Increase Water Productivity Research Articles

Sensor-Based Furrow Irrigation System (SBFIS) for Sunflower (Helianthus annuus L.) Production

The need to constantly monitor over-irrigation was one of the many challenges farmers confronted in their daily farming activities. Frequently, the farmer must travel a considerable distance to access their fields and irrigation pumps. This study further developed the feedback mechanism and program of the Central Luzon State University -Automated Furrow Irrigation System (CLSU-AFIS). The performance of the sensor-based furrow irrigation system (SBFIS) was determined in this study through the growth and yield of the sunflower. The study considered four treatments which were sensor-based furrow irrigation system with mulch (T1), sensor-based furrow irrigation system without mulch (T2), conventional furrow irrigation system with mulch (T3), and conventional furrow irrigation system without mulch (T4). The CLSU sunflower variety named CLSF-1 was used in this study. Results showed a significant difference between sensor-based and conventional furrow irrigation. Growth and yield parameters of the sunflower in a sensor-based furrow irrigation system with mulch obtained the highest value with average plant height of 74.14 cm, leaf number of 22.82, sunflower head weight of 184.87 g, sunflower head diameter of 17.23 cm, and yield of 80.14 kg. Mulch also reduced the irrigation frequency. Thus, it used less water but obtained the highest yield, increasing water productivity. The water productivity of using SBFIS without mulch in comparison with Conventional was found 54% higher while in SBFIS with mulch in comparison to Conventional with mulch was 72% higher. The water productivity of using SBFIS with mulch compared to SBFIS without mulch was found 39% higher while the Conventional with mulch compared to Conventional without mulch was also found 39% higher.

Energy, Exergy, and Economic Analysis of Solar Still Integrated with Phase Change Material Assimilated Evacuated Tube Collector for Wastewater Treatment

A comparative analysis has been carried out between traditional solar still (System I), stearic acid-embedded solar still (System II), and solar still embedded with stearic acid-based evacuated solar collector (System III). A comparative analysis of these three systems for two different depths of wastewater and three flow rates was done. Compared to System I, the maximum increase in potable water production by System III and System II was found to be 273.2% and 33% respectively at 40% depth. On the contrary for 60% depth, the increment was 257.5% and 21.5% respectively. The efficiency in terms of energy was 11.7-15.2% for System I, 14.1-20.0% for System II, and 35.9-52.2% for System III. Whereas, the daily second law efficiency of System III, System II, and System I was found in the range of 24.9-36.2% respectively. The potable water productivity unit cost from System I-III was 0.004 $L-1, 0.33 $L-1, and 0.030 $L-1 respectively. The proposed setup overcomes two major problems i.e., potable water and hot water demand with pollutant removal efficacy at a low cost. The developed system overcomes the problem of unavailability of potable/hot water during night time and low efficiency of the solar thermal system at an economical cost with pollutant removal efficacy.

Assessing the potential of geothermal energy in Cambrian complexes for renewable energy transition in Lithuania

Several depleted Cambrian oil fields in Lithuania, with water-cuts reaching 99 %, present promising opportunities for geothermal energy utilization. This study focused on Lithuania’s Cambrian reservoir complex, which has the highest water production rates. The study aimed to explore the advantages of horizontal wells, a technology not previously employed for geothermal production in Lithuania, over traditional vertical wells. To optimize field development, various scenarios were evaluated using mechanistic models, with insights subsequently applied to real field conditions. The results from the mechanistic model demonstrated that horizontal wells outperform vertical wells in both water production and power generation. Furthermore, increasing fracture intensity was shown to enhance water output and power generation by operating the wells at pressures above fracture propagation, facilitating re-injection. However, the study also emphasized the importance of thorough reservoir characterization and modeling to account for geological complexities and improve production outcomes. In conclusion, the research underscores that horizontal wells offer several advantages over vertical wells for geothermal energy production. These include increased water production, higher power generation, reduced drilling costs, and enhanced operational efficiency. These benefits align with technological advancements observed in the hydrocarbon industry, making horizontal wells a viable solution for maximizing geothermal energy potential in Lithuania’s depleted oil and gas fields.

Plant Biosensors Analysis for Monitoring Nectarine Water Status.

The real-time monitoring of plant water status is an important issue for digital irrigation to increase water productivity. This work focused on a comparison of three biosensors that continuously evaluate plant water status: trunk microtensiometers (MTs), trunk time-domain reflectometry (TDR), and LVDT sensors. During the summer and autumn seasons (DOY 150-300), nectarine trees were subjected to four different consecutive irrigation periods based on the soil Management Allowed Deficit (MAD) concept, namely: MAD10 (light deficit); MAD50 (moderate deficit); MAD100 (severe deficit), and MAD0 (full irrigation). Measurements of stem water potential (Ψstem) and leaf gas exchange were recorded on representative days. A continuous measurement of the plant water status of Ψtrunk, MDS, and Ktrunk revealed the water deficits imposed on the soil. The highest water deficit observed at the end of the MAD100 period (Ψstem = -2.04 MPa and Ɵv = 17%) resulted in a minimum value of Ψtrunk (-1.81 MPa). The maximum value of MDS (408 µm) was observed earlier than that of Ψtrunk, motivated by the low sensitivity of MDS at Ψtrunk < -1.2 MPa and Ψstem < -1.5 MPa due to a decrease in the tissue elasticity of the trunk when severe water deficit conditions are reached. Both Ψtrunk and Ψstem were more dependent on soil water content, while MDS was more responsive to environmental changes. Ktrunk was the weakest indicator for determining plant water status, although when expressed as a daily fraction of depletion (KtrunkFD), it improved, evidencing a process of hysteresis. Ψtrunk showed the highest sensitivity, suggesting the potential use of MTs as a valuable biosensor for monitoring nectarine water status in digital agrosystems.

Effect of Deficit Irrigation at Different Growth Stages on the Yield and Water Productivity of Tomato at Adami Tulu Agricultural Research Center

Improving irrigation water management and increasing water productivity are critical to address future water scarcity in arid and semi-arid areas. A promising strategy is to maximize water productivity by exposing crops to a certain level of water stress. The experiment was conducted on-site at the Adami Tulu Agricultural Research Center to study the effect of deficit irrigation at different growth stages on agronomic parameters as well as yield and yield components as well as water productivity of tomato plants. Treatments consisted of a factorial combination of full and three-deficit irrigation with four plant growth stages. The results showed that the interaction effect between deficit irrigation and different plant growth stages significantly affected plant height, fruit height, fruit diameter, fruit yield and water productivity. The highest plant height (75.23 cm), fruit length (84.56 mm), fruit diameter (77.10 mm), marketable fruit yield (48.64 t/ha) and total fruit yield (50.09 t/ha) were obtained under continuous full irrigation achieves levels. While the lowest plant height (54.43 cm), fruit length (55.92 mm), fruit diameter (50.04 mm), marketable yield (22.51 tons/ha) and total yield (28.14 tons/ha) at 60% Etc achieved in the middle were stage treatment. The highest water productivity of 7.85 kg/ha was achieved with the application of 80% ETc in the late season, while the lowest (4.61 kg/ha) was achieved with 60% ETc in the middle treatment phase. Therefore, the results of this study suggest that applying 80% ETc deficit irrigation in the late season stage is the best solution for water conservation without affecting tomato yield while improving water productivity under water-stressed conditions.

Performance enhancement of a modified solar still with inverted pyramid aluminum basin geometry: Experimental optimization, thermal, and economic assessment

Desalination is a promising solution to address the global challenges of water scarcity and energy demand, aided by industrialization and population growth. This study explores the potential to enhance solar still performance by redesigning the basin into an inverted pyramid shape constructed of aluminium. Aluminium’s superior thermal conductivity and solar radiation absorption properties aim to increase the effective surface area and optimize thermal storage, thereby improving evaporation and condensation processes. Comparative theoretical and experimental investigations between a modified solar still (MSS) and a conventional solar still (CSS) under varying saline water quantities revealed a significant increase in daily water production and thermal efficiency for the MSS. The MSS achieved a 46.67 % higher output (4.40 kg/m2/day at 30 liters) and a 14 % increase in thermal efficiency compared to the CSS (29 %). In terms of exergy efficiency, the calculated daily exergy efficiency for CSS and MSS was 2.0 % and 3.12 %, respectively. The energy payback time of the CSS and MSS was 17.18 and 7.2 years, respectively, and they reduced CO2 emissions by 13.668 tons and 20.05 tons per year. Moreover, the MSS demonstrated a 45.45 % reduction in the cost of freshwater production. Exergo-economic and exergo-environmental analyses further validate the MSS's potential as an efficient and sustainable solution for solar desalination, offering a significant advancement in addressing water scarcity and promoting environmental sustainability.

Maize yield is associated with abscisic acid and water potential under reduced soil water supply but with indoleacetic acid in genotypic renewal

Irrigation and breeding are important practices for improving yield and water use efficiency of maize (Zea mays L.) in arid regions. However, the physiological mechanisms of yield under varying water supplies and genotypes remain unclear. Here, we examine the different physiological mechanisms underlying maize yield responses to varying soil water supplies and three genotypes (MC670, ZD958, and ZD2#) cultivated in northwestern China over the past five decades. The declining water supply significantly reduced maize leaf hydraulic transport, stomatal conductance (gs), net photosynthetic rate (A), yield, kernel number, biomass, and evapotranspiration (ET). Conversely, it led to an increase in abscisic acid (ABA), hydrogen peroxide, intrinsic water use efficiency, and water productivity. Interestingly, there was no significant impact on indoleacetic acid (IAA), thousand kernel weight, or harvest index (HI). Breeding efforts increased leaf IAA levels, biomass, thousand kernel weight, yield, HI, and water productivity without altering physiological traits or ET. The superior yield of MC670 could be attributed to a simultaneous enhancement in both kernel number and thousand kernel weight, while ZD958 exhibited greater yield stability. ABA and hydraulic traits (predawn leaf water potential, leaf water potential, and whole-plant hydraulic conductance) coordinated gs under reduced soil water supply, while ABA and predawn leaf water potential regulated yield by modulating gs to affect both A and ET. Breeding for yield gains was associated with IAA-induced enhancements in biomass and HI, independent of key physiological traits (e.g., gs and A) and ET. The observed increase in water productivity primarily stemmed from notable yield improvements rather than alterations in ET. Hence, the selection of high-yielding genotypes under water-limited and well-watered conditions requires consideration of water-related physiological traits and IAA levels, respectively.

Performance enhancement in air gap membrane distillation using heat recovery configurations

Experimental investigations were conducted on an air gap membrane distillation (AGMD) unit to evaluate the impact of heat recovery on system performance. The study utilized a steady-state heat source in conjunction with a spiral air gap membrane module for water desalination. The process was implemented using two configurations aimed to minimize heat loss enhancing productivity, gain output ratio (GOR), and thermal efficiency. The experiments involved feedwater with salt concentrations ranging from 10,000 to 30,000 ppm. The measurements were recorded for inlet and outlet temperatures of the heat source, water productivity, and thermal efficiency at various coolant and water feed flow rates. These configurations effectively addressed critical technical challenges in thermal AGMD systems by optimizing heat recovery. The incorporation of heat recovery resulted in a significant increase in water productivity by 37.07 % compared to systems without heat recovery while maintaining the same initial heat input. The heat recovery in series (HRSS) and parallel (HRPS) configurations resulted in power consumption reductions of approximately 29.7 % and 23.1 %, respectively compared to the conventional configuration (CC) at a flow rate of 12 L/min. The levelized cost of water (LCOW) for the AGMD system was comprehensively evaluated and found to be $ 7.71 per cubic meter. This figure reflected the total cost of water production over the system's operational lifespan including capital expenditures, operating and maintenance costs, and energy consumption. The calculated LCOW provides a clear indicator of the system's economic viability, demonstrating the cost required to produce each cubic meter of water through the AGMD.

Studying performance, energy, exergy, economic, environmental, and sustainability analyses of solar still using different storage materials

The main goal of this study is to investigate the performance, energy, exergy, economic, environmental, and sustainability analyses of single-slope solar still using different sensible storage materials. Three different storage materials were used: pebbles and basalt, which are common storage materials, and aluminum dross, which is a new storage material. The performance of still with storage material was compared to that of the traditional solar still. The study findings indicated that, compared to a conventional solar still, using pebbles, basalt, and aluminum dross increased water productivity by 7 %, 11.4 %, and 21.2 %, respectively. The thermal efficiency increased by 5.4 %, 15.7 %, and 22 % for pebbles, basalt, and aluminum dross, respectively. The increase in exergy efficiency was 43 %, 15.3 %, and 22 % for pebbles, basalt, and aluminum dross, respectively. Based on sustainability analysis, aluminum dross achieved the lowest payback time based on energy which was lower than three years, followed by basalt and pebbles. Also, aluminum dross achieved the highest energy production factor, followed by basalt and pebbles. The total annual cost was $22.73, $25.4, and $26.91 for pebbles, basalt, and aluminum dross, respectively. The exergo-economic based on energy and exergy was the highest for aluminum dross followed by basalt and pebbles. The environmental analysis revealed that the mitigated carbon dioxide by pebbles, basalt, and aluminum dross was 5.59 tons, 7.23 tons, and 8.21 tons, respectively. In conclusion, regardless of aluminum dross having the highest annual cost, it achieved the highest water productivity and efficient operation based on environmental and sustainability levels.

Furrow Irrigation system in Ethiopia, a limitation in the rational use of water in agriculture and its performance

Ethiopia is among the many developing nations that prefer surface irrigation over underground and pressured irrigation systems due to its lower cost and energy consumption. This paper reviews the effects of furrow features, including length, flow rate, and influence on farm water productivity and yield gap. The furrow irrigation method can be highly effective when used correctly, but it can also be quite ineffective when used incorrectly. High efficiency can be attained if the design parameters of a furrow irrigation system, such as field length and flow rate, infiltration characteristics, and field slope, as well as its operational and management parameters, such as application depth, and frequency, are properly maintained. Over-irrigation in a furrow irrigation system can lead to a variety of detrimental consequences on crop productivity and the environment, including water runoff, reduced efficiency, deep percolation, waste of energy and resources, crop damage, and increased salinity. Therefore, checking the moisture content of the soil frequently to prevent over-irrigation by visual examination or soil moisture monitors, carefully planning furrows depending on soil type, crop requirements, and topography as well as gathering runoff water and reusing it improved farm irrigation water management in furrow irrigation system to reduce the yield gap and increase water productivity.

Case Study: Innovative Approach To Increase Well Productivity by Adapting Drilling Targets and Completion Methodology

_ The discourse regarding US land exploration and production has tended to primarily focus on shale development. While this has pushed the industry to adopt many technologies or applications, the general recipe has been to be faster and cheaper with hopefully more predictable BOE/ft production. However, there are limitations with this approach as it tends to boil down to a choice of substitution rather than true engineering to improve return on investment or improved net present value. The relationship of parent and child well production has introduced a variable that does not necessarily respond to faster and cheaper. In fact, operators may agree that a dissolvable frac plug has application to reduce completion costs while completely disagreeing on the methodology to manage field development and the parent-child interaction. Extensive field study and calibration can determine an optimal solution with varying degrees of predictability (SPE 211899). For example, reservoir depletion and fracture communication can be difficult to accurately plan for in advance. These and several additional parameters are specific to a section, field, or bench and the design and planning process begins anew when drilling locations move a sufficient distance away from the asset in question. The best outcome during the drilling and completion of a child well is to limit the negative impact on parent well production while delivering an economically viable addition to existing production. Acceptable ranges of underperformance with the child well vary, but can be summarized as 20 to 30% less than the parent well (SPE 209171). Additionally, contact from an offset child well fracturing operation can detrimentally affect parent well production temporarily or permanently by increasing water production and decreasing hydrocarbon production. Introduction This case study presents the development of a methodology for optimizing and controlling the hydraulic fracturing process’s parameters by increasing cluster efficiency to 100% and overcoming formation leakoff with eight to 10 times rate per cluster when compared with industry standards. The developed framework is validated through field completion and production data taken from wells located on the Northwest Shelf, within the San Andres formation, specifically straddling the state line of New Mexico and Texas with operations primarily in northeast Lea County, New Mexico, and Yoakum County, Texas. For the purposes of this study, parent wells are wells drilled during Segment 1 (2013 to 2016) and/or the first wells drilled in a section. Child wells are defined as any subsequent wellbore placed in a section amongst current producers Segment 2 (2017 to 2020) and Segment 3 (2022 to 2023). The offset true vertical depth (TVD) of the child wells relative to the parent wells is less than 100 ft and no geologic barrier exists, thus the contribution to production is from the same rock matrix regardless of well vintage.

تقييم تأثير نفاذية صخور المكمن في حقن الغاز وتحسين عامل استخلاص النفط بواسطة برنامج Eclipse

This paper examines on the effect of the reservoir rock permeability on gas injection by using reservoir simulation. This task will be performed by using reservoir simulation software (Eclipse). This injection interacts with CO2 to create conditions favorable for oil recovery. The main target of this project is to investigate the effect of the reservoir rock permeability on gas injection and the optimum injection rate to get the optimum recovery. The problems statement of this study is: As the oil and gas in a formation is produced, the hydrocarbons remaining in the reservoir may become trapped because the pressure in the formation has lessened, making production either slow dramatically or stop altogether. Climate change refers to long-term shifts in temperatures and weather patterns. Burning fossil fuels generates greenhouse gas emissions that act like a blanket wrapped around the Earth, trapping the sun’s heat and raising temperatures. Examples of greenhouse gas emissions that are causing climate change include carbon dioxide and methane. The result of effect of the reservoir rock permeability on gas injection by using reservoir simulation shows that with the increase in the permeability of reservoir rock, the rate of gas production increases. The greater the permeability of rocks, the rate of water production increases, which is a direct method relationship between water production and permeability. We note after this evaluation that the cumulative oil, water, and gas production increases with the increase in rock permeability. Keywords: Reservoir Rock Permeability: Gas Injection: Reservoir Simulation “ECLIPSE Software”.

The Israeli Water Policy and Its Challenges During Times of Emergency

In a time of growing climate crisis, and despite the global warming trend, Israeli citizens routinely enjoy a regular constant supply of clean fresh water thanks to local desalination plants. Establishment of the desalination plants has become a model of water management for many countries in an era of growing climate crisis. At the same time, Israel’s water sector is faced with challenges and threats related to earthquakes, various states of warfare, and security confrontations. In such times of emergency, Israel’s water sector is particularly vulnerable to disruptions of the water infrastructure and its adequate operation by both contamination of the water sources and damage to the desalination plants. This study examines the challenges of the Israeli water sector that require it to contend with these emergency situations in an era of reliance on desalination plants. The research findings lead to the conclusion that public policy on managing the water sector, manifested in the development and establishment of water desalination plants, has resolved Israel’s water crisis, put an end to its dependency on the amount of precipitation and on natural water sources, and allowed for an increase in water production to match the rise in consumption. Nonetheless, as successful as this public policy may be, it does not consider the possibility of extreme scenarios and does not develop the entire range of steps necessary to confront them, and thus it undermines the ability of the Israeli water sector to provide its citizens with water in times of emergency.

Thermal seawater desalination for irrigation purposes in a water-stressed region: Emerging value tensions in full-scale implementation

Water scarcity in arid regions has driven the spread of desalination. These systems contribute to water access but come at an intensive energy cost, and lead to brine discharge and associated environmental impacts. This work aims to investigate emerging societal issues and tensions when developing and implementing a thermal desalination system to produce irrigation water in the South of Spain. This has been done in a demonstration system for solar desalination able to recover water and salts from desalination brine. For this purpose, a context-sensitive design exercise has been implemented. First, tensions between social values expressed by diverse stakeholders have been identified. Then, a set of technical scenarios for the full-scale implementation of the system were designed and evaluated, comparing them to conventional membrane desalination. The analysis indicates high economic and energy costs to avoid the environmental impacts of increasing water production.

Palaeoecological Conditions in the South-Eastern and Western Baltic Sea during the Last Millennium

We present the reconstruction of palaeoenvironmental conditions in the Gdansk, Bornholm, and Arkona Basins of the Baltic Sea over the last millennium. A multiproxy study (including geochemical, XRF, grain size, AMS, and micropalaeontological analyses) of five short sediment cores was performed. The relative age of the sediments was determined based on the Pb distribution along the sediment sequences, as radiocarbon dating has resulted in an excessively old age. The retrieved cores cover two comparable warm periods, the Medieval Climate Anomaly and the Modern Warm Period, for which the increase in surface water productivity was reconstructed. Notably, the production of diatoms was higher during the colder periods (the Dark Ages and Little Ice Age), but this was also the case within the Modern Warm Period. In the Gdansk Basin, the initial salinity increase during the Littorina transgression started after 7.7 cal. a BP. The increased inflow activity was reconstructed during the Medieval Climate Anomaly, even in the Gdansk Basin, despite, in general, very low foraminiferal amounts and diversity. The strongly positive North Atlantic Oscillation Index during this period led to the prevalence of westerly winds over the Baltic region and stronger saltwater intrusions. In the recent sediments, the reconstructed inflow frequency demonstrates a variability against the reduction trend, and a general decline compared to the Medieval Climate Anomaly is seen.

Reducing initial cotton yield penalties in a transition to conservation agriculture through legume cover crop cultivation – evidence from Northern Benin

Much effort has been spent on promoting conservation agriculture (CA) in Northern Benin to sustain the transition of cotton (Gossypium hirsutum L.) cropping systems toward agroecology. However, its limited adoption by farmers is often ascribed to initial yield penalties during the transition to CA and to trade-offs around crop biomass use. Here, we assess the effect of different CA-based cropping systems promoted in the region on water productivity and cotton yield in a three-year cotton/maize (Zea mays L.) crop rotation during the initial transition phase to CA. Three CA options were assessed combining different levels of soil disturbance and cover, and introducing cover crops to alleviate the biomass trade-offs. Direct seeding (DS), strip tillage (ST), and direct seeding mulched-based cropping systems (DMC) were compared with conventional tillage (CT) from 2017 to 2019 under a dominant soil type in the region, Haplic Lixisols. Two legume species, Stylosanthes guianensis (Aubl.) Sw. and Crotalaria retusa L. were grown as cover crops with maize under ST and DMC. The experiment followed a randomized block design comprising six replicates. After 2–3 years of DMC, the cotton yield advantage with respect to CT increased from 5 % to 7 %. Cotton yield penalties of respectively 11 % in 2018 and 26 % in 2019 were found for DS. ST treatment went from a yield advantage of 8 % in 2017 to a yield penalty of 20 % in 2019. The DMC and CT treatments gave similar and highest boll weights compared to the ST and DS treatments. The treatments had no significant difference regarding the number of bolls per plant. Soil water storage in the upper 30 cm depth and water use efficiency (WUE) were the highest in the plots with the DMC treatment compared to CT, ST, and DS. At 28 days of active vegetative stage (between 34 and 62 days after sowing), the WUE of seed cotton was 0.11 kg ha−1 mm−1 under DMC, while it was 0.08, 0.07, and 0.04 kg ha−1 mm−1 under DS, CT, and ST, respectively. The performance of DMC at increasing water productivity could be an argument to improve adoptability by farmers in northern Benin who are facing increased weather variability, given that the yield penalties often associated with early transitions to CA were not observed here with full DMC.

Irrigation During Flowering Is Critical for Enhancing Productivity and Economics of Late-Sown Indian Mustard Compared to other Management in the Arid Regions of Western India

ABSTRACT Global warming delays the harvest of kharif crops, which delay the subsequent sowing of Indian mustard, especially in northwestern India and also causes dry winters that exacerbate challenges for the timely sowing of rabi-crops. To check this, a field experiment was conducted during the Rabi-seasons of 2018–19 and 2019–20 to assess the influence of sowing dates, irrigation, and fertilizer levels under late-sown conditions. A split-plot design was used with two sowing dates, two irrigation levels and four fertilizer levels (87.5%, 100%, 112.5% and 125% RDF; Recommended-fertilizers-dose). Crop sown in the 4th week of November significantly reduced seed (46.79 and 38.77%) and stover yield (43.72 and 41.62%) as compared to the 2nd week of November sowing during 2018–19 and 2019–20, respectively. Uptake of NPK by seed and stover was higher with the 2nd week of November sowing. The 2nd week of November sowing resulted in significant increase in water productivity by 63.72% and Benefit cost ratio (B:C) by 75.45% over the 4th week of November sowing. Irrigation at flowering stage increased the seed yield, water productivity and B:C by 11.94%, 1.72% and 9.17%, respectively, as compared to No post-sown irrigation. The biological yield of the Indian mustard increased with every increase in fertilizer doses but the response was significant up to 112.5% RDF (90 kg N, 33.75 kg P2O5 and 22.5 kg K2O ha−1). Application of 112.5% RDF increased the seed, stover yield, water productivity and B:C by 16.17%, 9.29%, 15.66% and 11.27%, respectively, over 87.5% RDF.

Improvement of low-cost solar-powered desalination technologies in low-light intensity

Enhancing the efficiency of low-cost solar-powered desalination technologies, such as solar stills (SS), is essential for ensuring continuous access to freshwater in remote, water-stressed areas, particularly during cloudy or rainy days when the performance of conventional SS systems is compromised. This study introduces an innovative stepped solar still design, optimized for ease of operation, maintenance, environmental compatibility, and improved efficiency, especially under low-light conditions. The impact of the inlet mass flow rate on the desalination process was investigated to enhance distilled water production. Light absorption and step hot spot temperatures were further improved by incorporating natural and cost-effective absorbers, such as carbon, and an innovative soil-carbon combination. The synergy of this soil-carbon combination, enhancing light absorption, heat transfer, and storage through increased surface contact during radiation exposure and its distribution during shutdown, led to a 12.8% and 3% increase in distilled water production over the 4-hour test duration, compared to the baseline and carbon-only tests, respectively. This innovative design, combined with the use of a soil and carbon mixture, significantly improves the performance of solar distillation systems. These findings contribute to the development of sustainable, low-cost, and energy-efficient solutions for freshwater provision in remote areas, addressing both water scarcity and energy conservation challenges.

Effects of Water and Nitrogen Regulation on Apple Tree Growth, Yield, Quality, and Their Water and Nitrogen Utilization Efficiency.

Apple tree productivity is influenced by the quantity of water and nutrients that are supplied during planting. To enhance resource utilization efficiency and optimize yields, a suitable strategy for supplying water and nitrogen must be established. A field experiment was conducted using a randomized block group design on five-year-old apple trees in Ningxia, with two irrigation lower limit levels (55%FC (W1) and 75%FC (W2)) and four N application levels (0 (N1), 120 (N2), 240 (N3), and 360 (N4) kg·ha-1). Our findings showed that leaf N content increased with a higher irrigation lower limit, but the difference was not statistically significant. However, the leaf N content significantly increased with increasing N application. The growth pattern of new shoots followed logistic curve characteristics, with the maximum new shoot growth rate and time of new shoot growth being delayed under high water and high nitrogen treatments. Apple yield and yield components (weight per fruit and number of fruits per plant) were enhanced under N application compared to no N application. The maximum apple yields were 19,405.3 kg·ha-1 (2022) and 29,607 kg·ha-1 (2023) at the N3 level. A parabolic relationship was observed between apple yield and N application level, with the optimal range of N application being 230-260 kg⸱ha-1. Apple quality indicators were not significantly affected by the irrigation lower limit but were significantly influenced by N application levels. The lower limit of irrigation did not have a significant impact on the quality indicators of the apples. Water and N utilization efficiencies improved with the W2 treatment at the same N application level. A negative relationship was observed between the amount of nitrogen applied and the biased productivity of nitrogen fertilizer. The utilization of nitrogen fertilizer was 127.6 kg·kg-1 (2022) and 200.3 kg·kg-1 (2023) in the W2N2 treatment. The apple yield was sustained, the quality of the fruit improved, and a substantial increase in water productivity was achieved with the W2N3 treatment. The findings of this study can be used as a reference for accurate field irrigation.

Augmenting thermal performance in tubular solar stills: A multifaceted strategy with wick cords, integrated baffles, reflectors, and nano-PCM

This study investigates the enhancement of freshwater production using a modified cords wick tubular solar still (CWTSS) compared to a traditional tubular solar still (TSS). The CWTSS design increased freshwater yield by 102 % over the baseline TSS. Also, the impact of using baffles (CWTSS-B) was tested. Incorporating reflectors into the CWTSS (CWTSS-B-R) further improved performance, achieving a 201 % increase in production with reflectors and 160 % without reflectors, highlighting the significant role of reflectors in solar energy capture and distillation efficiency. Various wick cord numbers (12, 22, 32, and 42) were tested to identify the optimal configuration. The use of nanoparticle-enhanced Phase Change Material (PCM) in the CWTSS (CWTSS-PCM) resulted in a 240 % production increase compared to the TSS, demonstrating the effectiveness of PCM in thermal energy storage and management. The most significant improvement was observed in the CWTSS-fan configuration, which employed a fan and an external condenser, leading to a 256 % increase in water production, reaching 15,300 mL/m2 compared to 4300 mL/m2 for the TSS. The modified design's freshwater production cost was $0.01/L, a 50 % reduction from the conventional design's cost of $0.02/L.