Freshwater Extraction Research Articles

A magnetic-enhanced 3D solar-absorbed structure inspired by cold evaporated heatsink for vapor generation

Solar energy is promising for application in vapor generation and desalination that is reliant on conventional high-temperature fluid methods due to its renewable energy properties. Existing desalination technology has encountered a bottleneck due to high energy consumption, low water purity and high costs. In this work, a novel magnetic three-dimensional solar vapor generator inspired by cold evaporated heatsink is designed based on carbon fiber felt, which has the ability to efficiently absorb solar energy and evaporate seawater. In addition, a seawater desalination coupling salt production device is built, utilizing the photo-thermal interface as a means of accelerating both the evaporation and salt extraction processes using a magnetic field. Experiments and simulations are conducted to analyze the effects of materials, surface properties, device structure, solar illumination intensities and magnetic field conditions on evaporation efficiency. The results show that the device is able to achieve cold evaporation and harvests energy from the environment, reaching an evaporation efficiency of 130.7% under 1 sun illumination. Furthermore, with a magnetic field power of 5 kW m−2, the device is able to achieve a remarkable evaporation rate of 7.05 kg m-2h−1 under 1 sun illumination, which enables rapid fresh water extraction in extreme conditions. The device is simple in structure, cost-effective, and can be widely used in areas that face water and salt shortages.

Magnetic photo-thermal evaporator with joule-assisted heating for stable vapour generation

Solar energy has the potential to be applied in the production of vapour that relies on high-temperature liquids in conventional ways because it is one of the reproducible energy sources. In this work, a magnetic photo-thermal evaporator (MPE) based on nickel foam coated with reduced-graphene-oxide is used to produce vapour. The increase of thermal conversion efficiency can be implemented by a solar absorbed structure that promotes the vaporization of generated water. MPE has its optimal energy conversion efficiency of 98 %. Due to the coupling joule heat and solar thermal processes, the efficient and stable interfacial evaporated performance could be controlled, which is to optimize the multi-process coupling and multi-energy complementary process and promote the actual applications of MPE. Under the solar power of 1000 W·m−2, the evaporation rates obtained were 1.75 kg·m−2·h−1 and 1.81 kg·m−2·h−1 for the coupled continuous and segmented magnetic fields for the 90 s, which are much higher than the theoretical evaporation rate limit for two-dimensional interfacial photo-thermal evaporator. In case of extreme water shortage, the magnetic field can be used to assist in the rapid extraction of fresh water. The advantages of rapid fabrication and lower cost of the MPE have made the developments of solar evaporator applications possible such as desalination and wastewater treatment.

Dual-hydrophilic Janus evaporator for Long-term and efficient Bimode solar evaporation

Solar steam generation has emerged as a promising and sustainable technology to solve the global water scarcity. However, the fabrication of low-cost and high-efficiency evaporator with long-term stability remains a great challenge. Herein, a dual-hydrophilic Janus evaporator coupled with inclined isolating structure is fabricated to realize long-term efficient solar evaporation and flexible salt manipulating, where the upper electrospun Mo2C-C@PAN membrane serves as the evaporation layer and the bottom nonwoven fabric functions is used as mass transporting layer. The encapsulating feature of the Mo2C-C@PAN enables better energy confinement and reduces the usage of solar absorber by ∼50 % without deteriorating the evaporation performance. The hydraulic conductivity difference prevents the Marangoni effect inner the Janus evaporator, while the inclined isolating structure enables unidirectional ions transporting. With features of adequate water transport, enhancement of energy confinement, and salt manipulation, the constructed inclined Janus evaporators can not only work stably for 200 h in 10 wt% NaCl solution without salt accumulation, but also achieve efficient salt harvesting with rate of ∼260 g m−2 d−1 under one sun. This study provides new possibilities for a dual-hydrophilic Janus evaporator for a long-term, efficient, and synergistic extraction of fresh water and mineral salt resources.

Simultaneous management of water and energy nexus: Economic and environmental assessment using stochastic p-robust optimization approach

The simultaneous management of water and energy sources, which are among the most primitive and prominent needs of each society, is one of the challenging issues. In this regard, an energy hub model comprised of two economic and environmental objective functions is studied in this paper, considering various uncertainties. Two objective functions, namely the extraction of fresh water from the water well, the environment objective function, and the operation cost, economic objective function, are handled simultaneously using the ɛ-constraint approach. Furthermore, to make the obtained results persist against various uncertainties, the stochastic optimization approach is used to model the uncertain nature of some parameters as market price, electrical, thermal and water demands. Then, the risk associated with considered uncertainties is managed using a stochastic p-robust optimization approach. Finally, the proposed model is optimized under time-of-use-based demand response program constraints, which reduces the suggested economic strategies, considering all restrictions and limitations. According to obtained results, with a slight increase in the operation costs level, the relative regret level, which has an inverse relationship with robustness level, can be decreased and make the studied model more robust against the risk associated with various uncertain parameters.

Water from Air Production System based on Solar Energy in Egypt

Fresh water supplies are among the most limiting conditions in arid regions. Drinking water shortage is chronic, acute and widespread in North Africa, the Middle East and South Asia. The extraction of fresh water from the atmosphere has been adopted and developed as a new technology to provide water in remote areas. This paper concentrates on the extracting of potable water from air in remote areas using solar energy. A theoretical study for extracting water from atmospheric air is presented and performance of water production system based on standalone PV system was simulated and evaluated for two sites in Egypt; namely, Hurghada and Khargha Oasis. The unit extracts water by using solar thermal energy as the heating source for air and solar photovoltaic energy for supplying water production system driven fan. Perturb and observe (P&O) method for maximum power point tracking (MPPT) has been designed and simulated for the proposed PV system. A Mathematical and simulation models using MATLAB/ SIMULINK software have been developed for evaluating the performance of the proposed system. The effect of climate conditions; ambient temperature and solar radiation on the PV system output power based on P&O controller was also demonstrated. It was found that more amount of water from atmosphere can be extracted from densely humid and highly solar radiation regions.

Plasmon Based Double‐Layer Hydrogel Device for a Highly Efficient Solar Vapor Generation

AbstractSolar vapor generation is a facile and an efficient way for solar energy harvesting, which is applied to address the issue of fresh water extraction from sewage or brine. Several solar vapor generation devices have been developed in the past few years, but the low evaporation rate still remains as a challenge. In this work, a novel double‐layer solar vapor generation device, named as Ag‐PSS‐AG/AG device, is reported. This device is based on the hierarchical composition of silver nanoparticles (Ag NPs) and poly (sodium‐p‐styrenesulfonate) (PSS) decorated agarose gel (AG). The device reveals a synergetic effect of the two layers with high light‐harvesting and water‐transfer performance, respectively, leading to an ultrahigh vapor generation rate of 2.10 kg m−2 h−1 with a solar thermal efficiency of 92.8% under 1 sun illumination. This high evaporation rate is mainly owing to the powerful light‐thermal conversion of Ag NPs as well as the outstanding water transfer capability of agarose hydrogel. Consequently, this device can be directly used for the purification of sewage and muddy water. It is also promising for applications in separation, humidity management, and others.

Extraction of Fresh Water from Atmospheric Air

The issues of water extraction from atmospheric air and the possibility of water extraction for Central Asia are considered.

Effects of changing retention time on efficiency of submerged MBR treating different types of grey water

Abstract It is known that grey water reused for non-potable purposes, provides a sustainable solution of water management by reduction of fresh water extraction and can contribute to water status improvement. Although reused grey water is not intended for potable use, the potential for certain contamination and pollution rate still exist and the treatment efficiency represents a key concern for grey water system utilization. Therefore, this paper explores and focuses on treatment efficiency of treatment technology specifically on submerged membrane bioreactor, what is considered as a successfully used technique of grey water treatment. The main aim was to evaluate the pollution removal in variously polluted grey water and consider a treatability of purposed technology, while changing the grey water retention time in bioreactor.

Modelling the Effect of Human Activity on Fresh Water Extraction from the Earth’s Reserves

This paper reports on dependencies in changes to fresh water extraction patterns on the various influencing factors. The aim of the study is to develop a mathematical model to predict the influence of human activity on fresh water extraction from the Earth’s reserves. The historical background of the process affects the current estimate for fresh water extraction. The current estimate of fresh water extraction is affected by various dynamic factors in human life as well as environmental processes. As a theoretical model for analysing the influence of human activities and their impact on the environment, the authors selected the autoregressive distributed lags model (ADL-model), in which the current values of the series depend both on past values of the series as well as current and past values of other time series. The authors described the methodology of empirical tests of the model. The paper presents the methods used to construct the model and approaches to determining model parameters. Statistical information for the model variables was collected from 1995 to 2016. Empirical testing of the model was carried out by the authors.

Millennial multi-proxy reconstruction of oasis dynamics in Jordan, by the Dead Sea

Vegetation reconstructions in the Dead Sea region based on sediment records are potentially biased, because the vast majority of them derive from the western side of the sea, and only focus on large areas and time spans, while little is known about extra-local (< 1,000 m radius) to local (< 20 m radius) changes. To fill this gap, we compared a vegetation survey with modern pollen assemblages from the “Palm Terrace” oasis ca. 300 m b.s.l. (below sea level), at the eastern edge of the Dead Sea. This revealed how the oasis vegetation is reflected in pollen assemblages. In addition, two sediment cores were collected from the centre and the edge of a mire at the oasis to reconstruct past vegetation dynamics. We analysed sedimentary pollen and microscopic charcoal, as well as the sediment chemistry by X-ray fluorescence (XRF) and conductivity, focusing on the past ~ 1,000 years. Pollen results suggest that mesophilous Phoenix dactylifera (date palm) stands and wetland vegetation expanded there around ad 1300–1500 and 1700–1900. During the past ca. 100 years, drought-adapted Chenopodiaceae gained ground, partly replacing the palms. Results from elemental analysis, especially of elements such as chlorine, provide evidence of enhanced evaporative salinization. Increasing desertification and the associated decline of mesophilous date palm stands during the past ca. 50 years is probably related to a decrease in annual precipitation and also corresponds to decreasing water levels in the Dead Sea. These have mainly been caused by increasing extraction of fresh water from tributaries and wells, mainly for local agriculture and industry. In the future, with hotter and drier conditions as well as increased use of water, oasis vegetation along the Dead Sea might be at further risk of contraction or even extinction.

Optimal design of energy and water supply systems for low-income communities involving multiple-objectives

This paper proposes the use of Combined Heat and Power systems for providing water and energy, and thermal and electric utilities, in geographically isolated communities, where the interconnection with the grid is not available. A common design practice is to implement different energy storage technologies, usually batteries, for reducing the gap between energy generation and electric consumption. However, in communities with low incomes, it is not possible to use batteries due to the high capital costs. This work presents a new approach for providing simultaneously electricity and water using the fresh water extraction and storage for reducing the gaps between generation and consumption. The proposed approach is based on a mixed integer nonlinear programming formulation, which accounts for the optimal selection of multiple combined heat and power technologies and the sizing of the water storage and pumping technologies. A multi-objective analysis is presented considering as objective functions the economic costs and environmental impact associated with the space used by the system and water consumption. A community in the mountains of Mexico is presented as case study. The results show that it is possible to provide energy and water at low costs and reducing the environmental impact, reaching a trade-off between the considered objective functions.

The Cost of Covering Costs: A Nationwide Model for Water Pricing

This study offers a high-resolution model of nationwide water supply. The model is sufficiently detailed to represent all main water sources in an economy, the principal segments of the conveyance system, urban, industrial and agricultural demand regions, and various water types, including fresh, saline and recycled. Calibrated for Israeli 2010 data, we find that the optimal extraction of fresh water is only 2% larger than the total observed supply from those sources. However, for some specific sources, the deviation between optimal and observed quantities is significant. Assuming average constant recharge, the optimal aggregated desalination is 57% of the 2010 desalination capacity and only 33% of the present desalination capacity. Even with an assumed 40% decline in recharge (for example, due to climate change), the model uses only 50% of the present desalination capacity. This may suggest that the construction of desalination facilities in Israel, which began in 2005, could have been delayed. The model establishes a comprehensive system of pumping levies and user fees that support the optimal allocation. However, due to considerable scale economies, the average cost is almost 50% larger than the marginal cost. The implications are that the welfare cost of the recent Israeli Balanced Budget Water Economy legislation is more than 100 million USD per year, about 10% of the water economy share of the GDP.

Membrane distillation and membrane electrolysis of coal seam gas reverse osmosis brine for clean water extraction and NaOH production

Membrane distillation (MD) and membrane electrolysis (ME) were evaluated for simultaneous fresh water extraction and NaOH production from a mixture of NaCl and NaHCO3 to simulate the composition of coal seam gas (CSG) reverse osmosis (RO) brine. Experimental results demonstrate the potential of MD for producing fresh water and simultaneously concentrating CSG RO brine prior to the ME process. MD water flux was slightly reduced by the increased feed salinity and the decomposition of bicarbonate to CO2 during the concentration of CSG RO brine. MD operation of CSG RO brine at a concentration factor of 10 (90% water recovery) was achieved with distillate conductivity as low as 18μS/cm, and without any observable membrane scaling. Exceeding the concentration factor of 10 could lead to deterioration in both water flux and distillate quality due to the precipitation of NaCl, NaHCO3, and Na2CO3 on the membrane. With respect to ME, current density and water circulation rates exerted strong influences on the ME process performance. Combining ME with MD reduced the thermal energy requirement of ME by 3MJ per kg of NaOH produced and the thermal energy consumption of MD by 22MJ per m3 of clean water extracted.

Forward osmosis process for supply of fertilizer solutions from seawater using a mixture of draw solutions

Novel desalination approaches are required to provide both drinking and agricultural water as there is ever increasing stress upon precious freshwater resources. It was our hypothesis that a modified Forward Osmosis (FO) process had the potential for production of irrigation water comprising of appropriate concentrations of fertilizers from a seawater feed. Four agents, KNO3, Na2SO4, CaNO3, and MgCl2, plus 35 g/L seawater were used as the draw and feed solutions of the FO process. Net Driving Pressure (NDP) in the FO process was manipulated either by increasing the concentration of draw solution (FO process) or by increasing feed pressure (Pressure Assisted FO (PAFO) process). A series of nanofiltration (NF) and reverse osmosis (RO) membranes were used for the regeneration of draw solution. The results suggested that a PAFO process was more energy efficient than simple forward osmosis, provided the energy relating to the brine flow from the NF/RO membrane for pressurizing the feed solution of PAFO process was used. Furthermore, this study suggested using a mixture of a primary draw solution, MgCl2, and a secondary draw solution, KNO3, for NO3 supply into the irrigation water was preferable. As such, MgCl2 provided the driving force for fresh water extraction while KNO3 was the source of fertilizer in the irrigation water. Results showed that water quality provided by application of a MgCl2+KNO3 draw solution was better than that from KNO3 or Ca(NO3)2. The concentrations of NO3 and SO4 in irrigation water were within recommended levels when the diluted draw solution was regenerated by a dual stage low pressure RO process.

Mapping of regional potential groundwater springs using Logistic Regression statistical method

Increasing demand for fresh water extraction in the semi-arid regions necessitates the exploration of groundwater spring potential areas notwithstanding the importance of both conservation and management aspects for planning development. Potential map of groundwater springs reduces the costs of horizontal well drilling that provides useful tool for engineers to locate probable region for groundwater existence. The objective of this study is to establish a model of the potential map of groundwater spring occurrences. A statistical and probabilistic Logistic Regression (LR) model was developed in association with the specified spring location and effective occurrence factors. The most statistically significant effective factors on spring occurrences were selected to zone groundwater spring potential areas. The proposed model was evaluated statistically. Results showed a satisfactory prediction for the proposed model. The outcome of this study facilitates the low-cost utilization of groundwater resources when policy makers need strategic development planning.

Involving integrated seawater desalination-power plants in the optimal design of water distribution networks

Water and energy consumption has increased substantially over the last decades. Water scarcity has led to an increase in the extraction of fresh water from aquifers, dams and lakes, and it has produced serious overexploitation problems. Furthermore, the population growth in urbanized areas and the increase in water and energy demands in industry, agriculture and households have amplified this problem. As consequence, there are several regions where is almost impossible to satisfy the water demands using the available water resources. In this context, the use of alternative water resources such as reclaimed water, rainwater harvesting and the potential use of desalinated water can be an option. However, desalinated seawater is very expensive because the high energy consumption, and this way to integrate a seawater desalination plant to a power plant to simultaneously produce clean water and power can be an attractive option. This way, this paper proposes an optimization formulation for synthesizing water networks to satisfy water and energy demands in a macroscopic system involving the use of existing water resources and the installation of integrated seawater desalination-power plants. A case study from Mexico (where satisfying the water demands has become a serious problem) is presented. Results show that the integrated system is able to satisfy the current water demands, the excess desalinated water can be used to recharge the overexploited aquifers and interesting profits can be obtained from the sales of power.

High recovery rate NF–FO–RO hybrid system for inland brackish water treatment

Brackish water desalination is a common method for fresh water supply in arid areas. Concentrated brine is the major waste stream generated from the desalination process. The current study proposes a multi-stage Nanofiltration (NF)–Forward Osmosis (FO)–Brackish Water Reverse Osmosis (BWRO) system to increase the recovery rate of brackish water. The simulation results showed that the NF–FO–BWRO system was able to achieve >90% recovery rate for a number of feed salinities varied from 1 to 2.4g/L. High permeability NF membrane was used in the first stage to produce the first permeate flow at relatively low power consumption. Concentrated brine from the NF was fed to an FO membrane for power for additional fresh water extraction before disposal. 0.25–0.5M NaCl was used as the draw solution in the FO membrane. The results showed that system recovery rate increased with increasing the concentration of the draw solution. NF process was responsible of 75% of the total recovery rate while BWRO process contribution was up to 20%. Almost 80% of the total power consumption for desalination was due to the BWRO process. NF and FO processes accounted for the rest 20% power consumption. The BWRO system also required 2 to 3 times more membranes than FO and NF processes. NF–FO–BWRO is flexible and can generate different proportions of permeate flows through controlling the recovery rates of each component.

Allelopathic Studies on Milk Thistle (Silybum marianum)

Declining crop yield due to weeds and their resistance to herbicides are major constraint for successful crop productions. Milk thistle (Silybum marianum) is common weed species in Australian cropping rotation. Allelopathic potentiality of milk thistle on different crops has been documented sporadically, but there is no literature on about ryegrass and canola. Therefore, a laboratory based allelopathic extracts bioassay was conducted. The hot water extracts was prepared from milk thistle plant parts added into water with ration of 1: 10 (plant sample: distilled water) where mixture was heated 10 minutes. After heat treatment samples was immediately sieved and centrifuged and the resulted solution was treated as 100% concentration. Separately, to get the fresh water extract plant sample was added into water (1:10) and kept 24 hours in room temperature. After 24 hours, the sample was sieved and centrifuged and collected samples result was treated 100% concentrations. To obtain 50% concentration, both hot and fresh samples were diluted with distilled water. Therefore the experiment was conducted with five different treatment concentrations (0, 50% hot water extracts, 50% fresh water extracts, 100% hot water extracts and 100% fresh water extracts). The experiment was comprised with RCBD design with three replications under control conditions. During experimental period the allelopathic effects of donor species on germination and seedling growth of ryegrass and canola was observed. Results shows, germination and seedling growth of both receiver species are inhibited by milk thistle extracts. Extracts from fresh water at 100% was more toxic to receiver species followed by 50% concentration of fresh and 100% from hot water extracts. This concentration reduced the root, shoot growth of ryegrass and canola 84.971%, 84.269% and 89.898%, 87.394%, respectively. The result also revealed that allelopathic pattern of hot water extracts was same however; it is less toxic to both receiver species. DOI: http://dx.doi.org/10.3329/ijarit.v2i1.14007 Int. J. Agril. Res. Innov. &amp; Tech. 2 (1): 62-67, June, 2012

MODELO TEÓRICO PARA PREDECIR EL LUGAR DEL CORTE Y OPTIMIZAR LA EXTRACCIÓN DE LA PULPA EN COCO

Coconut is an important crop produced in Mexican coastal regions. Coconut is sold as fresh water and dried pulp is used to produce vegetable oil. An industrial plant for fresh water extraction lets pulp as residue, which should be also sold. Workers have a great ability to extract coconut pulp after the shells are sun-dried for half a day. A machine for on-line pulp extraction has to be designed, requiring that coconut is sliced in two identical shell pieces for both: transversal and longitudinal cuts. A vision system acquired images from the sliced coconuts obtaining its circularity and Feret diameter. Coconuts cut transversally used a model that measured coconut length with a linear differential transformer; 93 % of the tests presented two identical shells. A simulation was carried out for positioning a round extractor for separating the pulp from the shell. When the centroide was used as the control coordinate pulp losses were over 35 %; a model for positioning the extractor decreased pulp losses to less than 16 %.

Antibacterial and Antitumor Activities of Some Wild Fruits Grown in Turkey

ABSTRACTTwo different bioassays (antibacterial and antitumor) were performed to show the biological activities of eight different wild fruits [Viburnum opulus L. (guelder rose), Viburnum lantana L. (wayfaring tree), Cornus mas L. (cornelian cherry), Pyracantha coccinea Roemer (firethorn), Rubus caesius L. (dewberry), Crataegus tanacetifolia (Lam.) Pers (tansy-leaved thorn), Crataegus monogyna Jacq. (hawthorn) and Rosa canina L. (dog rose)] grown in Turkey. For each fruit, 8 different extracts (aqueous and ethanol extracts prepared from hot and cold treatments offresh and dried fruits) were obtained and a total of 64 extracts were evaluated. The disc diffusion assay (Kirby-Bauer Method) was used to screen for antibacterial activity. Among the tested fruits, best antibacterial activity was obtained with fresh fruits of wayfaring tree, firethorn and hawthorn. Hot ethanol extracts of these fruits showed strong antibacterial activity against S. aureus, S. epidermidis and S. pyogenes. Antitumor activity was evaluated with potato disc tumor induction assay. Best antitumor activity was obtained with cold water extract offresh fruits of R. caesius (100% inhibition). Cold or hot ethanol extracts of fresh V. lantana fruits (90.5% and 95.2%, respectively), cold water extract of fresh C. monogyna fruits (85.7%) and hot ethanol extracts of fresh C. tanacetifolia fruits (71.4%) also exhibited strong tumor inhibition.