Water

25 pages, 9043 KiB

Open AccessArticle

Microbial and Biogeochemical Shifts in a Highly Anthropogenically Impacted Estuary (“El Sauce” Valparaíso)

by Francisco Pozo-Solar, Marcela Cornejo-D’Ottone, Roberto Orellana, Carla Acuña, Cecilia Rivera, Polette Aguilar-Muñoz, Céline Lavergne and Verónica Molina

Water 2023, 15(6), 1251; https://doi.org/10.3390/w15061251 - 22 Mar 2023

Cited by 1 | Viewed by 2220

Abstract

Coastal zones are ecosystems that are sensitive to climate change and anthropogenic pollution, resulting in a potential loss of biodiversity and ecosystem services through eutrophication and nutrient imbalances, among others. The coastal El Sauce catchment area, Central Chile, is under multiple anthropogenic pressures [...] Read more.

Coastal zones are ecosystems that are sensitive to climate change and anthropogenic pollution, resulting in a potential loss of biodiversity and ecosystem services through eutrophication and nutrient imbalances, among others. The coastal El Sauce catchment area, Central Chile, is under multiple anthropogenic pressures including wastewater treatment plant (WWTP) discharge, which its broad effect remains underexplored. In order to assess the impact of the WWTP on El Sauce stream, the benthic microbial communities and key functional groups variability (i.e., nitrifiers, methanogens and methanotrophs) were determined by 16S rDNA high-throughput sequencing and by functional genes quantification, respectively, during two contrasted seasons in three catchment areas (pre-, WWTP and post-discharge). The microbial communities’ structure profiles were associated with the water quality, nutrients, greenhouse gas (GHG) distribution, and the organic matter isotopic signatures in the sediments, for the first time, in this ecosystem. The results show that organic matter isotopic signatures using nitrogen and carbon (δ¹⁵N and δ¹³C) and the physicochemical conditions in El Sauce estuary changed from the pre- to WWTP discharge areas (i.e., a pH decrease of 0.5 units and an increase of 4–6 °C in the water temperature). The WWTP discharge area was characterized by a low nutrient concentration and significantly higher GHG distribution (>600 µM CO₂, >30,000 nM CH₄, and >3000 nM N₂O). In addition, the benthic microbial community structure shifted spatially and seasonally, including specific phyla known as sewage bioindicators, such as Firmicutes (Clostridiales order) and Bacteroidetes. In addition, other taxa were enriched or only retrieved in the sediments of the WWTP influenced area, e.g., Tenericutes, Lentisphaerae, Synergistetes, and LCP-89. Methanogens were more enriched near the WWTP discharge compared to those in the pre-discharge site in both seasons, while methanotrophs and ammonia oxidizers were unfavored only during winter. Our results indicate that the WWTP discharge impacts the biogeochemical conditions in El Sauce catchment area modifying the benthic microbial communities, including a decrease in the key functional groups able to mitigate CH₄ and regulate nutrients recycling in these aquatic ecosystems. Full article

(This article belongs to the Section Biodiversity and Functionality of Aquatic Ecosystems)

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Graphical abstract

30 pages, 16316 KiB

Open AccessArticle

Uncertainty Assessment of WinSRFR Furrow Irrigation Simulation Model Using the GLUE Framework under Variability in Geometry Cross Section, Infiltration, and Roughness Parameters

by Akram Seifi, Soudabeh Golestani Kermani, Amir Mosavi and Fatemeh Soroush

Water 2023, 15(6), 1250; https://doi.org/10.3390/w15061250 - 22 Mar 2023

Cited by 1 | Viewed by 1521

Abstract

Quantitatively analyzing models’ uncertainty is essential for agricultural models due to the effect of inputs parameters and processes on increasing models’ uncertainties. The main aim of the current study was to explore the influence of input parameter uncertainty on the output of the [...] Read more.

Quantitatively analyzing models’ uncertainty is essential for agricultural models due to the effect of inputs parameters and processes on increasing models’ uncertainties. The main aim of the current study was to explore the influence of input parameter uncertainty on the output of the well-known surface irrigation software model of WinSRFR. The generalized likelihood uncertainty estimation (GLUE) framework was used to explicitly evaluate the uncertainty model of WinSRFR. The epistemic uncertainties of WinSRFR furrow irrigation simulations, including the advance front curve, flow depth hydrograph, and runoff hydrograph, were assessed in response to change key input parameters related to the Kostiakov–Lewis infiltration function, Manning’s roughness coefficient, and the geometry cross section. Three likelihood measures of Nash–Sutcliffe efficiency (NSE), percentage bias (PBIAS), and the coefficient of determination (R²) were used in GLUE analysis for selecting behavioral estimations of the model outputs. The uncertainty of the WinSRFR model was investigated under two furrow irrigation system conditions, closed end and open end. The results showed the likelihood measures considerably influence the width of uncertainty bounds. WinSRFR outputs have high uncertainty for cross section parameters relative to soil infiltration and roughness parameters. Parameters of soil infiltration and roughness coefficient play an important role in reducing the uncertainty bound width and number of observations, especially by filtering non-behavioral data using likelihood measures. The simulation errors of advance front curve and runoff hydrograph outputs with a PBIAS function were relatively lower and stable compared with other those of the likelihood functions. The 95% prediction uncertainties (95PPU) of the advance front curve were calculated to be 87.5% in both close-ended and open-ended conditions whereas, it was 91.18% for the runoff hydrograph in the open-ended condition. Additionally, the NSE likelihood function more explicitly determined the uncertainty related to flow depth hydrograph estimations. The outputs of the model showed more uncertainty and instability in response to variability in soil infiltration parameters than the roughness coefficient did. Therefore, applying accurate field methods and equipment and proper measurements of soil infiltration is recommended. The results highlight the importance of accurately monitoring and determining model input parameters to access a suitable level of WinSRFR uncertainty. In conclusion, considering and analyzing the uncertainty of input parameters of WinSRFR models is critical and could provide a reference to obtain realistic and stable furrow irrigation simulations. Full article

(This article belongs to the Special Issue Artificial Intelligence, Machine Learning and Digital Innovation in Water Management)

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18 pages, 3472 KiB

Open AccessReview

Physicochemical Technique in Municipal Solid Waste (MSW) Landfill Leachate Remediation: A Review

by Hamidi Abdul Aziz, Siti Fatihah Ramli and Yung-Tse Hung

Water 2023, 15(6), 1249; https://doi.org/10.3390/w15061249 - 22 Mar 2023

Cited by 4 | Viewed by 2441

Abstract

Leachate generation is among the main challenging issues that landfill operators must handle. Leachate is created when decomposed materials and rainwater pass through the waste. Leachate carries many harmful pollutants, with high concentrations of BOD, COD, colour, heavy metals, ammoniacal nitrogen (NH₃ [...] Read more.

Leachate generation is among the main challenging issues that landfill operators must handle. Leachate is created when decomposed materials and rainwater pass through the waste. Leachate carries many harmful pollutants, with high concentrations of BOD, COD, colour, heavy metals, ammoniacal nitrogen (NH₃-N), and other organic and inorganic pollutants. Among them, COD, colour, and NH₃-N are difficult to be completely eliminated, especially with a single treatment. They should be handled by appropriate treatment facilities before being safely released into the environment. Leachate remediation varies based on its properties, the costs of operation and capital expenditures, as well as the rules and regulations. Up until now, much scientific and engineering attention was given to the development of comprehensive solutions to leachate-related issues. The solutions normally demand a multi-stage treatment, commonly in the form of biological, chemical, and physical sequences. This review paper discussed the use of contemporary techniques to remediate landfill leachate with an emphasis on concentrated COD, colour, and NH₃-N levels with low biodegradability that is normally present in old landfill or dumping grounds in developing countries. A semi-aerobic type of landfill design was also discussed, as this concept is potentially sustainable compared to others. Some of the challenges and future prospects were also recommended, especially for the case of Malaysia. This may represent landfills or dumpsites in other developing countries with the same characteristics. Full article

(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment III)

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19 pages, 6623 KiB

Open AccessArticle

A Field Experiment for Tracing Lateral Subsurface Flow in a Post-Glacial Hummocky Arable Soil Landscape

by Annelie Ehrhardt, Sylvia Koszinski and Horst H. Gerke

Water 2023, 15(6), 1248; https://doi.org/10.3390/w15061248 - 22 Mar 2023

Cited by 1 | Viewed by 1416

Abstract

Lateral subsurface flow (LSF) is a phenomenon that is widely occurring including the hummocky ground moraine landscape. Due to the heterogeneous structure of the subsurface, transport times of pesticides and nutrients from agricultural areas to adjacent water bodies are difficult to assess. Here, [...] Read more.

Lateral subsurface flow (LSF) is a phenomenon that is widely occurring including the hummocky ground moraine landscape. Due to the heterogeneous structure of the subsurface, transport times of pesticides and nutrients from agricultural areas to adjacent water bodies are difficult to assess. Here, LSF at Luvisol and Regosol plots of an experimental field were studied by applying potassium bromide along a 10 m trench below the plow pan in October 2019. The soil solution was collected in suction cups 3 m downslope of the trench and in April 2021, the soil was sampled down to 1 m depth. Almost no bromide was found in the soil solution except for the 160 cm depth of the Regosol plot after a 541 day period. After the same time, bromide was observed in the 90 cm soil depth directly underneath the application trench of the Luvisol plot. A 3D reconstruction of the subsurface horizon boundaries of the Regosol revealed subsurface heterogeneities such as sand lenses that might have been attributed to the heterogeneous subsurface flow pattern. Full article

(This article belongs to the Special Issue Identification and Quantification of Water Flow and Solute Transport Processes in Agricultural, Natural and Artificial Hillslopes)

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21 pages, 12983 KiB

Open AccessArticle

Slowing Down Quick Runoff—A New Approach for the Delineation and Assessment of Critical Points, Contributing Areas, and Proposals of Measures to Reduce Non-Point Water Pollution from Agricultural Land

by Tomáš Kvítek, Antonín Zajíček, Tomáš Dostál, Petr Fučík, Josef Krása, Miroslav Bauer, Barbora Jáchymová, Zbyněk Kulhavý and Martin Pavel

Water 2023, 15(6), 1247; https://doi.org/10.3390/w15061247 - 22 Mar 2023

Cited by 1 | Viewed by 1838

Abstract

Non-point sources of water pollution caused by agricultural crop production are a serious problem in Czechia, at present. This paper describes a new approach for the mutual delineation and assessment of different pollution sources where the critical points method is used to identify [...] Read more.

Non-point sources of water pollution caused by agricultural crop production are a serious problem in Czechia, at present. This paper describes a new approach for the mutual delineation and assessment of different pollution sources where the critical points method is used to identify the origin of contamination and the source areas. The critical points, i.e., sites presenting the entry of quick surface and drainage runoff into waters, are classified into three (for surface pollution sources using a WaTEM/SEDEM model) or four (subsurface = drainage sources via the catchment-measures need index) categories, respectively. This enabled us to prioritize the most endangered areas at different scales, ranging from the third-order catchments to very small subcatchments, and to design the appropriate combination of control measures to mitigate surface and drainage water runoff, with these being the main drivers of associated pollution. This methodology was applied to a study conducted in the Czech Republic within the entire Vltava River basin, with a total area of 27,578 km², and utilized in depth to assess a 543 km² catchment of the Vlašimská Blanice River. When the effect of the designed surface runoff control measures system had been assessed for sediment transport through outlet profiles of the fourth-order catchments, the average reduction reached 43%. The total reduction in the subsurface transport of nitrogen within the fourth-order catchments was 24%. The approach and results are planned to be projected into river basin management plans for the Vltava River basin. Nevertheless, a thorough reassessment of current legislations and strategies is needed to enable the broader adoption of mitigation measures and sustainable management patterns within agricultural landscapes. Full article

(This article belongs to the Section Water Quality and Contamination)

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10 pages, 1410 KiB

Open AccessArticle

Revealing the Gene Diversity and Candidate Gene Family for Adaption to Environment Depth in Leucosiid Crabs Comparing the Transcriptome Assembly

by Yi-Jia Shih, Yin-Ming Yang, Si-Te Luo and Jia-Ying Liu

Water 2023, 15(6), 1246; https://doi.org/10.3390/w15061246 - 22 Mar 2023

Cited by 1 | Viewed by 1343

Abstract

The study of gene diversity in interspecies contributes to our understanding of the environmental adaptation, evolutionary history, origin, and stability of biodiversity. Crabs are the main component of the macrobenthos community; therefore, how crabs adapt to different environments can be a guide to [...] Read more.

The study of gene diversity in interspecies contributes to our understanding of the environmental adaptation, evolutionary history, origin, and stability of biodiversity. Crabs are the main component of the macrobenthos community; therefore, how crabs adapt to different environments can be a guide to understand how to maintain community diversity. Previous studies on environmental adaptation have focused on differences in morphology, organ structure, and function, but there is a lack of research that explores this topic from the perspective of gene diversity in benthonic crabs. In this study, the leucosiid crab was selected for transcriptome assembly and was analyzed as this superfamily is one of the main clades in brachyuran crabs. Their transcriptome data were used to understand the gene diversity, phylogeny, and divergence time estimations. Subsequently, candidate gene families for depth adaptation were found in eight species that live in habitats with different depths. The results indicated that the number of total unigene sequences was between 65,617 (Philyra malefactrix) and 98,279 (Arcania heptacantha) in eight species. The total length of the genes was counted to be between 48,006,211 and 95,471,088 bp. The age of the superfamily Leucosioidea is over 150 Ma, dating back to at least the Jurassic geological period. The divergence of the family Leucosiidae would have occurred in the middle Cretaceous (around 100 Ma). After dividing into groups of three depth types, which carried the gene families, it was found that the three groups shared the solute carrier family, whereas bile acid secretion, organic solute transporter subunit alpha-like, and solute carrier organic anion transporter families only existed in the shallow group. This result shown that the gene function of ion concentration regulation might one of the candidate gene families related to the environmental adaptation of the leucosiid crab. Hence, these gene families will be analyzed in future studies to understand the mechanism of depth adaptation regulation in crabs. Full article

(This article belongs to the Special Issue Analysis of Sustainable Water Resources and Integrated Watershed Management)

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17 pages, 3589 KiB

Open AccessArticle

Analysis of the Driving Mechanism of Water Environment Evolution and Algal Bloom Warning Signals in Tai Lake

by Cuicui Li and Wenliang Wu

Water 2023, 15(6), 1245; https://doi.org/10.3390/w15061245 - 22 Mar 2023

Cited by 2 | Viewed by 1680

Abstract

Understanding the evolution characteristics and driving mechanisms of eutrophic lake ecosystems, especially over long time scales, remains a challenge. Little research on lake ecosystem mutation has been conducted using long-term time series data. In this study, long-term water quality indicators, as well as [...] Read more.

Understanding the evolution characteristics and driving mechanisms of eutrophic lake ecosystems, especially over long time scales, remains a challenge. Little research on lake ecosystem mutation has been conducted using long-term time series data. In this study, long-term water quality indicators, as well as ecological indexes, natural meteorological factors, and socio-economic indexes, were collected for Tai Lake to enable us to study the environmental evolution of the lake ecosystem. The key time nodes and early warning signals of the steady-state transformation of Tai Lake were also identified, which could provide a theoretical basis for early indication of the transformation of lake ecosystems. Furthermore, the characteristics and driving mechanism of the lake’s ecosystem evolution were analyzed based on the physical and chemical indexes of its sediments and its long-term water quality indexes. The results show that the early warning signals (variance, autocorrelation, and skewness) of ecosystem mutation included abnormal changes 10 years before the steady-state change, and the evolution of Tai Lake was driven by the complex nonlinear effects of biological, physical, chemical, and socio-economic factors in the lake basin. These results have important theoretical and practical value for pollution control and the management of eutrophic lakes. Full article

(This article belongs to the Special Issue Water Environment Pollution and Control)

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24 pages, 10670 KiB

Open AccessReview

Geo-Environmental Models of In-Situ Leaching Sandstone-Type Uranium Deposits in North China: A Review and Perspective

by Fuxin Zheng, Yanguo Teng, Yuanzheng Zhai, Jingdan Hu, Junfeng Dou and Rui Zuo

Water 2023, 15(6), 1244; https://doi.org/10.3390/w15061244 - 22 Mar 2023

Cited by 3 | Viewed by 2672

Abstract

Since the 1990s, sandstone-type uranium in the northern basin of China has become the main target for mining. Uranium mining can cause a series of impacts on the environment. A conceptual model of the geo-environment for sandstone-type uranium in northern China was described, [...] Read more.

Since the 1990s, sandstone-type uranium in the northern basin of China has become the main target for mining. Uranium mining can cause a series of impacts on the environment. A conceptual model of the geo-environment for sandstone-type uranium in northern China was described, which covers the changes in the geo-environmental characteristics in the natural state, in the mining process, during decommissioning and after treatment. Sandstone-type uranium is mainly distributed in the Songliao, Erlian, Ordos, Turpan–Hami and Ili Basins, which have arid climates and poor stratum permeability. Pitchblende is the main uranium-bearing mineral and is associated with iron, copper, coal, organic matter and other minerals. The mineral often has a low ore grade (0.01–1.0%) and high carbonate content (2–25%). Uranyl carbonate accounts for more than 90% of the total uranium in groundwater. The uranyl content is closely related to the TDS. The TDS of groundwater in the eastern and central ore belts is usually lower than 2 g/L, while in the western region, such as Xinjiang, it can exceed 10 g/L. In situ leaching (ISL) is the main mining method that results in groundwater pollution. Acid leaching leads to a pH decrease (<3), and heavy metals represented by U and Fe exceed the background values by hundreds of times, resulting in groundwater pollution. CO₂ leaching is more environmentally friendly, and the excess ions are usually Ca²⁺, Mg²⁺, NO₃⁻ and HCO₃⁻. Soil chemical anomalies originate mostly from wind erosion and precipitation leaching of decommissioned tailings. Uranium pollution is mainly concentrated within 20 cm of the surface, and the exceedance generally varies from two to 40 times. During ISL, a series of environmental measures will be taken to prevent pollution from being exposed to the surface. After treatment, the decommissioned uranium mines will likely have no impact on the surrounding environment. In the future, the protection of groundwater should be strengthened during production, and remediation methods based on electrokinetic, microbial and permeable reactive barrier (PRB) technology should be further researched. Full article

(This article belongs to the Special Issue River Ecological Restoration and Groundwater Artificial Recharge II)

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20 pages, 4484 KiB

Open AccessArticle

Spatial and Multivariate Statistical Analyses of Human Health Risk Associated with the Consumption of Heavy Metals in Groundwater of Monterrey Metropolitan Area, Mexico

by Edrick Ramos, Raja Karim Bux, Dora Ileana Medina, Héctor Barrios-Piña and Jürgen Mahlknecht

Water 2023, 15(6), 1243; https://doi.org/10.3390/w15061243 - 22 Mar 2023

Cited by 6 | Viewed by 1757

Abstract

Groundwater is the main source of drinking water supply in most urban environments around the world. The content of potentially toxic elements is increasing in many groundwater systems owing to inadequate groundwater recharge, aquifer overexploitation, natural source release, or various anthropogenic activities that [...] Read more.

Groundwater is the main source of drinking water supply in most urban environments around the world. The content of potentially toxic elements is increasing in many groundwater systems owing to inadequate groundwater recharge, aquifer overexploitation, natural source release, or various anthropogenic activities that lead to groundwater quality degradation. The ingestion of groundwater contaminated with potentially toxic elements has been reported to have harmful health effects. This study aimed to assess the presence of several potentially toxic elements (Al, As, B, Cr, Cu, Fe, Mn, and Zn) in groundwater of the Monterrey metropolitan area in Northern Mexico and the carcinogenic and noncarcinogenic human health risks associated with exposure. Multivariate statistics and geospatial analysis were applied to identify the causative determinants that modify the groundwater quality along the metropolitan area. Mean concentrations of trace metals remained below drinking water standards and World Health Organization guidelines. The risk of harmful effects on human health due to ingestion of all eight metal(loid)s in groundwater was assessed as 2.52 × 10⁻² for adults and 2.16 × 10⁻² for children, which can be considered as negligible chronic risk and a very low cancer risk. However, the risks of oral consumption of Cr being carcinogenic to children and adults were 7.9 × 10⁻³ and 9.2 × 10⁻⁴, respectively. As these values exceeded the target risk of 1 × 10⁻⁴, it can thus be considered “unacceptable”. Full article

(This article belongs to the Topic Health Risk Assessment of the Trace and Macro Elements)

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23 pages, 15699 KiB

Open AccessArticle

Evidence for Groundwater Salinity Origin Based on Hydrogeochemical and Isotopic (²H, ¹⁸O, ³⁷Cl, ³H, ¹³C, ¹⁴C) Approaches: Sousse, Eastern Tunisia

by Farah Nefzaoui, Mohamed Fethi Ben Hamouda, Paula Maria Carreira, José Manuel Marques and Hans G. M. Eggenkamp

Water 2023, 15(6), 1242; https://doi.org/10.3390/w15061242 - 22 Mar 2023

Cited by 1 | Viewed by 2126

Abstract

The key processes responsible for the rise in groundwater salinization in the Mio–Pliocene aquifer system of Sousse (Tunisia, eastern coastline) were identified through a multidisciplinary approach based on the use of geochemical, stable (²H, ¹³C, ¹⁸O and ³⁷Cl) [...] Read more.

The key processes responsible for the rise in groundwater salinization in the Mio–Pliocene aquifer system of Sousse (Tunisia, eastern coastline) were identified through a multidisciplinary approach based on the use of geochemical, stable (²H, ¹³C, ¹⁸O and ³⁷Cl) and radioactive (³H and ¹⁴C) isotope methods. In the study region, the mineralization of groundwaters is related to water–rock interaction ascribed to the dissolution of minerals in evaporite rocks, as well as to saltwater intrusion. Both processes explain the development of groundwaters in which Cl and Na dominantly determine the groundwater quality deterioration state. The isotopic and geochemical signatures of the studied groundwaters are clearly explained by the (i) occurrence of saline basins (sebkhas adjacent to the study region), (ii) type of rocks found below the ground surface, and (iii) cation exchange between clays and groundwaters. Full article

(This article belongs to the Section Hydrogeology)

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20 pages, 2855 KiB

Open AccessArticle

Multi-Actor Systems in Water–Energy Nexus: Identifying Critical Stakeholders in Floatovoltaic (Floating Photovoltaic) Project

by Corinthias P. M. Sianipar, Yi-Meng Chao and Satoshi Hoshino

Water 2023, 15(6), 1241; https://doi.org/10.3390/w15061241 - 22 Mar 2023

Cited by 3 | Viewed by 2267

Abstract

The intrinsic relation between water and energy has made the water–energy nexus a burgeoning issue in the discussion of sustainable development. Recently, research has begun to pay attention to stakeholders in the nexus. They, however, identified stakeholders as a given without employing methodically [...] Read more.

The intrinsic relation between water and energy has made the water–energy nexus a burgeoning issue in the discussion of sustainable development. Recently, research has begun to pay attention to stakeholders in the nexus. They, however, identified stakeholders as a given without employing methodically scientific processes with rigorous parameters. Filling in the gap, this study presents a heuristic approach to identifying critical stakeholders of multi-actor systems in the water–energy nexus. It involves three sources of influence (social roles, specific concerns, and key problems) along with four other boundary issues (motivation, control, knowledge, legitimacy), forming a matrix of the boundary categories of Critical Systems Heuristics (CSH). This study applied the heuristic analysis to the project of floating photovoltaics installed in a pond in Hyogo, Japan, as the case study. It is a unique case of the water–energy nexus since the location of the floatovoltaic installation is a privately owned pond that is also part of the public landscape and an irrigation source for the surrounding agricultural areas. The results identified two macrogroups of stakeholders (residents and project developers) driven by general interests in the project. They were derivable as overlapping micro-actors interested in more specific issues related to different facets of the project. Overall, conflicting interests in the multi-actor systems indicated deadlocked interactions due to a multidirectional tug-of-war between the microgroups of actors. Conceptually, this study significantly contributes to the literature on the water–energy nexus and stakeholder management. Practically, the approach used offers scientific processes to understand the multi-actor systems and conflicting interests involved in/affected by the nexus, paving the way for more comprehensive resolution processes of water–energy conflicts. Full article

(This article belongs to the Special Issue Feature Papers of Water-Energy Nexus)

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17 pages, 3081 KiB

Open AccessArticle

The Impact of Organic and Intensive Agricultural Activity on Groundwater and Surface Water Quality

by Laima Česonienė, Daiva Šileikienė, Laura Čiteikė, Gintautas Mozgeris and Koike Takayoshi

Water 2023, 15(6), 1240; https://doi.org/10.3390/w15061240 - 22 Mar 2023

Viewed by 1860

Abstract

The poor condition of surface water is still a problem in many countries, including Lithuania. To assess the impact of organic agricultural production on groundwater and surface water quality in Lithuania, surface water samples from rivers and other bodies of water are usually [...] Read more.

The poor condition of surface water is still a problem in many countries, including Lithuania. To assess the impact of organic agricultural production on groundwater and surface water quality in Lithuania, surface water samples from rivers and other bodies of water are usually studied, leaving the properties of groundwater in agricultural fields unknown. Samples of river water and groundwater collected from both organic and intensive farming fields bordering the studied rivers were investigated in this study. The study was conducted on five rivers located in the Nemunas River Basin District and in 23 cultivated neighboring fields, where wells were drilled 4–5 m deep for groundwater sampling. All five rivers corresponded to the values of good and very good in terms of their ecological status, according to the values of PO₄-P and NH₄-N. According to the total P value, one river did not correspond to the values of good or very good ecological status. According to the total N value, four rivers did not meet the values of good or very good ecological status. We found that, with the exception of one farm, the pH, total P, total N, and NO₃-N, as well as the concentrations of NH₄-N and PO₄-P, in the groundwater from organic farms were lower compared to the groundwater from intensive farming areas. This suggests the importance of ground water sampling in addition to surface water surveys in water quality studies related to agricultural production. Full article

(This article belongs to the Section Water Quality and Contamination)

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17 pages, 4729 KiB

Open AccessArticle

Energy Balance, Water Demand, and Crop Coefficient of Acid Lime in the Oriental Amazon

by Alberto Cruz da Silva Junior, Paulo Jorge de Oliveira Ponte de Souza, Denis de Pinho Sousa, Lucieta Guerreiro Martorano, Carina Melo da Silva, Carolina Melo da Silva, Hildo Giuseppe Garcia Caldas Nunes, Marcus José Alves de Lima, Adriano Marlisom Leão de Sousa, João Vitor de Nóvoa Pinto, Maria de Lourdes Pinheiro Ruivo, José Darlon Nascimento Alves and Heráclito Eugênio Oliveira da Conceição

Water 2023, 15(6), 1239; https://doi.org/10.3390/w15061239 - 22 Mar 2023

Cited by 2 | Viewed by 1648

Abstract

Energy and water dynamics are crucial for citrus development in the Eastern Amazon. This study aimed to determine the energy balance, water demand, and crop coefficient of acid lime in the northeast region of Pará. A micrometeorological tower was installed in the center [...] Read more.

Energy and water dynamics are crucial for citrus development in the Eastern Amazon. This study aimed to determine the energy balance, water demand, and crop coefficient of acid lime in the northeast region of Pará. A micrometeorological tower was installed in the center of the experimental area to monitor meteorological variables between October 2020 and December 2021. The energy balance and water demand were obtained by the Bowen ratio method. Kc was determined by the ratio between crop and reference evapotranspiration. The results obtained indicate that 63% of the available energy was used by latent heat in the rainiest period, while 60% was used during the less rainy period. Sensible heat used 32% and 34% during the most and least rainy periods, respectively. Soil heat presented a low variation, with an average of 5% for the entire period. Water consumption of the acid lime during the experiment was 1599 mm, with a daily mean of 3.70 mm day⁻¹, while the mean value of Kc was 1.4. These results allow for the design of adequate water supply protocols for the crop in the main citrus pole in the Amazon region. Full article

(This article belongs to the Section Water, Agriculture and Aquaculture)

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15 pages, 4227 KiB

Open AccessArticle

Photocatalytic Degradation of Organic Dyes from Clinical Laboratory Wastewater

by J. H. Ramírez Franco, S. D. Castañeda Cárdenas and H. R. Zea Ramírez

Water 2023, 15(6), 1238; https://doi.org/10.3390/w15061238 - 22 Mar 2023

Viewed by 1706

Abstract

Clinical laboratory wastewaters are of important environmental concern due to the highly complex chemical reagents and dyes used to identify various pathologies, which are difficult to degrade by conventional treatment methods. The present research aimed to assess the effects of ilmenite use in [...] Read more.

Clinical laboratory wastewaters are of important environmental concern due to the highly complex chemical reagents and dyes used to identify various pathologies, which are difficult to degrade by conventional treatment methods. The present research aimed to assess the effects of ilmenite use in the discoloration process of clinical laboratory wastewater. The wastewater originates from a Gram staining process used to identify pathogenic microorganisms present in biological samples. The active ingredient is crystal violet, a triphenylmethane dye derivative, highly toxic and non-biodegradable that causes a shiny purple color in the wastewater. The ilmenite was characterized by X-ray Fluorescence, X-ray Diffraction, Scanning Electron Microscopy, energy-dispersive spectroscopy and Nitrogen adsorption isotherm, while the discoloration process of the wastewater was measured by UV–Vis spectrophotometry and pH change trough the reaction time, evaluating different ilmenite loads, particle size and stability under light sources with different energies. Chemical oxygen demand analysis confirmed that acid formation and discoloration were associated with organic substance mineralization. Type C ultraviolet light and 0.7 g/L load were identified as the best operating conditions for the discoloration process. It was possible to establish that ilmenite is stable after four uses in the discoloration process, obtaining, in all cases, discoloration percentages higher than 90% after 3 h of irradiation. Full article

(This article belongs to the Special Issue Novel Insights on Wastewater Treatment Processes for Sustainable Removal of Emerging Contaminants)

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20 pages, 9026 KiB

Open AccessArticle

Defining Heat in Place for the Discovered Geothermal Brine Reservoirs in the Croatian Part of Pannonian Basin

by Martina Tuschl and Tomislav Kurevija

Water 2023, 15(6), 1237; https://doi.org/10.3390/w15061237 - 22 Mar 2023

Cited by 1 | Viewed by 1932

Abstract

One of the important sources of renewable energy is geothermal heat. Its special feature of being independent 24/7 ensures the stability and security of the system, either for electricity or heat production. Geothermal energy has a local character and is limited by the [...] Read more.

One of the important sources of renewable energy is geothermal heat. Its special feature of being independent 24/7 ensures the stability and security of the system, either for electricity or heat production. Geothermal energy has a local character and is limited by the geological characteristics of each state. In the Republic of Croatia, the development of geothermal energy is closely related to the development of the oil industry, as geothermal deposits were discovered during oil and gas exploration. Considering the established temperature gradients in Croatia, there is a greater possibility of using geothermal energy, and for this, it is necessary to evaluate its full potential and possibilities of use. The aim of this research is to determine the heat potential of the Croatian part of the Pannonian Basin System (CPBS), a part of Croatia with exceptional geothermal potential, based on the analysis of a large amount of well data with confirmed water inflow. In order to estimate the heat in place, the available data on the presence of inflow, temperature, and porosity, as well as permeability and volume for each well/reservoir included in the assessment, were considered. In geothermal reservoirs, one of the most important pieces of data besides petrophysical and thermodynamic data is the potential of the well, i.e., the maximum flow under certain permeability and porosity conditions. To define this, the productivity index was made dependent on the permeability of each well, and the inflow in each well was risked using Monte Carlo for three main geological phases in CPBS, which subsequently influenced inflow and spacing between production and injection wells. The beta-PERT distribution for permeability is used in Monte Carlo simulation to determine the most likely values and produce a distribution that resembles the real probability distribution. As a result, geothermal potential was mapped according to the obtained values of heat in place for part of the CPBS covered with analysed wells. Full article

(This article belongs to the Special Issue Sustainable Development of Water, Energy, and Environment Systems)

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24 pages, 6532 KiB

Open AccessArticle

Improving Groundwater Imputation through Iterative Refinement Using Spatial and Temporal Correlations from In Situ Data with Machine Learning

by Saul G. Ramirez, Gustavious Paul Williams, Norman L. Jones, Daniel P. Ames and Jani Radebaugh

Water 2023, 15(6), 1236; https://doi.org/10.3390/w15061236 - 22 Mar 2023

Cited by 1 | Viewed by 1553

Abstract

Obtaining and managing groundwater data is difficult as it is common for time series datasets representing groundwater levels at wells to have large gaps of missing data. To address this issue, many methods have been developed to infill or impute the missing data. [...] Read more.

Obtaining and managing groundwater data is difficult as it is common for time series datasets representing groundwater levels at wells to have large gaps of missing data. To address this issue, many methods have been developed to infill or impute the missing data. We present a method for improving data imputation through an iterative refinement model (IRM) machine learning framework that works on any aquifer dataset where each well has a complete record that can be a mixture of measured and input values. This approach corrects the imputed values by using both in situ observations and imputed values from nearby wells. We relied on the idea that similar wells that experience a similar environment (e.g., climate and pumping patterns) exhibit similar changes in groundwater levels. Based on this idea, we revisited the data from every well in the aquifer and “re-imputed” the missing values (i.e., values that had been previously imputed) using both in situ and imputed data from similar, nearby wells. We repeated this process for a predetermined number of iterations—updating the well values synchronously. Using IRM in conjuncture with satellite-based imputation provided better imputation and generated data that could provide valuable insight into aquifer behavior, even when limited or no data were available at individual wells. We applied our method to the Beryl-Enterprise aquifer in Utah, where many wells had large data gaps. We found patterns related to agricultural drawdown and long-term drying, as well as potential evidence for multiple previously unknown aquifers. Full article

(This article belongs to the Section Hydrogeology)

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14 pages, 1443 KiB

Open AccessArticle

The Hydraulic Connection Analysis of Dongying Geothermal Fluid Using Hydrochemical Information and Isotope Data in Tianjin Coastal Regions

by Jiulong Liu, Shuangbao Han, Fengtian Yang and Dongdong Yue

Water 2023, 15(6), 1235; https://doi.org/10.3390/w15061235 - 22 Mar 2023

Cited by 3 | Viewed by 1673

Abstract

Dongying’s Paleogene geothermal resources are an important part of the geothermal resources of the Tianjin coastal region. The extent of the geothermal fluid resources and the supply relationship have become increasingly important, and will determine whether demand targets can be met. Dongying’s Paleogene [...] Read more.

Dongying’s Paleogene geothermal resources are an important part of the geothermal resources of the Tianjin coastal region. The extent of the geothermal fluid resources and the supply relationship have become increasingly important, and will determine whether demand targets can be met. Dongying’s Paleogene formation in the Tianjin coastal regions is widely distributed to the east of the Cangdong fracture, but it is absent west of the Cangdong fracture. On the basis of introducing the geological characteristics and depositional characteristics of the Dongying formation, we analyzed the hydraulic conductivity of the Cangdong fracture to the Dongying formation geothermal reservoir from the aspects of geological condition, dynamic of groundwater level and hydrologic geochemistry. Based on the hydrochemical information and the isotope data gained during the water quality evaluation and isotope data analysis process, we discovered the main chemical composition, hydrogen and oxygen isotope data and geothermal fluid age are significantly different between the Dongying formation geothermal reservoir and the overlying and underlying geothermal reservoirs. It is inferred that the hydraulic conductivity of the Cangdong fracture to the Dongying formation geothermal reservoir in this area is weak, and along the Haihe fracture, where the Haihe fracture intersects with the Cangdong fracture, there is a certain hydraulic conductivity. In addition, there is no obvious hydraulic connection between the Dongying formation and the upper and lower geothermal reservoirs. Full article

(This article belongs to the Special Issue Hydrochemistry and Isotopes in Groundwater Investigations)

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21 pages, 3021 KiB

Open AccessReview

Reviews and Syntheses: Promoting the Advancement of Hillslope Hydrology and Stability in Taiwan from the Perspective of Critical Zone Science

by Ya-Sin Yang, Hsin-Fu Yeh, Chia-Chi Huang and Hsin-Yu Chen

Water 2023, 15(6), 1234; https://doi.org/10.3390/w15061234 - 21 Mar 2023

Viewed by 2211

Abstract

Owing to active orogenic movement and the monsoon climate, rainfall-induced landslide disasters often occur in Taiwan. Hence, hillslope hydrology and stability have received considerable research attention. However, it remains difficult to accurately estimate the duration and consequences of hillslope instability induced by hillslope [...] Read more.

Owing to active orogenic movement and the monsoon climate, rainfall-induced landslide disasters often occur in Taiwan. Hence, hillslope hydrology and stability have received considerable research attention. However, it remains difficult to accurately estimate the duration and consequences of hillslope instability induced by hillslope hydrology. Research on hillslope hydrology and stability is complicated by spatial heterogeneity, hydrological processes operating at various scales, spatiotemporal evolution, and geomorphological properties. Recent advances in critical zone science have provided an approach to extend geoscience studies. The “deep coupling” concept is essential for integrating physical, chemical, and biological processes on various spatiotemporal scales and for providing a macro and unified framework for evaluating internal properties and processes. Critical zone science and hillslope hydrology and stability both depend on interdisciplinary perspectives and approaches, monitoring strategies, and model analysis of integrating and coupling processes. They both share the characteristics of spatial heterogeneity, continuous evolution, and relevance to ecosystem services. To address the challenges related to hillslope hydrology and stability in Taiwan, we reviewed the progress in, relevance between, and common challenges to hillslope hydrology, stability, and critical zone science. We then presented a process-based integrated monitoring strategy, an interdisciplinary perspective, and a coupling analysis framework and model. The aim of this study was to promote the advancement of research on hillslope stability and hydrology in Taiwan. Full article

(This article belongs to the Section Hydrology)

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32 pages, 7529 KiB

Open AccessArticle

Downscaling and Merging of Daily Scale Satellite Precipitation Data in the Three River Headwaters Region Fused with Cloud Attributes and Rain Gauge Data

by Chi Xu, Chuanqi Liu, Wanchang Zhang, Zhenghao Li and Bangsheng An

Water 2023, 15(6), 1233; https://doi.org/10.3390/w15061233 - 21 Mar 2023

Cited by 1 | Viewed by 2312

Abstract

Complex terrain, the sparse distribution of rain gauges, and the poor resolution and quality of satellite data in remote areas severely restrict the development of watershed hydrological modeling, meteorology, and ecological research. In this study, based on the relationship between cloud optical and [...] Read more.

Complex terrain, the sparse distribution of rain gauges, and the poor resolution and quality of satellite data in remote areas severely restrict the development of watershed hydrological modeling, meteorology, and ecological research. In this study, based on the relationship between cloud optical and physical properties and precipitation, a daily geographically weighted regression (GWR) precipitation downscaling model was constructed for the Three Rivers Source region, China, for the period from 2010 to 2014. The GWR precipitation downscaling model combined three different satellite precipitation datasets (CMORPH, IMERG, and ERA5) which were downscaled from a coarse resolution (0.25° and 0.1°) to a fine resolution (1 km). At the same time, the preliminary downscaling results were calibrated and verified by employing the geographic difference analysis (GDA) and geographic ratio analysis (GRA) methods combined with rainfall data. Finally, the analytical hierarchy process (AHP) and the entropy weight method (EW) were adopted to fuse the three downscaled and calibrated satellite precipitation datasets into the merged satellite precipitation dataset (MSP), which provides a higher quality of data (CC = 0.790, RMSE = 2.189 mm/day, and BIAS = 0.142 mm). In summary, the downscaling calibration and precipitation fusion scheme proposed in this study is suitable for obtaining high-resolution daily precipitation data in the Three Rivers Source region with a complex climate and topography. Full article

(This article belongs to the Special Issue Machine Learning Applications in Hydrology: Current Trends and Future Challenges)

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12 pages, 2441 KiB

Open AccessArticle

Decreased Efficiency of Free Naked DNA Transformation by Chlorine and UV Disinfection and Its Detection Limitations

by Chi Zhang, Hanchen Miao, Zhongfang Lei, Tian Yuan, Zhenya Zhang, Ikko Ihara, Hideaki Maseda and Kazuya Shimizu

Water 2023, 15(6), 1232; https://doi.org/10.3390/w15061232 - 21 Mar 2023

Cited by 1 | Viewed by 1905

Abstract

Antibiotic resistance genes can be spread via gene horizontal transfer (GHT). Chlorination and UV irradiation are common disinfection methods used in wastewater treatment plants before the discharge of treated wastewater. This study aimed to elucidate the effects of disinfection on the transformation of [...] Read more.

Antibiotic resistance genes can be spread via gene horizontal transfer (GHT). Chlorination and UV irradiation are common disinfection methods used in wastewater treatment plants before the discharge of treated wastewater. This study aimed to elucidate the effects of disinfection on the transformation of naked DNA in the aquatic environment. The pUC19 plasmid possessing ampicillin-resistant beta-lactamase and subjected to different dosages of chlorine or UV irradiation was used for transformation in Escherichia coli to estimate the transformation efficiency and GHT in the environment after disinfection. The results showed that doses > 0.5 mg-Cl₂/L can effectively decrease transformation efficiency (1.21 to 8.83-log₁₀) based on pUC19 as the positive control. UV irradiation can decrease the efficiency (2.37 to 3.39-log₁₀) following 10–60 min of treatment. PCR and qPCR detection have limitations for determining transformation efficiency because they provide approximate estimates damaged DNAs. Overall, these results indicate that proper disinfection management using chlorine and/or UV for treated wastewater before discharge from wastewater treatment plants can prevent the spread of antibiotic resistant bacteria and genes, by decreasing the efficiency of naturally occurring bacterial transformations in wastewater treatment plants. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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14 pages, 1490 KiB

Open AccessArticle

Applying Linear Forms of Pseudo-Second-Order Kinetic Model for Feasibly Identifying Errors in the Initial Periods of Time-Dependent Adsorption Datasets

by Hai Nguyen Tran

Water 2023, 15(6), 1231; https://doi.org/10.3390/w15061231 - 21 Mar 2023

Cited by 15 | Viewed by 5642

Abstract

Initial periods of adsorption kinetics play an important role in estimating the initial adsorption rate and rate constant of an adsorption process. Several adsorption processes rapidly occur, and the experimental data of adsorption kinetics under the initial periods can contain potential errors. The [...] Read more.

Initial periods of adsorption kinetics play an important role in estimating the initial adsorption rate and rate constant of an adsorption process. Several adsorption processes rapidly occur, and the experimental data of adsorption kinetics under the initial periods can contain potential errors. The pseudo-second-order (PSO) kinetic model has been popularly applied in the field of adsorption. The use of the nonlinear optimization method to obtain the parameters of the PSO model can minimize error functions during modelling compared to the linear method. However, the nonlinear method has limitations in that it cannot directly recognize potential errors in the experimental points of time-dependent adsorption, especially under the initial periods. In this study, for the first time, the different linear types (Types 1–6) of the PSO model are applied to discover the error points under the initial periods. Results indicated that the fitting method using its linear equations (Types 2–5) is really helpful for identifying the error (doubtful) experimental points from the initial periods of adsorption kinetics. The imprecise points lead to low adjusted R² (adj-R²), high reduced χ² (red-χ²), and high Bayesian information criterion (BIC) values. After removing these points, the experimental data were adequately fitted with the PSO model. Statistical analyses demonstrated that the nonlinear method must be used for modelling the PSO model because its red-χ² and BIC were lower than the linear method. Type 1 has been extensively applied in the literature because of its very high adj-R² value (0.9999) and its excellent fitting to experimental points. However, its application should be limited because the potential errors from experimental points are not identified by this type. For comparison, the other kinetic models (i.e., pseudo-first-order, pseudo-nth-order, Avrami, and Elovich) are applied. The modelling result using the nonlinear forms of these models indicated that the fault experimental points from the initial periods were not detected in this study. Full article

(This article belongs to the Special Issue Adsorption Technology for Water and Wastewater Treatments)

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14 pages, 2961 KiB

Open AccessArticle

Fixation Effect of Modified Bamboo Charcoal on Typical Heavy Metals in Sediment

by Yizhuo Wang, He Li and Shaohua Lin

Water 2023, 15(6), 1230; https://doi.org/10.3390/w15061230 - 21 Mar 2023

Viewed by 1351

Abstract

In this study, we studied the influence of the dosage of modified bamboo charcoal (KAM-500-400-3) on the fixation effect of single Cu(II)-contaminated and mixed Cu(II)–Cd(II)-contaminated sediment. The results showed that it could effectively fix the heavy metals in both sediment types. In the [...] Read more.

In this study, we studied the influence of the dosage of modified bamboo charcoal (KAM-500-400-3) on the fixation effect of single Cu(II)-contaminated and mixed Cu(II)–Cd(II)-contaminated sediment. The results showed that it could effectively fix the heavy metals in both sediment types. In the single Cu(II)-contaminated sediment, when the amount of added KAM500-400-3 was greater than or equal to 5%, the Cu(II) content in the overlying and pore water was substantially reduced, and the form of heavy metal Cu(II) in the sediment changed from the acid-extractable state to a relatively stable, reducible, oxidizable, and residual state, its bioavailability markedly reduced, and the toxic leaching amount of heavy metal TCLP in the sediment also gradually reduced. In the sediment polluted by Cu(II)–Cd(II), the Cu(II) and Cd(II) could not be detected in the overlying or pore water when the addition amount was greater than or equal to 2.5%. The contents of Cu(II) and Cd(II) in the acid-extractable state considerably decreased and they transformed into other forms with low bioavailability, in which the content of Cd(II) in the oxidizable state was so low that it was lower than the detection limit. The TCLP toxicity of the leached amount of Cd(II) also gradually decreased. This showed that adding KAM500-400-3 to sediment helps with inhibiting the release of heavy metals from contaminated sediment into water bodies, so KAM500-400-3 is a material that can effectively adsorb and fix heavy metals Cu(II) and Cd(II) in sediment. Full article

(This article belongs to the Section Water Erosion and Sediment Transport)

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51 pages, 1590 KiB

Open AccessReview

Review of Experimental Investigations of Dam-Break Flows over Fixed Bottom

by Francesca Aureli, Andrea Maranzoni, Gabriella Petaccia and Sandra Soares-Frazão

Water 2023, 15(6), 1229; https://doi.org/10.3390/w15061229 - 21 Mar 2023

Cited by 8 | Viewed by 2732

Abstract

Laboratory experiments of dam-break flows are extensively used in investigations of geophysical flows involving flood waves, to provide insight into relevant aspects of the physics of the process and collect experimental data for validating numerical models. A dam-break flow is a typical example [...] Read more.

Laboratory experiments of dam-break flows are extensively used in investigations of geophysical flows involving flood waves, to provide insight into relevant aspects of the physics of the process and collect experimental data for validating numerical models. A dam-break flow is a typical example of a highly unsteady free surface flow with high reproducibility. Indeed, dam-break experiments can be repeated several times under the same test conditions obtaining large amounts of different types of data (possibly using various measuring techniques) that can be combined in a single rich dataset. Moreover, laboratory tests on dam-break flows are widely considered a valuable benchmark for the validation of numerical models, since field data from historical events are scarce, sparse, and highly uncertain. However, no systematic review of laboratory investigations of dam-break flows and existing related datasets are available in the literature to provide a comprehensive overview of the test conditions considered, the measuring techniques used, and the experimental data collected. This review article aims to fill this gap, focusing on laboratory tests in schematic and idealized setups with a fixed, non-erodible bed. In particular, this review aims to help researchers and modelers to: (a) select the most appropriate laboratory tests for validating their numerical models; (b) facilitate access to databases by indicating relevant bibliographic references; (c) identify specific challenging aspects worthy of further experimental research; and (d) support the development of new or improved technologies for the mitigation of the impact of dam-break flood waves. The references reviewed are organized into tables according to the purposes of the laboratory investigation, and comprehensive information is provided on test conditions, datasets, and data accessibility. Finally, suggestions for future experimental research on dam-break flows are provided. Full article

(This article belongs to the Special Issue Advances in Dam-Break Modeling for Flood Hazard Mitigation: Theory, Numerical Models, and Applications in Hydraulic Engineering)

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15 pages, 7911 KiB

Open AccessArticle

Photoinhibition of the Picophytoplankter Synechococcus Is Exacerbated by Ocean Acidification

by He Li, John Beardall and Kunshan Gao

Water 2023, 15(6), 1228; https://doi.org/10.3390/w15061228 - 21 Mar 2023

Cited by 1 | Viewed by 1774

Abstract

The marine picocyanobacterium Synechococcus accounts for a major fraction of the primary production across the global oceans. However, knowledge of the responses of Synechococcus to changing pCO₂ and light levels has been scarcely documented. Hence, we grew Synechococcus sp. CB0101 at [...] Read more.

The marine picocyanobacterium Synechococcus accounts for a major fraction of the primary production across the global oceans. However, knowledge of the responses of Synechococcus to changing pCO₂ and light levels has been scarcely documented. Hence, we grew Synechococcus sp. CB0101 at two CO₂ concentrations (ambient CO₂ AC:410 μatm; high CO₂ HC:1000 μatm) under various light levels between 25 and 800 μmol photons m⁻² s⁻¹ for 10–20 generations and found that the growth of Synechococcus strain CB0101 is strongly influenced by light intensity, peaking at 250 μmol m⁻² s⁻¹ and thereafter declined at higher light levels. Synechococcus cells showed a range of acclimation in their photophysiological characteristics, including changes in pigment content, optical absorption cross section, and light harvesting efficiency. Elevated pCO₂ inhibited the growth of cells at light intensities close to or greater than saturation, with inhibition being greater under high light. Elevated pCO₂ also reduced photosynthetic carbon fixation rates under high light but had smaller effects on the decrease in quantum yield and maximum relative electron transport rates observed under increasing light intensity. At the same time, the elevated pCO₂ significantly decreased particulate organic carbon (POC) and particulate organic nitrogen (PON), particularly under low light. Ocean acidification, by increasing the inhibitory effects of high light, may affect the growth and competitiveness of Synechococcus in surface waters in the future scenario. Full article

(This article belongs to the Special Issue The Relationship between Phytoplankton Ecology and Marine Pollution)

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16 pages, 8149 KiB

Open AccessArticle

Total Maximum Daily Load Application Using Biological Oxygen Demand, Chemical Oxygen Demand, and Ammoniacal Nitrogen: A Case Study for Water Quality Assessment in the Perai River Basin, Malaysia

by Siti Multazimah Mohamad Faudzi, Danial Nakhaie Mohd Souhkri, Muhammad Fitri Mohd Akhir, Hamidi Abdul Aziz, Muhammad Zaki Mohd Kasim, Nor Azazi Zakaria and Noor Aida Saad

Water 2023, 15(6), 1227; https://doi.org/10.3390/w15061227 - 21 Mar 2023

Cited by 2 | Viewed by 2382

Abstract

Water shortage has been an issue for urbanized areas. For the Penang state in Malaysia, it is forecast that there will be a significant increase in water demand in the future. Penang authorities in Malaysia are trying to find an alternative water source [...] Read more.

Water shortage has been an issue for urbanized areas. For the Penang state in Malaysia, it is forecast that there will be a significant increase in water demand in the future. Penang authorities in Malaysia are trying to find an alternative water source to overcome the problem, with one of the options being the Perai River catchment. However, the river water quality was found to be polluted and not suitable to be used for water extraction for domestic consumption. This paper aims to study the pollution level variation due to changes in rainfall during the year in the Perai River Basin, and estimate the TMDL of the river in a particular case for BOD, COD, and NH₃N parameters. A water quality model was developed for the Perai River, Jarak River and Kulim River using InfoWorks ICM. The year 2016 was selected as a model event due to data availability. BOD, COD and NH₃N concentrations were used for TMDL calculation, and the load duration curve approach was used to estimate TMDL. The tidal effect at the downstream of the Perai River was found to impact the data analysis in the river stretch. It was found that pollutant load exceedance was the highest during the rainy season and the problematic pollutant was NH₃N. Thus, local authorities need to focus on tidal and seasonal change factors when developing action plans to manage water quality issues in this basin. Full article

(This article belongs to the Special Issue Water Quality Assessment and Modelling)

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12 pages, 1824 KiB

Open AccessArticle

Fate and Spatial–Temporal Variation of 23 Elements at 7 Wastewater Treatment Plants in Southeast City of China

by Shanshan Guo, François Nkinahamira, Bob Adyari, Yiqing Zhang, Anyi Hu and Qian Sun

Water 2023, 15(6), 1226; https://doi.org/10.3390/w15061226 - 21 Mar 2023

Viewed by 1593

Abstract

Rapid urbanization has caused an increase in the discharge of inorganic elements into the environment; however, the knowledge about the fate and annual variations of multiple elements in wastewater treatment plants (WWTPs) is limited. To understand the distribution and change of those elements, [...] Read more.

Rapid urbanization has caused an increase in the discharge of inorganic elements into the environment; however, the knowledge about the fate and annual variations of multiple elements in wastewater treatment plants (WWTPs) is limited. To understand the distribution and change of those elements, we collected and analyzed wastewater and sludge samples from seven WWTPs in a southeast city of China. Results revealed the elemental concentration ranging from 0.06 μg·L⁻¹ (Tl) to 221.90 μg·L⁻¹ (Mn) in the influent, below the detection limit (Er), to 206.40 μg·L⁻¹ (Mn) in the effluent, and 0.58 mg·kg⁻¹ (Tl) to 309.30 mg·kg⁻¹ (Zn) in the sludge. The removal analysis revealed that rare earth elements (REEs) were removed well from the wastewater with removal efficiencies ranging from 88.03% (Tm) to 97.37% (Sm), while heavy metals were poor, with removal efficiencies ranging from 10.71% (Mn) to 89.17% (Pb). The elemental flux analysis highlighted that activated sludge served as a major temporary storage site for 23 elements, while excess sludge acted as the major sink for REEs. Significant spatial variations were detected among different WWTPs. On the contrary, the temporal variations were insignificant based on the monitoring data from 2010 to 2020, indicating the satisfactory implementation of current environmental regulations. Full article

(This article belongs to the Special Issue Water Treatment and Emerging Contaminants)

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15 pages, 1642 KiB

Open AccessArticle

Analysis of Desalination Performance with a Thermal Vapor Compression System

by Zineb Fergani, Zakaria Triki, Rabah Menasri, Hichem Tahraoui, Mohammed Kebir, Abdeltif Amrane, Nassim Moula, Jie Zhang and Lotfi Mouni

Water 2023, 15(6), 1225; https://doi.org/10.3390/w15061225 - 21 Mar 2023

Cited by 3 | Viewed by 2180

Abstract

Multi-effect distillation with thermal vapor compression (MED-TVC) is a highly energy-efficient desalination technology that can provide a reliable and sustainable source of high-quality water, particularly in areas with limited energy infrastructure and water resources. In this study, a numerical model based on exergoeconomic [...] Read more.

Multi-effect distillation with thermal vapor compression (MED-TVC) is a highly energy-efficient desalination technology that can provide a reliable and sustainable source of high-quality water, particularly in areas with limited energy infrastructure and water resources. In this study, a numerical model based on exergoeconomic approach is developed to analyze the economic performance of a MED-TVC system for seawater desalination. A parallel/cross feed configuration is considered because of its high energy efficiency. In addition, a parametric study is performed to evaluate the effects of some operational parameters on the total water price, such as the top brine temperature, seawater temperature, motive steam flow rate, and number of effects. The obtained results indicate that the total water price is in the range of 1.73 USD/m³ for a distilled water production of 55.20 kg/s. Furthermore, the exergy destructions in the effects account for 45.8% of the total exergy destruction. The MED effects are also identified to be the most relevant component from an exergoeconomic viewpoint. Careful attention should be paid to these components. Of the total cost associated with the effects, 75.1% is due to its high thermodynamic inefficiency. Finally, the parametric study indicates that adjusting the top brine temperature, the cooling seawater temperature, the motive steam flow rate, and the number of effects has a significant impact on the TWP, which varies between 1.42 USD/m³ and 2.85 USD/m³. Full article

(This article belongs to the Topic Sustainable Water Purification Technologies for Multiple Applications)

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17 pages, 4106 KiB

Open AccessArticle

Design for the Prediction of Peak Outflow of Embankment Breaching Due to Overtopping by Regression Technique and Modelling

by Deepak Verma, Parveen Berwal, Mohammad Amir Khan, Raied Saad Alharbi, Faisal M. Alfaisal and Upaka Rathnayake

Water 2023, 15(6), 1224; https://doi.org/10.3390/w15061224 - 21 Mar 2023

Cited by 3 | Viewed by 1745

Abstract

The study of embankment breaching is not an easy practice, as it includes various parameters to meet the suitability of the design approach, especially when we consider it for the long term. Embankment breach studies generally include the prediction of different breach parameters. [...] Read more.

The study of embankment breaching is not an easy practice, as it includes various parameters to meet the suitability of the design approach, especially when we consider it for the long term. Embankment breach studies generally include the prediction of different breach parameters. The important physical and hydrodynamic parameters of the flood wave generated from the embankment failure are breach width, breach slope, formation time, peak outflow, and time to failure. Out of these parameters, peak outflow is a very important breach parameter, as it deflects the magnitude of destruction on the downstream side of the embankment and affects the evacuation plans for the downstream population. The prediction of breach peak outflow due to overtopping of the embankment is very essential for dam failure prevention and mitigation, as well as for the design of an early warning system. Many researchers have used dam failure data, comparative studies, experimental studies, or regression techniques to develop various models for predicting peak outflow. The present paper analyzes the results of the design for forty experiments carried out in two different laboratory water channels (flumes). Different embankment models are overtopped with the objective of studying the breach behavior during overtopping. The study was inspired by reports in the open literature of embankment failures that resulted in catastrophic conditions. With experimental data, an efficient model is developed for predicting breach peak outflow (Q_p) by correlating with other independent embankment breach parameters for cohesive as well as non-cohesive embankments. The model is validated with historical and laboratory data compiled in the past. For the validation of current investigational work, the experimental data of the present study are compared with the model already developed by other researchers. From the study and analysis, it is observed that breach peak outflow depends upon hydraulic, geometric, and geotechnical parameters of embankments. Being a phenomenon that is active for a short duration only, the manual measurement of various parameters of the modeling process poses some limitations under laboratory conditions. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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14 pages, 4615 KiB

Open AccessArticle

Study on the Effect Mechanism of Inlet Pre-Swirl on Pressure Pulsation within a Mixed-Flow Centrifugal Pump

by Xiaogang Ma, Mengying Bian, Yang Yang, Tingting Dai, Lei Tang and Jun Wang

Water 2023, 15(6), 1223; https://doi.org/10.3390/w15061223 - 21 Mar 2023

Viewed by 1688

Abstract

This article explores the impact of inlet pre-swirl on pressure pulsation in a mixed-flow centrifugal pump through a combination of numerical simulations and experimental verification. Firstly, the mixed-flow centrifugal pump’s performance was initially determined through both numerical calculations and experiments. The comparison between [...] Read more.

This article explores the impact of inlet pre-swirl on pressure pulsation in a mixed-flow centrifugal pump through a combination of numerical simulations and experimental verification. Firstly, the mixed-flow centrifugal pump’s performance was initially determined through both numerical calculations and experiments. The comparison between them indicated the high accuracy of the numerical method adopted in this paper. Next, the flow pattern within the pump at various inlet pre-swirl angles was carefully compared and analyzed. It was found that positive impulse angle and inlet displacement could lead to circumferential inhomogeneity of the flow field within the impeller, while inlet pre-swirl can significantly counteract the effect of positive impulse angle. The impact of inlet pre-swirl on the flow pattern near the blade inlet will change the intensity of the secondary flow within the impeller passage. Variations in the intensity of the secondary flow can directly affect the strength of the wake and jet in the chamber. Then, the pressure pulsations within the chamber were compared and analyzed for various inlet pre-swirl angles. The results revealed that as the inlet pre-swirl angle increased, the intensity of pressure pulsation decreased significantly. This discovery sheds light on the influence mechanism of inlet pre-swirl on pressure pulsation within mixed-flow pumps, potentially serving as a theoretical foundation for enhancing the operational stability of mixed-flow centrifugal pumps. Full article

(This article belongs to the Special Issue Design and Optimization of Fluid Machinery)

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19 pages, 2467 KiB

Open AccessReview

2D Microfluidic Devices for Pore-Scale Phenomena Investigation: A Review

by Alice Massimiani, Filippo Panini, Simone Luigi Marasso, Matteo Cocuzza, Marzia Quaglio, Candido Fabrizio Pirri, Francesca Verga and Dario Viberti

Water 2023, 15(6), 1222; https://doi.org/10.3390/w15061222 - 21 Mar 2023

Cited by 3 | Viewed by 2492

Abstract

Underground porous media are complex multiphase systems, where the behavior at the macro-scale is affected by physical phenomena occurring at the pore(micro)-scale. The understanding of pore-scale fluid flow, transport properties, and chemical reactions is fundamental to reducing the uncertainties associated with the dynamic [...] Read more.

Underground porous media are complex multiphase systems, where the behavior at the macro-scale is affected by physical phenomena occurring at the pore(micro)-scale. The understanding of pore-scale fluid flow, transport properties, and chemical reactions is fundamental to reducing the uncertainties associated with the dynamic behavior, volume capacity, and injection/withdrawal efficiency of reservoirs and groundwater systems. Lately, laboratory technologies were found to be growing along with new computational tools, for the analysis and characterization of porous media. In this context, a significant contribution is given by microfluidics, which provides synthetic tools, often referred to as micromodels or microfluidic devices, able to mimic porous media networks and offer direct visualization of fluid dynamics. This work aimed to provide a review of the design, materials, and fabrication techniques of 2D micromodels applied to the investigation of multiphase flow in underground porous media. The first part of the article describes the main aspects related to the geometrical characterization of the porous media that lead to the design of micromodels. Materials and fabrication processes to manufacture microfluidic devices are then described, and relevant applications in the field are presented. In conclusion, the strengths and limitations of this approach are discussed, and future perspectives are suggested. Full article

(This article belongs to the Section Hydrogeology)

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Water, Volume 15, Issue 6 (March-2 2023) – 247 articles

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