Discharge Outlet Research Articles

Impact of a Sewage Treatment Plant on the Accumulation of Microplastics in Freshwater Organisms in the Lijiang River of the Guilin Urban Section

Microplastics (MPs, particle size<5 mm), as a new pollutant, have attracted wide attention in recent years. The distributions of MPs in effluent of a sewage treatment plant (STP) were examined. Surface water, sediment, and freshwater organism samples were taken from the STP discharge outlet in the Lijiang River tributary (S1), the confluence of tributaries and main streams in the Lijiang River (S2), and downstream locations in the Lijiang River (S3). The impact of STP discharge effluent on the characteristics and spatial distribution of MPs pollution in freshwater organisms was studied. The results showed that the freshwater organisms had a probability of uptake of MPs by 94.2%. The mean abundance of MPs in S1 (2.7 n·ind-1) was significantly higher than that of S3 (1.9 n·ind-1, P<0.05). The MPs found in S1 and S3 were mainly <0.10 mm, accounting for 46.0% and 30.5%, respectively. The fiber type of MPs was observed in the body of freshwater organisms. Polyethylene terephthalate was the major polymer form in S1 organisms, while polypropylene was the major polymer form in S3. The effluent discharged from the STP led to the accumulation of MPs in freshwater organisms.

The Complete Genome Sequence of a Bacterial Strain with High Alkalic Xylanase Activity Isolated from the Sludge Near a Papermill.

Many organisms secrete xylanase, an import group of proteins hydrolyzing xylan, and thus are able to use xylan as their carbon source. In this study, we sequenced the whole genome of a bacterial strain, YD01, which was isolated from the sludge near the sewage discharge outlet of a papermill and showed high alkalic xylanase activity. Its genome consists of a chromosome and two plasmids. Six rRNA genes, 46 tRNA genes, 3136 CDSs as well as 955 repetitive sequences were predicted. 3046 CDSs were functionally annotated. Phylogenetic analysis on 16S rRNA shows that YD01 is a new species in Microbacterium genus and is taxonomically close to M. jejuense THG-C31T and M. kyungheense THG-C26T. A comparative study on phylogenetic trees of 16S rRNA and xylanase genes suggests that xylanase genes in YD01 may originate from horizontal gene transfer instead of ancestral gene duplication.

Numerical simulation of the effects of Yangtze River runoff on pollutant transport and diffusion in the Yangtze River estuary

The coastal-estuary area is one of the areas most seriously affected by human activities, and the quality of the water environment has received extensive attention from society and scholars. In order to analyze the characteristics of pollutant transport in the Yangtze River Estuary, a two-dimensional hydrodynamic model of the Yangtze River Estuary waters was established, and the model was verified using measured hydrological data. On this basis, the effects of the dilution and diffusion of pollutants (COD) under different runoff rates are studied and the transport characteristics of the pollutants of the Yangtze River estuary are studied. The results show that after the calculation reaches a relatively stable level, the concentration at the measuring point of the pollutant input from the Yangtze River in the high and low water period is about 6mg/L and 1.2mg/L, which is diluted by 42.9% and 88.6% respectively compared with the pollutant concentration at the discharge outlet. When the sewage is discharged from the sewage outlet, the highest COD concentration does not exceed 3mg/l during the high and low water periods, indicating that the sewage discharged from the planned sewage project will not have a serious impact on water quality.

Investigation on Simultaneous Charging and Discharging Process of Water Thermocline Storage Tank Employed in Combined Heat and Power Units

Abstract Thermal energy storage (TES) has become a key component in combined heat and power (CHP) generation, which enhances the load regulation capability and overall thermal performance. In line with that concept, the present work addresses a numerical study that aims at investigating and predicting the transient thermal behavior of a water thermocline storage tank that integrates into a CHP plant. Investigations are carried out on two distinct two-dimensional models. The first model studies thermocline characteristics of the heat storage system through a single-charge/discharge operation. The influences of various operating parameters such as the inlet flowrate and the inlet temperature of HTF are investigated. Results indicate that the thermocline thickness increases as the inlet flowrate increases, and consequently, the heat storage/release period decreases. The second modified model discusses the technique of simultaneous charging and discharging operation applied in the CHP unit. Two types of operations are analyzing with (a) stable charging with steady discharging and (b) periodic charging with steady discharging. The results ravel out that the mixing ratio of charging and discharging flowrate (Qc/Qd) has a strong influence on the operation performance. When the ratio of Qc/Qd &amp;gt;1, the thermocline forms, and its thickness increases with time. The thermocline thickness remains constant as this ratio declines to 0.625. In the case of periodic charging, both larger charging flowrate and shorter non-charging periods result in maintaining the discharge outlet temperature of HTF stable for the heat-supply net, and discharge performance improved.

Investigations on Material Composition of Iron-containing Tails of Enrichment of Combined Mining and Processing in Kursk Magnetic Anomaly of Russia

The inevitable depletion of mineral resources, the constant deterioration of the geological and mining conditions for the development of mineral deposits and the restoration of raw materials from mining waste by recycling are all urgent problems we faced today. The solution to this problem may ensure: a considerable extension of raw material source; decrease of investments in opening new deposits; cost savings for dumping and handling of tailing dumps, disturbed land remediation; obtaining social and economic effect due to a considerable reduction in pollution of the environment. This article deals with the study of iron-containing tailings dumped at the tailing dumps of ore-refinery and processing facilities located in Kursk Magnetic Anomaly (KMA GOKs), where samples were taken for this study. The article contains the results of the materials composition study, namely: chemical composition, the mineral-petrographic study of thin and polished sections, grain size distribution and physical-mechanical properties of tailing samples. Regularities were revealed for the change of the useful component content due to gravity differentiation. It was also noted that the sulphur content increased near the pulp discharge outlet due to pyrite accumulation. The ratio of ore minerals in tailings and the fineness ratio of the sand fraction were measured. The examination with a focused beam microscope with x90 to x600 magnification showed a variety of grain sizes and shapes that facilitate using tailing materials after additional processing in the construction industry as sand.

INCREASING EFFICIENCY OF LIQUID SYSTEMS SEPARATION FOR FORMATION FLUID GATHERING

Considerable attention is paid to the improvement of the processes of high-quality and productive separation of liquid heterogeneous systems SHAPE \\* MERGEFORMAT in the oil and gas industry from both manufacturers and scientists. To carry out these operations, various types of designs of sedimentation tanks, separators, hydrocyclones, etc. are used, the principle of operation of which is based on gravitational and centrifugal separation of inhomogeneous masses of various densities. It should be noted that when designing separators with a high value of the performance index, it is insufficiently possible to use numerous theoretical studies in the field of hydromechanics of flow in a centrifugal field. This is due to the extreme complexity of the conditions for the flow of the separated fluid in the rotor space. Therefore, experimental studies of intra-rotor flows have become very important at present. So, it was experimentally shown that, during the intensification of the separation process, it is impossible to study the operation of individual parts of the rotor separately, but it is necessary to consider the operation of the system, including the plate package, sludge space, high-pressure channels and an unloading device. Thus, we can conclude that the increase in the performance of separators due to the increase in their size has approached the limit and the use of some more reserves in this direction is obviously associated with the need to overcome great and unjustified difficulties. Further development of this direction is irrational. However, there is a way to intensify the separation process by equalizing the distribution of the rotor and batch flows, improving the packages, eliminating the flotation effect and the destruction of the dispersed phase, adapting the operating mode of the separators depending on changes in the properties of the separated liquid. In industrial conditions, for example, when cleaning a highly paraffinized formation fluid, crusts form in the hydrocyclone, periodically clogging the discharge hole. In order to ensure the best hydrodynamic process conditions for the separation of formation fluid in a hydrocyclone and to prevent clogging of the discharge outlet, an apparatus is proposed that contains only the cylindrical part of the housing. A feature of the proposed design is that the optimal ratio of length to diameter is in the range of 3-5 with other ratios of other characteristics used in the calculation, equal to the ratios of characteristics in known hydrocyclones. This length of the hydrocyclone provides the conditions for the effective separation of the reservoir fluid and the withdrawal of the condensed fraction through the discharge opening. The obtained results of studies performed on a real product at pressure and flow rate, corresponding to the production ones, made it possible to design and manufacture an industrial model of the apparatus. The experimental data can be used to calculate similar hydrocyclones intended for use in other mixtures.

Meltwater Intrusions Reveal Mechanisms for Rapid Submarine Melt at a Tidewater Glacier

AbstractSubmarine melting has been implicated as a driver of glacier retreat and sea level rise, but to date melting has been difficult to observe and quantify. As a result, melt rates have been estimated from parameterizations that are largely unconstrained by observations, particularly at the near‐vertical termini of tidewater glaciers. With standard coefficients, these melt parameterizations predict that ambient melting (the melt away from subglacial discharge outlets) is negligible compared to discharge‐driven melting for typical tidewater glaciers. Here, we present new data from LeConte Glacier, Alaska, that challenges this paradigm. Using autonomous kayaks, we observe ambient meltwater intrusions that are ubiquitous within 400 m of the terminus, and we provide the first characterization of their properties, structure, and distribution. Our results suggest that ambient melt rates are substantially higher (×100) than standard theory predicts and that ambient melting is a significant part of the total submarine melt flux. We explore modifications to the prevalent melt parameterization to provide a path forward for improved modeling of ocean‐glacier interactions.

Distinct Frontal Ablation Processes Drive Heterogeneous Submarine Terminus Morphology

AbstractCalving and submarine melt drive frontal ablation and sculpt the ice face of marine‐terminating glaciers. However, there are sparse observations of submarine termini, which limit estimates of spatially varying submarine melt. Here we present a detailed survey of a west Greenland glacier to reveal heterogeneity in submarine terminus morphology. We find that the majority of the terminus (~77%) is undercut, driven by calving in the upper water column and submarine melting at depth. The remaining ~23% of the terminus is overcut, driven by calving alone. We use observations of six subglacial discharge outlets, combined with a plume model, to estimate spatially varying discharge fluxes. While small discharge fluxes (&lt;43 m3/s) feed numerous, deeply undercut outlets with subsurface plumes, ~70% of the net subglacial flux emerges at the terminus center, producing a vigorous, surface‐reaching plume. This primary outlet drives large, localized seasonal retreat that exceeds calving rates at secondary outlets.

Flow and heat transfer characters in the integral internal cooling channel of a turbine blade

A scaled model of the integral internal cooling channel of a turbine blade was established for the experimental investigation. The model was made by Perspex for its transparency so that the thermochromic liquid crystal measurement could be used easily. The cooling channel is composed of 3 legs of ribbed channels. Rib with angle 45° was settled in both pressure side and suction side, which forms a cross-rib structure. Three legs were connected by two 180° turns. The main inlet and two addition inlets were arranged in the root of the model channel. Two discharge outlets were located in the tip. A row of outlet holes was distributed along the trailing edge. The channel area gradually decreases along the blade height direction, while bending and torsion occur because of the blade airfoil shape. The aspect shapes and connection methods of the channel were kept in accordance with the real blade. The inlet Reynolds number is from 10000 to 32000. Five outlet discharge ratios were alternated in this investigation. The detailed heat transfer distributions, both in the pressure side and suction side, were measured by transient liquid crystal technic. The characters of heat transfer distribution and pressure drop along the channel were displayed. The effects of flow discharge ratio on heat transfer and pressure coefficient were also described.

Georeferenced multimedia environmental fate of volatile methylsiloxanes modeled in the populous Tokyo Bay catchment basin

We investigated the multimedia fate of decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) in the densely populated catchment basin of Tokyo Bay, Japan, by using a georeferenced multimedia model. We estimated the daily per person consumption rate of these compounds in Japan according to literature. Emissions to the atmosphere accounted for almost all of the emissions of these compounds to the environment. The majority of these compounds was predicted to be distributed in the atmosphere (about 60%) and sediment (about 40%). The advective flows in and out of the atmosphere over the Tokyo Bay catchment basin dominated the flows of these compounds. The sewerage systems contributed considerably to the transport and fate of D5 and D6 in water. They transported these compounds from households to discharge outlets of sewage treatment plants (STPs), which in turn accounted for approximately one quarter of the emission of these compounds to rivers and to Tokyo Bay. The wastewater treatment plants also effectively removed these compounds from the wastewater. The overall persistence of D5 and D6 in the catchment basin was estimated to be 3.8–9.5 days. The horizontal distributions of these compounds were similar among environmental compartments; high concentrations were generally observed in populated areas. A sensitivity analysis demonstrated that the D5 discharge rate to Tokyo Bay excluding the direct discharge from STPs and the D5 mass in the river compartment were sensitive to changes of the organic-carbon-water partition coefficient. Comparison with the concentrations in rivers measured recently in the target area showed that the model captured overall trends of low to high concentrations in rivers. However, there was some variability and a bias toward underprediction. The model provided a better fit to measurements for D5 than for D6. One potential factor contributing to the bias toward underprediction was underestimation of the consumption rates.

Numerical Analysis of an Impact of Planned Location of Sewage Discharge on Natura 2000 Areas – The Dead Vistula Region Case Study

Abstract This article presents results of an analysis of impact of a designed discharge of contaminated water into the Dead Vistula (Wisła Martwa) in the region of the Isthmus (Przesmyk) with the aim of determination of a possible effect of the pollution onto protected areas of Natura 2000 (bird habitats and sites, especially the Bird Paradise – Ptasi Raj) nature reserve. The analysis was conducted on the basis of the two-dimensional modelling of unsteady transport of non-degradable dissolved matter. To this end, a numerical model of a section of the Dead Vistula was worked out. Four scenarios of hydro-dynamical conditions (2 – for average weather conditions and 2 – for stormy weather conditions) were selected. To solving the equation of pollution migration the finite volumes method (MOS) was applied. Two localizations of contaminated water discharge outlet were considered, namely: the first from the side of Siennicki Bridge before the Isthmus and the other in the section of the Brave Vistula (Wisła Śmiała) downstream the Isthmus. The obtained results made it possible to assess positively the first localization of the designed discharge outlet. In the other case there is a fear that at unfavourable hydro-meteorological conditions a water pollution may happen over Natura 2000 protected areas.

Analysis on the Characteristics of Dissolved Organic Matter in Receiving River Water in Wastewater Treatment Plant

In this paper, Nash’s reagent luminosity and other methods were used to quantitatively and qualitatively study the content of ammonia nitrogen and other substances in the tailwater of urban sewage treatment plant, and to analyze the characteristics of organic matter by fluorescence spectrometry, focusing on different sampling points of rivers by three-dimensional fluorescence spectroscopy. The change in dissolved organic matter in the water sample was characterized. The results show that the dissolved organic matter in the upstream of the river channel is the tryptophan in the protein. After the tail water of the sewage treatment plant is discharged, the dissolved organic matter from the tail water discharge outlet to the downstream river channel is protein, sewage treatment. After the tail water is discharged, there is basically no influence on the composition and transformation of dissolved organic matter in the receiving river channel.

Using Stable Carbon and Nitrogen Isotopes to Investigate the Impact of Desalination Brine Discharge on Marine Food Webs

Stable isotope ratios were used to trace the impact of anthropogenically derived brine from desalination plants on organisms at different trophic levels (primary producers and consumers) along the highly urbanized ultra-oligotrophic Israeli coast (southeast Mediterranean). Primary producer and consumer organisms were collected from two sampling stations at two desalination plants sites: an “Impacted station”, near the brine discharge outlets, and a “Control station” situated further offshore to the impacted zone. δ(_^13)C and δ(_^15)N values of both producers and consumers displayed minor variations between the impacted and control stations, indicating little effect of brine discharge on the coastal trophic structure. The coastal δ(_^15)N values were generally higher than those of similar pelagic communities of the southeastern Mediterranean. These were particularly high in benthic invertebrates and benthic carnivores (fish) from the southern site, where high anthropogenically N loads from ground water amelioration are discarded alongside the brine. The observed differences in the δ(_^15)N of the benthic components between the two study sites suggest that brine derived density plumes from desalination plants are a possible vector of nutrients to benthic communities. The results indicate that the benthic components were the most sensitive group to anthropogenic derived N pollution, and provide insight into site-specific processes.

Flow characteristics of water delivery piping system and its effective flow area at discharge branches

When we scatter water uniformly over a wide area, we often make a large number of branches and discharge outlets in a main pipe and let water be discharged from each outlet. In order to achieve uniform sprinkling, it is necessary to understand the state of the water flowing out from each outlet properly. In the present paper, the flow field inside a water delivery pipe with multiple short branch pipes was investigated using numerical calculation and experimental measurement. As a result, computational results and experimental results showed good agreement, and the validity of the computational method was confirmed. At the discharge outlet, flow surface in which air and water were mixed was formed. It was confirmed that the water area was smaller on the upstream side and became larger as going downstream. It was clarified that the discharge flow rate and the water flow area changed greatly due to the change in the discharge outlet diameter and the terminal outlet diameter.

Stress states caused in chamber of reinforced concrete grain silo by non-centric emptying on large eccentricities

Abstract The article presents the analysis of complex stress states in the concrete structure of grain silos, caused by non-centric emptying. The authors present a combination of loads from the pressure of bulk solid on the silo chamber according to Eurocode 1, Part 4 [11], which should be taken into account when emptying on large eccentricities in action assessment class 3 (AAC3) silos. For the example of a cylindrical wheat silo with a height of 25 m and a diameter of 10 m, the researchers carried out an analysis regarding the impact of the size of the eccentric discharge outlet on the distributions of forces and bending moments in a reinforced concrete wall.

Physicochemical parameters and phytoplankton as indicators of the aquatic environment in karstic springs of South China

As the concentrated discharge outlet of an aquifer or groundwater system, a karst spring is partly independent from the aquifer, due to its formation of a pool or lake after outcropping onto the surface. Understanding how to evaluate the unique and sensitive environment of the karst spring is essential for water resource protection. Five karst springs in South China were investigated by analyzing their hydrodynamic conditions, variations in physicochemical parameters, and phytoplankton community structures. Dominated by regional or local groundwater flow, these springs had different catchment area characteristics and hydrogeological conditions. The results showed that, although they had similar water quality, their physicochemical parameters needed to be distinguished and evaluated in different ways in order to determine the cause of the observed degradation in spring water quality. Ca2+, HCO3−, and specific electrical conductivity were the major parameters reflecting the impact of regional flow from the aquifer; pH, dissolved oxygen, and water temperature indicated the local environment in and around the springs; while nitrogen and CODMn both related to the aquifer and local environment, depending on seasonal variation and human activities. The comparison of long-term nitrate data revealed that environmental pressure has increased over time. Water deterioration of Lingshui Spring was attributed to the strong interaction of surface water and groundwater. High nutrient concentrations did not correspond with the highest phytoplankton abundance or the most species. The phytoplankton community structures in the karst springs varied from place to place, depending on the hydrogeological conditions and the surrounding environment. The water environment status, as reflected by the combination of water quality indices and biological indicators, could more comprehensively represent overall water health.

Development of solar powered screen cleaner

Harvested grain mass contains various impurities that need to be removed before further processing. A solar powered screen cleaner was designed, fabricated and tested for separating impurities from soybean, lentil and chickpea grains. The machine consists of frame, feeding chute, screen cradle, discharge outlets, and drive unit. The angle of tilt of the sieve was varied between 3 and 8° while the hanger angle was maintained at 5°. Operating parameters such as screen cradle angle, oscillation and feed rate were optimized and the optimum performance was achieved at a screen cradle angle of 50, screen oscillation of 3.6 Hz, and feed rate of 150 kg/h.The slope of the sieve unit, cradle speed and stroke length could be adjusted easily. The developed unit was evaluated with 5 kg sample consisting of 80%, 85%, and 90% pure hand-cleaned grains mixed with 20%,15% and 10% impurities (chaff, stem, other crop seeds, weed seeds, clods, stones, etc.). The cleaning efficiency for whole chickpea, soybean and lentil was found to be 88.27%, 87.14% and 84.3%, respectively, and the losses observed was 2.12%, 1.25% and 1.73%, respectively. Overall machine efficiency was observed to be 83%.This machine assures good quality grain at affordable energycost to small and marginal farmers in rural India.

Water Quality and Public Health Complaints in Surrounding Watoetoelis Sugar Mills

Industry as an integral part of the development of the country, more less having effect on the surrounding environment. Sugar factory as a part the industry also affects the quality of the surrounding environment through wastewater discharge at which water pollution control is required to achieve an ideal level of environmental health. PG Watoetoelis pollution control can be assessed from the water quality of its surrounding. This study aims to identify water quality and health complaints around PG Watoetoelis. This study is a descriptive observational study with cross sectional design. Primary data collection was conducted in July and August 2014, in the form of: interviews with questionnaires, environmental observation, inspection parameters of water samples of water bodies and wells in both upstream and downstream within 100 meters of the point of waste water discharge outlet Watoetoelis Sugar Factory. The results showed: the examination of water body samples found high levels of BOD5 in the amount of: 24.34 mg/L (upstream) and 24.15 mg/L (downstream), all wells water samples did not reveal any signs of physical and chemical pollution of water, respondents around PG Watoetoelis who with health complaints (9 of 17) experienced health complaints such as coughs of 7 people, and complained about the odor of the sugar factory pollution as many as 15 of 17 people. The conclusion of this study are bad water bodies quality, physical and chemical quality of the water samples of wells qualified, there are health complaints by respondents, but this can be due to other variables than physical and chemical parameters of the well water, such as; microbiology, hygiene and sanitation, or poor quality of the air in the environment, especially the residence location of the respondents.

Study on Smoke Behavior in Under-viaduct Stations by using Scale Reduced Model.

In the event of fire at concourse of rail stations under elevated platforms, smoke may emit through stairways leading from the concourse to platforms as well as standard natural smoke discharge outlets decreed by the Building Standards Law. However there is little knowledge about smoke discharge from the concourse via the stairway. In this study, Experiments regarding smoke flow in the case of fire in concourse of rail stations below elevated platforms were carried out compare volume of smoke emitted through stairway opening with that emitted through standard natural smoke discharge outlets as decreed by the Building Standards Law, with a simple scale reduced model which stairway was placed at right angle to the concourse. As a result, in these experiments, relationship of smoke discharge between stair openings and standard natural smoke discharge outlet was found.

Mixing of swirling inclined dense jets – A numerical study

Recent experimental investigations demonstrated the possibility that the addition of swirls at the discharge outlet can lower the terminal rise height of inclined dense jets and increase the dilution at the return point, which can potentially influence the outfall design in coastal waters. In the present study, we further examined the effect of swirls on the mixing characteristics of 45 degree inclined dense jets using numerical simulations with two different approaches. The first approach was the Large Eddy Simulation (LES) with the dynamic Smargorinsky Sub-grid Model, and the second one was the Reynolds-Averaged Navier-Stokes (RANS) with the standard k − ε turbulence closure. The comparison showed that the trajectories of the non-swirling inclined dense jet predicted by LES were closer to the experimental results, while RANS underpredicted the centreline peak height. This was consistent with the previous findings and can be attributed to the fact that the turbulence characteristics of non-swirling dense jets were highly anisotropic. Both approaches however underestimated the additional spreading in the lower half of the inclined dense jet due to the convective mixing by the buoyancy induced instability, and also the dilution in general. With swirls, the RANS predictions matched the jet trajectory better compared to LES, which was probably because the turbulence anisotropy was reduced and the distributions were more axisymmetric. The dilutions of swirling jets remained underestimated by both approaches, until the Swirl Number became sufficiently large at 0.33. Finally, strong swirls up to twice the highest value in the experiments were attempted in the numerical simulations to explore the possibility of jet breakup and disintegration at the outlet. It was found that the high swirl intensity did not lead to significant changes beyond what were observed at G = 0.33. The turbulence kinetic energy spectrum of the swirling inclined dense jet was also analysed along the trajectory based on the LES results. The spectral analysis confirmed that the effects of swirls were different depending on the magnitude, with strong swirls producing turbulence energy at the range of frequencies just before the inertial range probably due to eddy break up around the vortical layer, while extremely strong swirls increased the turbulence energy production range overall with the additional formation of large eddies.