Bottom Of Water Body Research Articles

Sedimentary-migration of the magmatic hypothesis for the formation of oil

As a result of physical and chemical modeling of hydrocarbon formation conditions at the Ereminsko-Chonsky oil cluster (Leno-Tungusskoy oil and gas province), it was found that at the stage of sedimentogenesis at (T = 35 °C, P = 0.1 MPa) methane and organic matter accumulate at the bottom of the reservoir. With diagenesis (T = 60 °C and P = 5-10 MPa) at a depth of 60-100 m, films and oil droplets are observed in the formation of source formations in rocks, pentane C5H12 appears from liquid hydrocarbons. At the stage of catagenesis at a depth of 250 C6H14 hexene is formed, and at 2000 m - C7H16 heptene, at 3100 m - octane C8H12 and at 3800 m (at T = 90 °C and P = 110 MPa) - nonane C9H20. During the period of apocatagenesis and metamorphism (at T = 105 °C and P = 450 MPa), C10H22 dodecane is formed at a depth of 13-15 km, and C11H24 undecane is formed at T - 200 °C. When the temperature rises to 250 °C and the pressure reaches 490 MPa, at a depth of about 15 km, a large group of liquid hydrocarbons from dodecane C12H26 to pentadecan C15H32 and solids from hexadecan C16H34 to octadecane C18H38, as well as other groups, form in the basement rocks. When the pressure becomes 850 MPa, isoprenoids are observed at a depth of 25 km: from C19H40 to nonadecane to C24H50 to tetracosane, etc. Based on the simulation, it becomes obvious that it is not possible to explain the conditions for the formation of hydrocarbons in the range up to 25 km using only one of the hypotheses biogenic or abiogenic and a new sedimentary-migration-magmatic hypothesis of oil formation is proposed. Its essence is as follows: to a depth of 3800-4000 m, the source of hydrocarbons is methane, which accumulates at the bottom of water bodies, and organic matter of rocks, and at a depth of 13-15 and 25 km - mantle deep methane.

Convection pattern formation in a domain with a horizontal interface

For the classical constellation of a fluid heated from below and cooled at the top, convection patterns are examined, with the additional feature of a horizontal interface. The interface separates two subdomains of different types, which contain porous media with different properties. The case of a pure diffusive layer at the bottom and the case of a free fluid above a porous medium are considered also. It is outlined that the approach can also be valid for the case of haline convection. Using finite element modeling for the nondimensional formulation, 2-dimensional transient and steady state convection patterns are visualized and examined. The simulations show that the interface significantly changes the convection cells in the domain as well as the heat transfer through the system. In all cases, the emerging pattern on one side of the interface is related to the pattern on the other side. The results are relevant for the understanding of heat and mass flow through layered geological strata, at the bottom of water bodies and in technical devices, for example layered insulation systems.

Preparo de lote piloto de sedimento estuarino candidato a material de referência de composição química elementar

The sediments are solid materials deposited at the bottom of water bodies. The toxic heavy metals tend to be deposited as sediments, so they are monitored after being dredged to ensure their correct disposal. As there are no Brazilian reference materials for sediments, chemical-analysis laboratories use imported materials to control the quality of their measurements. In this work, a pilot batch of material was prepared from a sediment collected in the Upper Estuary of Santos (SP). The chemical characterization of the material was performed by ICP-OES and ICP-MS, using alkaline fusion or microwave digestion to sample dissolution according to the element to be analyzed. A material with a narrow particle size distribution and suitable homogeneity was obtained. The applied methodologies and the preparation process developed are suitable for the preparation of a future certified reference material. Keywords: sediment; reference material; ICP-OES; ICP-MS.

Evolution of the Juan Fernández diving beetle, Rhantus selkirki (Coleoptera, Dytiscidae)

Here we provide evidence that confinement in Robinson Crusoe Island (located about 660 km west of continental Chile) over evolutionary time leads to strong morphological modifications in diving beetle (Dytiscidae) larvae. We analysed a large set of morphological larval characters for all currently recognised genera of Colymbetinae as a framework, to infer phylogenetic relationships within the large genus Rhantus Dejean, 1833 and, in particular, of the charismatic Juan Fernández diving beetle, Rhantus selkirki Jäch, Balke & Michat, 2015, comparing our results with a recent phylogeny of the Colymbetinae based on DNA sequence data. We suggest that adaptation to the island's particular habitats resulted in the reversal of certain characters of R. selkirki back to the plesiomorphic states. This may cause the species to be erroneously interpreted as more ‘primitive’ if only morphological characters are analysed. Confinement in the particular, shallow and barely vegetated aquatic habitats of Robinson Crusoe Island for a long time seems to have led to this divergent morphology, particularly in characters related to swimming ability such as several leg and urogomphal setae. In this way, R. selkirki larvae secondarily resemble those of some earlier diverging dytiscid lineages such as Agabinae and Copelatinae, which typically creep on the bottom of water bodies and do not swim well.

Mathematical model of device for slurry concentration and desludging in near-bottom zone

There are many systems for extracting minerals from the bottom of water bodies, but none of them meets the requirements, so the actual task is to create technical means that provide the best performance and environmental safety. Increase the efficiency of the hydromechanical mining method is possible due to the maximum concentration and desludging of the slurry in the near-bottom zone, which allows reducing the energy and material consumption of hydrotransport of minerals. To achieve this goal, it is proposed to use a perforated section adjacent to the power unit, with a transverse cross section that reduces in its length in the direction of flow, in the pressure pulp pipeline system.

MOVEMENT AND EROSION OF ALBERTA BITUMEN ALONG THE BOTTTOM AS A FUNCTION OF TEMPERATURE, WATER VELOCITY AND SALINITY

AbstractWhile many trajectory models exist to predict the movement of oil floating in or on water, few are designed to address heavy oil on the bottom of water bodies. In addition, remobilization (erosion) of the material into the water column is also difficult to predict. While properties such as adhesion, viscosity and density of oil may be readily measured, the critical shear stress (CSS) and the effect of (current) velocity, salinity, and temperature are virtually unknown for most heavy oils. The Coastal Response Research Center (CRRC) has a 4,000 L annular flume, with a water depth of 0.43 m. An inner rectangular flume (1.2 m length, 0.2m width, 0.9 m height), placed inside the annular flume, was preceded by two flow straighteners to reduced turbulence and produce a uniform, one dimensional flow field. The current is generated by an electric thrust motor and measured in 3D by a Nortek AS (Norway) Vectrino II Profiling Velocimeter. A 20g circle of Alberta bitumen (API ~ 10°) was placed on a laminated grid (1cm2 square pattern) at the bottom of the straight flume. A total of 2.3m3 of water was then gradually added to the flume. The electric motor was started and the profiler began collecting data. Two cameras, placed along the side and above the oil, collected video of the erosions and length/width changes of the oil. Conditions were held steady for one hour once the desired current velocity was achieved. Temperatures, current velocity (X, Y, Z), and digital videographic data were collected during each run. Erosions and percent lengthening of the oil was monitored as a function of water temperature, salinity and velocity. The turbulent kinetic energy (TKE) method was used to calculate the bed shear stress (BSS). In addition to the expected impact of higher temperature on the movement along the bed and erosion into the water column, the viscoelastic and shear-thinning properties of the bitumen played a role in its behavior (lowering of viscosity at higher BSS slowing erosions and movement) and must be considered when predicting its behavior during a spill.

Analysis and correction of ocean wave pattern induced systematic coordinate errors in airborne LiDAR bathymetry

This contribution investigates the effects of ocean wave patterns on 3D underwater point coordinate accuracy for LiDAR bathymetry. The refraction of the finite diameter laser pulse passing the air/water interface is modeled differentially in a strict manner. Typical wave patterns and sensor configurations are simulated, and their impact on the 3D coordinates at the bottom of the water body are systematically analyzed. It can be shown that waves have a significant effect on both the planimetry and depth coordinates of underwater topography 3D point cloud coordinates, especially for modern small footprint LiDAR systems. Planimetric effects may reach several decimeters or even meters, and depth coordinate errors also reach several decimeters, even in the case of a horizontal water body bottom. The simulations show that the simplified assumption, that wave effects average out (as is made in most LiDAR bathymetry data processing tools) is not even fulfilled for large footprint systems (spreading the laser beam to a diameter of several meters at the water surface) under certain wave pattern conditions. Modern systems with smaller beam divergence are much more sensitive to wave-induced variations of the refraction conditions and will experience significant wave pattern dependent coordinate errors.The results presented here form a basis for a more strict coordinate correction, if the wave pattern can be modeled from the LiDAR bathymetry water surface reflections or from other observations. Moreover, it will be shown that the induced coordinate errors contain a non-zero bias in addition to a local wave surface dependent quasi-random part, which allows for the formulation of wave pattern dependent correction terms in order to increase the accuracy of LiDAR bathymetry by removing systematic wave pattern dependent effects.

An Approach to Determining Turbidity and Correcting for Signal Attenuation in Airborne Lidar Bathymetry

Airborne lidar bathymetry is an efficient technique for measuring the bottom of shallow water bodies. A characteristical feature of lidar bathymetry beam propagation is given by scattering and absorption effects in the water column, both leading to a loss of received signal intensity. This loss of signal intensity depends on the turbidity of the water body. Inversely, an analysis of the decay of the recorded waveform signal allows for deriving statements on the local degree of turbidity in the water. The paper shows a first approach on the determination of one turbidity measure per laser pulse by analysing the recorded waveform and fitting an exponential function, wherein the decay coefficient depicts an integral measure describing turbidity. The technique was applied to a shallow inland water, and the results were validated by conventional point-wise turbidity measurement techniques. An obvious consequence of attenuation and loss of signal intensity in lidar bathymetry is the fact that the bottom returns become rather weak. In many cases, conventional ground pulse echo detection techniques fail in detecting water bottom points, leading to a reduced number of water body bottom points and thus limiting the application range of the technique. To partly compensate for this effect, a differential backscatter cross section determination based signal attenuation correction method has been developed, which allows for a signal-derived re-amplification of the ground signal. Although the technique also amplifies noise, it could be shown that it is capable of delivering a higher number of additional ground points and thus extending the applicability of the technique.

ANALYSIS OF THE EFFECT OFWAVE PATTERNS ON REFRACTION IN AIRBORNE LIDAR BATHYMETRY

Abstract. This contribution investigates the effects of wave patterns on 3D point coordinate accuracy in LiDAR bathymetry. The finite diameter refracted laser pulse path passing the air/water interface is modelled differentially and in a strict manner. Typical wave patterns are simulated and their impact on the 3D coordinates at the bottom of the water body are analysed. It can be shown that the effects of waves within small LiDAR bathymetry footprints on the depth and planimetry coordinates is significant. Planimetric effects may reach several decimetres or even metres, and depth coordinate errors also reach several decimetres, even in case of horizontal water body bottom. The simplified assumption of averaging wave effects often made in many ALB applications is not only fulfilled in cases of a very large beam divergence under certain wave pattern conditions. Modern smaller beam divergence systems will mostly experience significant wave pattern dependent coordinate errors. The results presented here thus form a basis for a more strict coordinate correction if the wave pattern can be modelled from the LiDAR bathymetry water surface reflections or other observations. Moreover, it will be shown that the induced coordinate errors contain systematic parts in addition to the local wave surface dependent quasi-random part, which allows for the formulation of wave pattern type dependent correction terms.

ANALYSIS OF THE EFFECT OFWAVE PATTERNS ON REFRACTION IN AIRBORNE LIDAR BATHYMETRY

This contribution investigates the effects of wave patterns on 3D point coordinate accuracy in LiDAR bathymetry. The finite diameter refracted laser pulse path passing the air/water interface is modelled differentially and in a strict manner. Typical wave patterns are simulated and their impact on the 3D coordinates at the bottom of the water body are analysed. It can be shown that the effects of waves within small LiDAR bathymetry footprints on the depth and planimetry coordinates is significant. Planimetric effects may reach several decimetres or even metres, and depth coordinate errors also reach several decimetres, even in case of horizontal water body bottom. The simplified assumption of averaging wave effects often made in many ALB applications is not only fulfilled in cases of a very large beam divergence under certain wave pattern conditions. Modern smaller beam divergence systems will mostly experience significant wave pattern dependent coordinate errors. The results presented here thus form a basis for a more strict coordinate correction if the wave pattern can be modelled from the LiDAR bathymetry water surface reflections or other observations. Moreover, it will be shown that the induced coordinate errors contain systematic parts in addition to the local wave surface dependent quasi-random part, which allows for the formulation of wave pattern type dependent correction terms.

Sphincterodiplostomum musculosum (Digenea, Diplostomidae) in Geophagus brasiliensis (Perciformes, Cichlidae) collected in a lake at Dois Córregos, São Paulo, Brazil

ABSTRACT: Geophagus brasiliensis is a freshwater cichlid distributed throughout the whole South America. It is a territorial fish, generally omnivorous, which preferentially inhabits the bottom of water bodies. Previous studies have reported species of digenetic trematodes parasitizing G. brasiliensis. This study identifies the Sphincterodiplostomum musculosum Dubois, 1936, a Diplostomidae digenetic, commonly found in many teleostean species. More than 50% of the hosts analyzed had their eyes infected with metacercariae of S. musculosum. A positive correlation was observed between the hosts standard length and the abundance of S. musculosum, a fact that corroborates with other studies on this parasite. This paper reports the first occurrence of S. musculosum in G. brasiliensis, which is also the first record in Dois Córregos City, São Paulo State, Brazil.

사연호 수질 예측을 위한 2차원 수리·수질모델 구축 및 시나리오 분석

This study estimated water quality constituents especially in CBOD, TN, TP, and Chlorophyll-a in Sayeun reservoir by using CE-QUAL-W2 model. With water quality data in surface, middle, and bottom of water body, the model calibration was implemented by changing water quality parameters in the model. Using the calibrated model, we performed scenario analysis to investigate the variation of water quality in respond to different elevations. CBOD, TN, and Chlorophyll-a concentration predicted by the model showed a good agreement with the measured the trend of the concentrations. However, TP estimated was relatively low tendency by the model. We found that water quality (i.e., CBOD, TN, TP, and chlorophyll-a) at both water surface and middle layer was degraded in respond to the decrease of water level by 6.8m. Although results of CBOD in both surface and middle layers decreased to about 2% and 1%, respectively, in the surface layer, TN, TP, and Chlorophyll-a increased to about 4%, 3%, and 51% and, in the middle, TN and TP increased up to 12% and 3%, respectively. In the middle layer, especially, water quality degraded mainly due to increased organic matter from growth, mortality, decay, and sedimentation of algae and anaerobic release of nutrients from sediment. This study demonstrated that water quality could be influenced by controlling water surface elevation, implying that there is a need to control nutrient inflow and re-suspension from sediment in the reservoir.

Characterization of Sediments for Sustainable Development: State of the Art

Sediments are the particulate matter that are transported by the flow of water and eventually get deposited at the bottom of water bodies, such as oceans, rivers, lagoons, and so forth. The deposition of these materials due to continued intervention of natural as well as anthropogenic activities is a serious concern as the storage capacity (or health) of the system is reduced or otherwise affected. Keeping in view the emerging challenges associated with proper disposal and subsequent utilization of sediments, as a manmade resource, their extraction from such locations becomes necessary. Hence, it is essential to characterize the sediments in order to devise strategies to exploit them as a manmade resource in the best possible manner. With this in view, this article highlights the importance of different attributes and aspects of the sediments (viz., physical, chemical, morphological, geotechnical, toxicological, and microbial characteristics) deposited in the water bodies that will help in assessing their potential as a substitute material to natural resources.

Sorption-diffusion model of 137Cs uptake by a water body bottom in estimations of water contamination

For a sample including 22 lakes, the 137Cs concentrations in water were determined by the sorption-diffusion model. The 137Cs levels in waters of lakes of the Kola Peninsula and Karelian Isthmus are satisfactorily described by the suggested model at the distribution coefficient K d of 4000 L kg−1 and diffusion coefficient D of 1.0 × 10−7 cm2 s−1 for 2–4-year exposure. For mid-latitude lakes, the ranges of K d and D of 137Cs were 6000–1200 L kg−1 and 1.0 × 10−7–0.2 × 10−7 cm2 s−1, respectively. The 137Cs concentration in water is determined by the major contribution of silts, which are characterized by high K d of 137Cs and by large thickness of sediments on the bottom of lake hollows, to the watter-bottom sorption system. After 2-year exposure of “Chernobyl” 137Cs in lakes, its inventory in water relative to the amount that fell out in 1986 did not exceed 14% for deep lakes and 2–3.6% for shallow lakes.

Aluminosilicate microspheres in fly ashes from thermal power plants and their use for the removal of petroleum and phenol from water

Petroleum and petroleum products constitute a special group of pollutants in the hydrosphere. Water pollution by petroleum and petroleum products results from crude oil production, transportation, and refining; the use of petroleum products as fuel for marine engines; the washing of oil carrier tanks; water flows from territories contaminated with petroleum products; etc. The effect of petroleum products on living organisms manifests itself in physiological disorders, diseases caused by the insertion of hydrocarbons into the body, biological changes in the environment, etc. The deposition of petroleum residues at the bottom of water bodies can produce anaerobic conditions and become a source of secondary pollution in the hydrosphere [1‐3]. Phenol is a highly toxic organic pollutant that is haz

Simulation of resuspended sediments resulting from dredging operations by a numerical flocculent transport model

Environmental remediations such as dredging operations cause contaminated sediments from the bottom of water bodies to become suspended into the water column. These resuspended particles are significant water quality concerns and cause adverse effects to aquatic organisms. In this paper, we present a vertically integrated two-dimensional flocculent sediment transport model to better model concentration changes of resuspended bottom sediments. The flocculent transport model has been applied to the Savannah River cutterhead dredge field study involving the resuspension of bottom sediments. The results showed that the model predictions correlate reasonably well with field data. These comparisons suggest that the flocculent sediment transport model can be used to predict the concentration profiles of a plume of toxic compounds resulting from cutterhead dredge operation.

Ultrasonic Irradiation for Blue-Green Algae Bloom Control

A novel application of ultrasonic irradiation for rapid control of blue-green algae (BGA) bloom was investigated. Potassium iodide (KI) experiments demonstrated that frequency and input power are the major factors that affect the ultrasonic irradiation intensity. Short exposure (3 s) to ultrasonic irradiation (120 W input power, 28 kHz) effectively settled naturally growing BGA suspension. Electron microscopy reconfirmed that sedimentation was caused by the disruption and collapse of gas vacuoles after ultrasonic exposure. Moreover, even after 5 min of exposure to ultrasonic irradiation (1200 W input power, 28 kHz) the microcystin concentration in BGA suspensions did not increase. For the same input power (120 W), a lower frequency (28 kHz) was found to be more effective in decreasing the photosynthetic activity of BGA than a higher frequency (100 kHz). The sonicated cells did not proliferate when they were cultured in conditions that simulated the bottom of water bodies (i.e. with limited light (400 lx) or no light and non-aerated or aerated (1 l min−1)). Furthermore, ultrasonic irradiation did not only collapse gas vacuoles and precipitate BGA, but may have also inflicted damage on the photosynthetic system of the BGA.

Pellets of some mollusks in the biogeochemical flows of C, N, P, Si, and Al.

Aquatic invertebrates excrete pellets [1,2], which consist of products of incomplete digestion and pseudofeces. Different taxons are characterized by the following values of food assimilability (in percents): Rotatoria, 48‐80; Bryozoa, 41.6; Gastropoda, 42‐82; Bivalvia, 40‐47; Cladocera, 50.5‐85.5; Copepoda, 30‐ 88; Mysidacea, 84.2‐95; Isopoda, 68; Amphipoda, 5.5‐ 98; Decapoda, 38.7‐96.1; larvae of Odonata, 20‐97.2; Ephemeroptera, 41‐72; Plecoptera, 9‐73; Trichoptera, 5‐51; and Diptera, 1‐31.4 [2]. When settling to the bottom of water bodies by gravity, pellets contribute to vertical fluxes of chemical elements through the ecosystem level of the biospheric biogeochemical cycles or into “biogenic migration of atoms in the biosphere” [3]. The purpose of this study was to estimate the capacity of mollusk pellets for contributing into the vertical transfer of chemical elements through an aquatic ecosystem, using Limnaea stagnalis (L.) and bivalves (Unionidae) as examples. The mollusks L. stagnalis were collected in June in a pond in the floodplain of the upper Moskva River and were kept afterwards as described in [4]. Bivalve mollusks (Unionidae) collected from the partly silted sand bottom of the Moskva River upstream of the town of Zelinograd represented a sample from a natural benthic community dominated by Unio tumidus and U. pictorum (63.21 and 27.36%, respectively, of the overall number of specimens in the sample). The proportions of Crassiana crassa and Anodonta cygnea were lower (7.55 and 1.89%, respectively). The bivalves sampled from the natural ecosystem (the total biomass was 3302 g wet weight, including the shells; the average weight of one mollusk was 21.9 g), where they filtered natural seston, were incubated for 24 h in a wide flask containing settled tap water to obtain the pellet precipitate, which was afterwards resuspended in a 300-ml glass cylinder. The sand fraction, which precipitated within 15 s (fraction 1), was separated from the remaining suspension of the pellet material per se. The latter was transferred into another glass cylinder. From this suspension, pellets precipitated within 3 h (fraction 2); this precipitate was separated by means of decanting the supernatant. The dry weight of fraction 2 was 1434 mg. To determine the carbon content in the vegetative material and in pellets, they were oxidized by 10% K 2 Cr 2 O 7 in the presence of a mixture of concentrated H 2 SO 4 and H 3 PO 4 [5]; the CO 2 formed was trapped by 0.5 M NaOH, and the remaining alkaline was titered with hydrochloric acid. The photometric method was also used; the optic density of the solution was measured at a wavelength of 590 nm after oxidation of the material with bichromate. The amount of organic nitrogen was measured using a Kjeltec Auto 1030 Analyzer (Tecator, Sweden) by the Kjeldahl method after mineralization with a mixture of H 2 SO 4 and H 2 O 2 . Phospho

Release of atrazine ((14)C) from two undisturbed submerged sediments over a two-year period.

Through water erosion and runoff, sediment-adsorbed atrazine can undergo sedimentation and accumulation at the bottom of water bodies and become potential sources of atrazine to the water column. The purpose of this study is to determine the fate and release of atrazine ((14)C) to the water column from two simulated undisturbed submerged sediments at two temperature treatments (5 and 24 degrees C) over a 2-year period. Atrazine residue ((14)C) was released from the two sediments and was, primarily, diffusing from the sediment pore water to the water columns. The amount released was affected by sediment type and is related to the sediment's adsorption/desorption capacity. Larger amounts of residue ((14)C) were released to the water columns at 5 degrees C than at 24 degrees C. Atrazine degraded in the shallow submerged anaerobic sediment's water columns over the 2-year period. Less than 2% (percent of applied in atrazine equivalent) of extractable atrazine and metabolites remained in the sediment after 2 years. The amount of nonextractable atrazine residue ((1)(4)C) was significantly higher in sediments at 24 degrees C than at 5 degrees C. In conclusion, atrazine accumulating in shallow undisturbed submerged sediments from nonpoint sources would most likely degrade and/or become nonextractable over time and would have a low probability of becoming a significant source to the water body. The conditions where accumulation and future release of atrazine have a greater potential to occur are under very cold temperatures with low adsorption capacity sediments.

Use of biological indices of water quality

Biological monitoring can be used in studying the complex phenomenon of water pollution. The study of aquatic living organisms for the purpose of studying water quality was born at the beginning of the century with the development of the saprobity system by Kolkwitz and Marsson. Other systems of biological assessment of water quality have been developed since. Features of the composition and structure of diatom taxa colonizing the bottom of water bodies, or of fauna macroinvertebrates in rivers can be turned into numeric biotic indices. Such methods of water quality assessment have been successfully and repeatedly applied to Belgian and other European rivers. The experience shows that biomonitoring based on living aquatic communities can comple­ ment direct analysis of water contaminants for the purposes of global water quality assessment of the water body concerned, of detecting forms of pollution that cannot be usually found in direct analysis, and of integrating water quality over variable time spans, which depend on the length of the life cycle of the bioindicators involved.