Water

26 pages, 2835 KiB

Open AccessReview

Water Context in Latin America and the Caribbean: Distribution, Regulations and Prospects for Water Reuse and Reclamation

by Carolina Rodríguez, Bárbara García, Caterin Pinto, Rafael Sánchez, Jennyfer Serrano and Eduardo Leiva

Water 2022, 14(21), 3589; https://doi.org/10.3390/w14213589 - 7 Nov 2022

Cited by 9 | Viewed by 8350

Abstract

Water scarcity is a problem of global relevance that is affecting more and more people in the world. Latin America and the Caribbean (LAC) have around 35% of the world’s renewable water resources. However, the management of water resources and inequality in access [...] Read more.

Water scarcity is a problem of global relevance that is affecting more and more people in the world. Latin America and the Caribbean (LAC) have around 35% of the world’s renewable water resources. However, the management of water resources and inequality in access to water has made water scarcity a problem of growing interest in the region. The reuse of water could be an efficient measure to reduce the demand for water resources in the area. In particular, the reuse of greywater is a simple and decentralized method of water reuse, which would mitigate the impact of the lack of water in isolated or difficult-to-access areas. Using the Aquastat database, water consumption in the world and water availability in LAC were studied. In addition, the regulatory framework for water in LAC countries was studied, with an emphasis on water reuse and greywater legislation. Agriculture is one of the most demanding of water in the world, particularly, in LAC, which demands around 70% of renewable water resources. Furthermore, in LAC, the availability of drinking water in rural areas is lacking, with seven countries having less than 80% access to healthy drinking water. The water regulation in LAC is quite heterogeneous. The most general regulation around water is found in the political constitutions of each country. Some constitutions explicitly indicate access to water as a human right, while other constitutions do not include information in this regard. Although some countries have specific regulations on the reuse of wastewater, there is a general lack of regulations related to the reuse of greywater. In most cases, the term “greywater” is not even defined in the general water and wastewater laws. As of the date of this article, only Chile, Peru, and Brazil have bills to regulate the reuse of greywater, of which only the Chilean is approved. The reuse of greywater could help reduce water demand for non-drinking uses. However, the implementation of greywater treatment systems represents a cost that is difficult to cover, especially in the poorest countries of the region. Countries must improve their public policies to improve the management, use and reuse of water to mitigate water scarcity that severely affects human consumption in the region. The relevance of this study lies in providing a general framework of the water situation in LAC for studies and public policies focused on promoting water reuse as a measure to mitigate water scarcity. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

► Show Figures

Figure 1

31 pages, 2963 KiB

Open AccessEditor’s ChoiceReview

A General Overview of Heterogeneous Photocatalysis as a Remediation Technology for Wastewaters Containing Pharmaceutical Compounds

by Donia Friedmann

Water 2022, 14(21), 3588; https://doi.org/10.3390/w14213588 - 7 Nov 2022

Cited by 31 | Viewed by 8116

Abstract

The presence of persistent, difficult to degrade pharmaceutical compounds in wastewaters is a significant environmental concern. While heterogeneous photocatalysis can degrade a range of pharmaceutical compounds, as a technology, it is yet to be applied. Current research on heterogeneous photocatalysis for pharmaceutical removal [...] Read more.

The presence of persistent, difficult to degrade pharmaceutical compounds in wastewaters is a significant environmental concern. While heterogeneous photocatalysis can degrade a range of pharmaceutical compounds, as a technology, it is yet to be applied. Current research on heterogeneous photocatalysis for pharmaceutical removal is focused on the development of photocatalytic materials that are both efficient photocatalysts and solar driven as well as materials that combine both adsorption and photocatalysis. The formation of toxic by-products during photocatalytic degradation can be an issue, hence, mechanistic studies to identify reaction pathways and intermediates are important and are discussed in this review. The potential application of photocatalytic systems coupled with other technologies, to achieve complete pollutant removal and avoid toxin formation are also discussed. Given the broad range of properties of these pharmaceutical compounds and their corresponding wastewater matrices, each system needs to be optimised accordingly, with the need for pilot scale studies. Other than end of pipe solutions to reduce the occurrence of pharmaceutical pollutants in the environment, a comprehensive environmental management approach involving strategies such as the reduction of pharmaceutical prescriptions and the introduction of take back schemes are also needed to achieve a reduction of pharmaceutical compounds in the environment. Full article

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

► Show Figures

Graphical abstract

19 pages, 5482 KiB

Open AccessArticle

Identifying Critical Isolation Valves in a Water Distribution Network: A Socio-Technical Approach

by Noha Abdel-Mottaleb, Payman Ghasemi Saghand, Mathews J. Wakhungu, Hadi Charkhgard, E. Christian Wells and Qiong Zhang

Water 2022, 14(21), 3587; https://doi.org/10.3390/w14213587 - 7 Nov 2022

Cited by 6 | Viewed by 3103

Abstract

Isolation valves are critical for the reliable functioning of water distribution networks (WDNs). However, it is challenging for utilities to prioritize valve rehabilitation and replacement given it is often unclear if certain valves are operable in a given WDN. This study uses the [...] Read more.

Isolation valves are critical for the reliable functioning of water distribution networks (WDNs). However, it is challenging for utilities to prioritize valve rehabilitation and replacement given it is often unclear if certain valves are operable in a given WDN. This study uses the Gomory–Hu tree of the segment-valve representation (or dual representation) of WDNs to obtain the logical implications of inoperable valves (i.e., which segments should be isolated and merged unnecessarily due to valve inoperability). Multi-objective optimization is then used to identify the critical valves based on selected attributes (e.g., social vulnerability, flow volume) of segments that would be unnecessarily isolated as a result. This study developed three multi-objective formulations: first, deterministic; second, accounting for uncertainty; and third, accounting for both uncertainty and the likelihood of failure of pipes within segments. Identified critical valves are compared between the three developed formulations and a method considering only a single objective. Results demonstrated that multi-objective optimization provided additional information which can be used to discern valve importance for utilities in comparison with using a single objective. Further, though there was overlap between the results from the three formulations, the third formulation provided the most insight without overwhelming decision-makers with a large number of identified valves. Full article

(This article belongs to the Special Issue Urban Water Networks Modelling and Monitoring, Volume II)

► Show Figures

Figure 1

13 pages, 3628 KiB

Open AccessReview

Research Progress of Microplastic Pollution in the Vadose Zone

by Rui-Ping Liu, Fei Liu, Ping-Ping Sun, El-Wardany R.M., Ying Dong, Yi-Bing Zhang, Hua-Qing Chen and Jian-Gang Jiao

Water 2022, 14(21), 3586; https://doi.org/10.3390/w14213586 - 7 Nov 2022

Cited by 1 | Viewed by 2718

Abstract

Microplastics (MPs) are widely distributed in the environment. MP pollution has been found in the environment globally, which directly threatens human health. It is of great importance to study the influencing factors and mechanism of MP migration in the vadose zone to evaluate [...] Read more.

Microplastics (MPs) are widely distributed in the environment. MP pollution has been found in the environment globally, which directly threatens human health. It is of great importance to study the influencing factors and mechanism of MP migration in the vadose zone to evaluate its distribution and environmental risk accurately. Through a literature review, the source, migration, and transformation of MPs in the vadose zone were summarized, and the influencing factors of MP migration in the vadose zone were systematically expounded. The mechanism of MP migration was analyzed, and future research was suggested. The factors affecting the migration of MPs can be divided into chemical, physical, and biological categories. At present, research on the migration of MPs in the vadose zone is in its infancy. In a further study, the migration of MPs at the field scale, the synergistic migration and transformation of MPs with other pollutants and the mutual feedback mechanism, and the use of the properties and biological functions of the vadose zone to study the role and mechanism of MPs in global carbon neutralization are worthy of attention. Full article

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

► Show Figures

Figure 1

6 pages, 213 KiB

Open AccessCorrection

Correction: Verlicchi, P.; Grillini, V. Surface Water and Groundwater Quality in South Africa and Mozambique—Analysis of the Most Critical Pollutants for Drinking Purposes and Challenges in Water Treatment Selection. Water 2020, 12, 305

by Paola Verlicchi and Vittoria Grillini

Water 2022, 14(21), 3585; https://doi.org/10.3390/w14213585 - 7 Nov 2022

Viewed by 1500

Abstract

In the original publication [...] Full article

(This article belongs to the Special Issue Urban Water Management: A Pragmatic Approach)

21 pages, 2751 KiB

Open AccessArticle

On the Numerical Solution of Sparse Linear Systems Emerging in Finite Volume Discretizations of 2D Boussinesq-Type Models on Unstructured Grids

by Anargiros I. Delis, Maria Kazolea and Maria Gaitani

Water 2022, 14(21), 3584; https://doi.org/10.3390/w14213584 - 7 Nov 2022

Viewed by 1799

Abstract

This work aims to supplement the realization and validation of a higher-order well-balanced unstructured finite volume (FV) scheme, that has been relatively recently presented, for numerically simulating weakly non-linear weakly dispersive water waves over varying bathymetries. We investigate and develop solution strategies for [...] Read more.

This work aims to supplement the realization and validation of a higher-order well-balanced unstructured finite volume (FV) scheme, that has been relatively recently presented, for numerically simulating weakly non-linear weakly dispersive water waves over varying bathymetries. We investigate and develop solution strategies for the sparse linear system that appears during this FV discretisation of a set of extended Boussinesq-type equations on unstructured meshes. The resultant linear system of equations must be solved at each discrete time step as to recover the actual velocity field of the flow and advance in time. The system’s coefficient matrix is sparse, un-symmetric and often ill-conditioned. Its characteristics are affected by physical quantities of the problem to be solved, such as the undisturbed water depth and the mesh topology. To this end, we investigate the application of different well-known iterative techniques, with and without the usage of preconditioners and reordering, for the solution of this sparse linear system. The iiterative methods considered are the GMRES and the BiCGSTAB, three preconditioning techniques, including different ILU factorizations and two different reordering techniques are implemented and discussed. An optimal strategy, in terms of computational efficiency and robustness, is finally proposed which combines the use of the BiCGSTAB method with the ILUT preconditioner and the Reverse Cuthill–McKee reordering. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

► Show Figures

Figure 1

14 pages, 6942 KiB

Open AccessArticle

Coastal Groundwater Quality Evaluation and Hydrogeochemical Characterization Using Chemometric Techniques

by Hidayat Ullah, Iffat Naz, Aiyeshah Alhodaib, Muhammad Abdullah and Muhammad Muddassar

Water 2022, 14(21), 3583; https://doi.org/10.3390/w14213583 - 7 Nov 2022

Cited by 5 | Viewed by 2142

Abstract

The physicochemical parameters and heavy metals concentration in the groundwater of the coastal region of Lasbela, Baluchistan were investigated. Cations and anions were determined through ion chromatography. The concentration levels of eight heavy metals (Cr, Cd, Pb, Zn, Fe, Cu, and Mn) in [...] Read more.

The physicochemical parameters and heavy metals concentration in the groundwater of the coastal region of Lasbela, Baluchistan were investigated. Cations and anions were determined through ion chromatography. The concentration levels of eight heavy metals (Cr, Cd, Pb, Zn, Fe, Cu, and Mn) in the groundwater were analyzed through the analytical procedures of atomic absorption spectrophotometry. The cations were present in the descending order of magnesium > sodium > calcium > potassium and anions as bicarbonate > sulfate > chloride. Two parameters (bicarbonate and total dissolved solids) were above and other physicochemical indices of groundwater were below the threshold limits of the WHO. Positive correlations of pH and electrical conductivity were observed with cations and anions. The significant positive correlation between sodium and bicarbonate (0.427) indicated the dissolution of carbonate rocks. The concentration of heavy metals (Cu, Cd, Mn, Cr, Pb, Fe, Zn, and Ni) ranged from 0.1 to 0.4, 0.02 to 0.09, 0.04 to 0.9, 0.03 to 0.5, 0.01 to 0.91, 0.05 to 1.30, 0.01 to 0.60, and 0.02 to 0.90 mg/L. The highest concentration of Pb (0.21 mg/L) and Cd (0.16 mg/L) were approximately 20 and 50 times higher than the permissible limits of the WHO. Hierarchical cluster analysis classified the twelve physicochemical parameters into four clusters and the eight heavy metals into seven clusters. Principal component analysis extracted eight latent components for physicochemical properties and heavy metals with eigenvalues greater than 1.0 that had positive loads of fluoride, iron, electrical conductivity, sodium, cadmium, and sulfate. Major pollutants in the groundwater were accounted for by PC 1, and the main factors that affected the water quality were Pb, Cr, and Cu. Fe had a modest impact on the water quality in this region. From the findings, it can be concluded that the coastal groundwater of the region has a higher concentration of heavy metals, which makes it unfit for drinking purposes. Full article

(This article belongs to the Special Issue The Geochemical Behavior of Trace Elements in Inshore Environments)

► Show Figures

Figure 1

18 pages, 11016 KiB

Open AccessArticle

Hydraulic Modeling and Remote Sensing Monitoring of Floodhazard in Arid Environments—A Case Study of Laayoune City in Saquia El Hamra Watershed Southern Morocco

by El-Alaouy Nafia, Badreddine Sebbar, El Houssaine Bouras, Aicha Moumni, Nour-Eddine Laftouhi and Abderrahman Lahrouni

Water 2022, 14(21), 3582; https://doi.org/10.3390/w14213582 - 7 Nov 2022

Cited by 2 | Viewed by 2452

Abstract

Morocco often faces significant intense rainfall periods that can generate flash floods and raging torrents, causing serious damage in a very short period of time. This study aims to monitor wetland areas after a flash-flood event in an arid region, Saquia El hamra [...] Read more.

Morocco often faces significant intense rainfall periods that can generate flash floods and raging torrents, causing serious damage in a very short period of time. This study aims to monitor wetland areas after a flash-flood event in an arid region, Saquia El hamra Saharan of Morocco, using a technique that combines hydraulic modeling and remote sensing technology, namely satellite images. The hydrological parameters of the watershed were determined by the WMS software. Flood flow was modeled and simulated using HEC HMS and HEC-RAS software. To map the flooded areas, two satellite images (Sentinel-2 optical images) taken before and after the event were used. Three classifications were carried out using two powerful classifiers: support vector machines and decision tree. The first classifier was applied on both dates’ images, and the resulting maps were used as input for a constructed decision tree model as a post-classification change detection process. Full article

(This article belongs to the Section Hydrology)

► Show Figures

Figure 1

18 pages, 3115 KiB

Open AccessEditor’s ChoiceArticle

Geochemical Characterisation and Health Concerns of Mineral Bottled Waters in Catalonia (North-Eastern Spain)

by Josefina C. Tapias, Raquel Melián, Alex Sendrós, Xavier Font and Albert Casas

Water 2022, 14(21), 3581; https://doi.org/10.3390/w14213581 - 7 Nov 2022

Cited by 11 | Viewed by 3303

Abstract

Spain currently produces around 7000 million litres of mineral water a year, of which about 20% is produced in Catalonia, and there is a need for greater regulation and research into bottled waters and their impact on human health. A total of 29 [...] Read more.

Spain currently produces around 7000 million litres of mineral water a year, of which about 20% is produced in Catalonia, and there is a need for greater regulation and research into bottled waters and their impact on human health. A total of 29 samples were analysed from different brands of commercially bottled water, and 71 chemical elements were determined in each sample. The aim was to classify each brand based on composition, compare lithological origins, verify compliance with international standards for drinking water, and report benefits for human health. More than 60% of the samples were of the calcium bicarbonate type, had a low mineral content, and were associated with granitic aquifers, ranging from leucogranites to granodiorites. In contrast, 17% were of the sodium bicarbonate type, had harder waters, and were related to thermal springs. The thermal springs of the bottled waters from the Montseny-Guilleres massif (Vichy Catalán, Malavella, and San Narciso) emerge at a temperature of 60 °C with their own natural gas. Two samples exceeded European standards for As and Hg concentrations in water for human consumption, while one showed a concentration of U greater than that set out in international recommendations. Full article

(This article belongs to the Special Issue Geochemistry of Mineral Groundwater)

► Show Figures

Figure 1

11 pages, 1931 KiB

Open AccessArticle

Effects of Dissolved Organic Matter (DOM) on Perfluorooctanoic Acid (PFOA) in a Seagoing River—A Case Study of the Wanggang River Flowing into the East China Sea

by Qiuying Lai, Jian Shui, Jie Ma, Fei He, Longmian Wang, Fuquan Peng, Xiang Zhu, Qingqing Pang and Yuao Wang

Water 2022, 14(21), 3580; https://doi.org/10.3390/w14213580 - 7 Nov 2022

Viewed by 2076

Abstract

Perfluorooctanoic acid (PFOA) is an emerging environmental pollutant that has attracted widespread attention. In this study, water samples were collected from the Wanggang River in the eastern coastal area of China, and the PFOA and dissolved organic matter (DOM) levels were measured. The [...] Read more.

Perfluorooctanoic acid (PFOA) is an emerging environmental pollutant that has attracted widespread attention. In this study, water samples were collected from the Wanggang River in the eastern coastal area of China, and the PFOA and dissolved organic matter (DOM) levels were measured. The results show that the PFOA concentration in the water bodies ranges from 3.2 to 52.9 ng·L⁻¹, and the average value is 27.1 ± 13.4 ng·L⁻¹, indicating an intermediate level. Two protein-like (C2, C3) and two humus-like (C1, C4) DOM components in the Wanggang River are attributed to rainfall and human activities. Differences are observed in the DOM components before and after the flood season. The humus-like components are higher in the post-flood season, and are one of the factors affecting PFOA distribution and concentration in the Wanggang River. The results provide data support for monitoring and evaluating PFOA in rivers and help formulate PFOA pollution management strategies. In future research, it might be better to define the interaction between DOM and emerging organic pollutants by using 17 PFASs as subjects. Full article

(This article belongs to the Special Issue Biodegradation of Persistent Pollutants in Wastewater)

► Show Figures

Figure 1

13 pages, 1982 KiB

Open AccessArticle

Effect of Seawater Intrusion on the Formation of Chlorinated and Brominated Trihalomethanes in Coastal Groundwater

by Naseeba Parveen and Sudha Goel

Water 2022, 14(21), 3579; https://doi.org/10.3390/w14213579 - 7 Nov 2022

Cited by 5 | Viewed by 2407

Abstract

Around the world, coastal groundwater is increasingly subject to seawater intrusion (SWI). The quality and characteristics of such waters differ from those of surface and groundwater. In the current study, trihalomethane (THM) formation under varying levels of SWI, natural organic matter (NOM), and [...] Read more.

Around the world, coastal groundwater is increasingly subject to seawater intrusion (SWI). The quality and characteristics of such waters differ from those of surface and groundwater. In the current study, trihalomethane (THM) formation under varying levels of SWI, natural organic matter (NOM), and chloride-to-bromide (Cl/Br) ratio was evaluated. Different levels of SWI were simulated by mixing deionized water with real seawater (RSW) collected from the Indian Ocean or synthetic seawater (SSW) by varying seawater volumes from 0% to 3%. Humic acid (0 to 5 mg/L) was added to represent NOM at concentrations mimicking natural levels of dissolved organic carbon. The chlorine demand of the simulated water samples was significantly correlated to SWI levels and NOM concentrations. THM concentration in SSW increased from 12.64 µg/L to 105.34 µg/L after 24 h and to 115.8 µg/L after 48 h for an increase from 0% to 3% volume of seawater. For water samples simulated with RSW, maximum THMs after 24 h were 119.2 µg/L, and after 48 h were 126.4 µg/L. An increase in NOM concentration in seawater-intruded water samples resulted in increasing THMs, especially tribromomethane. However, the increment in THMs at higher NOM concentration was lower compared to that at low NOM concentration. Chlorine demand was positively correlated only to tribromomethane. An increase in bromide concentration resulted in lower Cl/Br ratio and a concomitant increase in brominated THMs. The bromine substitution factor corresponding to increasing SWI of 0.25–3% decreased from 2.67 to 1.81 over a reaction time of 24 to 48 h, indicating a shift from TBM dominance to chlorinated THMs. Full article

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

► Show Figures

Graphical abstract

16 pages, 9357 KiB

Open AccessFeature PaperArticle

Characteristics of Evapotranspiration and Crop Coefficient Correction at a Permafrost Swamp Meadow in Dongkemadi Watershed, the Source of Yangtze River in Interior Qinghai–Tibet Plateau

by Haonan Guo, Shaoyong Wang, Xiaobo He, Yongjian Ding, Yawei Fan, Hui Fu and Xiaofeng Hong

Water 2022, 14(21), 3578; https://doi.org/10.3390/w14213578 - 7 Nov 2022

Cited by 3 | Viewed by 2057

Abstract

The Qinghai–Tibet Plateau (QTP), known as the Earth’s third pole, is highly sensitive to climate change. Various environmental degradation has occurred due to the effects of climate warming such as the degradation of permafrost and the thickening of active layers. Evapotranspiration, as a [...] Read more.

The Qinghai–Tibet Plateau (QTP), known as the Earth’s third pole, is highly sensitive to climate change. Various environmental degradation has occurred due to the effects of climate warming such as the degradation of permafrost and the thickening of active layers. Evapotranspiration, as a key element of hydrothermal coupling, has become a key factor of the plateau environment for deciphering deterioration, and the FAO P-M model has a good physical foundation and simple model data requirements as a primary tool to study the plateau evapotranspiration. There has been a large research base, but the estimation of evapotranspiration in alpine regions is still subject to many uncertainties. This is reflected in the fact that the classification of underlying surface types has not been sufficiently detailed and the evapotranspiration characteristics of some special underlying surface types are still unclear. Therefore, in this work, we modified the FAO P-M coefficients based on the characteristics of actual evapotranspiration measured by the Eddy covariance system and the key influencing factors to better simulate the actual evapotranspiration in alpine swamp meadow. The results were as follows: (1) Both ET_a measured by the Eddy covariance system and ET₀ calculated by FAO P-M showed the same trend at the daily and annual scales and hysteresis was confirmed to exist, so the error caused by hysteresis should be considered in further research. (2) The annual ET_a was 566.97 mm and annual ET_a/P was 0.76, and about 11.19% of ET_a occurred during the night. The ET_a was 2.15 during the non-growing seasons, implying that a large amount of soil water was released into the air by evapotranspiration. (3) The evapotranspiration characteristics of alpine swamp meadow are formed under the following conditions: control of net radiation (R_n) affected by VPD during the growing season and affected by soil temperature and humidity during the non-growing season. Precipitation and soil water content are no longer the main controlling factors of evapotranspiration during the growing season at the alpine swamp meadow as the volume soil water content tends to saturate. (4) The basic corrected K_c was 1.14 during the initial and mid-growing season, 1.05 during the subsequent growing season, and 0–0.25 during the non-growing season, and the correction factor process can also provide ideas for correcting the K_c of other vegetation. Full article

(This article belongs to the Special Issue Hydrometeorological Observation and Modeling)

► Show Figures

Figure 1

23 pages, 18739 KiB

Open AccessArticle

Factors Affecting the Rates and Modes of Landslide Colluvium Removal in River Channels of Podhale (Western Carpathians)

by Józef Kukulak, Karol Augustowski and Janusz Olszak

Water 2022, 14(21), 3577; https://doi.org/10.3390/w14213577 - 7 Nov 2022

Cited by 2 | Viewed by 2029

Abstract

This paper presented some hydrological factors affecting the course and rate of fluvial erosion of landslide colluvium at its contact with river flow. Volumes of colluvium eroded by rivers in the period 2013–2019 were measured at Podhale (a part of Polish West Carpathians) [...] Read more.

This paper presented some hydrological factors affecting the course and rate of fluvial erosion of landslide colluvium at its contact with river flow. Volumes of colluvium eroded by rivers in the period 2013–2019 were measured at Podhale (a part of Polish West Carpathians) on four landslides representing various geological settings. At each landslide, changes in shape and position of the contact zone between colluvium and river water were registered after episodes of high river stage. The obtained data on changes in relief of the landslide fronts and adjacent river channels were used to calculate volumes of colluvium removed during each episode. The course of erosion and volumes of colluvium eroded were compared with the water stage records for the studied period of time. Intensity of colluvium erosion was found to be strongly dependent on the water levels and cohesion of colluvium. Volumes of removed colluvium were the greatest during short-lived (1–2 days) and prolonged (7–10 days) periods of high river stages. The rate of erosional removal was the highest for colluvium consisting of poorly consolidated Quaternary matrix-supported massive gravel and overlying fine deposits stored within river terraces. Colluvium composed of Neogene mudstones and sandstones was removed at a lower rate and the rate of removal was lowest for large blocks and slices composed of solid layers of alternating sandstone and shales belonging to the Podhale Flysch series. Erosion of the landslide toes was more intense at those sites where the river flow approached the landslide front at a wider angle. Full article

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

► Show Figures

Figure 1

18 pages, 5539 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Adsorption of Methylene Blue by Coal-Based Activated Carbon in High-Salt Wastewater

by Jinlong Wang, Jingqian Ma and Yongjun Sun

Water 2022, 14(21), 3576; https://doi.org/10.3390/w14213576 - 7 Nov 2022

Cited by 25 | Viewed by 4877

Abstract

High-salt printing and dyeing wastewater is a difficult industrial wastewater to treat. Coal-based activated carbon (CBAC) can be used as an adsorbent to treat high-salt printing and dyeing wastewater and realize the resource utilization of CBAC. In this study, simulated wastewater that contained [...] Read more.

High-salt printing and dyeing wastewater is a difficult industrial wastewater to treat. Coal-based activated carbon (CBAC) can be used as an adsorbent to treat high-salt printing and dyeing wastewater and realize the resource utilization of CBAC. In this study, simulated wastewater that contained methylene blue (MB) was used as the research object, and CBAC was used as the adsorbent. The effects of CBAC dosage, NaCl concentration, coexisting ions, adsorption time, MB concentration, humic acid concentration, and solution pH on the adsorption performance of CBAC with MB were discussed. The results showed that when the CBAC dosage was 0.6 g/L, the solution pH was greater than 6, the adsorption time was 8 h, the adsorption temperature was 308 K, and the MB concentration was 10 mg/L. Thus, the maximum adsorption capacity of CBAC with MB was obtained. The maximum adsorption capacity and removal rate were 15.5 mg/L and 90%, respectively. High-salt wastewater can inhibit the adsorption of methylene blue by coal-based activated carbon. In addition, 20 g/L of NaCl reduced the adsorption capacity of coal-based activated carbon by 1.8 mg/g. Compared to the other coexisting ions, the influence of the presence of Cu²⁺ and Fe³⁺ on the removal of methylene blue was greater. However, when Cu²⁺, Fe³⁺ and high-salt wastewater coexist, the inhibition effect decreases. Full article

(This article belongs to the Special Issue Water-Sludge-Nexus)

► Show Figures

Figure 1

23 pages, 4219 KiB

Open AccessArticle

A Hydrograph-Based Approach to Improve Satellite-Derived Snow Water Equivalent at the Watershed Scale

by Charles Whittaker and Robert Leconte

Water 2022, 14(21), 3575; https://doi.org/10.3390/w14213575 - 7 Nov 2022

Cited by 2 | Viewed by 1973

Abstract

For the past few decades, remote sensing has been a valuable tool for deriving global information on snow water equivalent (SWE), where products derived from space-borne passive microwave radiometers are favoured as they respond to snow depth, an important component of SWE. GlobSnow, [...] Read more.

For the past few decades, remote sensing has been a valuable tool for deriving global information on snow water equivalent (SWE), where products derived from space-borne passive microwave radiometers are favoured as they respond to snow depth, an important component of SWE. GlobSnow, a novel SWE product, has increased the accuracy of global-scale SWE estimates by combining remotely sensed radiometric data with other physiographic characteristics, such as snow depth, as quantified by climatic stations. However, research has demonstrated that passive microwaves algorithms tend to underestimate SWE for deep snowpack. Approaches were proposed to correct for such underestimation; however, they are computer intensive and complex to implement at the watershed scale. In this study, SWE_max information from the near real time 5-km GlobSnow product, provided by Copernicus and the European Space Agency (ESA) and GlobSnow product at 25 km resolution were corrected using a simple bias correction approach for watershed scale applications. This method, referred to as the Watershed Scale Correction (WSC) approach, estimates the bias based on the direct runoff that occurs during the spring melt season. Direct runoff is estimated on the one hand from SWE_max information as main input. Infiltration is also considered in computing direct runoff. An independent estimation of direct runoff from gauged stations is also performed. Discrepancy between these estimates allows for estimating the bias correction factor. This approach is advantageous as it exploits data that commonly exists i.e., flow at gauged stations and remotely sensed/reanalysis data such as snow cover and precipitation. The WSC approach was applied to watersheds located in Eastern Canada. It was found that the average bias moved from 33.5% with existing GlobSnow product to 18% with the corrected product, using the recommended recursive filter coefficient β of 0.925 for baseflow separation. Results show the usefulness of integrating direct runoff for bias correction of existing GlobSnow product at the watershed scale. In addition, potential benefits are offered using the recursive filter approach for baseflow separation of watersheds with limited in situ SWE measurements, to further reduce overall uncertainties and bias. The WSC approach should be appealing for poorly monitored watersheds where SWE measurements are critical for hydropower production and where snowmelt can pose serious flood-related damages. Full article

(This article belongs to the Section Hydrology)

► Show Figures

Figure 1

17 pages, 3378 KiB

Open AccessFeature PaperArticle

Hydrology and Nutrient Dynamics in Managed Restored Wetlands of California’s Central Valley, USA

by Sharon N. Kahara, Buddhika D. Madurapperuma, Breana K. Hernandez, Luke Scaroni and Eric Hopson

Water 2022, 14(21), 3574; https://doi.org/10.3390/w14213574 - 7 Nov 2022

Cited by 1 | Viewed by 2330

Abstract

Extensive wetland losses in California’s Central Valley have led to significant reductions in their natural functions, such as nutrient removal. Past studies suggest that individual wetland restoration efforts in the region yield mixed results mainly due to differences in management practices and degree [...] Read more.

Extensive wetland losses in California’s Central Valley have led to significant reductions in their natural functions, such as nutrient removal. Past studies suggest that individual wetland restoration efforts in the region yield mixed results mainly due to differences in management practices and degree of access to limited water resources, yet few studies have examined their hydrology or nutrient dynamics with any detail. Our objective was to explore nutrient reduction across a range of hydrological regimes. We recorded hydroperiods and nutrient concentrations of the received and discharged applied water at 21 managed wetlands on national wildlife refuges and private lands over 6 years from 2015 to 2020. Water depths at 18 of these wetlands were monitored continuously for over 400 days. Climatic variation over the observation period included exceptional drought, above-average flooding and relatively stable water conditions. Privately managed wetlands retained water for longer durations of time, but at shallower depths than seasonal wetlands in wildlife refuges. An assessment of nutrient concentrations at inflows relative to outflows was inconclusive and varied among years. However, assessment of nutrient loads indicated consistent retention of ammonium and nitrates across all management types, locations and time periods. Multivariate analysis indicated that climate and location played a role in influencing nutrient concentrations among wetlands. In conclusion, restored wetlands in the central valley provide ecosystem service functions such as removing nutrients from ambient water and provide unique habitats for waterfowls with the presence of seasonal flood and drain management practices. Full article

(This article belongs to the Special Issue Wetland Response to Climate Change)

► Show Figures

Figure 1

20 pages, 7675 KiB

Open AccessArticle

Treatment and Recycle of Greenhouse Nutrient Feed Water Applying Hydrochar and Activated Carbon Followed by Reverse Osmosis

by Abu-Taher Jamal-Uddin, Takashi Matsuura, Fadi Al-Daoud and Richard G. Zytner

Water 2022, 14(21), 3573; https://doi.org/10.3390/w14213573 - 7 Nov 2022

Cited by 4 | Viewed by 2471

Abstract

Leached greenhouse nutrient feed (GNF) water is a great challenge for greenhouse (GH) producers. Unbalanced higher micronutrient metal’s phytotoxicity impact GH plant growth, and the high phosphorous levels can cause lake eutrophication if not treated. The analytical results of three GNFs revealed no [...] Read more.

Leached greenhouse nutrient feed (GNF) water is a great challenge for greenhouse (GH) producers. Unbalanced higher micronutrient metal’s phytotoxicity impact GH plant growth, and the high phosphorous levels can cause lake eutrophication if not treated. The analytical results of three GNFs revealed no microbial contamination in any of the GNFs, but the potassium, calcium, magnesium levels, and pH range were above the target level for root zone conditions. Both higher and lower limit concentrations are phytotoxic, causing poor or non-developed roots, leaves, and stems. Sodium was also not in the balanced range. Phosphate and nitrate nutrients were above the measurable range, showing that it would be a threat to lake eutrophication if disposed of. Due to uptake by plants at varied rates, nutrient ion imbalance in GNF is usual, but proper control or treatment is essential as GNF is not a waste but a resource providing fertilization to plants. Potential treatment options investigated include coagulation filtration, sorption with hydrochar (HC), and activated carbon (AC), followed by reverse osmosis (RO) membrane filtration. The HC and AC were produced from waste tomato plants biomass (TPB) of the same GHs to enhance the recycle–reuse of wastes. Neither metals nor nutrient concentrations were reduced to the desired levels by coagulation treatments. The HC and AC treatment provided the recycle–reuse possibility of GNF. RO membrane filtration provided about 97–99% reduction of metals and 99% reduction of nutrients, allowing GNF preparation by adding new fertilizer to the RO permeate. In such a case, the RO reject needs to be reused as feed for TPB carbonization. Different options for GHs to manage TPB and GNF are provided. As RO is an energy-expensive process, an assessment of technical know-how to provide an energy economic process is demonstrated. Full article

(This article belongs to the Special Issue Water Quality for Sustainable Development)

► Show Figures

Figure 1

18 pages, 14047 KiB

Open AccessArticle

Flood Risk Assessment of Buildings Based on Vulnerability Curve: A Case Study in Anji County

by Shuguang Liu, Weiqiang Zheng, Zhengzheng Zhou, Guihui Zhong, Yiwei Zhen and Zheng Shi

Water 2022, 14(21), 3572; https://doi.org/10.3390/w14213572 - 6 Nov 2022

Cited by 6 | Viewed by 3131

Abstract

Following the huge economic losses and building damage caused by yearly flooding in China, increased attention to flood risk management within the urban and suburban areas is required. This paper provides an example of the flood risk management of suburban buildings in Anji [...] Read more.

Following the huge economic losses and building damage caused by yearly flooding in China, increased attention to flood risk management within the urban and suburban areas is required. This paper provides an example of the flood risk management of suburban buildings in Anji County. The temporal and spatial characteristics of inundation in the study area are simulated and analyzed based on a verified coupled hydrodynamic model. The vulnerability curve of local masonry buildings to flood risk is established from the theory of structural static mechanics and the empirical equation of flood load. According to the consequences of the hydrodynamic model and vulnerability curve, a flood risk assessment of suburban buildings is conducted. The results show that severe inundation will occur once the dikes are broken. In the 20-, 50-, and 100-year return periods, there are, respectively, 43, 286 and 553 buildings at extremely high risk, distributed in almost each building region. Over half involved buildings are high risk. Buildings at low-lying lands should worry about the great hydrostatic actions caused by terrible waterlogging. This approach can be popularized in urban, suburban, and rural areas, aimed at frame, masonry and even informal structure. The results can provide a scientific reference for Anji County to reduce the flood loss and enhance the flood resistance. Full article

(This article belongs to the Special Issue Assessment of Urban Pluvial Flood Risk and Utilization of Rainwater & Flood Resources)

► Show Figures

Figure 1

23 pages, 6714 KiB

Open AccessFeature PaperArticle

Hydrological Impact Assessment of Future Climate Change on a Complex River Basin of Western Ghats, India

by R. Visweshwaran, RAAJ Ramsankaran, T. I. Eldho and Manoj Kumar Jha

Water 2022, 14(21), 3571; https://doi.org/10.3390/w14213571 - 6 Nov 2022

Cited by 9 | Viewed by 4559

Abstract

Climate change (CC) affects millions of people directly or indirectly. Especially, the effect of CC on the hydrological regime is extensive. Hence, understanding its impact is highly essential. In this study, the Bharathapuzha river basin (BRB) lying in the Western Ghats region of [...] Read more.

Climate change (CC) affects millions of people directly or indirectly. Especially, the effect of CC on the hydrological regime is extensive. Hence, understanding its impact is highly essential. In this study, the Bharathapuzha river basin (BRB) lying in the Western Ghats region of southern India is considered for CC impact assessment, as it is a highly complex and challenging watershed, due to its varying topographical features, such as soil texture, land use/land cover types, slope, and climatology, including rainfall and temperature patterns. To understand the CC impact on the hydrological variables at BRB in the future, five downscaled global circulation models (GCMs) were used, namely BNU-ESM, Can-ESM, CNRM, MPI-ESM MR, and MPI-ESM LR. These GCMs were obtained for two representative concentration pathway (RCP) scenarios: 4.5 representing normal condition and 8.5 representing the worst condition of projected carbon and greenhouse gases concentration on the lower atmosphere. To obtain the continuous simulation of hydrological variables, the SWAT hydrological model was adopted in this study. Results showed that rainfall pattern, evapotranspiration, and soil moisture will increase at moderate to significant levels in the future. This is especially seen during the far future period (i.e., 2071 to 2100). Similar results were obtained for surface runoff. For instance, surface runoff will increase up to 19.2% (RCP 4.5) and 36% (RCP 8.5) during 2100, as compared to the average historical condition (1981–2010). The results from this study will be useful for various water resources management and adaptation measures in the future, and the methodology can be adopted for similar regions. Full article

(This article belongs to the Section Hydrology)

► Show Figures

Figure 1

10 pages, 2001 KiB

Open AccessArticle

Natural Flocculant from a Combination of Moringa oleifera Seeds and Cactus Cladodes (Opuntia ficus-indica) to Optimize Flocculation Properties

by Christian Eichhorn, Sina Weckmüller and Wilhelm Urban

Water 2022, 14(21), 3570; https://doi.org/10.3390/w14213570 - 6 Nov 2022

Cited by 3 | Viewed by 4150

Abstract

The lack of access to clean water worldwide and organic, inorganic as well as biological contamination of existing freshwater sources are a major problem for around 2 billion people, especially in the countries of the global south. One sign of polluted water is [...] Read more.

The lack of access to clean water worldwide and organic, inorganic as well as biological contamination of existing freshwater sources are a major problem for around 2 billion people, especially in the countries of the global south. One sign of polluted water is turbidity. It is generally caused by colloidal and particulate suspended solids. Chemical flocculants are often used to reduce turbidity and thus eliminate the mostly harmful substances that cause it. However, these have some disadvantages, such as cost and availability, so increasingly natural plant-based flocculants are coming into focus and are considered as an alternative option. In this study, Moringa seeds (Moringa oleifera) and cactus cladodes (Opuntia ficus-indica) were investigated as innovative and environmentally friendly flocculants for water treatment. The parameters investigated included absolute turbidity reduction and flocculation activity, as well as shear strength of the resulting flocs. The flocculation experiments were conducted as simultaneous tests in beakers. Experiments were conducted using both a laboratory-prepared model suspension with an initial turbidity of approximately 139 NTU and natural surface water with an initial turbidity of approximately 136 NTU. The flocculant dosages used ranged from 100 to 300 mg/L. The results show that although Moringa seeds had the highest flocculation activity (up to 93%), the flocs were very fragile and were destroyed again even at low induced shear forces. Flocculants from cactus yielded stable flocs, but the flocculation activity (maximum at 54%) was not as high as that of Moringa. The combination of the two materials resulted in a flocculant with sufficiently high flocculation activity (76%) and stable flocs, which could withstand higher shear forces potentially induced in further treatment steps. Full article

(This article belongs to the Special Issue Water Quality for Sustainable Development)

► Show Figures

Figure 1

4 pages, 1145 KiB

Open AccessEditorial

Pumped Storage Technology, Reversible Pump Turbines and Their Importance in Power Grids

by Ran Tao, Xijie Song and Changliang Ye

Water 2022, 14(21), 3569; https://doi.org/10.3390/w14213569 - 6 Nov 2022

Cited by 11 | Viewed by 5405

Abstract

Pumped storage hydro is a mature energy storage method [...] Full article

(This article belongs to the Special Issue Advancement in the Fluid Dynamics Research of Reversible Pump-Turbine)

► Show Figures

Figure 1

20 pages, 1561 KiB

Open AccessFeature PaperArticle

Critical Evaluation of Different Passive Sampler Materials and Approaches for the Recovery of SARS-CoV-2, Faecal-Indicator Viruses and Bacteria from Wastewater

by Davey L. Jones, Jasmine M. S. Grimsley, Jessica L. Kevill, Rachel Williams, Cameron Pellett, Kathryn Lambert-Slosarska, Andrew C. Singer, Gwion B. Williams, Rafael Bargiela, Robert W. Brown, Matthew J. Wade and Kata Farkas

Water 2022, 14(21), 3568; https://doi.org/10.3390/w14213568 - 6 Nov 2022

Cited by 9 | Viewed by 4215

Abstract

During the COVID-19 pandemic, wastewater-based epidemiology (WBE) has proven to be an effective tool for monitoring the prevalence of SARS-CoV-2 in urban communities. However, low-cost, simple, and reliable wastewater sampling techniques are still needed to promote the widespread adoption of WBE in many [...] Read more.

During the COVID-19 pandemic, wastewater-based epidemiology (WBE) has proven to be an effective tool for monitoring the prevalence of SARS-CoV-2 in urban communities. However, low-cost, simple, and reliable wastewater sampling techniques are still needed to promote the widespread adoption of WBE in many countries. Since their first use for public health surveillance in the 1950s, many types of passive samplers have been proposed, however, there have been few systematic studies comparing their ability to co-capture enveloped viruses and bacteria. Here, we evaluated the laboratory and field performance of 8 passive sampler materials (NanoCeram, ZetaPlus, nylon and ion exchange membranes, cellulose acetate filters, glass wool, cotton-based Moore swabs and tampons) to capture viruses and bacteria from wastewater. Viral capture focused on SARS-CoV-2, the bacteriophage Phi6 and the faecal marker virus, crAssphage. We showed that the best performing passive sampler in terms of cost, ease of deployment and viral capture were the electronegative cotton-based swabs and tampons. We speculate that viral capture is a combination of trapping of particulate matter to which viruses are attached, as well as electrostatic attraction of viral particles from solution. When deployed at wastewater treatment plants, the passive samplers worked best up to 6 h, after which they became saturated or exhibited a loss of virus, probably due to night-time wash-out. The patterns of viral capture across the different sampling materials were similar providing evidence that they can be used to monitor multiple public health targets. The types of bacteria trapped by the passive samplers were material-specific, but possessed a different 16S rRNA gene profile to the wastewater, suggesting preferential retention of specific bacteria. We conclude that the choice of passive sampler and deployment time greatly influences the pattern and amount of viral and bacterial capture. Full article

(This article belongs to the Special Issue SARS-CoV-2 in Wastewater: Methods, Epidemiology and Future Goals)

► Show Figures

Figure 1

13 pages, 2114 KiB

Open AccessArticle

A Dual Media Filter using Zeolite and Mortar for the Efficient Removal of Heavy Metals in Stormwater Runoff

by Do-Gun Kim and Seok-Oh Ko

Water 2022, 14(21), 3567; https://doi.org/10.3390/w14213567 - 6 Nov 2022

Cited by 1 | Viewed by 1967

Abstract

Stormwater runoff from expressways contains high concentrations of various heavy metals. However, heavy metal removal in most current runoff treatment facilities, using infiltration and filtration, is limited and poses substantial risks. Therefore, this study proposes and evaluates a dual media system of mortar [...] Read more.

Stormwater runoff from expressways contains high concentrations of various heavy metals. However, heavy metal removal in most current runoff treatment facilities, using infiltration and filtration, is limited and poses substantial risks. Therefore, this study proposes and evaluates a dual media system of mortar and Na-zeolite, which are inexpensive and readily available, using long-term continuous column experiments for the removal of heavy metals. The results showed significant Cu²⁺ removal with Na-zeolites that was improved by the addition of a thin mortar layer, while a sand layer provided negligible improvements. The removal of Cu was further enhanced by increasing mortar layer thickness. The removal of Cu²⁺, Zn²⁺, Fe³⁺, and Ni²⁺ in a mixture was enhanced as the mortar layer’s thickness increased, while the contribution of Na-zeolite was significant in 232 h experiments with a fixed empty bed contact time (EBCT) of 1.8 min. Moreover, the media were not saturated with Fe throughout the operation period. These results suggest that the dual media system is cost-effective and efficient in the removal of heavy metals from stormwater runoff via precipitation, filtration, and adsorption with a short EBCT. Full article

(This article belongs to the Section Urban Water Management)

► Show Figures

Graphical abstract

18 pages, 8178 KiB

Open AccessArticle

Numerical Simulation Study on Interactions between the Wave and Newborn Sandbank in the Xisha Islands of the South China Sea

by Huiming Huang, Zhenwen Liu, Chun Chen, Xiang Lin, Siqi Li, Xiantao Huang, Mee Mee Soe and Mohammad Saydul Islam Sarkar

Water 2022, 14(21), 3566; https://doi.org/10.3390/w14213566 - 6 Nov 2022

Viewed by 1666

Abstract

As a unique landform in the island and reef area, the newborn sandbank is not only the initial stage of island development, but also has a rapid evolution and a complex dynamic mechanism. However, the dynamic geomorphology mechanism of the newborn sandbank is [...] Read more.

As a unique landform in the island and reef area, the newborn sandbank is not only the initial stage of island development, but also has a rapid evolution and a complex dynamic mechanism. However, the dynamic geomorphology mechanism of the newborn sandbank is still lacking extensive study and direct evidence of the interaction process between the marine dynamics and the newborn sandbank geomorphology. Therefore, in order to reveal the interaction mechanisms between marine dynamics and newborn sandbanks, a newborn sandbank in the sea area of the Xisha Islands, in the South China Sea, has been selected as the focus of this research. The method of numerical simulation was used to discuss and analyze the wave field characteristics around the newborn sandbank and their impacts on the sandbank’s migration and development. The results show that: (1) The islands and reefs have significant refraction, diffraction, and energy dissipation effects on waves, and the newborn sandbank has the same effect, but with a weaker function. The wave height around the reef islands reduced by approximately 60–67% in dominated and strong wave directions. At the same time, the wave height attenuation in the wave shadow zone, behind the newborn sandbank, can reach approximately 27–33%. (2) Wind is important for the evolution of wave fields; in particular, when the wind speed exceeds grades four and five, the effect of the wind on the waves is particularly significant, causing the winds to control the wave characteristics around the islands and newborn sandbanks. This results in significant seasonal differences in wave fields within the sea area. (3) The wave direction primarily controls the migration direction of the newborn sandbank, and the wave height primarily controls the migration speed and distance. After one month of wave action in the strong wave direction, the maximum eastward deposition length was approximately 50 m. After one month of wave action in the dominated wave direction, the maximum eastward deposition length was approximately 60 m. Therefore, the topography of the newborn sandbank affects the wave propagation, meanwhile, the wave conversely determines migration and development of the newborn sandbank in a short term. The dynamic geomorphology action between the wave and newborn sandbank is a fast two-way process, and occurs not only during storms or the winter monsoon, but also during other, more common, weather events. Full article

(This article belongs to the Special Issue Numerical Modelling of Ocean Waves and Analysis of Wave Energy)

► Show Figures

Figure 1

17 pages, 3984 KiB

Open AccessArticle

Quality Characterization of Groundwater for Drinking Purposes and Its Network Distribution to Assure Sustainability in Southern Region of Saudi Arabia

by Saad M. Alramthi, Gamila H. Ali, Ahmed M. Shaban, Tarek A. Abdou, Atiah M. Elthagafi, Saad H. Eldosari, Bao-Ku Zhu and Hosam M. Safaa

Water 2022, 14(21), 3565; https://doi.org/10.3390/w14213565 - 6 Nov 2022

Cited by 4 | Viewed by 3901

Abstract

Water demand per capita will rise in the Arab world as a result of climate change and population expansion. One of the most important aims in coping with population increase around the world is to conserve water supplies. As a result, the Kingdom [...] Read more.

Water demand per capita will rise in the Arab world as a result of climate change and population expansion. One of the most important aims in coping with population increase around the world is to conserve water supplies. As a result, the Kingdom of Saudi Arabia (KSA) constructed the Al Wajeed Water Treatment System to meet the demands of its southern population. This research aims to assess the drinking water quality produced from the Al Wajeed Water Treatment System. Monthly water samples were collected (January 2018 to January 2021) from the Al Wajeed Water Treatment Framework (4 sites), extending to governorates, Bishah`s distribution system (5 sites), and Tathleeth`s distribution system (7 sites). Water quality criteria, such as physical-, chemical-, and microbiological-parameters, revealed that the majority of water samples collected from the Al Wajeed Water Framework and its environs are of a good quality and matched the national and International standards. Few sites showed water quality criteria such as turbidity, fluoride, and total coliform, which did not comply with national and global standards. The obtained results explained the importance of monitoring and follow-up programs for drinking water criteria. In addition, they can help the authorities and stakeholders in the sustainable development. Full article

(This article belongs to the Special Issue Drinking Water Pipe Network and Water Quality Safety)

► Show Figures

Figure 1

16 pages, 3688 KiB

Open AccessArticle

Trace Element Compositions and Water Quality Assessment in the Angara River Source (Baikal Region, Russia)

by Vera I. Poletaeva, Mikhail V. Pastukhov and Pavel G. Dolgikh

Water 2022, 14(21), 3564; https://doi.org/10.3390/w14213564 - 6 Nov 2022

Cited by 4 | Viewed by 2437

Abstract

The relevance of studying the spatial-temporal dynamics in the trace element composition of the water at the Angara River source is associated not only with determining the degree of anthropogenic load on the local area of the water body but also with the [...] Read more.

The relevance of studying the spatial-temporal dynamics in the trace element composition of the water at the Angara River source is associated not only with determining the degree of anthropogenic load on the local area of the water body but also with the use of the water chemical composition of the Angara River source as an integral indicator of the hydrochemical state of the entire Lake Baikal. The current work is based on monthly monitoring studies conducted from March 2021 to February 2022 along the left shore, middle part, and right shore of the Angara River source. In water samples, the concentrations of Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Sn, Cs, Tl, Pb, Th, and U were measured by inductively coupled plasma mass spectrometry. The results indicated that the concentrations of the trace elements lie within mean + 1SD: Cd in 97% of samples; U in 94% of samples; Tl in 92%; Al, Cr, Co, Ni, Cu, Zn, Sn, Pb, and Cs in over 80%; Fe in 78% of samples; and Mn and Th in over 60% of samples. Such results show a high degree of consistency in the water trace element composition at the source of the Angara River. The major factors responsible for the water hydrochemistry at the Angara River source include the runoff of Lake Baikal, the anthropogenic effect of Listvyanka and Port Baikal settlements, and water transport activity. The concentrations of all trace elements in the water of the Angara River source are substantially below the standards for drinking water. At the same time, the single-factor pollution index revealed water samples with considerable contamination by Fe, Zn, Sn, Al, Cs, Mn, Cu, Tl, Cd, Pb, and Th and very high contamination by Cr, Fe, Co, Cs, Tl, Pb, and Th. The pollution load index has classified most of the water samples as having baseline levels of pollutants. Three samples taken from the left shore, four from the middle part, and seven from the right shore were classified as polluted. This means that the ongoing anthropogenic impact may worsen the water quality and have a negative impact on living organisms. The obtained results make a clear case for strengthening environmental protection measures to minimize the anthropogenic effect on the ecosystems of Lake Baikal and Angara River. Full article

(This article belongs to the Special Issue Water Quality Modeling and Monitoring)

► Show Figures

Figure 1

14 pages, 2618 KiB

Open AccessArticle

Effects of Rice Husk Biochar on Nitrogen Leaching from Vegetable Soils by ¹⁵N Tracing Approach

by Ying Ding, Siyu Zhu, Run Pan, Jiangping Bu, Yong Liu and Aifang Ding

Water 2022, 14(21), 3563; https://doi.org/10.3390/w14213563 - 5 Nov 2022

Cited by 5 | Viewed by 2378

Abstract

The application of biochar can affect soil properties and retention of fertilizer nitrogen, but its effects and mechanism on the retention capacity of different forms of nitrogen in soils are still uncertain. In this study, an indoor soil column leaching experiment was conducted [...] Read more.

The application of biochar can affect soil properties and retention of fertilizer nitrogen, but its effects and mechanism on the retention capacity of different forms of nitrogen in soils are still uncertain. In this study, an indoor soil column leaching experiment was conducted using vegetable soil samples with 3% rice husk biochar by mass prepared at 450 °C by pyrolysis and 150 mg N/kg ¹⁵N-labeled urea. Adding biochar increased the soil pH, thus alleviating soil acidification caused by fertilizer nitrogen application. It also increased the content of soil organic carbon, total nitrogen and available phosphorus while decreasing that of NH₄⁺-N and NO_X⁻-N(NO₃⁻-Nand NO₂⁻-N) in soils. NO_X⁻-N was the predominant form in the leachate of all treatments, accounting for 63.15–87.90% of the total N loss. Compared to the urea-alone application (the N treatment), incorporating biochar and urea (the RBN treatment) significantly reduced total N and NO_X⁻-N loss by 19.99% and 25.95%, respectively, while showing slight effects on NH₄⁺-N loss. The ¹⁵N results show that fertilizer N retention in soil increased by 13.67%, while inorganic ¹⁵N leaching decreased by 25.97% after the biochar addition, compared to that in the N treatment. The RBN treatment increased fertilizer N losses in other ways (e.g., organic N leaching, ammonia and NO_x volatilization) by 21.72%. Effects of biochar application on other N losses need to be further investigated. Biochar application can reduce the leaching of inorganic ¹⁵N and improve fertilizer N retention in the soil. Thus, the potential risk of fertilizer N on the quality of water bodies can be reduced. Full article

(This article belongs to the Section Soil and Water)

► Show Figures

Figure 1

16 pages, 3185 KiB

Open AccessArticle

An Analytical Solution to Predict the Distribution of Streamwise Flow Velocity in an Ecological River with Submerged Vegetation

by Jiao Zhang, Zhangyi Mi, Wen Wang, Zhanbin Li, Huilin Wang, Qingjing Wang, Xunle Zhang and Xinchun Du

Water 2022, 14(21), 3562; https://doi.org/10.3390/w14213562 - 5 Nov 2022

Cited by 2 | Viewed by 1834

Abstract

Aquatic submerged vegetation is widespread in rivers. The transverse distribution of flow velocity in rivers is altered because of the vegetation. Based on the vegetation coverage, the cross-section of the ecological channels can be divided into the non-vegetated area and the vegetated area. [...] Read more.

Aquatic submerged vegetation is widespread in rivers. The transverse distribution of flow velocity in rivers is altered because of the vegetation. Based on the vegetation coverage, the cross-section of the ecological channels can be divided into the non-vegetated area and the vegetated area. In the vegetated area, we defined two depth-averaged velocities, which included the water depth-averaged velocity, and the vegetation height-averaged velocity. In this study, we optimized the ratio of these two depth-averaged velocities, and used this velocity ratio in the Navier–Stokes equation to predict the lateral distribution of longitudinal velocity in the open channel that was partially covered by submerged vegetation. Based on the Navier–Stokes equations, the term “vegetation resistance” was introduced in the vegetated area. The equations for the transverse eddy viscosity coefficient ξ, friction coefficient f, drag force coefficient C_d, and porosity α were used for both the non-vegetated area and the vegetated area, and the range of the depth-averaged secondary flow coefficient was investigated. An analytical solution for predicting the transverse distribution of the water depth-averaged streamwise velocity was obtained in channels that were partially covered by submerged vegetation, which was experimentally verified in previous studies. Additionally, the improved ratio proposed here was compared to previous ratios from other studies. Our findings showed that the ratio in this study could perform velocity prediction more effectively in the partially covered vegetated channel, with a maximum average relative error of 4.77%. The improved ratio model reduced the number of parameters, which introduced the diameter of the vegetation, the amount of vegetation per unit area, and the flow depth. This theoretical ratio lays the foundation for analyzing the flow structure of submerged vegetation. Full article

(This article belongs to the Special Issue Fluvial Hydraulics in the Presence of Vegetation in Channels)

► Show Figures

Figure 1

22 pages, 4638 KiB

Open AccessArticle

The Key Parameters Involved in a Rainfall-Triggered Landslide

by Elisangela do Prado Oliveira, Andrés Miguel González Acevedo, Virnei Silva Moreira, Vitor Pereira Faro and Alessander Christopher Morales Kormann

Water 2022, 14(21), 3561; https://doi.org/10.3390/w14213561 - 5 Nov 2022

Cited by 3 | Viewed by 2466

Abstract

In addition to the intensity of precipitation, the different hydraulic and mechanical properties of a soil hill can also be responsible for landslides. More specifically, the same rainfall amount can trigger or not trigger a mass movement depending on its characteristics. This issue [...] Read more.

In addition to the intensity of precipitation, the different hydraulic and mechanical properties of a soil hill can also be responsible for landslides. More specifically, the same rainfall amount can trigger or not trigger a mass movement depending on its characteristics. This issue represents a great geotechnical hazard in mountainous regions such as Brazil, Italy, South Africa, Japan and Hong Kong. The understanding of each of the key factors involved in a rainfall-triggered landslide can be deepened and also quantified. Thus, this research defines, through a numerical model, which parameters are the key factors involved in slope stability. A homogeneous and unsaturated hill was studied. Its different hydraulic and mechanical properties were varied. Geometry and mechanical parameters were shown to exert the greatest influence on stability. Hydraulic parameters, for the same amount of rain, showed a lower influence. The fitting parameters of the soil–water characteristic curve of the materials had a low impact on stability when compared to other parameters assessed. Our conclusions can help future laboratory and field studies to focus more on the accuracy and confidentiality of the key parameters. The results are also important as they give direction to studies related to precipitation threshold definition. Full article

(This article belongs to the Special Issue Landslides Induced by Surface and Groundwater)

► Show Figures

Figure 1

24 pages, 7601 KiB

Open AccessArticle

Wet Grassland Sites with Shallow Groundwater Conditions: Effects on Local Meteorological Characteristics

by Ottfried Dietrich and Axel Behrendt

Water 2022, 14(21), 3560; https://doi.org/10.3390/w14213560 - 5 Nov 2022

Cited by 1 | Viewed by 1438

Abstract

Agriculturally used wet grassland sites (WGSs) with shallow water tables are considered to be sites with a special microclimate. Meteorological measurement series, examining the air temperature (Ta) and vapour pressure (VP) in three regions, reveal differences between WGSs and outside the lowland. The [...] Read more.

Agriculturally used wet grassland sites (WGSs) with shallow water tables are considered to be sites with a special microclimate. Meteorological measurement series, examining the air temperature (Ta) and vapour pressure (VP) in three regions, reveal differences between WGSs and outside the lowland. The results show that the average annual Ta at all three WGSs is significantly lower than in their surrounding area (0.7 to 1.0 K). The differences are minimally larger in the summer half-year than in the winter half-year (1.0 vs. 0.7 K in the Spreewald region, 0.7 vs. 0.6 K in the Havelland region). The differences cannot only be explained by higher evapotranspiration (ET), but are mainly due to the ground heat balance of the sites with shallow water tables and organic soils. The VPs of the WGSs and the surrounding area only differ significantly from each other in the summer months and do not vary as clearly as the Ta. While the VP is higher in the Spreewald wetland than in the surrounding area (+0.05 kPa), it is lower in Paulinenaue than in that surrounding area (−0.04 kPa). The reason for this is different ET due to the different site conditions. Full article

(This article belongs to the Section Ecohydrology)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Water, Volume 14, Issue 21 (November-1 2022) – 239 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI