Surface Water Concentrations Research Articles

Model evaluation of total phosphorus prediction based on model accuracy and interpretability for the surface water in the river network of the Jiangnan Plain, China.

Due to climatic and hydrological changes and human activities, eutrophication and frequent outbreaks of cyanobacteria are prominent in the Jiangnan Plain basin of China. Therefore, building a suitable model to accurately predict the phosphorus concentration in surface water is of practical significance to prevent the above problems. This study built 10 models to predict the phosphorus element in the surface water of the river network in the Jiangnan Plain. The main water types in the basin include the Yangtze River, the Beijing-Hangzhou Canal, and the Gehu Lake. The 10 models in different datasets have been comprehensively evaluated by the prediction accuracy and interpretability of the model, and the calculation of the partial dependence diagram (PDP) and SHAP has proved that there is a transparent response relationship between phosphorus and different factors. The results show that the Yangtze River, Beijing-Hangzhou Canal, and Gehu Lake are suitable for random forest, linear regression, and random forest models, respectively, under the comprehensive evaluation of the prediction accuracy and interpretability of the model. Models with low prediction accuracy often show strong interpretability. In different water body types, turbidity, water temperature, and chlorophyll-a are the three factors that affect the model in predicting phosphorus.

Health Risks from Intake and Contact with Toxic Metal-Contaminated Water from Pager River, Uganda.

Pollution of water resources is one of the major impediments to the realization of Sustainable Development Goals, especially in developing countries. The aim of this study was to investigate the physicochemical quality and potentially toxic element (lead and cadmium) concentrations in surface water sampled from Pager River, a tributary of the Nile River in Northern Uganda. Water samples (n = 18) were taken from six different points upstream (A, B, and C) and downstream (D, E, and F) of the river and analyzed following standard methods for their physiochemical properties. Atomic absorption spectroscopy was used to quantify lead and cadmium concentrations. Human health risks from ingestion and dermal contact with potentially toxic metal-contaminated water were calculated. The results obtained indicated that the mean temperature (27.7 ± 0.5-29.5 ± 0.8 °C), turbidity (40.7 ± 2.1-50.1 ± 1.1 NTU), lead (0.296 ± 0.030-0.576 ± 0.163 mg/L) and cadmium (0.278 ± 0.040-0.524 ± 0.040 mg/L) occurred at levels that surpassed their permissible limits as per World Health Organization guidelines for drinking water. Human health risk assessment showed that there are potential non-cancer risks from the ingestion of water from Pager River by adults, as the total hazard quotients were greater than one. These results emphasize the urgency to restrict the dumping of wastes into the river to minimize chances of impacting the Nile River, which flows northwards to the Mediterranean Sea. Further studies should perform routine monitoring of the river during both dry and wet seasons to establish the spatiotemporal variations of physicochemical, microbial, and trace metal profiles of the river and the associated health risks.

Inputs, amplification and sinks of perfluoroalkyl substances at coastal Antarctica

The sources, biogeochemical controls and sinks of perfluoroalkyl substances, such as perfluoroalkyl acids (PFAAs), in polar coastal regions are largely unknown. These were evaluated by measuring a large multi-compartment dataset of PFAAs concentrations at coastal Livingston and Deception Islands (maritime Antarctica) during three austral summers. PFAAs were abundant in atmospheric-derived samples (aerosols, rain, snow), consistent with the importance of atmospheric deposition as an input of PFAAs to Antarctica. Such PFAAs deposition was unequivocally demonstrated by the occurrence of PFAAs in small Antarctic lakes. Several lines of evidence supported the relevant amplification of PFAAs concentrations in surface waters driven by snow scavenging of sea-spray aerosol-bound PFAAs followed by snow-melting. For example, vertical profiles showed higher PFAAs concentrations at lower-salinity surface seawaters, and PFAAs concentrations in snow were significantly higher than in seawater. The higher levels of PFAAs at Deception Island than at Livingston Island are consistent with the semi-enclosed nature of the bay. Concentrations of PFOS decreased from 2014 to 2018, consistent with observations in other oceans. The sink of PFAAs due to the biological pump, transfer to the food web, and losses due to sea-spray aerosols alone are unlikely to have driven the decrease in PFOS concentrations. An exploratory assessment of the potential sinks of PFAAs suggests that microbial degradation of perfluoroalkyl sulfonates should be a research priority for the evaluation of PFAAs persistence in the coming decade.

Upward migration of calanoid copepods is driven by high food quality in surface waters in an alpine lake

Abstract The diel vertical migration of zooplankton includes downward migration to deep water during the day and upward migration to surface water at night. Diurnal downward migration has been well explained; zooplankton migration to surface water at night remains unclear. This study aimed to explore the reason of the nocturnal upward migration of the calanoid copepod Arctodiaptomus sp. In Lake Heihai, an alpine lake (elevation 4,090 m above sea level) without predators. Herein, we present the vertical profiles of the lake, including water temperature, chlorophyll a (Chl‐a), fatty acids, and astaxanthin synthesis precursors (ASPs) of seston in the water column. The distributions and concentrations of fatty acids and astaxanthin in Arctodiaptomus sp. were characterised through field investigations during the day and at night. Meanwhile, the effect of ultraviolet radiation (UVR) on ASPs in seston was explored through indoor experiments. Lake Heihai had the characteristics of low temperature, low food availability, high transparency, and high UVR intensity. Arctodiaptomus sp. was distributed in water layers below 6 m during the day and throughout the water column at night. Arctodiaptomus sp. accumulated large amounts of fatty acids, especially polyunsaturated fatty acids (PUFAs), and inhibitors of fatty acid oxidation–astaxanthin in the cold alpine lake. The concentrations of lutein, a kind of ASP, and PUFAs in seston were highest in surface waters. The indoor experiment verified that UVR can enhance the synthesis of ASP. The calanoids migrated to surface waters at night to obtain ASPs and PUFAs in seston, which were at high concentrations in surface waters. PUFAs and ASP may be of high food quality for zooplankton in alpine lakes. The findings indicated that the upward migration of Arctodiaptomus sp. at night was driven by the high quality of food sources (PUFAs and ASP) in surface waters. Arctodiaptomus sp. adapts behaviour and physiology to the environment of the alpine lake. We explored why zooplankton migrated to surface waters at night from the perspective of their physiological characteristics and adaptability to the environment. Our findings provide a new way to investigate the diel vertical migration of zooplankton, especially in alpine lakes.

Experimental Study on the Cleaning Performance of Hot Air Flow Cleaning Device

When processing wet rice, the efficiency of the combine harvester diminishes due to the heightened surface water content of the paddy. To address this, a hot air flow cleaning apparatus was engineered, and the effects of its operational parameters on cleaning performance were investigated. Outlet temperature, fan speed, louver sieve temperature, louver sieve inclination, and eccentric wheel speed were selected as experimental factors, and a single-factor test was carried out, with cleaning loss rate and impurity rate as test indexes. The results of the single-factor test show that louver sieve inclination and eccentric wheel speed had no obvious influence on the cleaning loss rate or impurity rate. The cleaning loss rate decreased with the increase in outlet temperature and louver sieve temperature but increased with the increase in fan speed. The cleaning impurity rate increased with the increase in outlet temperature and louver sieve temperature but decreased with the increase in fan speed. Based on the results of the single-factor test, a central composite rotatable test was adopted to attain the optimal operation parameters of the hot air flow cleaning equipment. Parameters like outlet temperature, fan speed, and louver sieve temperature were established as test factors, with the loss and impurity rates chosen as the evaluation metrics. Optimization using response surface methodology yielded the following parameters: an outlet temperature of 40.7 °C, a fan speed of 1300 rpm, and a louver sieve temperature of 50 °C. Under these conditions, the loss rate was observed to be 0.75% and the impurity rate stood at 1.75%. These findings can guide the design of cleaning mechanisms and the determination of operational parameters.

Numerical modeling of laundry drying in a commercial laundry plant: Incorporating water potential as a driving force for heat and mass transfer

Increasing energy efficiency and reducing emissions in industrial processes through waste-heat recovery systems are vital. The energy-intensive nature of professional laundry care generates waste heat from machines such as washers, dryers, and boilers. We focused on a waste-heat recovery system tailored for this sector. An accurate drying model is essential for analyzing its energy-saving potential.This study presents a water-potential-based drying model using equilibrium thermodynamics. Two measurement experiments and numerical simulations were conducted to verify the accuracy of the proposed model, and the experimental results were incorporated into the simulations. The first experiment collected and determined laundry samples' basic information and hygrothermal properties, including the surface area, initial weight, and heat and moisture transfer coefficients. The second experiment attempted to determine each laundry item's equilibrium water content and capacity at various humidity levels. Through simulations, a comparison was made between the surface temperature and water content predictions of the existing and proposed models. Experimental results revealed that the laundry surface temperature remained constant during the constant-rate drying period. However, during the falling rate period, it was influenced by water content. The drying characteristics differ based on the material and quilting method. The proposed model improved the temperature and water content predictions by approximately 80.07% and 63.08%, respectively, compared with the existing model. This model can effectively assess laundry drying processes, including the latent heat flux assessment of the indoor environment.

Application of classification machine learning algorithms for characterizing nutrient transport in a clay plain agricultural watershed

Excess nutrients in surface water and groundwater can lead to water quality deterioration in available water resources. Thus, the classification of nutrient concentrations in water resources has gained significant attention during recent decades. Machine learning (ML) algorithms are considered an efficient tool to describe nutrient loss from agricultural land to surface water and groundwater. Previous studies have applied regression and classification ML algorithms to predict nutrient concentrations in surface water and/or groundwater, or to categorize an output variable using a limited number of input variables. However, there have been no studies that examined the application of different ML classification algorithms in agricultural settings to classify various output variables using a wide range of input variables. In this study, twenty-four ML classification algorithms were implemented on a dataset from three locations within the Upper Parkhill watershed, an agricultural watershed in southern Ontario, Canada. Nutrient concentrations in surface water were classified using geochemical and physical water parameters of surface water and groundwater (e.g., pH), climate and field conditions as the input variables. The performance of these algorithms was evaluated using four evaluation metrics (e.g., classification accuracy) to identify the optimal algorithm for classifying the output variables. Ensemble bagged trees was found to be the optimal ML algorithm for classifying nitrate concentration in surface water (accuracy of 90.9%), while the weighted KNN was the most appropriate algorithm for categorizing the total phosphorus concentration (accuracy of 87%). The ensemble subspace discriminant algorithm gave the highest overall classification accuracy for the concentration of soluble reactive phosphorus and total dissolved phosphorus in surface water with an accuracy of 79.2% and 77.9%, respectively. This study exemplifies that ML algorithms can be used to signify exceedance of recommended concentrations of nutrients in surface waters in agricultural watersheds. Results are useful for decision makers to develop nutrient management strategies.

Germanium: distribution, migration and accumulation in the natural environment

In this paper we attempt to generalize information published in the scientific literature about the distribution, migration and accumulation of chemical forms of germanium in the natural environment, with the main attention paid to the content of this trace element in various components of the environment. Despite the fact that germanium is found in the lithosphere, hydrosphere and atmosphere it is one of the least studied elements in mineral and geochemical terms. It belongs to rare scattered elements with a relatively high migration capacity in the earth's crust and on its surface. Depending on the physical and chemical conditions, the mineral and lithogenesis of germanium can exhibit different properties, which determines the variety of ways of its migration. The nature and form of migration of germanium in the natural environment is not determined only by its chemical properties but also by a complex set of reactions of interaction with various underground water addendums, the granulometric and chemical-mineralogical composition of soil-forming rocks and soils, biogenic and technogenic processes. Studies have shown that the content of germanium in natural waters, soils and plants can vary widely and depends on many factors. In particular, its concentration in groundwater and surface water depends on the natural geological environment, pressure, temperature, meteorological and anthropogenic factors; soil by their type, region, features of soil-forming processes, chemical composition of the parent rocks, climatic conditions and amounts of organic substances; in plants by their species and varietal facilities, the growth stage of the plants, the availability of soils by this element, the forms of germanium compounds in the soil (inorganic or organic), the ability of soil to retain labile form of germanium and climatic conditions. Analysis of the actual content of germanium in diets indicates an insufficient level of provision of the human body with this trace element, due to its low concentrations in food and water. However, it has been suggested that any products with a high content of germanium may pose a risk to human health through its toxic effects.

Impacts of Basal Melting of the Totten Ice Shelf and Biological Productivity on Marine Biogeochemical Components in Sabrina Coast, East Antarctica

AbstractTo clarify the impacts of basal melting of the Antarctic ice sheet and biological productivity on biogeochemical processes in Antarctic coastal waters, concentrations of dissolved inorganic carbon (DIC), total alkalinity (TA), inorganic nutrients, chlorophyll a, and stable oxygen isotopic ratios (δ18O) were measured from the offshore slope to the ice front of the Totten Ice Shelf (TIS) during the spring/summer of 2018, 2019, and 2020. Modified Circumpolar Deep Water (mCDW) intruded onto the continental shelf off the TIS and flowed along bathymetric troughs into the TIS cavity, where it formed a buoyant mixture with glacial meltwater from the ice shelf base. Physical oceanographic processes mostly determined the distributions of DIC, TA, and nutrient concentrations. However, photosynthesis and dilution by meltwater from sea ice and the ice shelf base decreased DIC, TA, and nutrient concentrations in surface water near the ice front. These causes also reduced the partial pressure of CO2 (pCO2) in surface water by more than 100 μatm with respect to mCDW in austral summer of 2018 and 2020, and the surface water became a strong CO2 sink for the atmosphere. Phytoplankton photosynthesis changed DIC and TA in a molar ratio of 106:16. Thus, pCO2 decreased mostly as a result of photosynthesis while dilution by glacial and sea ice meltwater had a small effect. The nutrient consumption ratio suggested that photosynthesis was stimulated by iron in the water column, supplied to the surface layer via buoyancy‐driven upwelling and basal ice shelf meltwater in addition to sea ice meltwater.

Utilization of Remote Sensing Data in the Simulation of the Water and Heat Regime of Land Areas: A Review of Publications

The article presents a revue of the estimates of soil surface moisture, soil water content, and evapotranspiration as elements of water and heat regimes of land surface areas at various spatial scales, made with the use of remote sensing data for Earth in various spectral ranges. In most cases considered in the study, such estimates were obtained with the use of land surface models. A special section is focused on the results of estimating soil surface moisture and water content using satellite data from microwave range, including radar data. Estimates of soil surface moisture content obtained with the use of neural networks are presented. A brief description is given to international hydrological–atmosphere experiments carried out under world research projects aimed to obtain data on the processes of moisture and heat exchange between the land surface and the surface atmosphere layer. Land surface, satellite, and model databases that have been formed using the results of studies in the field under consideration since the mid-1980s are reviewed. Prospects of further studies based on the development of new multispectral instrumentation, the creation of new databases, and the use of a new generation of satellites—global-coverage microsatellites with high-resolution sensors are presented.

Seasonal characterization of mercury contamination along the Portuguese coast: human health and environmental risk assessment

A seasonal characterization of mercury (Hg) accumulation in three different estuaries along the Portuguese coast (i.e. Ria de Aveiro, Tagus estuary and Ria Formosa) was done. For that, it was evaluated: (1) Hg concentrations in abiotic (water) and biotic matrices (flora and fauna); (2) the risk of consumption of local seafood species (e.g. bivalves) to human health; and (3) the environmental risk to Hg exposure. During 1 year, water and biological samples were collected during low tide, in each system for Hg quantification. Our findings revealed that total Hg concentrations in surface waters were higher in Ria de Aveiro and Tagus estuary than in Ria Formosa. In Ria de Aveiro, a particular attention should be given in autumn periods, where Hg levels (≈ 100 µg L−1) were considered quite high according to European quality parameters. The same was observed for the Tagus estuary during spring time. Regarding macrofauna Hg levels, no clear seasonal trend was observed. Also, total Hg concentrations in edible species (< 0.5 µg. g−1 ww) represent no risk for consumption. However, considering the environmental risk, in Ria de Aveiro, there is a moderate risk (RQ > 0.1) in autumn periods, which can be a matter of concern.

Douglas-fir plantations impact stream and groundwater chemistry in western Europe: Insights from three case studies in France and Luxembourg

In rural areas, nitrate concentrations in surface waters most often originate from the leaching of excess N fertilizer in agricultural lands, whereas forested catchments often have good water quality. However, Douglas-fir plantations may induce nitrogen cycle unbalances which may lead to an excess of nitrate production in the soil. We hypothesize that the excess of production of nitrate in the soil and nitrate leaching to streamwater is greater in catchments planted with Douglas fir. We used paired catchments in both France and Luxembourg with different land covers (Douglas-fir, Spruce, Deciduous, Grassland and clearcut) which were monitored over a 3–5 year period in order to assess the effect of Douglas-fir plantations on the chemical composition of surface water. Nitrate concentration in the soil and groundwater were also monitored. The results show that nitrate concentrations in streams draining Douglas-fir catchments were two to ten times higher than in streams draining other land covers, but were similar to the clearcut catchment. Nitrate concentrations under Douglas-fir in groundwater (up to 50 mg L−1) and in the soil were also higher than under all other land covers. Soil nitrate concentration was related to stream nitrate concentration. This suggests that soil processes, through excessive nitrate production under Douglas-fir, are driving the nitrate concentration in the stream water and our hypothesis of a transfer of a fairly large proportion of this excessive production from the soil to the stream is supported. This study also shows that nitrate concentrations in surface and ground waters in rural areas could also originate from Douglas fir forested catchments. The impact of Douglas-fir is nevertheless reduced downstream through a dilution effect: mixing tree species at the catchment scale could thus be a solution to mitigate the effect of Douglas-fir on nitrate concentration in surface waters.

Anthropogenic carbon estimation in the surface ocean from atmospheric CO2 fugacity at the BATS (Bermuda Atlantic Time-series Study) station

In surface seawater, it is usually very difficult to quantify anthropogenic carbon concentrations. Many processes (such as air-sea exchanges of gases and heat, biological activity, and mixing of water masses), are at play and often on different timescales. Thus, various hypotheses are used to estimate the anthropogenic concentrations in surface waters. Here, using the relatively long (1980s to present) time series data sets from the Bermuda Atlantic Time-series Study site (BATS; 31°40′N, 64°10′W) in the North Atlantic Ocean, we evaluate results based upon two different hypotheses. The results clearly confirm that it is very difficult to assess anthropogenic carbon concentrations in surface waters from sole oceanic properties. However, this study further indicates that at this ocean site, they can be appropriately determined from low-frequency variations of atmospheric CO2 concentrations. Consequently, the impact of anthropogenic carbon penetration in surface waters on their acidification could be predicted.

Enhanced Methanol Oxidation Using Polymer-Incorporated Ultra Rough Pt Electrodes

We report on the methanol oxidation reaction (MOR) on very rough Pt surfaces. Numerous previous studies show that the cyclic voltammetry of MOR on Pt exhibits hysteretic behavior due to Pt oxide poisoning during the anodic scan at higher potentials. Only after the Pt oxide is removed during the cathodic scan is the Pt surface reactivated and MOR activity resumed (Fig. 1). We developed an electrodeposition method yielding Pt electrodes with high roughness factors (Rf > 80) controlled by varying deposition time. These rough electrodes exhibit linear MOR without hysteresis (Fig. 1), indicating the rougher Pt surface is resistant to poisoning during MOR up to potentials of 1.4 V vs. RHE. The effect is found in either acidic or basic electrolyte. Further studies show the roughness effect is related effective increase in the surface concentration of methanol and effective decrease in the surface concentration of water. The lower water activity inhibits Pt surface oxidation and facilitates methanol oxidation. Treatments to artificially decrease surface water concentration have a similar effect. This study provides methods to increase the rate of organic molecule oxidation at electrode surfaces and is relevant to both electro synthesis and direct methanol fuel cell applications. Figure 1

Rapid Environmental Impact Assessment of Penicillin G in a Veterinary Product Using an Original Software Method and Monitoring by SPE-Online-UHPLC-MS/MS.

Veterinary antibiotics have become a major concern due to potential environmental effects. This study presents an investigation of the exposure and environmental effects of the veterinary medicinal product in powder form, administered in the drinking water of piglets, chickens and turkeys, containing 250 mg/g penicillin G (benzylpenicillin potassium), performed according to the European Medicines Agency (EMEA) guideline and the results obtained by an analytical method based on online solid-phase extraction, ultra-high performance liquid chromatography coupled to a triple quadrupole mass spectrometer (SPE-online-UHPLC-MS/MS). The study presents the determination of the environmental risk and through an original, interactive, fast software method, created on the basis of a proprietary calculation algorithm that goes through all the prescriptions and recommendations of the EMEA guide. The results demonstrated that the concentration value for penicillin G determined in surface water by SPE-online-UHPLC-MS/MS is much lower than that predicted by calculation (predictable concentration in surface water, PECsurface water = 37.66 µg/L and the concentration SPE-online-UHPLC-MS/MS = 0.032 µg/L). Both results lead to a sub-unit risk quotient (R) indicating that the treatment carried out with the considered veterinary product does not present any risk to the environment.

An Application of Machine-Learning Model for Analyzing the Impact of Land-Use Change on Surface Water Resources in Gauteng Province, South Africa

The change in land-use diversity is attributed to the anthropogenic factors sustaining life. The surface water bodies and other crucial natural resources in the study area are being depleted at an alarming rate. This study explored the implications of the changing land-use diversity on surface water resources by using a random forest (RF) classifier machine-learning algorithm and remote-sensing models in Gauteng Province, South Africa. Landsat datasets from 1993 to 2022 were used and processed in the Google Earth Engine (GEE) platform, using the RF classifier. The results indicate nine land-use diversity classes having increased and decreased tendencies, with high F-score values ranging from 72.3% to 100%. In GP, the spatial coverage of BL has shrunk by 100.4 km2 every year over the past three decades. Similarly, BuA exhibits an annual decreasing rate of 42.4 km2 due to the effect of dense vegetation coverage within the same land use type. Meanwhile, water bodies, marine quarries, arable lands, grasslands, shrublands, dense forests, and wetlands were expanded annually by 1.3, 2.3, 2.9, 5.6, 11.2, 29.6, and 89.5 km2, respectively. The surface water content level of the study area has been poor throughout the study years. The MNDWI and NDWI values have a stronger Pearson correlation at a radius of 5 km (r = 0.60, p = 0.000, n = 87,260) than at 10 and 15 km. This research is essential to improve current land-use planning and surface water management techniques to reduce the environmental impacts of land-use change.

Evaluation of uranium content and annual ingestion dose in the surface and ground water bodies of Chittorgarh, Rajasthan, India.

Uranium, naturally occurring radionuclide is chemotoxic and nephrotoxic beyond acceptable limit. The presence of uranium beyond acceptable limit in surface and ground water, adversely affecting people's health. In the present investigation, the uranium concentration in surface and ground water of Chittorgarh, Rajasthan was studied along with the physico-chemical parameters of water (n = 87). The ground water was further sub-categorised into well water, handpump water, and borewell water. The mean uranium concentration was observed at 2.5 ± 1.9 µgL-1 and 16.5 ± 1.4 µgL-1 in the surface and ground water samples, respectively. In sub-categories of ground water, the highest uranium concentration was found in borewell water (23.3 ± 17.0 µgL-1), followed by handpump water (13.5 ± 9.1 µgL-1) and well water (6.0 ± 5.5 µgL-1). The uranium concentration was correlated significantly with the depth of the ground water table. It also correlated significantly with electrical conductivity, total dissolved solids and nitrate concentration. 100% of surface water and 88.9% of ground water samples carried uranium concentration within the acceptable limit of WHO (30 µgL-1). The annual ingestion dose was found at 3.8 µSvy-1 (for males) and 2.8 µSvy-1 (for females) in surface water and 25.4 µSvy-1 (for males) and 18.5 µSvy-1 (for females) in ground water. In the sub-categories of the ground water sample, the annual ingestion dose followed the trend in males 35.8 µSvy-1 (borewell water) > 20.7 µSvy-1 (hand pump water) > 9.2 µSvy-1 (well water) and in females 26.1 µSvy-1 (borewell water) > 15.1 µSvy-1 (hand pump water) > 6.7 µSvy-1 (well water).

Effect of the surface water content on dry saltation cloud dynamics: A wind tunnel simulation with particle tracking velocimetry

AbstractThe mass transport rate of wind‐borne particles, and indeed the fluid stress required for their entrainment, is strongly governed by inter‐particle cohesion arising from water retained through adsorption and capillary force. This paper reports on a series of wind tunnel experiments in which high‐speed photography was used to record the motion of dry sand particles as they impinged on test beds of systematically varied target gravimetric pore water content (0% ≤ W ≤ 10%). The wind friction velocity was preset to 0.33 m s−1, sufficient to maintain a saltation cloud above an upwind strip of dry sand, which then was blown over the wetted surface. Discrete particle trajectories were identified in the camera images using expected particle area searching–particle tracking velocimetry (EPAS‐PTV). Adding progressively more water produced an exponential decrease in the normalized particle number density over the test surface. The largest response was achieved by wetting the bed surface to just 2%. To reduce the number of particles by a further 40%, it was necessary to add eight times more water, signifying a diminishing return regarding water use. Relative to particles either rebounding or splashed from a dry bed, the total particle velocity increased incrementally by a factor between 1.5 and 2 with increasing water content. Increasing amounts of pore water were associated with progressively higher saltation trajectories, reaching a plateau beyond W ~8%. The spatio‐temporal adjustment in the sand cloud was observed to be extremely rapid. There is no consensus in the literature on how to measure the water content that effectively governs aeolian transport. In this study, all approaches to sampling W produced strong correlation (R2 ≥ 0.85). Sampling the topmost grains, however, provided the most accurate prediction of the normalized number density over the full range of water content.

Bisphenol A in surface waters in Germany: Part I. Reassessment of sources and emissions pathways for FlowEQ modeling.

Bisphenol A (BPA) enters the environment through various industrial and consumer-related pathways. Industrial sources include BPA manufacturing and secondary industrial uses such as the manufacturing of polymers and other substances based on or containing BPA. However, secondary sources and emissions to the environment, such as those related to the consumer use of articles containing BPA, may be more important than industrial emissions. Although readily biodegradable, BPA is widely distributed in various environmental compartments and living organisms. It is still not well understood which specific sources and pathways are responsible for releasing BPA into the environment. Therefore, we developed FlowEQ, a coupled flow network and fugacity-based fate and transport model for the assessment of BPA in surface water. The work is divided into two parts. In Part I, inputs needed to support the modeling and model validation were collected. Bisphenol A was measured at 23 wastewater treatment plants (WWTPs) and 21 landfills in Germany. In addition, the BPA content of 132 consumer articles from 27 article classes was analyzed. Bisphenol A concentrations in WWTPs ranged from 0.33 to 910 µg L-1 in influents and from less than 0.01 to 0.65 µg L-1 in effluents, resulting in removal efficiencies of 13%-100%. Average BPA concentrations in landfill leachate ranged from less than 0.01 to approximately 1400 µg L-1 . Bisphenol A concentrations measured in consumer articles varied significantly by type, ranging from less than 0.5 µg kg-1 in printing inks up to 1 691 700 µg kg-1 in articles made from recycled polyvinyl chloride (PVC). These concentrations were combined with information on use, leaching, and contact with water to develop estimates of loadings. Together with the results of the FlowEQ modeling presented in Part II, this assessment improves our understanding of the sources and emission pathways of BPA in surface water. The model considers various sources of BPA and can estimate future surface water concentrations of BPA based on changes in use. Integr Environ Assess Manag 2024;20:211-225. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Field conditions is a risk factor for traumatic injury in youth football-A joint venture of medicine and hydrology.

The risk of traumatic injury in football has been suggested to be affected by field conditions. This study, therefore, aimed to investigate whether near surface water content of the football field, influenced the risk of traumatic injuries during a youth football tournament. At Dana Cup, an annual international youth football tournament in Denmark, all injuries were registered and classified at the on-site emergency department over 7 years. The incidence rate of traumatic injury was computed. Meteorological data and soil characteristics were used to simulate near surface water content of the playing fields. The incidence rate ratio (IRR) between water content and injury incidence rate was analyzed using a multivariate Poisson regression, controlling for tournament stage and demographical parameters. About 2704 injuries were recorded corresponding to a risk time of 284 905 player hours. An inverse relation between water contents and the incidence rate of traumatic injury was found (IRR = 0.24 95% CI 0.1-0.7, p = 0.01). The incidence rate of traumatic injury increased with advancing tournament stage, that is, for the finals (IRR = 4.30 95% CI 2.8-6.6, p < 0.001). Also we found an interaction between dry fields and the final stage of tournament, further exacerbating this effect. Our data suggest that the incidence rate of traumatic injury is increased with drier field conditions and advanced tournament stages.