bottom sediment Articles
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Accumulation of heavy metals in the bottom sediments of the Irkutsk Reservoir
The chemical composition of the bottom sediment, and more particularly the heavy metals content, reflects human developments and impacts on the catchment and reservoir's natural environment. The bottom sediments of the reservoir retained by the Irkutsk Dam have been analysed. The reservoir is mainly supplied by water from Lake Baikal. The following amounts of heavy metals have been found in the ...
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Sediment phosphorus fractions in an urban lake and its usability for predicting of the internal loading phenomenon
The object of present study was Sukiel Lake (area 20.8 ha, max. depth 25 m), localised in north–eastern Poland (Mazurian Lake District), in Olsztyn city. The aim of this study was to analyse the phosphorus fractions in the sediments of two lake bottom zones - profundal (25 m) and sublittoral (7 m). Observed high P concentrations in the deposits of Sukiel Lake and quantitative domination of hard ...
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What are Characteristics of good core samplers?
Perpendicular placement: The core sampler must make a vertical or straight entry into sediments to secure a reliably representative cross-section sample. Penetration: It must penetrate the sediments you expect to find and adaptable for many field situations. Core retention: There should be minimal loss of any part of the sample during return to the surface. Maximum sample validity: This ...
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3D modelling of transport, deposition and resuspension of highway deposited sediments in wet detention ponds
The paper presents results from an experimental and numerical study of flows and transport of primarily particle bound pollutants in highway wet detention ponds. The study presented here is part of a general investigation on road runoff and pollution in respect to wet detention ponds. The objective is to evaluate the quality of long term simulation based on historical rains series of the ...
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Houghton Lake, MI - Case Study
Location: Houghton Lake, MI Cofferdam Size: 8′ high x 150′ long. Water Depth: 6′ Installation Time: 4.5 hours Project Description: Remove bottom sediment to deepen canal for improved boat access. The dredging process can be greatly expedited with the use of water-filled cofferdams from Dam-It Dams. By holding back water on the site, excavators ...
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Long-term changes in the effluent loads from pulp and paper mills, the introduction of BAT technology, and their effects on extractable organic halogens concentrations in sediment in part of the Bothnian Bay
The Bothnian Bay at Kemi, which is the northernmost basin of the Gulf of Bothnia in the Baltic Sea, is affected by effluents from point sources such as pulp and paper mills and municipal sewage plant. During the period 1988–2008, the accumulated values of effluent volume, BOD7, CODCr, Tot-P, Tot-N, TSS and AOX from these point sources fell considerably as follows: 1) effluent volume by 24%, BOD7 ...
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Distribution of mercury in the water and bottom sediment of the J.A. Alzate Dam, Mexico
In this paper, mercury concentration in the soluble, particulate and total fractions of water and in the sediment from the Jose Antonio Alzate Dam in the State of Mexico was evaluated using neutron activation analysis in order to determine the bioavailability and distribution of this metal. Sampling was carried out on three separate seasons – cold dry season, hot dry season and rainy season – ...
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Bioremediation of Occom Pond at Dartmouth College Clears Water - Ecosystem Restoration
Pine Park is a ninety-acre forest of 125-year-old pine trees at Dartmouth College. This park begins at the north end of campus, along the edge of the Hanover Country Club golf course, and extends along the Connecticut River from Ledyard Canoe Club northward. The trees were saved from the Diamond Match Company in 1900 by local residents who later turned the land over to the College and to the Town ...
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Underwater interpretative trail: guidance to improve education and decrease ecological damage
Studies of environmental education on trails in the sea and their impact are scarce, especially as regards the Brazilian coast. Herein is analysed an implemented model of an interpretative guided underwater trail (free diving), undertaken in the Anchieta Island's Park, southeast Brazil. The activity consisted of a preparatory lecture, followed by a 350 m trail along the rocky shore. The results ...
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The blooming Baltic Sea case study
The Baltic Sea is one of the world’s most polluted seas. This easternmost extension of the Atlantic Ocean suffers from a slow residence time which makes the small and shallow water pool particularly vulnerable to the pollution generated by 14 surrounding countries, including Russia, Scandinavia and the Baltic States. Over the course of centuries, a massive amount of nutrients originating ...
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Analysis of reconstruction of the composition of liquid radioactive waste released into the Techa River in 19491956
An analysis of archival data of liquid radioactive waste samples and Techa River bottom sediments was made, taking into consideration the radiochemical methods for extraction and beta-emitting radionuclide activity measurements existing in the early 1950s. It was stated that the radionuclide composition of the routine and accidental liquid radioactive waste releases in 19491951 corresponded to ...
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Coastal water quality in the Kihei and Lahaina districts of the island of Maui, Hawaiian Islands. Impacts from physical habitat and groundwater seepage: implications for water quality standards
Water quality in terms of nutrient concentrations, turbidity, suspended solids, and chlorophyll a, was studied during 2000–2001 at a total of 27 beaches in the Kihei and West Maui–Lahaina districts of Maui, Hawaiian Islands. Nitrate concentrations varied widely and averaged as much as 15–20 µM at some beaches. Most turbidities fell in the range 1–10 nephelometric turbidity units. Resuspension of ...
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Trace metals: Inputs, sedimentation and accumulation in San Vicente Bay, Chile
The present study deals with sediment dynamics affecting sediment-associated metal distributions in an embayment system experiencing pollution from coastal industries. Sedimentary metal content may originate from diagenetic processes of foundation rock on the bottom, allochthonous minerals from natural sources, and metals from industrial effluents along the coast. The study presents experimental ...
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The use of aquatic plant Elodea canadensis to assess toxicity and genotoxicity of sediments of the Yenisei River
We estimated toxicity, cyto‐ and genotoxicity of bulk sediments from the Yenisei River in laboratory bioassay based on using several endpoints of aquatic plant Elodea canadensis (Elodea). The samples of bottom sediments (BS) were collected in the Yenisei River upstream and downstream of the sources of chemical and radioactive contamination. The testing revealed different sensitivities of ...
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BTs, PAHs, OCPs and PCBs in sediments and bivalve mollusks in a mid‐latitude environment from the Patagonian coastal zone
BTs, PAHs, OCPs and PCBs were assessed in a mid‐latitude environment of the Patagonian coast, distant from important pollutant sources. Bioaccumulation processes through bottom sediment re‐suspension were suggested by BTs level found in surface sediment (
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Centrifugal Separators: Working Principle and Design
If you’ve ever bought Italian salad dressing, you understand the fundamental principles of sedimentation and centrifugal separation. Before you dig into your salad, you give that bottle a good hard shake, mixing together the vinegar, olive oil and herbs. As you munch, the herbs sink to the bottom (sedimentation) and the vinegar and oil form two distinct layers (separation). After a few ...
By Trucent
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Cluster analysis approach to identify metal sources in bottom sediments of Sultan Marsh canals, Turkey
The aim of this study was to determine heavy metal contents of the bottom sediments in Sultan Marsh water canals and drainage canals and possible sources of those heavy metals. The dendogram based on cluster analyses of the elements revealed two distinct groups of metals. There was a strong, positive correlation between some elements and their possible sources. Fe, Mn, Al, Ti, Cu, Zn and Cd ...
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Numerical prediction of suspended sediment concentrations in the Ariake Sea, Japan, using a time-dependent sediment resuspension and deposition model
The Ariake Sea, a typical semi-closed bay located in Kyushu Island, western Japan, has a maximum tidal range of 6 m in spring tide, and its vast tidal flats are composed of both sandy bottom areas and muddy bottom areas. In this study, two-dimensional depth-averaged finite difference numerical models have been developed for predicting the tidal flow velocity and suspended sediment concentration ...
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Distribution and removal efficiency of heavy metals in two constructed wetlands treating landfill leachate
The results of heavy metals (Fe, Mn, Zn, Ni, Cu, Cr, Pb, Cd) removal and partitioning between aqueous and solid phases at two treatment wetlands (TWs) treating municipal landfill leachates are presented. One of the TWs is a surface flow facility consisting of 10 ponds. The other TW is a newly constructed pilot-scale facility consisting of three beds with alternately vertical and horizontal ...
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How Not to Lose Cadmium While Measuring?
Today cadmium finds a better usage than a hundred years ago. For example, metal cadmium plating is used for anticorrosion coatings that are more stable than zinc, nickel and tin-plated. Cadmium plating of steel parts gives greater resistance to corrosion, especially in sea water. About 20% of cadmium goes to the manufacture of cadmium electrodes used in batteries. Also for the manufacture of ...
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