Adjacent Water Research Articles

Levels and Compositions of Polycyclic Aromatic Hydrocarbons in Rainwater and Their Implication for Aquatic Environments in Urban Area in Saitama, Japan

In this study, we investigated concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) in rainwater and surface water samples collected in Saitama, an urban city located in Japan. The volume-weighted mean concentration of total PAHs in rainwater samples (dissolved + particulate) was 108.8 ng L−1 with a range of 17.6–192.9 ng L−1. Two and three benzene ring PAHs were predominantly detected, occupying 67.0% of the total concentration in rainwater samples. Individual PAH concentrations were negatively correlated with their K ow, suggesting that low-molecular-weight PAHs are preferentially scavenged owing to the higher hydrophilicity. The toxic equivalent calculated based on the relative potencies of individual PAHs showed high toxic contributions by chrysene and benz[a]anthracene in the rainwater samples. Those PAHs levels in rainwater were comparable or higher than those in adjacent river water. Correlation coefficient of PAH signatures between rainwater and surface water samples was high particularly in the dissolved phase, supporting the source/sink relationships of PAHs between wet deposition samples and receiving waters. The mean deposition flux of PAHs was 2000 ng m−2 and considered to increase with precipitation amounts.

Satellite Geological Indication of Morphostructural Elements of the Coasts and Bottom of Adjacent Water Areas (Peter the Great Bay, Sea of Japan)

Satellite Geological Indication of Morphostructural Elements of the Coasts and Bottom of Adjacent Water Areas (Peter the Great Bay, Sea of Japan)

Ground-State Structures of Hydrated Calcium Ion Clusters From Comprehensive Genetic Algorithm Search.

We searched the lowest-energy structures of hydrated calcium ion clusters Ca2+(H2O)n (n = 10–18) in the whole potential energy surface by the comprehensive genetic algorithm (CGA). The lowest-energy structures of Ca2+(H2O)10–12 clusters show that Ca2+ is always surrounded by six H2O molecules in the first shell. The number of first-shell water molecules changes from six to eight at n = 12. In the range of n = 12–18, the number of first-shell water molecules fluctuates between seven and eight, meaning that the cluster could pack the water molecules in the outer shell even though the inner shell is not full. Meanwhile, the number of water molecules in the second shell and the total hydrogen bonds increase with an increase in the cluster size. The distance between Ca2+ and the adjacent water molecules increases, while the average adjacent O-O distance decreases as the cluster size increases, indicating that the interaction between Ca2+ and the adjacent water molecules becomes weaker and the interaction between water molecules becomes stronger. The interaction energy and natural bond orbital results show that the interaction between Ca2+ and the water molecules is mainly derived from the interaction between Ca2+ and the adjacent water molecules. The charge transfer from the lone pair electron orbital of adjacent oxygen atoms to the empty orbital of Ca2+ plays a leading role in the interaction between Ca2+ and water molecules.

Plant transpiration in constructed treatment wetland: Effects on water budget and management consequences

Plant transpiration is an important feature of wetlands with biological and hydraulic impacts. The global objective of this study was to question the influence of transpirational water losses on constructed treatment wetland water budget for a variety of wetland design and time of the year. Biomass and transpiration field measurements were carried out in constructed treatment wetlands (CTWs) submitted to oceanic climate and used for waste- or stormwater management. Measurements were carried out during spring, summer and fall. Biomass and transpiration rate were both significantly affected by season and site configuration, although the effect appears more sharply for season than for site. Transpiration can reach 26% of the incoming flow during the warmest part of the year for wastewater management CTW, when the effect on adjacent water courses is likely to be the most significant. The impact on multi-monthly water budget plummets to 2% of the incoming water volume. For stormwater CTW, transpiration can lead to strong water scarcity, virtually emptying all available water in these stochastically fed systems. As transpiration also plays a significant role in biogeochemical processes in wetlands, it seems important to design this type of ecological infrastructure in close relation with the pursued objectives, be it either the quality of outlet water (emphasis on treatment efficiency) or the quantity of outlet water (emphasis on flow regulation).

Water‐Wave Driven Route Avoidance Warning System for Wireless Ocean Navigation

AbstractThe internet of things in the context of the ocean is vitally important. For ships sailing on the wide ocean in adverse weather conditions, evasion of marine islands and reefs is crucial to ensure safe navigation. Here, a hybrid wave energy harvesting nanogenerator is proposed (HW‐NG) as a power source for long‐distance wireless transmission, and demonstrated a self‐powered route avoidance warning system for ocean navigation. The HW‐NG is developed based on a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG), integrated by a pendulum structure. The TENG based on a contact‐separation mode is designed into a spring‐assisted multilayered structure, in which the EMG unit is well hybridized. Simply relying on the energy extracted from water waves, the HW‐NG can establish long‐distance (1.5 km) communication nodes on the sea. In application, a large HW‐NG network could be developed in the adjacent water areas of islands or reefs. With a network formed by hundreds of thousands of HW‐NGs, the forewarning signal transmission could be realized per second on the sea. More importantly, the wireless emitting is spontaneous through the designed automatic switch module. This work demonstrates a practicable strategy for ensuring safety of sea transportation based on wave energy collection.

Octopus-like side chain grafted poly(arylene piperidinium) membranes for fuel cell application

Octopus-like side chains are introduced in poly(arylene piperidinium)-based alkaline anion exchange membranes (AEMs) to enhance the conductivity and stability. This type of side chain consists of a bulky rigid β-cyclodextrin (β-CD) as the “octopus head”, and long flexible piperidinium ionic liquids as the “arms”. The β-CD unit can enlarge internal free volume of the AEM to reduce ion transport resistance; the “arms” can interact with adjacent hydrophilic ionic groups and water, constructing continuous ion transport channels. The prepared poly(biphenyl piperidinium) AEM with “octopus” side chains at an ion exchange capacity (IEC) of 1.29 mmol g−1 exhibits higher hydroxide conductivity (121.5 mS cm−1 at 80 °C) than that without the “octopus” structure (57.4 mS cm−1) although the latter has a larger IEC (1.55 mmol g−1). This “octopus” AEM retains 87.2% of its conductivity after being treated in a 1 M NaOH at 80 °C for 480 h. The alkaline H2/O2 fuel cell constructed with this “octopus” AEM produces a peak power density of 469 mW cm−2; the cell voltage can be maintained by 85% during 16 h operation. This work illustrates the advantage of “octopus” side chain for enhancement of AEM performance.

Strong anisotropy in aqueous salt solutions revealed by terahertz-induced Kerr effect

Terahertz Kerr effect technology, as a novel tool, is expected to study the low-frequency molecular dynamics of liquids since it can directly distinguish the time-resolved anisotropy information on the sub-picosecond scale. Here, this technology is used to measure a variety of aqueous salt solutions and observe the effects of different anions and cations on the structure and dynamics of water network. The obtained bipolar anisotropic response increases under the influence of multiple ions, which is mainly due to the energy transfer between the permanent dipole moment rotation of water molecules and the restricted translational motion of adjacent water molecules with THz electric field excitation. The classic viscosity-related coefficient B is used to analyze the amplitude and characteristics of the obtained anisotropic response, which implies the relationship between the intermolecular hydrogen bond dynamics and the macroscopic thermodynamic properties in the ionic aqueous solution. This work provides a new perspective for observing the low-frequency molecular motion in aqueous salt solutions.

Impact of Wetlands Loss and Migration, Induced by Climate Change, on Chesapeake Bay DO Standards

AbstractA predictive wetlands module is added to an existing eutrophication model of Chesapeake Bay in order to evaluate the impact of wetlands loss and migration on dissolved oxygen (DO) standards. Loss and migration are expected due to increases in sea level associated with climate change. The module calculates fluxes of carbon, nitrogen, and phosphorus between wetlands and the adjacent water column. Calculations are performed for a range of sea‐level increments up to 1 m. Wetlands areas, as a function of sea level, are obtained from an existing, independent, model applied to Chesapeake Bay. The results indicate two risks to DO standards. The first results from wetlands loss and simultaneous reductions in nutrient removal and burial by wetlands. Reduction in burial is the equivalent of a nutrient load increase and produces diminished DO in deep water and deep channel portions of the Bay. The second risk results from wetlands migration into upland areas adjoining shallow embayments and tidal fresh waters of the Bay. An increase in wetlands area in these regions may result in diminished DO concentration in adjacent open water due to direct wetlands respiration.

Cover crops differentially influenced nitrogen and phosphorus loss in tile drainage and surface runoff from agricultural fields in Ohio, USA

Nitrogen (N) and phosphorus (P) loss from crop production agriculture is transported to adjacent and downstream water bodies, resulting in negative environmental impacts including harmful and nuisance algal blooms. Cover crops are a conservation management practice that replaces bare soil with vegetation outside of the cash crop growing season, purportedly reducing N and P loss by increasing water and nutrient demand in agroecosystems. In this study, we compared nitrate (NO3−-N), total N (TN), dissolved reactive P (DRP), and total P (TP) loads in subsurface (tile) drainage and surface runoff from fields with cover crop management (CC) and fields without cover crop management (NoCC) using continuous monitoring data from 40 agricultural fields located throughout northcentral Ohio, United States (US). We found that average monthly tile NO3−-N and TN loads from CC fields were ~50% less than NoCC fields, while average monthly tile discharge, DRP, and TP loads did not differ between CC and NoCC fields. Cover crops also did not significantly influence average monthly surface metrics. Cover crops reduced monthly totals of tile NO3−-N and TN loads by ~1.0–2.6 kg N ha−1 from January to June (winter and spring), coinciding with critical periods of nutrient loss from agroecosystems in the midwestern US, but increased monthly totals of tile DRP (by 0.4–12.1 g DRP ha−1) and TP (by 1.2–31.6 g TP ha−1) loads during some months. We found similar patterns at the annual time scale whereby CC fields had lesser cumulative annual totals of tile NO3−-N and TN but greater cumulative annual totals of tile DRP and TP. These results show that the influence of cover crops on N loads, but not P, were consistent across temporal scales of examination, demonstrating that cover crops effectively increased N demand and mitigated N losses from agricultural fields. The variable influence of cover crops on P loads underscores the need for greater understanding of the factors and mechanisms that control P loss in systems that include cover crop management. Furthermore, these findings stress the importance of identifying and selecting conservation management practices tailored to the natural resource concern.

Controls on Nutrient Cycling in Estuarine Mangrove Lake Sediments

We estimated the net exchange of nitrogen and phosphorus species using core incubations under light and dark conditions in estuarine lakes that are the aquatic interface between the freshwater Everglades and marine Florida Bay. These lakes and adjacent shallow water Florida Bay environments are sites where the restoration of hydrological flows will likely have the largest impact on salinity. Sediment respiration, measured by oxygen uptake, averaged (±S.D.) −2400 ± 1300, −300 ± 1000, and 1900 ± 1400 μmol m−2 h−1 for dark incubations, light incubations, and gross photosynthesis estimates, respectively, with dark incubations consistent with oxygen uptake measured by microelectrode profiles. Although most fluxes of soluble reactive phosphorus, nitrate, and N2–N were low under both light and dark incubation conditions, we observed a number of very high efflux events of NH4+ during dark incubations. A significant decrease in NH4+flux was observed in the light. The largest differences between light and dark effluxes of NH4+ occurred in lakes during periods of low coverage of the aquatic macrophyte Chara hornemannii Wallman, with NH4+ effluxes > 200 μmol m−2 h−1. Increasing freshwater flow from the Everglades is expected to expand lower salinity environments suitable for Chara, and therefore, diminish the sediment NH4+ effluxes that may fuel algal blooms.

Diversity and distribution of harmful microalgae in the Gulf of Thailand assessed by DNA metabarcoding

Information on the diversity and distribution of harmful microalgae in the Gulf of Thailand is very limited and mainly based on microscopic observations. Here, we collected 44 water samples from the Gulf of Thailand and its adjacent water (Perhentian Island, Malaysia) for comparison in 2018. DNA metabarcoding was performed targeting the partial large subunit ribosomal RNA gene (LSU rDNA D1–D3) and the internal transcribed spacers (ITS1 and ITS2). A total of 50 dinoflagellate genera (made up of 72 species) were identified based on the LSU rDNA dataset, while the results of ITS1 and ITS2 datasets revealed 33 and 32 dinoflagellate genera comprising 69 and 64 species, respectively. Five potentially toxic Pseudo-nitzschia (Bacillariophyceae) species were detected, with four as newly recorded species in the water (Pseudo-nitzschia americana/brasilliana, Pseudo-nitzschia simulans/delicatissima, P. galaxiae and P. multistriata). The highest relative abundances of P. galaxiae and P. multistriata were found in Trat Bay and Chumphon (accounting for 0.20% and 0.06% of total ASVs abundance, respectively). Three paralytic shellfish toxin producing dinoflagellate species were detected: Alexandrium tamiyavanichii, Alexandrium fragae, and Gymnodinium catenatum. The highest abundance of A. tamiyavanichii was found in the surface sample of Chumphon (CHO7 station), accounting for 1.95% of total ASVs abundance. Two azaspiracid producing dinoflagellate species, Azadinium poporum ribotype B, Azadinium spinosum ribotype A, and a pinnatoxin producing dinoflagellate species Vulcanodinium rugosum, with two ribotypes B and C, were revealed from the datasets although with very low abundances. Six fish killing dinoflagellate species, including Margalefidinium polykrikoides group IV, Margalefidinium fulvescens, Karenia mikimotoi, Karenia selliformis ribotype B, Karlodinium australe, and Karlodinium digitatum were detected and all representing new records in this area. The findings of numerous harmful microalgal species in the Gulf of Thailand highlight the potential risk of human intoxication and fish killing events.

A Global Ecological Classification of Coastal Segment Units to Complement Marine Biodiversity Observation Network Assessments

A new data layer provides Coastal and Marine Ecological Classification Standard (CMECS) labels for global coastal segments at 1 km or shorter resolution. These characteristics are summarized for six US Marine Biodiversity Observation Network (MBON) sites and one MBON Pole to Pole of the Americas site in Argentina. The global coastlines CMECS classifications were produced from a partitioning of a 30 m Landsat-derived shoreline vector that was segmented into 4 million 1 km or shorter segments. Each segment was attributed with values from 10 variables that represent the ecological settings in which the coastline occurs, including properties of the adjacent water, adjacent land, and coastline itself. The 4 million segments were classified into 81,000 coastal segment units (CSUs) as unique combinations of variable classes. We summarize the process to develop the CSUs and derive summary descriptions for the seven MBON case study sites. We discuss the intended application of the new CSU data for research and management in coastal areas.

Post-mining ponds in the Sandomierz Forest (SE Poland) as an important site for the conservation of a species-rich odonate assemblage

In this study, the species composition and diversity of dragonfly and damselfly assemblages of six post-mining ponds differing in habitat conditions, located within a single sand pit in the central part of the Sandomierz Forest (SE Poland) were assessed. In total, 42 species were recorded in 2019, including 35 species considered resident to the site. In the six studied ponds, a range of 8 to 30 species were recorded, including 5 to 26 resident species. In each pond, at least one unique species was found, and one-third of all species were confined to single ponds only. As a result, the qualitative (Jaccard) and quantitative (Bray-Curtis) similarity indices between the pairs of ponds were low, reaching 12-61% and 19-53%, respectively. Thus, despite a lack of distinct barriers and negligible distances between the ponds (max. 350 m), the structure of assemblages in adjacent water bodies differed considerably. This is probably largely due to the habitat selectivity of species. A redundancy analysis (RDA) showed, that factors such as area and plant diversity of the pond were shaping odonate assemblages, explaining 49.1% of the total variance in the dataset. Due to the high species richness and the identification of several species of special concern, the studied sand pit should be considered a valuable secondary habitat for odonates, which – after termination of exploitation – should be regarded as a good candidate for a site designated for the conservation of biodiversity.

A Comprehensive Assessment of Sediment Dynamics in the Barataria Basin (LA, USA) Distinguishes Riverine Advection from Wave Resuspension and Identifies the Gulf Intracoastal Waterway as a Major Sediment Source

Barataria (LA, USA) is an interdistributary deltaic basin that has experienced extensive marsh loss. The fate of these marshes is strongly controlled by the concentration of total suspended sediments (TSS) in the adjacent open bay water. This parameter, however, is poorly constrained, thus limiting the ability to predict the future marsh evolution. Here we investigate the open bay water sediment dynamics using three complementary approaches: monthly field surveys at 37 locations along the bay axis over 22 years, remote sensing over 20 years, and turbidity time series at 5 locations over 4 years. Monthly field sampling and remote sensing reveal that the TSS is highly seasonal and spatially variable. In particular, the sediment delivered through the Gulf Intracoastal Waterway (GIWW) during the flood season (January–April) dominates the TSS signal in mid-Barataria. This sediment originates mainly from the Atchafalaya River and is advected for more than 100 km before reaching Barataria. Because of a hysteresis in sediment transport, the TSS in the river water, and hence in the GIWW, is not uniquely related to the river discharge. As such, late flood season discharges do not contribute much sediment to Barataria. We estimate that the GIWW delivers on average 0.21 Tg of sediment per year to mid-Barataria. A different sediment input is instead present in lower Barataria, where river-borne sediment exiting the “birdfoot” of the Mississippi Delta is advected by easterly winds, especially during spring. At all five stations within Barataria, turbidity time series reveal that the daily sediment dynamics is mainly associated with local wind wave resuspension. River inputs and wave resuspension contribute nearly equally to the yearly averaged TSS, of about 80 mg/l on average. The GIWW, built in the 1920s, is an important but overlooked source of sediments for Barataria that can serve as a present-day analogue for the proposed Mississippi River sediment diversions.

Review of amphipods of the family Pleustidae Buchholz, 1874 (Crustacea: Amphipoda) from the coastal waters of Sakhalin Island (Far East of Russia). I. Subfamily Neopleustinae Bousfield amp; Hendrycks, 1994.

Taxonomic analysis of the subfamily Neopleustinae Bousfield Hendrycks, 1994, is performed. Cladistic analysis of morphological relationships within the genera Hendrycksopleustes gen. nov., Neopleustes Stebbing, 1906, and Shoemakeroides Hendrycks Bousfield, 2004, is performed. A new genus Hendrycksopleustes gen. nov. is described. A review of the subfamily Neopleustinae from the shelf of Sakhalin Island and adjacent water area, based on all literature and own data, is provided. Based on new material, a new species Hendrycksopleustes neimanii sp. nov. is described from the shelf of Sakhalin Island. Status of the species Neopleustes euacanthus (G. Sars, 1877) is restored. New subspecies Neopleustes boecki pacifica ssp. nov. and Neopleustes pulchellus asiaticus ssp. nov. are described from the shelf of Sakhalin Island. Keys to the amphipod genera of the subfamily Neopleustinae and to the world species of the genera Neopleustes and Shoemakeroides are provided.

Evaluation of private well contaminants in an underserved North Carolina community

On-site sewage treatment systems can be an important source of antibiotic resistant bacteria and organic micropollutants into adjacent groundwater. Due to the frequent proximity of private wells to septic systems, this contamination is a concern to communities that do not have access to public municipal services. In both rural and urban environments, low-income communities, indigenous communities and those of color are disproportionately affected by well contamination. The objective of this study was to assess well water quality in an underserved North Carolina community by performing a comprehensive evaluation of microbial and organic micropollutant occurrence and determining possible sources of contamination. Well water, septic tanks, and adjacent municipal water were sampled. Culture- and molecular biology-based microbial analysis and non-targeted, high resolution mass spectrometry chemical analysis were conducted to assess water quality in comparison to nearby municipal water. Three of thirteen homes had between 1 and 6.3 CFUs/100 mL of E. coli and two homes had fecal bacteria resistant to antibiotics in their well water. The water of four homes showed concentrations of the artificial sweetener sucralose, a wastewater tracer, higher than the municipal water (range ~ 60–1500 ng L−1). The human-specific HF183 fecal marker was detected in 79% of the wells tested. The presence of pharmaceuticals and personal care products in four home wells, along with the presence of pesticides and insecticides in two homes, suggest possible contamination from septic tanks and lawn care runoff. The implications of this work highlight the necessity of wider scale contaminant evaluation of well water.

Comparison of bacterial communities from surface and adjacent bottom layers water of Billings reservoir

Comparison of bacterial communities from surface and adjacent bottom layers water of Billings reservoir

Dramatic catalytic activation of kinetically inert disilane hydrolysis in metallic iron particulate via barrierless chemical dissociation: First-principles study

Disilane (Si2H6) is a key substance for chemical industries designing semiconductors and graphene materials. Its reaction mechanism is, however, still elusive, as evident from serious chemical accidents when exposed to open air. Using first-principles density functional theory calculations, we investigate the thermodynamic and kinetic mechanisms of Si2H6 hydrolysis, with and without oxidative conditions of adjacent water, oxygen gas and metallic Fe particulates. Despite the remarkable thermodynamic spontaneity, direct hydrolysis is kinetically sluggish due to the high energy barrier. Hydrolysis initiated by O2 is identified with a multi-step radical mechanism, which is kinetically more favored than the direct hydrolysis. The energy barrier of rate-determining step is, however, still too high for Si2H6 to react in a humid and oxidative environment. Surprisingly, we report that metallic iron serves as an of interest heterogeneous catalyst for the Si2H6 hydrolysis dramatically lowing the activation energy barrier for the dissociation. Our results propose that fine air particulates including Fe can play a key role in facilitating the explosive reaction of Si2H6 potentially leading to severe chemical accidents, otherwise very inert.

Spatial decoupling of legacy phosphorus in cropland: Soil erosion and deposition as a mechanism for storage

Agricultural production continues to be implicated as one cause of eutrophication of water courses and water bodies in many agro-ecosystems. The generally-held consensus is that soil erosion by water is a major mechanism for loss of phosphorus (P) to adjacent water bodies and down-stream reservoirs from crop and grazing lands. Nonetheless, it does not explain the whole story of the fate of P losses applied to soils. This study assessed the spatial distribution of P as a consequence of historical erosion and redistribution of soil in an agricultural field in the Lake Erie basin in southern Ontario. Combining stratified random sampling with geospatial analysis of landscape position, plant-available (Olsen) P concentrations and stocks were measured and compared to other soil properties and related to soil erosion and redistribution. Toe-slope and foot-slope positions had two to three times the Olsen P stocks compared to summit landscape positions (mean of 52 +/- 9 kg P ha−1 and 47 +/- 9 kg P ha−1 versus 20 +/- 2 kg P ha-1, respectively) which was attributed to both water and tillage erosion. Burial of P beneath the plowing depth showed that the toe-slopes had over two to three times more Olsen P stocks below 25 cm depth compared to all other landscape positions. Olsen P stocks were significantly related (R2 = 0.50; p < 0.001) to soil organic carbon (SOC) stocks which was a consequence of historical soil erosion and redistribution in the field. The fate of legacy P in soils may be dependent upon the history of erosion and redistribution resulting in deposition of P in toe-slope and foot-slope positions in an agricultural landscape.

Hydrogeology, hydrogeochemistry, and isotope method application to investigate the hydraulic connection between Emam-Gheis karst spring and adjacent water wells (Iran)

The Emam-Gheis Karst Aquifer is located in the southeast of Borujen city in Iran. The Emam-Gheis Spring with the average flow rate of about 90 L s−1 has emerged in the south of the aquifer. Seven deep drinking water wells have been drilled in the east of the aquifer (15 years ago). The spring flow rate has decreased significantly after water harvesting from the water wells began. In this study, the presence or lack of a hydraulic connection between the Emam-Gheis karst spring and its adjacent water supply wells has been investigated. The hydrogeology, water chemistry, and isotopic investigations were done in the catchment area of the spring and the wells from December 2016 to December 2017. The obtained results revealed that there were significant differences between the spring and the wells regarding the electrical conductivity, major ions concentrations, ion ratios, saturation indices (of calcite, dolomite, gypsum, and halite), and water stable isotopes. In addition, the hydrogeological investigations implied that the existence of a hydraulic connection between the spring and the wells seems unlikely. It seems that due to the excessive groundwater extraction in recent years, the groundwater level has declined in the adjacent alluvial plains. This seems to have intensified the water discharge from the karst aquifer toward the alluvial deposits and resulted in a decrease in water discharge rate at Emam-Gheis spring.