Limited Freshwater Supplies Research Articles

Optimizing sustainable multiple biomass-to-biofuel conversion network with integrated water resource management utilizing data-driven robust planning

Until now, the biofuel supply chain has lacked an integrated approach to address its fundamental challenges in real-world implementation. The first challenge is maintaining a continuous supply flow in the biofuel network, which can significantly impact economic outcomes and performance measures. The second challenge involves managing water resources for biofuel production to preserve freshwater reserves. The third challenge is managing operational risks, such as uncertainty in biofuel demand, which leads to conservative planning and underscores the need for realistic uncertain programming approaches. To address these challenges, the proposed study designs a biofuel conversion network that utilizes third-generation feedstocks and non-edible seed sources, sourcing necessary water from wastewater resources. This practical solution addresses water-energy relationship concerns, reducing dependency on limited freshwater supplies. To achieve a continuous and cost-effective feed supply, this study incorporates a pre-processing phase using a hybrid Multi-Criteria Decision-Making model. This approach ensures the feed supply remains consistent, economical, and sustainable. To manage the uncertainty in biofuel demand, we developed a robust optimization model with an intersected uncertainty set using a data-driven approach. This approach aims to reduce conservatism in the obtained solutions, making the model more practical for real-world implementation. The numerical results reveal some practical implementation for policymakers. The proposed robust optimization using the configured uncertainty set offers a tool to manage the conservatism of renewable energy demand uncertainty and operational risks more effectively than traditional approaches (0.914%). This formulation can help policymakers to maintain greater robustness against fluctuations in confidence levels. Additionally, the simultaneous use of third-generation and non-edible feedstocks creates a multi-biomass-to-biofuel conversion network, offering practitioners a practical solution that significantly reduces reliance on freshwater resources. Furthermore, policymakers can leverage the proposed pre-processing phase to promote economic and continuous supply feed based on geographical, resource accessibility, and infrastructure criteria.

A complementary eco-friendly approach to heavy metal removal from wastewater/produced water streams through mineralization

With the world's ever-increasing population, portable water needs have significantly increased. This has put enormous pressure on the limited supply of freshwater around the globe and has necessitated the development of water treatment technologies that would convert saline waters into potable water for domestic and industrial uses. As saline water is treated for usage, so is wastewater generated from domestic and industrial processes. More prominently, another wastewater source is produced water consequent to oil production. Wastewater and produced water are similar in that they are both high in pollutants (heavy metals), which in discharge streams need to be kept within a threshold. The fact that heavy and rare earth metals linked to the produced water cannot be completely removed by state-of-the-art technologies is even more concerning. Thus, a complementary technology must be developed for this reason. This study investigates the mineralization of water-polluting heavy metals. The approach adopted involves the exposure of contaminated water to atmospheric or captured CO2 and the use of additives to achieve the removal. To gain a deeper understanding of how these innovative efforts function, the study also looked into the mechanism used to eliminate the heavy metals. The findings show that heavy metals in produced water and industrial effluent can be precipitated and immobilized to remove them. More so, this is made possible by the infusion of heavy metals into the crystal structures of precipitates like aragonite, calcite, and halite. Furthermore, the mechanism of the heavy metal removal involves their dehydration, immobilization and precipitation. Additionally, DFT calculations were utilized to support the experimental results by shedding light on the heavy metal hydration's ground-state structures and how EDTA chelates the heavy metals and enhances the process kinetics. The study's findings show how this strategy complements the most advanced wastewater treatment method in terms of increasing its efficiency and water security and safety. More so, as this is a pioneering effort, the optimum concentration of chelating agent and route (atmospheric or captured CO2) must be determined on a case-to-case basis for field implementation. Furthermore, the limitation of this study is that the efficiency of heavy metal removal may differ based on the starting brine composition, thus, optimization must be conducted beforehand.

Comparison of Water Utilization Patterns of Sunflowers and Maize at Different Fertility Stages along the Yellow River

Currently, there is a limited supply of freshwater on a worldwide scale, and finding effective ways to use agricultural freshwater resources has become a widely discussed subject. To investigate the most suitable crops and the efficient use of water resources in dry regions, we performed a comparison study of water consumption between two common crops, maize and sunflowers, in the irrigation area located on the south bank of the Yellow River in Northwest China. Both sunflowers and maize have diverse water sources at various reproductive phases. We discovered that sunflower predominantly consumes 0–50 cm soil water throughout the reproductive cycle, whereas maize mostly utilizes 0–50 cm soil water in the early reproductive phase and 50–90 cm soil water in the late reproductive period. The comparison of yield sustainability between sunflowers and maize demonstrated that sunflowers exhibited more resilience than maize when subjected to the same level of water decrease. Sunflowers’ yield sustainability score stayed consistently over 0.95, while maize had a lowest score of 0.84. We observed via correlation analysis that it was the fraction of subsurface water contribution and the water contribution of the 50~70 cm soil layer that impacted the yield of sunflowers and maize, with coefficients of 0.88 or higher. Ultimately, sunflowers exhibited a lower level of responsiveness to water scarcity compared to maize. Sunflowers have greater drought tolerance compared to maize since they rely less on soil layers replenished by a limited water supply. Based on our findings, sunflowers are well suited to arid conditions and limited spaces that do not have access to irrigation, while maize is better suited to well-watered conditions and expansive cultivation areas.

Long-term Effects of Irrigation with Treated Municipal Wastewater on Soil Chemical and Physical Responses in Commercial Vineyards in the Coastal Region of South Africa

The prolonged drought in the Western Cape province of South Africa in recent years has been particularly detrimental to the wine industry. Water restrictions imposed by authorities and the limited supply of fresh water that can be stored, have emphasisedthe need for alternative water sources for vineyard irrigation. Treated municipal wastewater has been used successfully as an alternative source of irrigation water in other countries. A long-term trial was conducted in commercial vineyards in the Coastal region of South Africa to assess the impact of treated municipal wastewater irrigation on vineyards. Cabernet Sauvignon and Sauvignon blanc grapevines were irrigated using treated municipal wastewater from the Potsdam wastewater treatment works for 11 years. Grapevines were either rainfed (RF), irrigated with treated municipal wastewater via a single dripper line (SLD), or received twice the volume of wastewater via a double dripper line (DLD). Irrigation using treated municipal wastewater increased soil pH(KCl), the electrical conductivity of the saturated extract (ECe) and Cl-. Substantial amounts of Na+ and K+ accumulated in the topsoil due to irrigation with treated municipal wastewater. These soil K+ increases could have a negative effect on wine colour stability should the levels of soil K+ be such that they are absorbed excessively by grapevines. The near-saturation hydraulic conductivity (Kns) at the surface of the soil could be related to the ECe in the topsoil. The results represent specific in-field situations in three commercial vineyards under one set of climatic conditions.

Applicability and limitations of using seawater and sea sand in concrete

The concrete Industry is responsible for the large consumption of raw materials, such as limestone, potable water, steel, and sand, knowing that consuming these materials comes with large economic and environmental costs. Millions of tons of concrete are produced annually, requiring a significant quantity of water. Given the scarcity of fresh water (only 3% of the total water on earth), using seawater as an alternative can greatly conserve potable water. Similarly, replacing natural sand with sea sand can also help conserve natural resources. Consequently, using seawater and sea sand in concrete gained significant attention worldwide, particularly in countries with limited freshwater supply. Much research has been conducted on concrete produced with seawater and sea sand. Whereas seawater is beneficial in some aspects, it can enhance the free chloride content in concrete increasing the corrosion vulnerability. In this paper, the beneficial effects of using seawater and sea sand in concrete have been reviewed. The resulting mechanical, hydration, and durability properties have been assessed and compared with ordinary concrete. The focus has been not only on the material properties but also on the structural attributes. Prospects, challenges, and limitations have also been discussed. The study serves as a basis for efficiently using seawater and sea sand in concrete for sustainable development.

Interventions and solutions for water supply on small islands: The case of New Providence, The Bahamas

Small island nations make up more than one-quarter of the countries on earth, yet information on the limitations of the hydrologic cycle in small islands and strategies to address freshwater availability are lacking. Typically, all islands are characterized by their limited supply of freshwater, and their governments commonly rely on large-scale interventions to provide residents with potable water. The island of New Providence in The Bahamas is home to the capital city of Nassau and almost three-quarters of the country's population. New Providence has a long history of hydrologic interventions to supply domestic and industrial water. Historic groundwater sources have been over-extracted to severe levels of salinization, and some groundwater aquifers have not recovered after more than 8 years later. Fresh water was barged in from the larger Andros Island for ~40 years, which ultimately became insufficient to meet demand on New Providence. In addition to an aggressive Non-Revenue-Water (NRW) Program, desalination of ocean water via diesel-operated reverse osmosis plants has served as the primary source of potable water for the island. Present concerns have grown due to its contributions to greenhouse gas emissions. The Bahamas is also investigating alternative mechanisms for providing clean drinking water to the country, with Ocean Thermal Energy Conversion (OTEC) under consideration to co-generate clean energy in addition to drinking water. This article reveals that historic interventions to source drinking water for New Providence Island have proven to be unsustainable and ultimately have threatened the freshwater availability. Current efforts to investigate drinking water provision through OTEC are promising, particularly for the potential co-generation of energy and to promote sustainable development. This solution may be promising for other small islands where development is often challenged by water availability and sustainable energy provision.

Identification and Quantification of Actual Evapotranspiration Using Integrated Satellite Data for Sustainable Water Management in Dry Areas

Evapotranspiration (ET) is a significant consumer of irrigation water and precipitation on cropland. Global and regional interest in the sustainable management of limited freshwater supplies to meet the rapidly increasing population and food demands has resulted in advanced scientific research on ET measurement, rapid water accounting, and irrigation schedules in the NENA region. The primary goal of this paper is to compare actual daily evapotranspiration (ET) collected by a remote sensing model and validated by Energy Balance (EB) flux tower field measurements. The flux tower was installed in a wheat field in Sids Agricultural Research Station in Beni Suef Governorate. Through the integration of Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Sentinel-2 data, a new remote sensing-based ET model is built on two parties: Thermal condition factor (TCF) and vegetation condition fraction (VCF). The remote sensing-based ET estimation model was evaluated using ET field measurements from the Energy Balance flux tower. The land use and land cover maps were created to assist the interpretation of remotely sensed ET data. Field data for five categories were collected to test the accuracy of the land use and cover maps: Water bodies (93 points), urban areas (252 points), trees (104 points), other field crops (227 points), and wheat (249 points), for a total of 925 ground points. The Google Earth Engine (GEE) imported sentinel-2 datasets and filtered the necessary dates and regions. From 1 October 2020 to 30 May 2021, sentinel-2 data were processed and transformed into the Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), and Normalized Difference Built-up Index (NDBI), which were then combined. The composite layer data were classified using the Random Forest (RF) method on the GEE platform, and the results showed an overall accuracy of 91 percent. The validation factors revealed good indices when RS-based ET results were compared to ground-measured ET. The Root Mean Square Error (RMSE) was 0.84 mm/day. The ‘r’ and ‘d’ values indicated satisfactory results, where ‘r’ yielded a value of 0.785, which indicates that the correlation between predicted and reference results is robust. The analysis of d values revealed a high degree of correlation between predicted (RS-based ET) and reference results (measured ET). The d value was found to be 0.872. Between 21 November 2020 and 30 April 2021, RS-based accumulated ET was 418 mm/season, while ground-measured ET was 376 mm/season. The new RS-based ET model produced acceptable daily and seasonal results.

Quality Testing of Raw and Filtered Grey-water Emerging from Kitchen Sink: A Case Study

The limited freshwater supplies in arid regions have created alternative water management strategies. Data indicates that grey-water generation varies from 39-85% in various countries. Grey-water treatment and reuse can be a helpful nonpotable water source for toilet draining, watering gardens, car and floor washing, etc. Treated grey-water should be clean, hygienic, environment-friendly and cost-effective. The goal of this research is (i) to test the parameters of raw grey-water (ii) create a filter bed (iii) test parameters of treated grey-water (iv) Compare the parameters of raw and treated grey-water (v) describe the area of use.

An IUWM incorporated model to improve water supply reliability in intermittent and no service areas

Water supply reliability is an increasingly important aspect of water system design, especially in regions with unreliable water supply. Most water systems initially designed as continuous supply systems are affected by constraints such as limited freshwater supply, infrastructure inadequacy and insufficient expansion, poor operations and management, contributing to Intermittent Water Supply (IWS) or no services in some regions. IWS is a common condition in developing countries like India. Many approaches have been developed to address water availability and quality challenges, including Integrated Urban Water Management (IUWM). The main principle of IUWM is to incorporate non-conventional water supply sources, such as stormwater, rooftop rainwater and recycled wastewater, to augment water supply and provide fit-for-purpose water. However, in developing countries, IUWM principles have not been sufficiently investigated to understand how they can improve water supply reliability in regions with IWS or no centralized water supply. In this study, an IUWM incorporated model was developed to understand how supply reliability can be improved in areas with IWS or no services, with Bangalore city in India, as a case study. Five different supply configurations to incorporate IUWM principles were analyzed and compared to identify the most efficient way to incorporate non-conventional water sources. The analysis identifies potential supply issues in the area under the current centralized water supply. The results show that the traditional water supply system can not meet the minimum water demand. The reliability can be improved from <50% to 100% with the incorporation of non-conventional water sources.

Analysis of Brackish Water Desalination for Municipal Uses: Case Studies on Challenges and Opportunities

Brackish water is a widely available, nontraditional water resource that can augment limited freshwater supplies. Although brackish water desalination has been continuously implemented in the United States and worldwide, it is necessary to reduce further its energy consumption, costs, and environmental impacts. This study conducted technoeconomic analyses to evaluate the current desalination and brine management technologies, focusing on the key factors and opportunities for sustainable brackish water desalination for municipal uses. Three case studies were selected as baseline representative of different geographic and operational conditions, including water quality, plant size, pretreatment, desalination, and concentrate management. The technoeconomic analyses and model simulations identified challenges, opportunities, and research priorities to achieve specific pathways for enhanced brackish water desalination regarding levelized costs of water, electricity intensity, water recovery, zero liquid discharge, and brine valorization.

Effect of high-voltage spark discharges on reduction of the concentration of total bacterial count in wastewater

The limited supply of fresh water on the planet stimulates the reuse of wastewater in various areas. It is proposed to use disinfected wastewater for irrigation in agriculture. The possibility of reducing the total bacterial count in wastewater by high-voltage spark discharges using a developed experimental setup has been investigated. The total bacterial count was measured by the rapid method using a luminometric mini-laboratory EnSURE Touch and a standard method for counting bacteria, capable of forming colony-forming units on nutrient agar. Wastewater from the Zhulebinsky storm collector with an initial concentration of 1012 CFU ml−1 with a volume of 103 ml is disinfected up to the norm 6 log in 120 s with capacitance 0.1 μF and in 180 s with capacitance 0.05 μF. Wastewater from the Kuryanovsky storm channel with an initial concentration of 109 CFU ml−1 with a volume of 103 ml is disinfected up to the norm 6 log in 100 s with capacitance 0.1 μF and in 160 s with capacitance 0.05 μF. To reduce the concentration of total bacterial count by 1 log, the minimum duration of disinfection of 103 ml of wastewater it took about 30 s at a discharge energy of 5 J ml−1. The advantages of bacterial inactivation in wastewater by high-voltage spark discharges were revealed, such as low operating voltage of 10 kV, high energy efficiency of 600 J l−1 and capacity 30 l h−1, increased service life and operational reliability, portability and environmental friendliness.

Hydroponic production of ‘Biquinho’ pepper with brackish water

In order to generate information about the potential of ‘Biquinho’ pepper as an alternative crop for regions with limited supply of freshwater but with availability of brackish water, such as the semiarid region, a study was carried out with this crop grown in NFT (Nutrient Film Technique) hydroponic system for 120 days after transplanting (DAT). The experiment used nutrient solution prepared in water from the local municipal supply system (electrical conductivity of water –ECw = 0.34 dS m−1) and six other brackish waters prepared artificially by the addition of NaCl, with electrical conductivity of the nutrient solution -ECsol: 2.70 (control), 3.64, 4.58, 5.28, 6.09, 6.90 and 7.77 dS m−1, composing seven treatments repeated six times in randomized blocks. Fruit yield, salt tolerance and yield earliness index were evaluated. The yield of ‘Biquinho’ pepper cultivated in NFT hydroponic system, without restriction of salinity, was 2.87 kg per plant, corresponding to 46.1 Mg ha−1, considering an estimated area of 0.62 m2 per plant. A plateau followed by exponential decay model was fitted to determine the threshold salinity of ‘Biquinho’ pepper, which was 5.22 dS m−1 in the nutrient solution, corresponding to the relative potential yield. Salinity reduced the yield earliness index of ‘Biquinho’ pepper.

Grand theft hydro? Stemflow interception and redirection by neighbouring Tradescantia ohiensis Raf. (spiderwort) plants

AbstractWhen it rains over vegetation, plants have an opportunity to get a limited supply of freshwater. A portion of rain drains directly to the soil down a plant stem in a hydrologic flux called “stemflow.” For short plants with shallow roots, which provide ground cover for most vegetated ecosystems around the globe (including forest understories), stemflow has rarely been examined although it may be ecologically important. This study investigates how much rainwater is funnelled into stemflow for a perennial herb that can densely populate urban environments, Tradescantia ohiensis Raf., spiderwort), in Savannah, Georgia (USA). Given the stem density of spiderworts (19–31 stems m−2), experiments were conducted to assess whether and how much stemflow can be passively intercepted and diverted by leaves in contact with neighbouring plant stems. Spiderworts' stemflow represented a significant portion (20%–60%) of rain and neighbouring plants intercepted and diverted ~50% of another plants' stemflow. This is the first documentation of stemflow interception and redirection by neighbouring plants, to the authors' knowledge. Because physical contact between plants occurs in various vegetated ecosystems (like lianas in forests), future research on this topic may be merited.

The challenge of achieving safely managed drinking water supply on San Cristobal island, Galápagos.

Achievement of United Nations Sustainable Development Goal 6.1 centers on the availability of a safely managed drinking water source for all. However, meeting the criteria for this goal is challenging on island systems and elsewhere with limited freshwater supplies. We measured microbial and chemical water quality over three years on San Cristobal Island, Galapagos, an island with limited freshwater supply, necessitating use of cisterns or roof tanks to ensure water availability in households. Our results showed that the municipal water treatment plants generally produced high quality drinking water but detection of Escherichia coli in 2-30% of post-treatment distribution samples suggests contamination and/or regrowth during distribution and storage. Linear regression revealed a modest, negative relationship between residual chlorine and microbial concentrations in drinking water samples, while 24-h antecedent rainfall only slightly increased microbial counts. Taken together, our results underscore the challenge of providing a safely managed drinking water source where limited freshwater quantities result in intermittent flow and require storage at the household level. Efforts to meet sustainable development goals for island systems will likely need to consider water availability for any treatment technologies or programs aimed at meeting water quality goals.

Inference of Magnetized Water Impact on Salt-Stressed Wheat

Whether at high or low levels, the presence of salt in water can potentially be harmful to crops as well as the environment. Saline water is already used by irrigators around the world to produce food owing to limited freshwater supplies. In addition to the common methods for reducing salinity stress, some magnetic devices have recently been spread by many combines grounded on the fact that after passing saline water through these devices, it gets structured and reduces the harmful effects on crops. Considering their claim, two pot experiments were carried out in the greenhouse of the Egyptian National Research Center to determine the influence of magnetic and normal water under three salinity levels (320, 3000 and 6000 ppm) on growth, yield and yield components of wheat. Results demonstrated that irrigation of wheat plants with saline-magnetized water reduced the harmful effect from 66.12 to 25.96% and 87.68 to 69.30% in grain yield per tiller under 3000 and 6000 ppm salinity levels, respectively, compared to those irrigated with the same levels dissolved in normal water. Similar trends were recorded in all tested parameters. Besides, the application of the Fruchterman–Reingold algorithm showed that salinity decreases the growth and yields. However, the magnetic treatment exhibits an opposite influence. Bayesian modeling confirmed these findings and highlighted that whatever the salinity is, the magnetic field reduced the salinity impact.

Characterisation of selected micro-estuaries and micro-outlets in South Africa using microalgal, zooplanktonic and macrozoobenthic assemblages

South Africa has approximately 200 micro-estuaries and micro-outlets along its more than 3 000 km of coastline. Many of these microsystems (i.e. micro-outlets and micro-estuaries) share some characteristics with temporarily open/closed estuaries, but differ in that they are supplied by localised catchments with limited supply of freshwater and less connectivity to the marine environment. Between 2015 and 2016 we investigated whether micro-outlets and micro-estuaries can be differentiated from each other and other estuaries based on physico-chemical properties, microalgal dynamics, as well as species diversity and composition of invertebrate communities. The micro-outlets were dominated by oligohaline or freshwater conditions, whereas micro-estuaries were mostly mesohaline. Microalgal biomass in both system types was influenced by temperature, nutrient concentration and light availability. The micro-estuaries had a higher microalgal biomass than the micro-outlets. Chironomidae and Ephemeroptera numerically dominated benthic macroinvertebrate micro-outlet communities, whereas Amphipoda and Mysida were most dominant in micro-estuaries. Calanoid copepods dominated zooplankton assemblages in micro-estuaries and macroinvertebrate larvae in micro-outlets. In addition, the zooplankton densities were significantly higher (p < 0.05) in micro-estuaries compared with micro-outlets. Study results confirm that there are major differences between the biota in the two microsystem types, accordingly making biotic assemblages, together with physico-chemical parameters, a viable tool for differentiating between micro-estuaries and micro-outlets.

Modelling the kinetics of chalcocite leaching in acidified cupric chloride media under fully controlled pH and potential

The use of seawater in heap leaching of secondary copper sulfide minerals is a feasible alternative to freshwater in regions with limited freshwater supply. Seawater contains high concentrations of chloride ions that facilitate the formation of cupric/cuprous chloride complexes. The cupric ions formed can serve as an oxidizing agent for chalcocite oxidation. Even though copper leaching in chloride media has been well studied, most of the kinetics data were collected under uncontrolled leaching conditions. In this study, we modelled chalcocite leaching kinetics in chloride media using leaching data collected under fully-controlled pH and solution potential. Specifically, we carried out leaching tests with high-purity chalcocite sample in jacketed reactors to quantify the effects of chloride concentration, cupric concentration, particle size, and temperature on the copper extraction rate. The experimental results show that increases in chloride concentration and temperature remarkably enhanced the leaching rate; chalcocite leaching was insensitive to the initial cupric chloride concentration. Using the leaching data collected, we derived two individual kinetic models to describe the first and second stage of chalcocite leaching. This study provides fundamental kinetic models for predicting the performance of chalcocite leaching in cupric chloride for heap leach operations that intend to use seawater.

Investigating the Possibility of Using Recycled Industrial Wastewater Instead of Potable Water in Concrete Mixture

Iran is located in the Middle East with a population of approximately 81 million people (2017). The Middle East in general and Iran in particular are located in an arid region of the world. Iran has a chronic shortage of water. It is estimated there is some form of drought in 97 percent of the country. In an 8-month period (September 23, 2017-May 21, 2018) the country has received 151.5 millimeters of rain while the long-term averages are 214.6 millimeters which indicates a 29-perecnt drop in mean precipitation nationwide. The driving factors behind water shortages are numerous. Some are natural and others man-made. One of the biggest factors is population growth. The population of Iran doubled between 1976 and 2001, going from 33 million to 66 million Iranians. The population is still rising, and currently stands at over 80 million people. And as this figure rises, the volume of renewable water resources available per capita drops. It is already critically low. 35% of the populations are living in areas experiencing water shortages and droughts. Global warming is contributing to bodies of water drying out, and the problem is expected to worsen as climate change increases. The socio-economic changes happening alongside this exacerbate the problem. Fresh water is a precious commodity here. Population and economic growth has increased the demand for fresh water in the region. Limited supply and increased demand has created a challenge for governments and construction industry. Therefore this article is investigating the possibility of using alternative sources of water with the aim of reducing the demand for the limited supply of fresh water. Ibrahim al Ghusain and his Colleague used car wash wastewater on investigate effect of reusing wastewater in concrete mixture in different situation as Temperature and long term and varying degrees of treatment on compressive strength and they found that territory treated car wash wastewater has more compressive strength than others [1]. In another case Shahiron Shahidana and his colleagues worked on effect of reusing car wash wastewater in different quantity for measuring, tensile strength and Modulus of Elasticity (MOE) and compressive strength of concrete. In this paper was shown the optimum percentage of car wash wastewater as fresh water replacement in concrete mixes is 20% [2]. For the purpose of the article recycled industrial wastewater from an industrial park in the city of Yazd of Iran was used in mixing concrete and its effect on compressive strength of concrete was analyzed. Concrete samples for testing purposes were mixed using ordinary Portland cement and common aggregate used in concrete work for general construction purposes. Samples were prepared according to ASTM standard of C 192 and after curing in the laboratory environment for different periods they were crushed to determine the compressive strength. In this experiment test results indicated that all samples prepared with treated industrial wastewater exhibit an increased compressive strength compared to the samples prepared with potable water. This finding shows promising results for conservation of fresh water supplies by using alternative sources of water for concrete mix.

Delineation of groundwater prospective resources by exploiting geo-spatial decision-making techniques for the Kingdom of Saudi Arabia

Saudi Arabia is a water deficit and an arid land with limited fresh water supplies. Owing to the burgeoning population, ascending living standards and desert agriculture, there is a tremendous stress on the current water reserves. Towards such ends, this paper introduces a remote sensing and geographic information system (GIS)-based multi-factor decision-making system to identify the regions in Saudi Arabia with groundwater potential. The proposed model is capable of producing groundwater suitability map built on the synthesis of several hydrological factors such as rainfall, slope, lithological features, land use/land cover, geological structures, soil type, lineaments density and drainage network using an analytical hierarchical process. The synthesis of these parameters has resulted in improved rendering of groundwater probable hotspots in the study area. According to obtained results, 0.66% (587.90 km2), 38.97% (34162.12 km2), 58.55% (51328.34 km2), 1.8% (1588.36 km2) and 0.004% (3.26 km2) of the study area was ranked as ‘Best’, ‘Very good’, ‘Good’, ‘Fair’ and ‘Poor’, respectively. The delineated zones were validated by mapping water wells on the suitability map. The results showed that 35.88 and 62.35% of the water wells belong to ‘Very good’ and ‘Good’ regions, while 0.58 and 1.17% belong to ‘Best’ and ‘Fair’ regions. This indicates that model-generated results were in good agreement with the ground truth and majority of the existing wells belong to ‘Very good’ to ‘Good’ regions of the generated map. This demonstrated the potential of remote sensing and GIS techniques to successfully discover groundwater plausible regions which could be further exploited to find suitable locations for groundwater withdrawal.

Evaluation of magnetic nanoparticles performance as photocatalyst for the catalytic treatment of direct red 28 dye in synthetic and real water effluents

ABSTRACTIntegrated water resources management practice is gaining popularity as an alternative water source due to the limited supply of freshwater. The present study was carried out on the photocatalytic degradation of Direct red 28 (DR-28) dye using magnetic nanoparticles (MNPs; Fe3O4) as a photocatalyst. The study was conducted on the photocatalytic degradation of DR-28 dye in synthetic dye effluent water, to understand the effects of different photoreaction parameters on the degradation kinetics. The influence of different parameters such as time, amount of photocatalyst, concentration of H2O2 and pH was investigated. At the optimum dosage of MNPs (0.6 g/L) with 4 mmol/L of H2O2, significant photocatalytic degradation of DR-28 dye (93.2%) was observed. The kinetic study revealed that the photocatalytic degradation followed pseudo-first-order kinetics. The degradation performance of Fe3O4 nanoparticles as a photocatalyst for DR-28 dye was compared with titanium dioxide (TiO2) and it was found that the performance of Fe3O4 as a photocatalyst is superior to TiO2 photocatalyst. The real dye effluent was also degraded at optimum conditions and promising results were achieved.