and strain rate were used to describe the blends’ shakedown stress limits. Results showed that IBA blends gave a favorable performance as foundation layers in comparison with the control limestone blend. Enzyme addition improved the permanent deformation resistance for the control limestone blend; however, it did not have any noticeable effect on the IBA blends. According to the shakedown concept analysis, all blends, at a cyclic stress level of more than 21% of the static failure stress, underwent excessive plastic strain.

Management of natural aggregate resources has become one of the most important challenges in construction, especially for high demand applications such as roads. Incinerator bottom ash (IBA), which is produced from burning domestic waste, has been considered a useful solution to the shortage of natural resources. In this research, IBA was mixed with limestone to produce an acceptable blend for use as a road foundation layer. Novel and traditional additives were adopted to improve the mechanical properties of IBA blends. The study focused on the treatment effect of additives on the mechanical characteristics of IBA blends under monotonic and cyclic triaxial stresses. The investigation evaluated fundamental material properties, including resilient modulus, initial Young’s modulus and Poisson’s ratio. Two nonlinear empirical models were adopted to depict the experimental resilient modulus results of the IBA blends. An approach has been proposed to predict realistic and representative values of resilient modulus for the material. In addition, a new relationship has been established between Young’s modulus, resilient modulus and Poisson’s ratio. Triaxial test results revealed that additives are more efficient with the control limestone blend than with the IBA blends. Novel additives, such as enzyme I and silica fume, produced a noticeable improvement in IBA properties in comparison to traditional additives.

Summarization: Since prehistoric times, water conflicts have occurred as a result of a wide range of tensions and/or violence, which have rarely taken the form of traditional warfare waged over water resources alone. Instead, water has historically been a (re)source of tension and a factor in conflicts that start for other reasons. In some cases, water was used directly as a weapon through its ability to cause damage through deprivation or erosion or water resources of enemy populations and their armies. However, water conflicts, both past and present, arise for several reasons; including territorial disputes, fight for resources, and strategic advantage. The main reasons of water conflicts are usually delimitation of boundaries, waterlogging (e.g., dams and lakes), diversion of rivers flow, running water, food, and political distresses. In recent decades, the number of human casualties caused by water conflicts is more than that of natural disasters, indicating the importance of emerging trends on water wars in the world. This paper presents arguments, fights, discourses, and conflicts around water from ancient times to the present. This diachronic survey attempts to provide water governance alternatives for the current and future. Presented on