scholarly journals Legacy of Past Mining Activity Affecting the Present Distribution of Dissolved and Particulate Mercury and Methylmercury in an Estuarine Environment (Nalón River, Northern Spain)

2021 ◽  
Vol 11 (10) ◽  
pp. 4396
Author(s):  
Elena Pavoni ◽  
Efren García-Ordiales ◽  
Stefano Covelli ◽  
Pablo Cienfuegos ◽  
Nieves Roqueñí
Keyword(s):  
River Flow ◽  
Fine Particles ◽  
River Estuary ◽  
Environmental Issues ◽  
Mining Activity ◽  
Strong Interactions ◽  
Northern Spain ◽  
Complementary Effect ◽  
Present Distribution ◽  
Total Hg

At the Nalón River estuary (Asturias, Northern Spain), the occurrence of Hg is due to historical mining activity which has resulted in environmental issues of great concern. Although several studies have investigated the sediment compartment regarding Hg contamination, no information is currently available on the fate of Hg and MeHg in the water column. Considering different hydrodynamic/seasonal conditions, water samples were collected along the estuary to evaluate Hg and MeHg distribution and partitioning behaviour between solid and aqueous phases. The complementary effect of the river discharge and tidal currents contributed to the prevalence of the dissolved (4.02 ± 1.33 ng L−1) or particulate (8.37 ± 4.20 ng L−1) Hg under different conditions of discharge in summer and autumn, respectively. Conversely, particulate MeHg prevailed when the river flow was low, especially at the estuary mouth (25.8 ± 19.1 pg L−1) and most likely due to the resuspension of fine particles promoted by a stronger tidal current. In comparison with the total Hg concentration, extremely low amounts of dissolved and particulate MeHg were observed, and strong interactions between MeHg and organic carbon highlighted a negligible risk of increased mobility and potential bioaccumulation of MeHg.

Depletion of coating color components in the blade coating process circulation

TAPPI Journal ◽  
2011 ◽  
Vol 10 (9) ◽  
pp. 17-23 ◽  
Author(s):  
ANNE RUTANEN ◽  
MARTTI TOIVAKKA
Keyword(s):  
Fine Particles ◽  
Particle Density ◽  
Stable Process ◽  
Size Fraction ◽  
Color Stability ◽  
Strong Interactions ◽  
Coating Process ◽  
Size Segregation ◽  
Coating Color ◽  
Average Size

Coating color stability, as defined by changes in its solid particle fraction, is important for runnability, quality, and costs of a paper coating operation. This study sought to determine whether the size or density of particles is important in size segregation in a pigment coating process. We used a laboratory coater to study changes in coating color composition during coating operations. The results suggest that size segregation occurs for high and low density particles. Regardless of the particle density, the fine particle size fraction (<0.2 μm) was the most prone for depletion, causing an increase in the average size of the particles. Strong interactions between the fine particles and other components also were associated with a low depletion tendency of fine particles. A stable process and improved efficiency of fine particles and binders can be achieved by controlling the depletion of fine particles.

Sources of Chlorophenolic Compounds to the Fraser River Estuary

1988 ◽  
Vol 23 (1) ◽  
pp. 55-68 ◽  
Author(s):  
J. H. Carey ◽  
J. H. Hart
Keyword(s):  
River Flow ◽  
River Estuary ◽  
Low Flow ◽  
Fraser River ◽  
Pulp Mills ◽  
Flow Conditions ◽  
Downstream Site ◽  
Upstream Site ◽  
The North ◽  
Main River

Abstract The identity and concentrations of chlorophenolic compounds in the Fraser River estuary were determined under conditions of high and low river flow at three sites: a site upstream from the trifurcation and at downstream sites for each main river arm. Major chlorophenolics present under both flow regimes were 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), pentachlorophenol (PCP), tetrachloroguaiacol (TeCG) and a compound tentatively identified as 3,4,5-trichloroguaiacol (3,4,5-TCG). Under high flow conditions, concentrations of the guaiacols were higher than any of the Chlorophenols and concentrations of all five chlorophenolics appeared to correlate. Under low flow conditions, concentrations of chloroguaiacols were higher than Chlorophenols at the upstream site and at the downstream site on the Main Arm, whereas at the downstream site on the North Arm, concentrations of 2,3,4,6-TeCP and PCP were higher than the chloroguaiacols in some samples. Overall, the results indicate that pulp mills upstream from the estuary are important sources of chlorophenolics to the estuary under all flow conditions. Additional episodic inputs of 2,3,4,6-TeCP and PCP from lumber mills occur along the North Arm. When these inputs occur, they can cause the concentrations of Chlorophenols in the North Arm to exceed provisional objectives. If chloroguaiacols are included as part of the objective, concentrations of total chlorophenolics in water entering the estuary can approach and exceed these objectives, especially under low flow conditions.

scholarly journals Size and Ambundance of glass eel Anguilla spp in mouth of Poigar River

2019 ◽  
Vol 7 (1) ◽  
pp. 212
Author(s):  
Kristanto R. Lumi ◽  
Victor N. R. Watung ◽  
Nego E. Bataragoa
Keyword(s):  
River Flow ◽  
Average Length ◽  
Sampling Site ◽  
River Estuary ◽  
Average Density ◽  
Fishing Gear ◽  
Sampling Area ◽  
Glass Eel ◽  
Phase Sampling ◽  
New Moon

The  aims of this study are determine the composition of the length and abundance of glass eel Anguilla spp that migrates at the mouth of the Poigar River. Sampling is done every month for four months in the new moon phase. Sampling site on one side of the Poigar River estuary, by making a 10 meter track in the direction of the river flow. The fishing gear used is a triangle-shaped handy scoop net with a length of 100 cm and a width of 75 cm. The catch of Glass eel eel for four months (from April to July 2018) as many as 3,551 individuals. Average length (± SD) in April was 44.4 ± 1.4 cm, May 48.7 ± 1.6 cm, June 51.1 ± 2.0 cm and July 51.1 ± 2.4 cm. The highest number of catches in May was 1,841 individuals, followed by June 785, July 860 individuals and April as many as 55 individuals. The average density of eels in April, Mai, June and July 2018 migrating in the sampling area of 10 x 0.7 meters is 1,160 individuals.Keywords: glass eel, size, abundance, Poigar River.ABSTRAKPenelitian ini bertujuan untuk mengetahui komposisi ukuran panjang dan kelimpahan  ‘‘glass eel’’ sidat Anguilla spp yang bermigrasi di muara Sungai Poigar.  Pengambilan sampel dilakukan setiap bulan selama empat bulan pada  fase  bulan baru. Tempat sampling  pada  satu sisi muara Sungai Poigar, dengan membuat lintasan sepanjang 10 meter searah aliran sungai. Alat tangkap yang digunakan adalah seser (handy scoop net) berbentuk segitiga dengan panjang 100 cm dan lebar 75 cm. Hasil tangkapan Glass eel sidat selama empat bulan (dari bulan April sampai Juli 2018) sebanyak 3.551 individu.  Rata-rata  panjang (± SD) pada bulan April 44,4±1,4 cm, Mei 48,7±1,6 cm, Juni 51,1±2,0 cm dan Juli 51,1±2,4 cm.  Jumlah tangkapan terbanyak pada bulan Mei 1.841 individu, diikuti bulan Juni 785, bulan Juli 860 individu dan bulan April sebanyak 55 individu.  Rata-rata kepadatan sidat pada bulan April, Mai, Juni dan Juli 2018 yang bermigrasi dalam wilayah sampling 10 x 0,7 meter adalah 1.160 individu.Kata kunci: glass eel, ukuran, kelimpahan, Sungai Poigar.

A new genus of frenulates (Annelida: Siboglinidae) from shallow waters of the Yenisey River estuary, Kara Sea

2021 ◽  
Author(s):  
N. P. Karaseva ◽  
N. N. Rimskaya-Korsakova ◽  
I. A. Ekimova ◽  
M. M. Gantsevich ◽  
V. N. Kokarev ◽  
...  
Keyword(s):  
New Genus ◽  
River Flow ◽  
Posterior Part ◽  
River Estuary ◽  
Molecular Study ◽  
Morphological Characters ◽  
Kara Sea ◽  
The Arctic ◽  
Permafrost Degradation ◽  
Bottom Water Temperature

Only seven frenulate species are currently known along the Eurasian coast of the Arctic Ocean. We describe a new genus and a new species of frenulates Crispabrachia yenisey, gen. nov. et sp. nov. The morphological analysis involved standard anatomical techniques, semithin sections and scanning electron microscopy (SEM). The molecular study included four markers (partial COI, 16S, 18S and 28S) and implemented Bayesian and Maximum likelihood phylogenetic approaches. The description of Crispabrachia gen. nov. is the first documented finding of frenulates in the Kara Sea at the estuary of the Yenisey River in rather shallow water (28 m). The establishment of a new genus is warranted based on the composition of morphological characters and several specific features including free, comparatively short curly tentacles, a triangular cephalic lobe with amplate base, the valvate extension of the posterior part of the forepart and prominent papillae on the nonmetameric region. The tube structure with prominent frills and the worm’s numerous tentacles, metameric papillae with cuticular plaques and segmental furrow on the forepart indicate that the new genus belongs to the polybrachiid group. Although the type locality in the Yenisey River estuary is unusual for siboglinids in general, the physical conditions here are common for other frenulates habitats, i.e. salinity ~30–33, bottom water temperature –1.5°C. This finding was made in the Yenisey Gulf in the region with the highest methane concentrations in the southern part of the Kara Sea that reflects permafrost degradation under the influence of river flow. Further study of the region would help to understand the factors influencing frenulate distributions and improve our knowledge of their biodiversity.

scholarly journals Dynamics of the Estuarine Turbidity Maximum Zone from Landsat-8 Data: The Case of the Maroni River Estuary, French Guiana

2020 ◽  
Vol 12 (13) ◽  
pp. 2173 ◽  
Author(s):  
Noelia Abascal-Zorrilla ◽  
Vincent Vantrepotte ◽  
Nicolas Huybrechts ◽  
Dat Dinh Ngoc ◽  
Edward J. Anthony ◽  
...  
Keyword(s):  
River Flow ◽  
Temporal Dynamics ◽  
Spring Tide ◽  
River Estuary ◽  
Turbidity Maximum ◽  
Sediment Supply ◽  
Estuarine Turbidity Maximum ◽  
Landsat 8 ◽  
Residual Circulation ◽  
Spatio Temporal

The estuarine turbidity maximum (ETM) zone occurs in river estuaries due to the effects of tidal dynamics, density-driven residual circulation and deposition/erosion of fine sediments. Even though tropical river estuaries contribute proportionally more to the sediment supply of coastal areas, the ETM in them has been hardly studied. In this study, surface suspended particulate matter (SPM) determined from OLI (Operational Land Imager)-Landsat 8images was used to gain a better understanding of the spatio-temporal dynamics of the ETM of the tropical Maroni estuary (located on the Guianas coast, South America). A method to estimate the remotely-sensed ETM location and its spatiotemporal evolution between 2013 and 2019 was developed. Each ETM was defined from an envelope of normalized SPM values > 0.6 calculated from images of the estuary. The results show the influence of the well-marked seasonal river discharge and of tides, especially during the dry season. The ETM is located in the middle estuary during low river-flow conditions, whereas it shifts towards the mouth during high river flow. Neap–spring tidal cycles result in a push of the ETM closer to the mouth under spring-tide conditions or even outside the mouth during the rainy season. An increase in SPM, especially since 2017, coincident with an extension of the ETM, is shown to reflect the periodic influence of mud banks originating from the mouth of the Amazon and migrating along the coast towards the Orinoco (Venezuela). These results demonstrate the advantages of ocean color data in an exploratory study of the spatio-temporal dynamics of the ETM of a tropical estuary, such as that of the Maroni.

scholarly journals Study on the Transport of Terrestrial Dissolved Substances in the Pearl River Estuary Using Passive Tracers

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1235
Author(s):  
Bo Hong ◽  
Guangyu Wang ◽  
Hongzhou Xu ◽  
Dongxiao Wang
Keyword(s):  
Water Resource Management ◽  
River Flow ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Dry Season ◽  
Pearl River ◽  
Transport Time ◽  
The Pearl River Estuary ◽  
Passive Tracers ◽  
The Pearl River

Highly populated river deltas are experiencing marine environment degradation resulting from the tremendous input of terrestrial dissolved substances (TeDS). The Pearl River Delta is one of the deltas with degradation of the water quality and ecological condition. The Pearl River Estuary (PRE) was investigated to reveal the fate and transport timescales of TeDS in order to provide guidance on water resource management and pollutant transport prediction. By using passive tracers in a calibrated 3D numerical model, the TeDS transports from five different outlet groups were investigated systematically. The TeDS transport time was computed by using the concept of water age, which is a measure of the time that has elapsed since the tracer was transported from the upstream boundary to the downstream concerned area. The tracer impacted area was defined by the area with tracer concentrations > 0.2 (arbitrary unit). The domains that were impacted by the tracer coming from each outlet group were identified separately. In the wet season, the impacted area was larger than in other seasons. The most prominent variations appeared in the Jiaomen–Hengmen–Hongqili (JHH) and Modaomen (MD) outlets. The hydrodynamic conditions controlled the offshore spreading of the TeDS. Assuming the TeDS were conservative, it took approximately 10–20 days for the TeDS to be transported from the head water to the entrance of the outlet. For the TeDS coming from the head water of the Humen outlet, it took approximately 40 (80) days for the TeDS to be transported out of the mouth of the Lingding Bay during the wet (dry) season. For the case of the TeDS coming from the head water of the JHH outlets, it took approximately 20 (40) days for the TeDS to be transported out of the Lingding Bay during the wet (dry) season. For the MD, Jiti and Yamen–Hutiao outlets, it usually took approximately 10 days for the TeDS to be transported from the head water to the inner shelf. The correlation coefficient between the river flow and tracer concentrations was 0.78, and between the river flow and transport time it was −0.70 at a station in the lower Lingding Bay. At the estuary mouth, the impacts of other forcing fields got stronger.

Salt-Wedge Response to Variable River Flow and Sea-Level Rise in the Microtidal Rječina River Estuary, Croatia

2017 ◽  
Vol 33 (4) ◽  
pp. 802-814 ◽  
Author(s):  
Nino Krvavica ◽  
Vanja Travaš ◽  
Nevenka Ožanić
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
River Flow ◽  
River Estuary ◽  
Salt Wedge ◽  
And Sea Level

Landscape and river self-organization limit the flux of fine particles

2020 ◽  
Author(s):  
Colin Phillips ◽  
Carlos Rogéliz ◽  
Daniel Horton ◽  
Jonathan Higgins ◽  
Aaron Packman
Keyword(s):  
Suspended Sediment ◽  
Fine Particle ◽  
River Flow ◽  
Fine Particles ◽  
Strong Support ◽  
Sediment Concentration ◽  
Sediment Flux ◽  
Suspended Sediment Transport ◽  
Erosion Rates ◽  
Suspended Sediment Flux

&lt;p&gt;Fine particles in rivers comprise a substantial fraction (&gt;50%) of the mass leaving a landscape, while at shorter timescales they represent significant carriers of nutrients and contaminants with the potential to both degrade and enhance aquatic habitats. Predicting fine particle dynamics within rivers remains challenging due to a complex relationship between sediment and water availability from the landscape. This inherent complexity results in watershed-specific understandings of suspended sediment dynamics, typically parameterized as empirical functions of catchment land use, geology, and climate. However, observations of significant fine particle storage within river corridors may indicate that the flux of suspended sediment depends on reach-scale hydraulics. To better understand these dynamics, we synthesized over 40 years of suspended sediment concentration (SSC), hydraulic geometry, river flow, and grainsize data collected by the US Geological Survey from hundreds of rivers spanning a large variety of environments across the continental United States. This data synthesis reveals a strong nonlinear trend between reach-scale hydraulics and the suspended sediment flux, with a secondary dependence on particle properties. The multi-site synthesis reveals that by normalizing the suspended sediment flux by the bankfull shear stress and flux results in a collapse of the observed data onto a single function that describes a self-organizing structure for suspended sediment transport in watersheds. This general relationship indicates strong support for the role of autogenic processes in setting the flux of fine particles and erosion rates of watersheds.&lt;/p&gt;

scholarly journals Using flushing rate to investigate spring-neap and spatial variations of gravitational circulation and tidal exchanges in an estuary

2010 ◽  
Vol 7 (2) ◽  
pp. 1621-1654
Author(s):  
D. C. Shaha ◽  
Y.-K. Cho ◽  
G.-H. Seo ◽  
C.-S. Kim ◽  
K.-T. Jung
Keyword(s):  
River Flow ◽  
Spring Tide ◽  
Vertical Mixing ◽  
River Estuary ◽  
Spatial Variations ◽  
Tidal Exchange ◽  
Tidal Amplitude ◽  
Gravitational Circulation ◽  
Flushing Rate ◽  
Rate Method

Abstract. Spring-neap and spatial variations of gravitational circulation and tidal exchanges in the Sumjin River Estuary (SRE) were investigated using the flushing rate method. This method was applied to multiple estuarine segments to estimate both the exchanges. The strength of gravitational circulation and tidal exchanges modulated significantly between spring and neap tides, where stratification alternated between well-mixed and highly-stratified conditions over the spring-neap cycle. Strong gravitational circulation developed during neap tide along the SRE due to the significant reduction in vertical mixing that accompanied strong stratification. The tidal exchanges dominated over gravitational circulation near the mouth during spring tide due to the larger tidal amplitude that caused well-mixed conditions and rapid exchange. In contrast, the central and inner regimes were found to be partially stratified during spring tide due to the reduction in tidal amplitude which induced gravitational circulation and weakened the tidal exchange. Only the gravitational circulation dominated at the upstream end during spring and neap tides which was governed by the river flow.

scholarly journals Jumlah dan Jenis Fitoplankton Di Muara Sungai Banjir Kanal Barat Semarang

2020 ◽  
Vol 9 (3) ◽  
pp. 261-270
Author(s):  
Anantya Setya Perdana ◽  
Raden Ario ◽  
Hadi Endrawati
Keyword(s):  
Water Quality ◽  
River Flow ◽  
Diversity Index ◽  
Evaluation Criteria ◽  
River Estuary ◽  
Aquatic Organisms ◽  
Household Waste ◽  
The West ◽  
Dominance Index ◽  
Polluted Waters

ABSTRAK: Muara Sungai Banjir Kanal Barat merupakan muara sungai terbesar di Semarang yang alirannya langsung menuju ke laut. Terdapat beberapa aktifitas yang terjadi di sepanjang aliran ini, diantaranya yaitu aktifitas industri dan pemukiman penduduk. Selain itu, adanya pembuangan limbah rumah tangga yang masuk ke dalam badan sungai yang juga berdampak bagi perubahan kualitas perairan serta kehidupan ekosistem di sepanjang aliran sungai tersebut. Fitoplankton merupakan organisme perairan yang keberadaannya dapat dijadikan sebagai indikator kualitas perairan. Penelitian ini bertujuan untuk mengetahui komposisi, kelimpahan, indeks keanekaragaman, indeks keseragaman, dan indeks dominasi fitoplankton di Muara Sungai Banjir Kanal Barat Semarang. Penelitian ini dilakukan pada Oktober-Desember 2019. Metode yang digunakan adalah metode deskriptif eksploratif. Pengambilan sampel dilakukan sebanyak tiga periode dengan interval dua minggu sekali di tiga stasiun. Stasiun 1 merupakan perairan air tawar, stasiun 2 merupakan muara dan stasiun 3 merupakan perairan air laut. Hasil penelitian menunjukkan bahwa terdapat 24 genus fitoplankton dari 3 kelas, yaitu 17 genus dari kelas Bacillariophyceae, 5 genus dari kelas Dinophyceae dan 2 genus dari kelas Cyanophyceae dengan kelimpahan terbesar terdapat pada Stasiun 3 sebesar 67669 sel/L dan terendah pada Stasiun 1 sebesar 52287 sel/L, indeks keanekaragaman termasuk kategori sedang. Indeks keseragaman termasuk dalam kategori tinggi, indeks dominansi termasuk dalam kategori tidak ada jenis yang mendominasi. Berdasarkan kriteria penilaian menurut Shannon – Wiener bahwa perairan tersebut tergolong ke dalam perairan tercemar sedang. ABSTRACT: The Banjir Kanal Barat River Canal is the largest river estuary in Semarang that flows directly to the sea. There are several activities that occur along this flow, including industrial activities and human settlements. In addition, the disposal of household waste that enters the river body also has an impact on changes in water quality and ecosystem life along the river flow. Phytoplankton is aquatic organisms whose existence can be used as indicators of water quality. This study aims to determine the composition, abundance, diversity index, uniformity index, and a dominance index of phytoplankton in the West Banjir Canal River Estuary in Semarang. This research was conducted in October-December 2019. The method used is a descriptive exploratory method. Sampling was conducted in three periods with biweekly intervals at three stations. Station 1 is freshwater waters, station 2 is estuary and station 3 is seawater waters. The results showed that there were 24 genera of phytoplankton from 3 classes, namely 17 genera from the Bacillariophyceae class, 5 genera from the Dinophyceae class and 2 genera from the Cyanophyceae class with the greatest abundance at Station 3 at 67669 cells/L and lowest at Station 1 at 52287 cells/L, the diversity index is in the medium category. Uniformity index is included in the high category, dominance index is included in the category of no species that dominates. Based on the evaluation criteria according to Shannon-Wiener that the waters are classified as medium polluted waters.

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