Water Discharge Research Articles

Design and optimization of bilayer structure in metal foam flow field for proton exchange membrane fuel cell

The balance between water discharge and mass transfer within metal foam flow field is vital for elevating the performance of proton exchange membrane fuel cell (PEMFC). To obtain an improved balance, this work designs a novel bilayer structure with two types of PPI (pore per inch) for metal foam flow field. Experimental and numerical results confirmed that arranging a metal foam featuring a smaller PPI in the layer 1 near the membrane electrode assembly (MEA) and a larger PPI in the layer 2 away from the MEA is beneficial to enhance the output performance. The excellent PPI combination for balancing mass transfer and water discharge involves utilizing a 50 PPI metal foam for the layer 1 and 110 PPI metal foam for the layer 2. Compared to conventional metal foam with 50 PPI, metal foam flow field with excellent PPI combination showcases a 11.2 % increase in water discharge and a 13.2 % boost in mass transfer, leading to a notable 23.5 % performance enhancement. Similarly, compared to conventional metal foam with 110 PPI, there is a 7.3 % decrease in mass transfer but a significant 29.5 % increases in water discharge, leading to a 15.2 % performance improvement.

Modeling root effects on soil detachment capacity using critical flow depth and unit energy of cross section in soils under Fraxinus excelsior L. species

The flow depth is an important hydraulic parameter for calculating other hydraulic parameters of overland flow. There is notable changes in hydraulic parameter when the roots of a plant develop in the topsoil. A power regression equation between soil detachment capacity (Dc) and unit energy of cross section (UEC) was established in soils under Fraxinus excelsior L. species based on the Froude number. For measuring Dc, samples collected from soils under the studied species and subjected to five slopes (from 13.9 to 33.9%) and five water discharges (from 0.39 to 0.77 l m−1 s−1) by a hydraulic flume. Compared with the soil with absence of root, the soil with presence of root had lower Dc. The results showed a strong power relationship between the unit energy of cross section and Dc, suggesting that soil detachment rate in rill erosion can be estimated using this hydraulic parameter (R2 = 0.84). This finding is particularly relevant for hillslopes with slopes from 12% to 31%, where the proposed mathematical model could be applied to predict Dc. Overall, this investigation supports a broader use of native species (such as the european ash Fraxinus excelsior L.), as a useful eco-engineering conservation practice and an alternative technique instead of utilizing artificial and expensive conservation practices.

Influence of different types of superabsorbent polymers on fresh mechanical properties and interlayer adhesion of 3D printed concrete

3D printed concrete (3DPC) is an essential technology for achieving efficient, precise, and sustainable construction. Nevertheless, due to limitations in materials and processes, 3DPC is prone to insufficient green strength and weakness in the interlayer area, which can result in print collapse and diminish its interlayer adhesion strength. Therefore, understanding green strength and interlayer adhesion strength of 3DPC is crucial for ensuring its structural safety. Superabsorbent polymer (SAP) serves as a novel type of concrete admixture, demonstrating the potential to promote green strength development and augment interlayer adhesion properties by facilitating the hydration process through water absorption and release. This study presents the first investigation into the effects of two commercially available SAPs on green strength and interlayer adhesion of 3D printed concrete. The role of SAP in improving interlayer adhesion performance in 3DPC is further elucidated through X-ray diffraction (XRD), Scanning electron microscopy (SEM). The results indicate that, compared to the control group, in the absence of added compensated water to SA1, the compressive strength at 15min and splitting tensile strength of the printed specimen at 28 d increased by 282% and 24.9%, respectively, whereas SA2 demonstrates a relatively weaker enhancement effect. This study demonstrates that SAP promotes structural accumulation during the 3DPC printing stage, thereby presenting itself as a favorable material choice for applications involving 3DPC.

High microplastic pollution in marine sediments associated with urbanised areas along the SW Bulgarian Black Sea coast

This study aims to provide baseline data on microplastic (MP) concentrations in beach and seabed sediments of the SW Black Sea coast, and to identify possible sources of MP pollution in the area. MP concentrations in beach sediments in urbanised coastal areas, as well as in all seabed sediments, were on average higher than in other parts of the Black Sea and most other European seas. Urban coastal areas showed the highest average MP concentrations (mean ± SD): 464.44 ± 272.50 MP·kg−1 dry sediment in beach samples, 825.93 ± 396.30 MP·kg−1 dry sediment in seabed samples, while coastal sediments in an area with no local anthropogenic activities had significantly lower average MP concentrations: 84.44 ± 147.57 MP·kg−1 in beach samples, and 550.62 ± 245.71 MP·kg−1 in seabed samples. Possible identified sources of MPs include sewage water discharges, urban waste, coastal fisheries and aquaculture, as well as accumulation of marine litter on beaches and in adjacent offshore areas, serving as sources of secondary MP pollution.

Geochemical fingerprinting and statistical variation of 35 elements in produced water and rock material from offshore chalk reservoirs

Trace metals and metalloids occur in small quantities in the subsurface water generated from oil wells, called produced water (PW). While these substances are present in low concentrations, PW volumes are sufficiently large that they are still a potential environmental concern. This study has focused on quantifying 71 trace metals and metalloids present in PW from Danish offshore oil production sites. These metals are often a challenge to measure and are globally underreported. By employing optimized sample treatment and ICP-OES and ICP-SFMS methods, the full elemental screening of PW samples collected from various offshore platforms has been carried out with high accuracy. Distinct geochemical signatures involving 35 elements have been discovered and they are associated with significant site-specific variations in the concentrations of key trace metals, including W, Ba, Mo, Cu, and Tl. Utilizing Principal Component Analysis (PCA), the study has effectively distinguished between PW samples from different fields, highlighting the relevance of certain trace metals and elemental ratios as potential geochemical markers. Geochemical analysis of the chalk rock material from the same production wells as the fluid samples has shown a correlation of key elements Tl, W, Cu, Mo, Ba, and As in the chalk with the produced water, indicating the origin of the metals. The study has revealed a high compositional variability of PW and found that elements including Zn, Co, Hg, and Cs occur in concentrations of magnitude higher than previous estimates. In addition, there is high variability in concentrations at different sampling times, underlining the need for environmental monitoring and developing more informed management strategies for the main offshore PW stream. The variability in concentrations in space and time leads to large uncertainties in environmental reporting based on a few samples. The detailed sampling campaign reported here for the first time highlights need for much more frequent sampling, ideally continuous monitoring. The safety of produced water discharge to sea can be significantly underestimated by limited sampling. This paper provides the first field-specific and time varied screening of heavy metals in real produced water and shows the discrepancy in our understanding of the environmental impact of PW.

Precipitation and water discharge for internet of things based flood disaster prediction improvement

Precipitation and water discharge for internet of things based flood disaster prediction improvement

Optimizing Hygroscopic Metal–Organic Frameworks via EDTA‐Mediated Structural Reinforcement and Photothermal Modification

AbstractHygroscopic metal–organic frameworks (MOFs) are considered as superior moisture sorbents due to their highly adjustable and desired water adsorption/release performance, enabling effective atmospheric water harvesting (AWH) in arid regions. However, the water adsorption capacity, recycling stability, and functionality of current MOFs should be further improved to meet the requirements of practical AWH systems. Here the hydrophilicity at low relative humidity (RH) and cycling stability of MOF‐808 are simultaneously enhanced through the ethylenediaminetetraacetic acid (EDTA)‐mediated post‐modification. Based on the structural reinforcement, EDTA‐modified MOF‐808 (E‐MOF‐808) delivers a stable water uptake capacity of 0.39 g g−1 at 25% RH even after 50 water adsorption–desorption cycles, more than five times that of pristine MOF‐808. In addition, bridging by EDTA with the strong chelating ability, the E‐MOF‐808 can spontaneously capture Cu2+ for further functional improvement. Accordingly, light‐absorbing CuS nanoparticles can be in situ decorated on E‐MOF‐808 for facilitating solar‐driven water release. It is envisioned that this EDTA‐mediated function enhancement should provide valuable insights into the all‐in‐one design of versatile MOFs sorbents.

A comparative analysis of deep-learning models for dam discharge forecasting for disaster management

ABSTRACT This paper represents a comprehensive study of dam water discharge prediction using various deep-learning models. The main aim of this paper is to provide a data-driven solution for effective water resource management and thereby controlling the effects of floods and droughts. The Malampuzha dam, which has a spillway, a right bank canal (RBC), and a left bank canal (LBC), is considered for the study. While the spillway helps to control the water level in the reservoir by allowing extra water to flow downstream during times of severe rainfall or high inflow, hence reducing the risk of floods, the LBC and RBC are intended to divert water for agriculture. Altogether, 10 years of consecutive meteorological and dam-related data are utilized for training and testing the models in forecasting water discharge through LBC, RBC, and the spillway. Different deep-learning models, namely, long short-term memory, Bi-directional long-short term memory, recurrent neural network, gated recurrent unit, one-dimensional convolutional neural network (1D-CNN), deep neural network, autoencoder, and residual networks are explored in predicting the accuracy of dam water discharge. After testing eight deep-learning models, it was discovered that 1D-CNN performed well in predicting the discharge of water.

Electronic asymmetry of lattice oxygen sites in ZnO promotes the photocatalytic oxidative coupling of methane.

Photocatalytic oxidative coupling of methane with oxygen is promising to obtain valuable muti-carbon products, yet suffering low reactivity. Here, we apply cerium modifications on zinc oxide-supported gold catalysts based on the electronic asymmetry design of lattice oxygen to improve the coupling activity. The methane conversion rate exceeds 16000 μmol g-1 h-1 with muti-carbon selectivity of 94.9% and catalytic durability of 3 days, and it can increase to 34000 μmol g-1 h-1 under more thermal assistance, with a turnover frequency of 507 h-1 for ethane and an apparent quantum efficiency of 33.7% at 350 nm. According to systematic characterizations and theoretical analysis, cerium dopants not only can boost the formation of reactive oxygen species but also intervene in the vivacity of lattice oxygen by manipulating metal-oxygen bond strength, thereby leading to favorable methyl desorption to form ethane and quick water release. This work provides insight into the rational design of efficient photocatalysts for aerobic methane-to-ethane conversion.

Effect of N,N′-Methylenebisacrylamide on properties of porous semi-IPN hydrogels from Acrylamide, Maleic Acid, and its use for Urea absorption

Hydrogel is a three-dimensional polymer that can absorb large amounts of reagents while maintaining structural integrity. This material has been applied in many fields especially in smart agriculture. To improve the economic viability, the reusability of hydrogels in agricultural engineering over multiple cycles of adsorption and desorption is an urgent requirement. This can be solved if the crosslinker is used properly. Therefore, in this work, a series of porous semi-IPN hydrogels based on linear polyacrylamide, acrylamide, maleic acid, and N,N′-methylenebisacrylamide (MBA) were synthesized. The hydrogels were evaluated for the impact of MBA content on the characteristics and applicability as a urea fertilizer carrier. The chemical composition, morphology, mechanical, and rheological properties, swelling behavior, urea absorption and desorption of hydrogels with crosslinker content in the range of 0.5-2.0 % were investigated. The porous structure was confirmed by scanning electron microscopy images. Changing the MBA content significantly affected all characteristics of the hydrogels. In particular, increasing the MBA content decreased the equilibrium swelling ratios in all investigated environments. The maximum amount of urea loaded into the hydrogel was also reduced from 435.88 to 188.50 mg/g. This increase also changed the swelling mechanism from non-Fickian to Fickian, whereas the urea release mechanism changed from Fickian to non-Fickian. Finally, the hydrogels demonstrated stability in soil over multiple cycles of water absorption and release. This study provides valuable insights into designing a semi-IPN hydrogel with desired properties that meet the application requirements of modern farming techniques.

UJI EKSPERIMEN PENGARUH JUMLAH SUDU DAN DEBIT TERHADAP DAYA DAN EFISIENSI TURBIN AIR TIPE VORTEX

<p class="StyleAuthorBold"><em>The electrification ratio in Indonesia is currently still 87%. This means that there are still 8.5 million residents or the equivalent of 2500 villages that have not received electricity. Indonesia has a lot of potential for renewable energy such as water energy. 7 GW capacity from renewable energy, 66% of which comes from hydropower. The manufacture of pico-hydro scale power plants can be a cheap alternative. Pico-hydro can be applied to irrigation canals so that it can produce small-scale electrical energy. One type of water turbine that can be utilized is a vortex type water turbine. The study used experimental methods. The independent variables are variations in the number of blades 2, 4, and 6 and the distance between the blades and the outlet is 1 cm. The dependent variable of the research is the power and efficiency produced by the vortex water turbine. The data analysis technique in this study used quantitative descriptive analysis techniques. The basin used is a conical basin type with the upper diameter is 40 cm, the lower/oulet diameter is 6.5 cm, and the height is 32 cm. The water discharge in this test has 7 variations, that is 1,12 l/s, 1,26 l/s, 1,54 l/s, 1,68 l/s, 1,82 l/s, 1,96 l/s, and 2,11 l/s. This test produced the highest electrical output power of 9.66 Watts, at a total of 2 blades, the discharge is 1,86 l/s. At the number of blades 6 at a discharge of 1.96 l / d is the highest efficiency value of 6.3%.</em></p>

ICP-MS determination of background I-129 in seaweed samples around Fukushima Daiichi NPS.

TEPCO planned the release of Advanced Liquid Processing System (ALPS)-treated water, which is decontaminated stagnated water by ALPS, to the Pacific Ocean in 2023 after diluting it more than a hundred times in accordance with the policy of the Japan government. Since the low level of I-129 can remain in ALPS-treated water, the background I-129 concentration in seaweed samples around 1F NPS before the release of ALPS-treated water was recorded in this study. The iodine in seaweed samples was extracted via TMAH alkali-dissolution, and the I-129 concentration was measured by 8900 Triple Quadrupole ICP-MS. The resulting I-129 concentration was <5.4×10-2Bq/kg-wet (sargassum) and <2.7×10-2Bq/kg-wet (laminaria), respectively.

Tritium transfer from seawater into marine organisms TFWT.

Tokyo Electric Power Company, TEPCO, has started tritiated water release into the Pacific Ocean. In order to reduce unreasonable rumor caused by tritium release, flounder, abalone, and sarggasum were exposed to tritium enriched seawater, and time dependent Tissues Free Water Tritium (TFWT) concentration was measured. Estimating the concentration of Organically Bound Tritium (OBT) is important to assess tritium impact because it has a longer biological half-life than TFWT. Current models estimate OBT concentrations using TFWT concentration. Understanding equilibration time is critical for making accurate TFWT concentration predictions. TFWT intake rate was analysed by the compartment model.

Influence of straw degradation on dredged sludge consolidation under vacuum preloading

Vacuum preloading with straw drainage has been used as an eco-friendly soil-reinforcement method to promote the consolidation of dredged sludge. In previous studies, the degradation of straw, an essential factor influencing dredged-sludge consolidation, has often been disregarded. In this study, laboratory tests were conducted to investigate the effects of straw degradation on the consolidation efficiency of dredged sludge. The vacuum level within the straw drainage decreased with increasing degradation time, causing a reduction in water discharge and settlement. Consequently, the moisture content increased and the shear strength of the soil decreased. After 60 days of degradation, the water discharge and settlement decreased by 46% and 25%, respectively. The impact of degradation time was most significant during the first 15 days, which was when most straw degradation occurred. The average moisture difference from 0-15 days was 5.0%, whereas from 45-60 days it was 0.8%, which was negligible. The increase in the organic matter content enhanced the Atterberg limits and hydrophilic properties of the soil. The findings of this study promote the engineering application of vacuum preloading with straw drainage and confirm it as an effective and eco-friendly method for consolidating dredged sludge.

‘Par mesure de prudence’. Flood prevention and river regulation in Demer-Dijle confluence area (NE Belgium), 1840s–1880s

Abstract This article analyses the views of experts and political discourse on river regulation, its objectives, and flood prevention in the rural Demer-Dijle catchment areas, the 1840s–1880s – a period marked by climatological extremes and agricultural transition. Via a close read of state archives and parliamentary discussions, we unravel different opinions and interests and find that not all flooding was unwanted. While the Ministry of Public Works, at first, aimed to better regulate water discharge and to improve watercourses for navigational purposes, it later prioritised agricultural interests. However, managing rivers coherently and efficiently was challenging because river powers were dispersed over ministerial departments, provinces, and municipalities that made coordinating upstream and downstream river works difficult. Floods often resulted in the drawing up of new plans, but their implementation often failed to materialise because the government had other worries and insufficient resources available while parliamentarians prioritised the interests of their constituencies.

Exploring the growth and phytoremediation efficacy of Suaeda fruticosa in agricultural soil contaminated by shrimp aquaculture

Plants face numerous environmental challenges from biotic and abiotic stressors, with soil salinization emerging as a significant global concern. The coastal regions of Tamil Nadu, face severe environmental challenges due to discharge of saline water from shrimp farms exacerbates this issue, compromising the viability of paddy and other crops in the vicinity. This study explores the phytoremediation potential of Suaeda fruticosa in addressing soil salinity resulting from shrimp farming activities under field conditions over a 120-day period to restore soil health in salt affected soil. This research demonstrates Suaeda fruticosa’s exceptional salt tolerance and bioaccumulation potential in facilitating soil restoration. Significant enhancements were observed in various growth parameters, including 466% increase in plant height, 338% in fresh weight and 387% in dry weight. Biochemical parameters also showed substantial enhancements with total chlorophyll, protein, proline, phenol, and glycinebetaine levels increasing by 655%, 588%, 690%, 153%, and 531%, respectively. Enzymatic activities exhibited notable elevations as well, with catalase, peroxidase, and polyphenol oxidase activities escalating by 258%, 587%, and 121% respectively, indicating robust adaptation to saline environments. Moreover, Suaeda fruticosa exhibited remarkable bioaccumulation capabilities, accumulating 461 kg NaCl ha−1. This led to substantial improvements in soil characteristics, including a reduction in pH from 8.8 to 6.49, electrical conductivity from 5.7 to 1.53 dSm−1, and sodium adsorption ratio from 16.1 to 4.4 mmol L−1. The successive cultivation of Suaeda fruticosa in this study, has proven to be a viable strategy for reclaiming salt-affected lands, thereby alleviating a significant constraint on crop productivity.

Exploring factors influencing Koreans’ intention to visit Japan through decision tree analysis: focusing on discharge of ALPS-treated water and low-yen perception

ABSTRACT In this study, factors influencing Koreans’ intention to visit Japan were examined using a decision tree. It is known that a negative national image generally adversely affects the intention to visit tourist destinations. Japan and Korea have maintained various political, economic and historical conflicts from the past. However, Koreans accounted for the largest proportion of tourists visiting Japan. Therefore, this study aimed to explore the decision-making process for Koreans’ intention to visit Japan and analyse the priority of influencing factors using a decision tree. As a result of the analysis, low-yen perception, historical animosity, interest in treated water, cultural familiarity and age were identified as major influencing factors. These results confirm that changes in Koreans’ perceptions of Japan are progressing despite the fact that the anti-Japanese sentiment towards Japan still exists. Such changes are affecting the selection of tourist destinations. This study is significant in that it considers factors influencing international tourism demand from various perspectives by inputting various predictive variables such as politics, economy, social culture and so on.

Assessment of the level of heavy metals contamination via sediments quality indices of the Koudiet Medouar Dam and its tributary (Batna, Algeria)

The present study assesses the level of heavy metals concerning sediment from the Koudiet Medouar dam. This dam is intended for the production of drinking water and irrigation. In order to assess the level of contamination of the dam by toxic metals, 216 sediment samples were taken at nine stations upstream and downstream of the dam from 2012 to 2014. At the same time, the physical characteristics of the water and the physicochemical parameters of the sediments were determined. The results, expressed by the mean ± standard deviation, are for water: temperature, 15.5 ± 7 °C; potential of hydrogen, 8.05 ± 0.36; conductivity, 1125 ± 228 μS/cm. For sediments the values are potential of hydrogen, 8.55 ± 0.22; conductivity, 730 ± 347 μS/cm; carbonates, 49.18 ± 18.1%; fraction less than 63 μm 27.06 ± 6.95%; organic matter 3.02 ± 1.2%. Trace metal concentrations followed the order: Mn > Zn > Cr > Cu > Co > Ni > Pb > Cd. The strong correlation among trace metal indicates that these elements have common sources suggesting their association with silted sands. The geo-accumulation index, contamination factors, degree of contamination, and sediment pollution index reveal a polymetallic contamination dominated by two or more elements in which Cd, Cr, and Cu are of greatest concern. The levels of trace metals in the sediments record high concentrations upstream of the dam, especially in the second station of the village, near the dam. Our results reflect the footprint of anthropogenic inputs of cadmium, chromium, and copper resulting from agricultural activities by runoff water and soil erosion as well as domestic water discharges.

Analysis of Flood Risk in the Lower Hydrographic Basin of the Río Negro (Argentina)

The recurrent floods in the lower hydrographic basin of the Río Negro (RN), documented since 1899, have caused significant damage to the resident population settled in flood-prone areas, whose socioeconomic condition is unfavorable. The aim of this study was to analyze the risk associated with flood occurrences in this area by integrating the flood susceptibility level (hazard) of the study area and the vulnerability of the population. The risk analysis was derived from the algebraic overlay of hazard and vulnerability maps, developed according to criteria published by Renda et al. (2017). In the study area, floods are primarily caused by intense rainfall and winds, upstream water discharges from the Limay and Neuquén rivers, and interactions between increased upstream flow from the lower hydrographic basin of the RN and extreme meteorological events known as Sudestadas. Every certain period, such as every 2 years for winds exceeding 75 km/h and precipitation exceeding 37 mm in 24 hours, as well as every 100 years for flows exceeding 4,000 , the occurrence of floods in the lower basin of the RN is expected to be derived from these events. Based on terrain characteristics and topography, 41.7% of the lower RN basin area showed moderate to high susceptibility to flooding. INDEC data (2010) indicated that 51.0% of the population in the study area was vulnerable to floods due to unfavorable socioeconomic conditions. According to hazard and vulnerability analyses, 43.2% of residents in the lower RN basin lived in high-risk areas, with homes located near the riverbank and on the outskirts of the Viedma-Carmen de Patagones urban conglomerate, hence being the most vulnerable. The results obtained in this research showed the influence of the natural and anthropogenic factors on the occurrence of flood-related disasters in the lower hydrographic basin of the RN. In addition, they served as a preliminary study that will enable decision-makers to create better prevention and mitigation plans contributing to improving the quality of life of its inhabitants.

Driving Forces in the Formation of Biocondensates of Highly Charged Proteins: A Thermodynamic Analysis of the Binary Complex Formation

A thermodynamic analysis of the binary complex formation of the highly positively charged linker histone H1 and the highly negatively charged chaperone prothymosin α (ProTα) is detailed. ProTα and H1 have large opposite net charges (−44 and +53, respectively) and form complexes at physiological salt concentrations with high affinities. The data obtained for the binary complex formation are analyzed by a thermodynamic model that is based on counterion condensation modulated by hydration effects. The analysis demonstrates that the release of the counterions mainly bound to ProTα is the main driving force, and effects related to water release play no role within the limits of error. A strongly negative Δcp (=−0.87 kJ/(K mol)) is found, which is due to the loss of conformational degrees of freedom.