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1

Determination of radioactive elements and heavy metals in sediments and soil from domestic water sources in northern peninsular Malaysia.  

PubMed

Soil serves as a major reservoir for contaminants as it posseses an ability to bind various chemicals together. To safeguard the members of the public from an unwanted exposure, studies were conducted on the sediments and soil from water bodies that form the major sources of domestic water supply in northern peninsular Malaysia for their trace element concentration levels. Neutron Activation Analysis, using Nigeria Research Reactor-1 (NIRR-1) located at the Centre for Energy Research and Training, Zaria, Nigeria was employed as the analytical tool. The elements identified in major quantities include Na, K, and Fe while As, Br, Cr, U, Th, Eu, Cs, Co, La, Sm, Yb, Sc, Zn, Rb, Ba, Lu, Hf, Ta, and Sb were also identified in trace quantities. Gamma spectroscopy was also employed to analyze some soil samples from the same area. The results indicated safe levels in terms of the radium equivalent activity, external hazard index as well as the mean external exposure dose rates from the soil. The overall screening of the domestic water sources with relatively high heavy metals concentration values in sediments and high activity concentration values in soil is strongly recommended as their accumulation overtime as a consequence of leaching into the water may be of health concern to the members of the public. PMID:21901308

Muhammad, Bashir G; Jaafar, Mohammad Suhaimi; Abdul Rahman, Azhar; Ingawa, Farouk Abdulrasheed

2012-08-01

2

Toxicity Identification Evaluation (Phase I) of water and sediment samples from a tropical reservoir contaminated with industrial and domestic effluents.  

PubMed

The Funil Reservoir (Rio de Janeiro State, Brazil) is an environment degraded by constant discharge of nutrients and pollution coming from the most industrialized region of the country. As a consequence of eutrophication, there are continuous cyanobacteria blooms, which cause acute and chronic toxicity to zooplankton. In this context, Phase I of Toxicity Identification Evaluation (TIE) was performed on Daphnia similis using water and interstitial water from the reservoir, with the aim of identifying classes of compounds responsible for toxicity. The results indicated that water toxicity was due to cyanobacteria resulting from blooms in the reservoir and surfactants. Metals, especially copper, contributed to sediment toxicity. This research is the first attempt to describe the nature of toxicity in this reservoir using this method. PMID:25103213

Matos, Mariana de F; Botta, Clarice Maria Rispoli; Fonseca, Ana Lúcia

2014-11-01

3

Domestic wash water reclamation  

NASA Technical Reports Server (NTRS)

System consists of filtration unit, reverse-osmosis module, tanks, pumps, plumbing, and various gauges, meters, and valves. After water is used in washing machine or shower, it is collected in holding tank. Water is pumped through series of five particulate filters. Pressure tank supplies processed water to commode water closet.

Hall, J. B., Jr.; Batten, C. E.; Wilkins, J. R.

1974-01-01

4

STATE OF CALIFORNIA DOMESTIC HOT WATER (DHW)  

E-print Network

STATE OF CALIFORNIA DOMESTIC HOT WATER (DHW) CEC- CF-6R-MECH-01 (Revised 08/09) CALIFORNIA ENERGY COMMISSION INSTALLATION CERTIFICATE CF-6R-MECH-01 Domestic Hot Water (DHW) (Page 1 of 3) Site Address: Enforcement Agency: Permit Number: 2008 Residential Compliance Forms August 2009 1. WATER HEATING SYSTEMS

5

Residential conservation demonstration program: domestic hot water  

Microsoft Academic Search

Four types of domestic hot water (DHW) systems installed in 80 homes throughout Florida are currently monitored by the Florida Solar Energy Center (FSEC) under a demonstration program for the Florida Public Service Commission. DHW systems selected for the program are located in four major population areas of Florida: Jacksonville, Orlando\\/Brevard County, North Palm Beach\\/Ft. Lauderdale, and the Tampa Bay

Merrigan

1982-01-01

6

Economic valuation of domestic water uses.  

PubMed

There are many reasons of concern about the quality of water for domestic uses. The strategic goals of water tariffs must include savings, efficient management and equity in order to optimise availability of the best quality water. The main domestic uses of water are food preparation, personal hygiene and household cleaning; not all of them need the same quality, and for some of them there are even potential substitutes. In order to contribute to this debate, we need to know how these different uses are valued by direct users. This article focuses on eliciting values for different domestic uses, using discrete choice experiments. As far as we know, this is the first time that a differentiated valuation per use has been defined. The paper introduces three innovations in the design of the experiment. The design takes into account decisive variables in household water consumption, such as family size, together with the consumption level, and the options offered in the choice task are combinations of different prices for each of the uses. A latent class model with both common and class-specific random parameters is applied to better account for the influence of heterogeneity in the respondents' choices. The results show that the most valued use depends on the consumption level class. PMID:24333993

Justes, Antón; Barberán, Ramón; Farizo, Begoña A

2014-02-15

7

Quantifying Urban Water Subsidies with Hydrological Tracers of Domestic Water  

NASA Astrophysics Data System (ADS)

Connections between urban hydrological systems and human water infrastructure are well established. Interactions between these systems occur at a wide range of scales, from large inter-basin transfers to individual leaking pipes. However, much of the interest in these connections arises from practical considerations, for example, substantially altered in-stream flow or the presence/absence of sewage in surface water systems. Less recognized is that in smaller urban catchments, daily water flux through human water distribution systems is often much larger than low flow surface water flux from the catchment. As infrastructure ages and cross-connections grow, transfers from the substantial human fluxes to the catchment will increasingly subsidize urban water budgets. Tools for quantifying the contribution of this subsidy to urban hydrological systems can clarify both practical questions for urban managers and our understanding of flow generation in catchments. Stream water chemistry from a multi-year sampling campaign in Nine Mile Run (Pittsburgh, PA) is used to examine potential hydrological tracers of human domestic water. In particular, we examine the use of fluoride added in precise quantities as a dental health supplement as a tracer of human domestic water (e.g., drinking and waste water). While fluoride is not necessarily a conservative tracer, equilibrium reactions governing fluoride solubility generally require substantially higher cationic concentrations than those observed in surface water chemistry. Further, during periods where human subsidies dominate (e.g., water line breaks or hydrant flushes discharging to the stream) fluoride concentrations generally approach the concentration added to domestic water. We use multiple modeling approaches to demonstrate the appropriateness of fluoride as a tracer, infer contributions of human domestic water to the hydrologic budget, and explore fluoride dynamics in the Nine Mile Run basin. A fluoride tracer is particularly exciting due to applicability in a large number of urban systems fluoridating drinking waters and due to robust, high-frequency measurement capacity via off-the-shelf drinking water treatment technologies.

Bain, D. J.; Sikora, M. T.; Wozniak, E.; Fisher, K. R.; Carr, J.; Elliott, E. M.

2011-12-01

8

Accounting for Water Insecurity in Modeling Domestic Water Demand  

NASA Astrophysics Data System (ADS)

Water demand management uses price elasticity estimates to predict consumer demand in relation to water pricing changes, but studies have shown that many additional factors effect water consumption. Development scholars document the need for water security, however, much of the water security literature focuses on broad policies which can influence water demand. Previous domestic water demand studies have not considered how water security can affect a population's consumption behavior. This study is the first to model the influence of water insecurity on water demand. A subjective indicator scale measuring water insecurity among consumers in the Palestinian West Bank is developed and included as a variable to explore how perceptions of control, or lack thereof, impact consumption behavior and resulting estimates of price elasticity. A multivariate regression model demonstrates the significance of a water insecurity variable for data sets encompassing disparate water access. When accounting for insecurity, the R-squaed value improves and the marginal price a household is willing to pay becomes a significant predictor for the household quantity consumption. The model denotes that, with all other variables held equal, a household will buy more water when the users are more water insecure. Though the reasons behind this trend require further study, the findings suggest broad policy implications by demonstrating that water distribution practices in scarcity conditions can promote consumer welfare and efficient water use.

Galaitsis, S. E.; Huber-lee, A. T.; Vogel, R. M.; Naumova, E.

2013-12-01

9

AMBIENT WATER, POREWATER, AND SEDIMENT  

EPA Science Inventory

Sediment assessments may be performed for a variety of purposes; these include: dredging and dredged sediment disposal, for evaluations of sediments as a capping material, to determine sediment quality, to assess biological impairment and to assess the status of environment monit...

10

Sedimentation problem in water Conservancy in China  

SciTech Connect

The state-of-the-art of river sedimentation management in China is reviewed. Attention is focused on the sediment load carried by main rivers in China; the related sediment problems encountered in developing water resources; and the methods in dealing with those problems. There are 50 rivers with annual maximum sediment load exceeding 10 million tons in China. There are more than 400,000 sq km of loess plateaus and hills in the drainage basin of the Yellow River. Inadequate conservation of soil and water leads to erosion, transportation and deposition of sediment, giving rise to much trouble in water conservation works. These problems include flood control, navigational concerns, reservoir sedimentation, and sediment problems of lowhead diversion dams or hydroelectric projects. Methods for dealing with sediment problems include water and soil conservation and use of turbid water with emphasis on terracing, strip cropping, forestation, grass and crop rotation. Several types of structures may be built along a gully such as small reservoirs, check dams, drop structures, drainage ditches, and irrigation canal systems for diverting hyperconcentrated flow into farmland or to warp land. Processes for diverting water while preventing sediment from entering water intakes at hydroelectric plants are becoming more advanced. 4 references, 3 figures, 2 tables.

Wu, D.

1984-12-01

11

Exergy analysis of domestic-scale solar water heaters  

Microsoft Academic Search

Solar water heater is the most popular means of solar energy utilization because of technological feasibility and economic attraction compared with other kinds of solar energy utilization. Earlier assessments of domestic-scale solar water heaters were based on the first thermodynamic law. However, this kind of assessment cannot perfectly describe the performance of solar water heaters, since the essence of energy

Wang Xiaowu; Hua Ben

2005-01-01

12

Domestic applications for aerospace waste and water management technologies  

NASA Technical Reports Server (NTRS)

Some of the aerospace developments in solid waste disposal and water purification, which are applicable to specific domestic problems are explored. Also provided is an overview of the management techniques used in defining the need, in utilizing the available tools, and in synthesizing a solution. Specifically, several water recovery processes will be compared for domestic applicability. Examples are filtration, distillation, catalytic oxidation, reverse osmosis, and electrodialysis. Solid disposal methods will be discussed, including chemical treatment, drying, incineration, and wet oxidation. The latest developments in reducing household water requirements and some concepts for reusing water will be outlined.

Disanto, F.; Murray, R. W.

1972-01-01

13

CONTAMINANTS IN WATER AND SEDIMENT  

EPA Science Inventory

The Detroit River has experienced over a century of heavy contaminant discharges from industry and municipalities. The sources of contaminants vary, and include non-point sources, combined sewer overflows, point sources, tributaries, sediments, and upstream inputs. --- Demonst...

14

Design package for solar domestic hot water system  

NASA Technical Reports Server (NTRS)

The initial design of a solar domestic hot water system is considered. The system performance specification and detailed design drawings are included. The hot water systems consist of the following subsystems: collector, storage, control, transport, auxiliary energy, and government-furnished site data acquisition. The two systems are installed at Tempe, Arizona, and San Diego, California.

1980-01-01

15

Benefits of insulating domestic hot water pipework. Research memo  

SciTech Connect

A computer program was developed to simulate a domestic hot-water system and was used to investigate the likely losses of energy and hot water in distribution pipework. Predictions were obtained on the effects of insulating pipework and the improvements in system efficiency for various daily draw-off patterns.

Stephen, F.R.

1986-03-01

16

Analysis Model for Domestic Hot Water Distribution Systems: Preprint  

SciTech Connect

A thermal model was developed to estimate the energy losses from prototypical domestic hot water (DHW) distribution systems for homes. The developed model, using the TRNSYS simulation software, allows researchers and designers to better evaluate the performance of hot water distribution systems in homes. Modeling results were compared with past experimental study results and showed good agreement.

Maguire, J.; Krarti, M.; Fang, X.

2011-11-01

17

Par Pond Fish, Water, and Sediment Chemistry  

SciTech Connect

The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond.

Paller, M.H. [Westinghouse Savannah River Company, AIKEN, SC (United States); Wike, L.D.

1996-06-01

18

Phytotoxicity Assessment Of Effluent Waters, Surface Water And Sediments  

Microsoft Academic Search

Bioassays are valuable tools for environmental risk assessment, because they respond to bioavailable fraction of pollutants\\u000a in water, sediments and soil. The phytotoxicity of water and sediments from Ignalina NPP area, Lithuania, industrial areas\\u000a in Lithuania and Sweden, and a municipal landfill, and its potential impacts on receiving water was determined by Lepidium sativum, Spirodela polyrrhiza and Tradescantia clone 02.

Danguol? Montvydien?; Danut? Mar?iulionien?; Vilmant? Karlavi?ien?; William Hogland

19

Prototype solar domestic hot water systems  

NASA Technical Reports Server (NTRS)

Construction of a double wall heat exchanger using soft copper tube coiled around a hot water storage tank was completed and preliminary tests were conducted. Solar transport water to tank potable water heat exchange tests were performed with a specially constructed test stand. Work was done to improve the component hardware and system design for the solar water heater. The installation of both a direct feed system and a double wall heat exchanger system provided experience and site data to enable informative decisions to be made as the solar market expands into areas where freeze protection is required.

1978-01-01

20

Electrochemical chlorination for purifying domestic water supplies  

E-print Network

. 9 amps, the total residual was 0. 1 mg 1 With the decreased current density, there was considerably less anode deterioration; but it was still excessive, wearing down the anode and deczessing the quality of the water. An asbestos diaphragm... was used between the cathode and anode I in the sixth model to make it more similar to a diaphragm chlorine cell, The asbestos diaphragm keeps the hydroxide iona at the cathode, thereby reducing the amount of water electrolysis. The cathode...

Peters, Joseph Ludwig

2012-06-07

21

SOLAR DOMESTIC HOT WATER SYSTEM ANALYSIS USING TRNSYS  

Microsoft Academic Search

The objective of this paper is to simulate the solar based domestic hot water system and perform the sensitivity analysis. The house for the study was Net Zero Energy Healthy Housing project located in Toronto. The purpose of the sensitivity analysis was to study the effects of various components in the hybrid model on electricity consumption and GHG emissions per

Gurjot S. Gill; Alan S. Fung

22

NORTH PORTAL - DOMESTIC COLD WATER CALCULATION - CHANGE HOUSE FACILITY #5008  

SciTech Connect

The purpose of this design analysis and calculation is to determine the demand for domestic cold water and to size the supply main piping for the Change House Facility No.5008 in accordance with the Uniform Plumbing Code (Section 4.4.1) and US Department of Energy Order 6430.1A-1540 (Section 4.4.2).

S. Mastilovic

2000-03-02

23

Uranium in US surface, ground, and domestic waters  

SciTech Connect

The report Uranium in US Surface, Ground, and Domestic Waters comprises four volumes. Volumes 2, 3, and 4 contain data characterizing the location, sampling date, type, use, and uranium concentrations of 89,994 individual samples presented in tabular form. The tabular data in volumes 2, 3, and 4 are summarized in volume 1 in narrative form and with maps and histograms.

Drury, J.S.; Reynolds, S.; Owen, P.T.; Ross, R.H.; Ensminger, J.T.

1981-04-01

24

Uranium in US surface, ground, and domestic waters  

SciTech Connect

The report Uranium in US Surface, Ground, and Domestic Waters, comprises four volumes. Volumes 2, 3, and 4 contain data characterizing the location, sampling date, type, use, and uranium concentrations of 89,994 individual samples presented in tabular form. The tabular data in volumes 2, 3, and 4 are summarized in volume 1 in narrative form and with maps and histograms.

Drury, J.S.; Reynolds, S.; Owen, P.T.; Ross, R.H.; Ensminger, J.T.

1981-04-01

25

Residential conservation demonstration: domestic hot water. Final report  

Microsoft Academic Search

Four types of domestic hot water (DHW) systems installed in 80 homes throughout Florida were monitored from July 1982 to June 1983 by the Florida Solar Energy Center (FSEC) under a demonstration program for the Florida Public Service Commission. DHW systems selected for the program are located in four major population areas of Florida: Jacksonville, Orlando\\/Brevard County, Broward\\/Palm Beach Counties,

Merrigan

1983-01-01

26

Water saving potential of domestic water reuse systems using greywater and rainwater in combination  

Microsoft Academic Search

For a sustainable urban future, society must move towards the goal of efficient and appropriate water use. Reuse of domestic greywater and rainwater has a significant role to play in this task. In this study, rainfall time series have been used in conjunction with estimates of domestic water appliance usage generated by the Monte-Carlo simulation technique to predict long term

A. Dixon; D. Butler; A. Fewkes

1999-01-01

27

Dissolved organic matter in Chesapeake Bay sediment pore waters  

E-print Network

Dissolved organic matter in Chesapeake Bay sediment pore waters David J. Burdige * Department of recent studies of dissolved organic matter (DOM) in Chesapeake Bay sediment pore waters are summar- ized water DOM. This analysis shows that much of the DOM accumulating in sediment pore waters appears

Burdige, David

28

Remobilization of trace metals induced by microbiological activities near sediment-water interface, Aha Lake, Guiyang  

Microsoft Academic Search

The Aha Lake, as a seasonally oxygen-absent man-made reservoir, has been polluted by acidic mining drainage and domestic sewages\\u000a for a long time, with iron, manganese and sulfate excessively enriched in water and sediment. By means of microbe counting,\\u000a the analysis of trace metals in pore water and electronic acceptors for organic matter decomposing, we have found that strong\\u000a biogeochemical

Fushun Wang; Congqiang Liu; Xiaobing Liang; Zhongqing Wei

2003-01-01

29

Review of domestic water conservation practices in Saudi Arabia  

NASA Astrophysics Data System (ADS)

The Kingdom of Saudi Arabian (KSA) has a substantial water shortage problem where water demand far exceeds water resources sustainable yields. This fact has motivated the Ministry of Water and Electricity (MOWE) to launch a massive water conservation awareness program to enhance water-using efficiency in the country. The MOWE among other water awareness activities has introduced a four-stage program of free distribution of water conservation tools. This research reviewed the domestic water conservation awareness program in Saudi Arabia and assessed the program performance through conducting questionnaire surveys. The latter was designed and implemented in Al-Khobar city in the Eastern Province to measure public awareness regarding water issues. The survey started on April 28, 2012, and continued for 3 weeks. A total of 197 questionnaires were completed. The survey results showed a relatively low awareness among respondents about water shortage problem in the Kingdom. A low percentage of respondents have water conservation tools installed in their houses, but a high percentage is willing to buy and install water conservation tools. The majority of respondents consider the water price low and are willing to pay more for water. The respondents' feedback highlighted the need to improve the current water conservation awareness program.

Ouda, Omar K. M.; Shawesh, Ahmad; Al-Olabi, Tareq; Younes, Firas; Al-Waked, Rafat

2013-12-01

30

The flocculation of fine-grained sediments in estuarine waters  

Microsoft Academic Search

Experimental and theoretical investigations of the effects of salinity, fluid shear, and sediment concentration on the rates of aggregation and disaggregation of a fine-grained sediment in estuarine waters were made. Experiments were performed in fresh water, in seawater, and in an equal mixture of fresh and sea waters. The applied shears ranged from 100 to 600 s-1, while the sediment

Pierre-Yves Burban; Wilbert Lick; James Lick

1989-01-01

31

Estimated Domestic, Irrigation, and Industrial Water Use in Washington, 2000  

USGS Publications Warehouse

Since 1950, the U.S. Geological Survey has published a series of Circulars and other reports on the estimated use of water in the United States at 5-year intervals. This report presents State, regional, and county estimates of the amount of water used for domestic, irrigation, and industrial purposes in the State of Washington during the year 2000. Domestic water use was estimated to be 674 million gallons per day and the per-capita rate, 114 gallons per day. Crop-irrigation water use was estimated to be 3,005 million gallons per day and the application rate, 2.2 acre-feet per acre per year, or feet per year. Golf-course irrigation water use was estimated to be 23.6 million gallons per day and the application rate, 1.4 feet per year. Industrial water use was estimated to be 681 million gallons per day. Historically, these core categories account for about 92 percent of the estimated offstream water used in Washington.

Lane, R. C.

2004-01-01

32

Harvesting Energy from the Marine Sediment-Water Interface  

E-print Network

Harvesting Energy from the Marine Sediment-Water Interface C L A R E E . R E I M E R S * College the net oxidation of sediment organic matter by dissolved seawater oxygen. Considering typical sediment in the coastal ocean. Introduction Microbial decomposition of marine sediment organic matter consumes

Rosen, I. Gary

33

Water-sediment flow models for river reaches sediment related pollution control.  

PubMed

Hybrid water-sediment flow models for river reaches have been for predicting sediment and sediment related pollutions in water courses. The models are developed by combining sediment rating model and the Muskingum model applicable for a reach. The models incorporate sediment concentration and water discharge variables for a river reach; allow defining downstream sediment rating curve in terms of upstream water discharges. The model is useful in generating sediment concentration graph for a station having no water discharge records. The hybrid models provide forecasting forms that can be used to forecast downstream sediment concentration/water discharges 2kx time unit ahead. The forecasting models are useful for applications in real time namely, in the real time management of sediment related pollution in water courses and in issuing flood warning. Integration of sediment rating model and the Muskingum model increases model parameters and nonlinearity requiring efficient estimation technique for parameter identification. To identify parameters in the hybrid models genetic algorithm (GA) based optimization technique can be used. The new model relies on the Muskingum model, obey continuity requirement and the parameters can be used in the Muskingum model with water discharges to estimate/predict downstream water discharge values. The proposed model formulations are demonstrated for simulating and forecasting sediment concentration and water discharges in the Mississippi River Basin, USA. Model parameters are estimated using non-dominated sorting Genetic Algorithm II (NSGA-II). Model results show satisfactory model performances. PMID:24749192

Sil, Briti Sundar; Choudhury, Parthasarathi

2012-07-01

34

Domestic water conservation practices in Tlemcen City (Algeria)  

NASA Astrophysics Data System (ADS)

During the last three decades, citizens of an Algerian city are concerned with the problem of drinking water supply. Time discontinuation service became the rule. The central idea of the analysis based on interviews is to assess the role of water in the organization of the relationship between habitat and users. The fundamental question is how users, in particular women, incorporate water in their daily lives due to rationing. Having to deal with the discontinuous and frequent weak water supply, the inhabitants of the city of Tlemcen who are connected to the water supply system, as well as those connected to the water system of all Algerian towns, have developed an internal water storage system to sort out this problem. The imposed rationing has proved to be expensive for consumers. The water shortage pushed the consumers to invest in relatively expensive storage and pumping facilities to satisfy their domestic needs. As the frequency of the water supply is on a two times per week basis, the survey reveals a discrepancy in terms of volumes consumed and stored by each household. The use of water depends on the individual storage facility and the frequency of the supply. The life of the households, particularly that of the housewives, depends on the availability of water and thus on the schedules of the Company of Production of Water "Algerian Des Eaux'' (ADE). This is particularly the case when they are supplied during the night.

Habi, Mohammed; Harrouz, Omar

2014-03-01

35

Fluorescent dissolved organic matter in marine sediment pore waters  

E-print Network

Fluorescent dissolved organic matter in marine sediment pore waters David J. Burdige*, Scott W of organic matter diagenesis (e.g., dissolved peptides and proteins) produced near the sediment­water February 2004 Available online 1 June 2004 Abstract Fluorescent dissolved organic matter (FDOM) in sediment

Burdige, David

36

Survey-Based Estimation of Domestic Water Saving Potential in the Case of Manisa City  

Microsoft Academic Search

In this paper, domestic water saving potential in the case of Manisa, Turkey has been investigated. Firstly, domestic water\\u000a use forms are analyzed in an attempt to estimate how much water is used by a particular use in total domestic use. Then, the\\u000a water conservation measures for each water practice are examined and some easy-to-apply measures proposed. Finally, an experimental

M. A. Yurdusev; A. A. Kumanl?o?lu

2008-01-01

37

A rating procedure for solar domestic water heating systems  

SciTech Connect

A rating procedure for solar domestic hot water systems is described which combines the advantages of short-term system tests and correlations of long-term thermal performance. The testing procedure consists of two indoor tests which are in accordance with ASHRAE Standard 95-1981, except for one additional measurement needed only for systems employing a heat exchanger between the collector fluid and the potable water. The test results are plotted in a manner in which they can be used to estimate the long-term performance of the solar water heating system for any location where site-specific, monthly-average meterological data are available. The annual solar function obtained in this manner provides the recommended rating indicator. The validity of this rating procedure is first demonstrated by simulations. Further support is provided by experiments conducted at the National Bureau of Standards.

Klein, S.A.; Fanney, A.H.

1983-11-01

38

Patterns, structures and regulations of domestic water cycle systems in China  

Microsoft Academic Search

Domestic water cycle systems serving as one critical component of artificial water cycle at the catchment's scale, is so closely related to public healthy, human rights and social-economic development, and has gained the highest priority in strategic water resource and municipal infrastructure planning. In this paper, three basic patterns of domestic water cycle systems are identified and analyzed, including rural

Junying Chu; Hao Wang; Jianhua Wang; Dayong Qin

2010-01-01

39

Mycobacterium avium subsp. paratuberculosis in Lake Catchments, in River Water Abstracted for Domestic Use, and in Effluent from Domestic Sewage Treatment Works: Diverse Opportunities for Environmental Cycling and Human Exposure  

PubMed Central

Mycobacterium avium subsp. paratuberculosis from infected animals enters surface waters and rivers in runoff from contaminated pastures. We studied the River Tywi in South Wales, United Kingdom, whose catchment comprises 1,100 km2 containing more than a million dairy and beef cattle and more than 1.3 million sheep. The River Tywi is abstracted for the domestic water supply. Between August 2002 and April 2003, 48 of 70 (68.8%) twice-weekly river water samples tested positive by IS900 PCR. In river water, the organisms were associated with a suspended solid which was depleted by the water treatment process. Disposal of contaminated slurry back onto the land established a cycle of environmental persistence. A concentrate from 100 liters of finished water tested negative, but 1 of 54 domestic cold water tanks tested positive, indicating the potential for these pathogens to access domestic outlets. In the separate English Lake District region, with hills up to 980 m, tests for M. avium subsp. paratuberculosis in the high hill lakes and sediments were usually negative, but streams and sediments became positive lower down the catchment. Sediments from 9 of 10 major lakes receiving inflow from these catchments were positive, with sediment cores indicating deposition over at least 40 to 50 years. Two of 12 monthly 1-liter samples of effluent and a single 100-liter sample from the Ambleside sewage treatment works were positive for M. avium subsp. paratuberculosis. Since Lake Ambleside discharges into Lake Windermere, which is available for domestic supply, there is a potential for these organisms to cycle within human populations. PMID:16751517

Pickup, R. W.; Rhodes, G.; Bull, T. J.; Arnott, S.; Sidi-Boumedine, K.; Hurley, M.; Hermon-Taylor, J.

2006-01-01

40

The human right to water: the importance of domestic and productive water rights.  

PubMed

The United Nations (UN) Universal Declaration of Human Rights engenders important state commitments to respect, fulfill, and protect a broad range of socio-economic rights. In 2010, a milestone was reached when the UN General Assembly recognized the human right to safe and clean drinking water and sanitation. However, water plays an important role in realizing other human rights such as the right to food and livelihoods, and in realizing the Convention on the Elimination of All Forms of Discrimination against Women. These broader water-related rights have been recognized but have not yet been operationalized. This paper unravels these broader water-related rights in a more holistic interpretation of existing international human rights law. By focusing on an emerging approach to water services provision-known as 'domestic-plus' services-the paper argues how this approach operationalizes a comprehensive range of socio-economic rights in rural and peri-urban areas. Domestic-plus services provide water for domestic and productive uses around homesteads, which challenges the widespread practice in the public sector of planning and designing water infrastructure for a single-use. Evidence is presented to show that people in rural communities are already using their water supplies planned for domestic uses to support a wide range of productive activities. Domestic-plus services recognize and plan for these multiple-uses, while respecting the priority for clean and safe drinking water. The paper concludes that domestic-plus services operationalize the obligation to progressively fulfill a comprehensive range of indivisible socio-economic rights in rural and peri-urban areas. PMID:24337891

Hall, Ralph P; Van Koppen, Barbara; Van Houweling, Emily

2014-12-01

41

Domestic water and sanitation as water security: monitoring, concepts and strategy.  

PubMed

Domestic water and sanitation provide examples of a situation where long-term, target-driven efforts have been launched with the objective of reducing the proportion of people who are water-insecure, most recently through the millennium development goals (MDGs) framework. Impacts of these efforts have been monitored by an increasingly evidence-based system, and plans for the next period of international policy, which are likely to aim at universal coverage with basic water and sanitation, are being currently developed. As distinct from many other domains to which the concept of water security is applied, domestic or personal water security requires a perspective that incorporates the reciprocal notions of provision and risk, as the current status of domestic water and sanitation security is dominated by deficiency This paper reviews the interaction of science and technology with policies, practice and monitoring, and explores how far domestic water can helpfully fit into the proposed concept of water security, how that is best defined, and how far the human right to water affects the situation. It is considered that they fit well together in terms both of practical planning of targets and indicators and as a conceptual framework to help development. The focus needs to be broad, to extend beyond households, to emphasize maintenance as well as construction and to increase equity of access. International and subnational monitoring need to interact, and monitoring results need to be meaningful to service providers as well as users. PMID:24080628

Bradley, David J; Bartram, Jamie K

2013-11-13

42

Domestic water and sanitation as water security: monitoring, concepts and strategy  

PubMed Central

Domestic water and sanitation provide examples of a situation where long-term, target-driven efforts have been launched with the objective of reducing the proportion of people who are water-insecure, most recently through the millennium development goals (MDGs) framework. Impacts of these efforts have been monitored by an increasingly evidence-based system, and plans for the next period of international policy, which are likely to aim at universal coverage with basic water and sanitation, are being currently developed. As distinct from many other domains to which the concept of water security is applied, domestic or personal water security requires a perspective that incorporates the reciprocal notions of provision and risk, as the current status of domestic water and sanitation security is dominated by deficiency This paper reviews the interaction of science and technology with policies, practice and monitoring, and explores how far domestic water can helpfully fit into the proposed concept of water security, how that is best defined, and how far the human right to water affects the situation. It is considered that they fit well together in terms both of practical planning of targets and indicators and as a conceptual framework to help development. The focus needs to be broad, to extend beyond households, to emphasize maintenance as well as construction and to increase equity of access. International and subnational monitoring need to interact, and monitoring results need to be meaningful to service providers as well as users. PMID:24080628

Bradley, David J.; Bartram, Jamie K.

2013-01-01

43

Effects of Water Chemistry on the Bioavailability of Metals in Sediment to Hyalella azteca : Implications for Sediment Quality Guidelines  

Microsoft Academic Search

Risk assessments of metals in sediments are often based on sediment-quality guidelines (SQGs) and do not take into account the chemistry of the overlying water. To determine the effects of water chemistry on the toxicity of metals in sediments, both water and sediment were collected from five metal-contaminated lakes with widely differing water chemistry near Canadian smelters. Metal bioaccumulation by

M. Nowierski; D. G. Dixon; U. Borgmann

2005-01-01

44

Occurrence of Polychlorinated Diphenyl Sulfides (PCDPSs) in Surface Sediments and Surface Water from the Nanjing Section of the Yangtze River.  

PubMed

Polychlorinated diphenyl sulfides (PCDPSs) are dioxin-like compounds that could induce various adverse effects to organisms. However, little is known about the occurrence of PCDPSs in the riverine environment. In the present study, the concentrations of twenty-one types of PCDPSs in the surface sediments and in surface water from the Nanjing section of the Yangtze River were examined. A total of 19 types of PCDPSs were detected and ?PCDPSs concentrations in surface sediment and surface water ranged from 0.10 to 6.90 ng/g and 0.18 to 2.03 ng/L, respectively. The 2,2',4,4',5-penta-CDPS was the dominant congener in sediment (19.9%) and 2,2',3,3'-tetra-CDPS was the most abundant congener in water (12.2%). The tetra-CDPSs were the dominant congeners both in sediment and in water. Compared with sediment, the percentage of lower chlorinated PCDPSs in water increased distinctly. Source analysis revealed that the PCDPSs in the sediment and in the water mainly came from chemical wastewater rather than domestic sewage. There was a significant linear correlation between ?PCDPS concentrations and sediment TOC contents, while no linear correlation existed between ?PCDPS concentrations and water DOC contents. This study demonstrated the prevalent contamination by PCDPSs in sediments and in water from the Nanjing section of the Yangtze River. PMID:25168171

Zhang, Xuesheng; Qin, Li; Qu, Ruijuan; Feng, Mingbao; Wei, Zhongbo; Wang, Liansheng; Wang, Zunyao

2014-10-01

45

Survival of Vibrio cholerae in African domestic water storage containers.  

PubMed

Although much has been published about growth of Vibrio cholerae in natural sources of water, little or nothing has been written on its survival in common household water storage containers. This study compared the behaviour of the El Tor and Classical biotypes of V. cholerae in different containers commonly used in Africa for domestic water storage. These included traditional clay pots, wooden barrels, galvanised iron drums (corroded and non-corroded) and plastic (polyethylene) drums. The findings are considered to be of public health interest with reference to selection of the most suitable containers for the storage of water drawn from a treated source. Although survival of V. cholerae was much shorter in clay pots than in any of the other containers, the numbers of viable V. cholerae were higher than in non-corroding iron drums and plastic drums. The clay pots, being porous, also showed a tendency to constant outward seepage of water which, when collected, was also shown to harbour cholera bacilli. These containers are therefore considered hazardous as pathogens in the stored water are easily disseminated to contaminate either hands or food prepared in the vicinity. The longest survival occurred in damaged metal drums. Presence of other bacteria greatly inhibited survival of V. cholerae. The response of the two biotypes was much the same in all the experiments. PMID:2799584

Patel, M; Isaäcson, M

1989-10-01

46

Water and sediment quality in a tropical swamp used for agricultural and oil refining activities.  

PubMed

The Godineau Swamp in Trinidad receives anthropogenic input from agricultural and oil refining activities, sewage and domestic waste. This study was conducted in order to provide a comprehensive baseline dataset for the swamp, to assess water and sediment quality in the swamp, and to identify hotspots and possible sources of pollutants to the swamp. Ten sampling stations were established in the swamp during April/May and July 2002. Water quality parameters monitored included physicochemical measurements (pH, temperature, dissolved oxygen and salinity), total suspended solids, and nutrients (ammonia, nitrites, nitrates and total phosphorus). Sediments were analyzed for hydrocarbons, heavy metals and total organic carbon. Temperatures and pH of water in the swamp were ambient; dissolved oxygen was low in many instances (<3 mg/L). In the dry season, there was saltwater intrusion along the Oropuche River up to the most easterly station. Levels of ammonia and phosphorus concentrations were suggestive of periodic inputs of agricultural and domestic wastes. Hydrocarbons concentrations in sediment were above ambient levels and suggestive of contamination from industrial activities. Sediments from the Godineau River contained elevated nutrients, hydrocarbons, metals and TOC compared with other stations. The results of this study indicate some degree of pollution of the Godineau swamp, which prompts the need for the implementation of measures beneficial for wise use of the swamp. PMID:21240702

Norville, Wendy; Banjoo, Darryl

2011-01-01

47

Benthic invertebrate bioassays with toxic sediment and pore water  

USGS Publications Warehouse

The relative sensitivities of bioassays to determine the toxicity of sediments were investigated and three methods of making the sample dilutions required to generate dose-response relationships were compared. The assays studied were: (a) Microtox(R), a 15-min assay of Photobacterium phosphoreum bioluminescence inhibition by pore water; (b) 48-h Daphnia magna lethality test in pore water; (c) 10-d subchronic assay of lethality to and reduction of weight gain by Chironomus tentans performed in either whole sediment or pore water; (d) 168-h acute lethality assay of Hexagenia limbata in either whole sediment or pore water. The three methods of diluting sediments were: (a) extracting pore water from the toxic location and dilution with pore water from the control station; (b) diluting whole sediment from the toxic location with control whole sediment from a reference location, then extracting pore water; and (c) diluting toxic, whole sediment with whole sediment from a reference location, then using the whole sediment in bioassays. Based on lethality, H. limbata was the most sensitive organism to the toxicity of Detroit River sediment. Lethality of D. magna was similar to that of H. limbata in whole sediment and can be used to predict effects of whole sediment toxicity to H. limbata. The concentration required to cause a 50% reduction in C. tentans growth (10-d EC50) was approximately that which caused 50% lethality of D. magna (48-h LC50) and was similar to the toxicity that restricts benthic invertebrate colonization of contaminated sediments. While the three dilution techniques gave similar results with some assays, they gave very different results in other assays. The dose-response relationships determined by the three dilution techniques would be expected to vary with sediment, toxicant and bioassay type, and the dose-response relationship derived from each technique needs to be interpreted accordingly.

Giesy, John P.; Rosiu, Cornell J.; Graney, Robert L.; Henry, Mary G.

1990-01-01

48

Thermal-energy stores for supplying domestic hot-water and space-heating  

Microsoft Academic Search

Factors influencing the ability of a conventional domestic hot-water tank to deliver domestic hot water rapidly have been culled, collated or assessed experimentally. It has been deduced that, with a horizontal-axis coiled, finned-type, heat exchanger--immersed in the traditional domestic hot-water tank--for extracting heat from the tank where and Ra are the mean Nusselt and Rayleigh numbers, respectively, for the freely-convecting

L. P. Chauvet; S. D. Probert; D. J. Nevrala

1994-01-01

49

Similarity-Based Optimal Operation of Water and Sediment in a Sediment-Laden Reservoir  

Microsoft Academic Search

Reservoir sedimentation is a severe problem because it leads to the loss of reservoir storage capacity. Therefore, the sustainable\\u000a management of water and sediment constitutes a critical measure in reservoir operation. In this research, a model of similarity-based\\u000a operation method of water and sediment which can improve the efficiency of reservoir operation strategies is presented. Two\\u000a parts comprise this method:

Xin Yu Wan; Guang Qian Wang; Peng Yi; Wei Min Bao

2010-01-01

50

Description of 2005-10 domestic water use for selected U.S. cities and guidance for estimating domestic water use  

USGS Publications Warehouse

Domestic water-use and related socioeconomic and climatic data for 2005-10 were used in an analysis of 21 selected U.S. cities to describe recent domestic per capita water use, investigate variables that potentially affect domestic water use, and provide guidance for estimating domestic water use. Domestic water use may be affected by a combination of several factors. Domestic per capita water use for the selected cities ranged from a median annual average of 43 to 177 gallons per capita per day (gpcd). In terms of year-to-year variability in domestic per capita water use for the selected cities, the difference from the median ranged from ± 7 to ± 26 percent with an overall median variability of ± 14 percent. As a percentage of total annual water use, median annual domestic water use for the selected cities ranged from 33 to 71 percent with an overall median of 57 percent. Monthly production and water sales data were used to calculate daily per capita water use rates for the lowest 3 consecutive months (low-3) and the highest 3 consecutive months (high-3) of usage. Median low-3 domestic per capita water use for 16 selected cities ranged from 40 to 100 gpcd. Median high-3 domestic per capita water use for 16 selected cities ranged from 53 to 316 gpcd. In general, the median domestic water use as a percentage of the median total water use for 16 selected cities was similar for the low-3 and high-3 periods. Statistical analyses of combined data for the selected cities indicated that none of the socioeconomic variables, including cost of water, were potentially useful as determinants of domestic water use at the national level. However, specific socioeconomic variables may be useful for the estimation of domestic water use at the State or local level. Different socioeconomic variables may be useful in different States. Statistical analyses indicated that specific climatic variables may be useful for the estimation of domestic water use for some, but not all, of the selected cities. National average public supply per capita water use declined from 185 gpcd in 1990 to 171 gpcd in 2005. National average domestic delivery per capita water use declined from 105 gpcd in 1990 to 99 gpcd in 2005. Average State domestic delivery per capita water use ranged from 51 to 189 gpcd in 2005. The average annual total per capita water use in 19 selected cities that provided data for each year declined from 167 gpcd in 2006 to 145 gpcd in 2010. During this time period, average per capita water use measured during the low-3 period each year declined from 115 to 102 gpcd, and average per capita use measured during the high-3 period declined from 250 to 211 gpcd. Continued collection of data on water deliveries to domestic populations, as well as updated estimates of the population served by these deliveries, is recommended for determination of regional and temporal trends in domestic per capita water use. Declines in various measures of per capita water use have been observed in recent years for several States with municipal water use data-collection programs. Domestic self-supplied water use historically has not been metered. Estimates of self-supplied domestic water use are made using estimates of the population that is not served by public water suppliers and per capita coefficients. For 2005, the average State domestic self-supplied per capita use in the United States ranged from 50 to 206 gpcd. The median domestic self-supplied per capita use was 76 gpcd for States in which standard coefficients were used, and 98 gpcd for States in which coefficients were based on domestic deliveries from public supply. In specific areas with scarce resources or increasing numbers of households with private wells, an assessment of domestic water use may require metering of households or development of more specific per capita coefficients to estimate water demand.

Kenny, Joan F.; Juracek, Kyle E.

2012-01-01

51

Development of impact factors on damage to health by infectious diseases caused by domestic water scarcity  

Microsoft Academic Search

Background, aim, and scope  Water scarcity is a critical environmental issue. In particular, domestic water is a necessary resource for our fundamental\\u000a activities, and poor water quality may lead to damage to health caused by infectious diseases. However, there is no methodology\\u000a to assess the damage of domestic water scarcity (low accessibility to safe water) caused by water consumption. The main

Masaharu Motoshita; Norihiro Itsubo; Atsushi Inaba

2011-01-01

52

Water retention curve for hydrate-bearing sediments  

NASA Astrophysics Data System (ADS)

water retention curve plays a central role in numerical algorithms that model hydrate dissociation in sediments. The determination of the water retention curve for hydrate-bearing sediments faces experimental difficulties, and most studies assume constant water retention curves regardless of hydrate saturation. This study employs network model simulation to investigate the water retention curve for hydrate-bearing sediments. Results show that (1) hydrate in pores shifts the curve to higher capillary pressures and the air entry pressure increases as a power function of hydrate saturation; (2) the air entry pressure is lower in sediments with patchy rather than distributed hydrate, with higher pore size variation and pore connectivity or with lower specimen slenderness along the flow direction; and (3) smaller specimens render higher variance in computed water retention curves, especially at high water saturation Sw > 0.7. Results are relevant to other sediment pore processes such as bioclogging and mineral precipitation.

Dai, Sheng; Santamarina, J. Carlos

2013-11-01

53

Suspending sediment transport, sedimentation, and resuspension in Lake Houston, Texas: Implications for water quality  

SciTech Connect

Lake Houston is a man-made reservoir located northeast of Houston, Texas. The purpose of this investigation was to document suspended sediment transport, sedimentation, and resuspension in the lake with a view towards estimating the influence of sedimentation on water quality. Sediment traps were placed in strategic locations in the lake to collect suspended sediments. Samples were analyzed for bulk density, grain size, organic carbon, and a number of trace elements. These data were analyzed along with meteorological data to examine those factors which regulate suspended sediment input and dispersal, and the role of suspended sediments in controlling water quality within the lake. Sediment input to the lake depends primarily on the intensity of rainfall in the watershed. Sediment movement within the lake is strongly influenced by wave activity, which resuspends sediments from shallow areas, and by wind-driven circulation. The increased residence time of suspended sediments due to resuspension allows greater decomposition of organic matter and the release of several trace elements from sediments to the water column. Virtually all samples from sediment traps suspended between 1 and 5 m above the lake bottom contain medium to coarse silt, and even some very fine sand-sized material. This implies that circulation in Lake Houston is periodically intense enough to transport this size material in suspension. During winter, northerly winds with sustained velocities of greater than 5 m/sec provide the most suitable condition for rapid (< 1 d) transport of suspended sediment down the length of the lake. Fluctuations in current velocities and the subsequent suspension/deposition of particles may explain variations in the abundance of coliform bacteria in Lake Houston.

Matty, J.M.; Anderson, J.B.; Dunbar, R.B. (Rice Univ., Houston, TX (United States))

1987-01-01

54

TOXICITY EVALUATION OF LOWER FOX RIVER WATER AND SEDIMENTS  

EPA Science Inventory

Many persistent, xenobiotic compounds have been identified from Lower Fox River water, biota, sediment, and effluent discharges; some of which are suspected of causing adverse effects to aquatic organisms. Water and sediment were collected as grab samples from the Lower Fox River...

55

Bank Erosion, Mass Wasting, Water Clarity, Bathymetry and a Sediment  

E-print Network

Bank Erosion, Mass Wasting, Water Clarity, Bathymetry and a Sediment Budget Along the Dam-Regulated Lower Roanoke River, North Carolina By Edward R. Schenk, Cliff R. Hupp, Jean M. Richter, and Daniel E, mass wasting, water clarity, bathymetry, and a sediment budget along the dam-regulated lower Roanoke

56

DEVELOPING WATER QUALITY CRITERIA FOR SUSPENDED AND BEDDED SEDIMENTS  

EPA Science Inventory

The U.S. EPA?s Framework for Developing Suspended and Bedded Sediments (SABS) Water Quality Criteria (SABS Framework) is a nationally-consistent process for developing ambient sediment quality criteria for surface waters. The SABS Framework accommodates natural variation among wa...

57

Evaluation of a multifiltration water reclamation subsystem to reclaim domestic clothes wash water  

NASA Technical Reports Server (NTRS)

An evaluation has been performed of a multifiltration water reclamation subsystem to determine its capability to recover water from domestic clothes wash water. A total of 32.89 kg (72.5 lb) of clothes were washed during eight wash cycles which used 1.4 lb of detergent, 145 gallons of hot water and 133.9 gallons of cold water. Water recovered at a weighted average process rate of 3.81 gallons per hour met the majority of the 23 requirements established for potable water by the U.S. Public Health Service. Average power consumed during this evaluation was approximately 71 watt-hours per gallon of water recovered. Filter replacement, which was required primarily for the control of micro-organisms in the recovered water averaged 4.86 filters per 100 gallons of wash water processed. The subsystem removed approximately 98 percent and virtually 100 percent of the phosphates and surfactants, respectively, from the wash water.

Hall, J. B., Jr.

1973-01-01

58

Domestic water supply, competition for water resources and IWRM in Tanzania: a review and discussion paper  

NASA Astrophysics Data System (ADS)

This paper reviews the historical development of domestic water supplies in Tanzania, the consequences of major policy shifts during the last seven decades, and some of the reasons for the failure of water supply systems. It considers the extent to which water resource issues are constraints in meeting the water supply needs of rural and urban populations, and the relevance of integrated water resources management to the WSS sector. Drawing upon case-study material from two major river basins, the Pangani and Rufiji, it reviews some of the practical steps being taken to implement IWRM principles in Tanzania.

Maganga, Faustin P.; Butterworth, John A.; Moriarty, Patrick

59

Mathematical Simulation of Sediment and Radionuclide Transport in Surface Waters  

SciTech Connect

The study objective of "The Mathematical Simulation of Sediment and Radionuclide Transport in Surface Waters" is to synthesize and test radionuclide transport models capable of realistically assessing radionuclide transport in various types of surface water bodies by including the sediment-radionuclide interactions. These interactions include radionuclide adsorption by sediment; desorption from sediment into water; and transport, deposition, and resuspension of sorbed radionuclides controlled by the sediment movements. During FY-1979, the modification of sediment and contaminant (radionuclide) transport model, FETRA, was completed to make it applicable to coastal waters. The model is an unsteady, two-dimensional (longitudinal and lateral) model that consists of three submodels (for sediment, dissolved-contaminant, and particulate-contaminant transport), coupled to include the sediment-contaminant interactions. In estuaries, flow phenomena and consequent sediment and radionuclide migration are often three-dimensional in nature mainly because of nonuniform channel cross-sections, salinity intrusion, and lateral-flow circulation. Thus, an unsteady, three-dimensional radionuclide transport model for estuaries is also being synthesized by combining and modifying a PNL unsteady hydrothermal model and FETRA. These two radionuclide transport models for coastal waters and estuaries will be applied to actual sites to examine the validity of the codes.

,

1981-04-01

60

Influence of wave and current flow on sediment-carrying capacity and sediment flux at the water-sediment interface.  

PubMed

In nearshore waters, spatial and temporal scales of waves, tidal currents, and circulation patterns vary greatly. It is, therefore, difficult to combine these factors' effects when trying to predict sediment transport processes. This paper proposes the concept of significant wave velocity, which combines the effects of waves, tides, and ocean currents using the horizontal kinetic energy superposition principle. Through a comparison of the relationship between shear stress at the water-sediment interface and sediment-carrying capacity, assuming equilibrium sediment flux, a new formula for sediment-carrying capacity, which incorporates the concept of significant wave velocities, is derived. Sediment-carrying capacity is a function of the critical velocity, which increases with water depth and decreases with increasing relative roughness of the seabed. Finally, data from field observation stations and simulations are used to test the proposed formula. The results show that the new formula is in good agreement with both field and simulation data. This new formula for sediment-carrying capacity can be used to simulate nearshore sediment transport. PMID:25259499

Zheng, Jun; Li, Ruijie; Yu, Yonghai; Suo, Anning

2014-01-01

61

Control strategies for domestic hot water recirculation systems  

SciTech Connect

The purpose of a domestic hot water (DHW) recirculation system is to decrease the time spent waiting for the water to be delivered at acceptable temperatures when called for and also decrease the subsequent water consumption. The research detailed in this paper considered whether it is necessary to continuously run these recirculation pumps, as is general practice, or whether it is possible to reduce DHW system energy consumption by operating these pumps with some type of control strategy. Three different control strategies were evaluated by employing detailed monitoring. The different operating modes were: (1) base case (continuous operation), (2) shutdown during the overnight period, (3) shutdown during the peak morning and evening periods, and (4) cycling by a return line aquastat set at 110 F (61 C). In order to accomplish the research, six sites each had an aquastat installed onto the DHW return line and a programmable timeclock wired into the pump. The analysis identifies the relative energy use for each of the strategies during four round-robin rounds of two weeks each during the spring, summer, fall, and winter periods. When compared to the base case, (pump running 24 hours per day), Strategy B saves an average of 6%, Strategy C saves 6%, and Strategy D saves 11% of the DHW portion of a building's DHW energy requirements annually. This is significant in that for Strategy D, this translates into a savings of 4% of the building's total annual fuel bill. All of the control strategies evaluated were simple and employed low-cost devices (under $250 installed), which should help in achieving an extremely large implementation rate for the control strategy recommended. Tenant water quality survey questionnaires show that there was always an acceptable level of satisfaction, regardless of system control strategy.

Goldner, F.S.

1999-07-01

62

Subcritical water extraction of polychlorinated biphenyls from soil and sediment  

Microsoft Academic Search

Two certified reference materials, an industrial soil (CRM 481) and a river sediment (NIST 1939), were extracted by subcritical water at 50 atm and temperatures ranging from 50 to 300°C. The extraction efficiency of PCBs is extremely dependent on water temperature, since the polarity (dielectric constant) of water can be dramatically lowered by raising the water temperature. While only traces

Yu. Yang; S. Bewadt; Steven B. Hawthorne; David J. Miller

1995-01-01

63

Sediment pore water distribution coefficients of PCB congeners in enriched black carbon sediment  

PubMed Central

More than 2300 sediment pore water distribution coefficients (KPCBi ds) of 93 polychlorinated biphenyls (PCBs) were measured and modeled from sediments from Indiana Harbor and Ship Canal. KPCBi ds were calculated from previously reported bulk sediment values and newly analyzed pore water. PCBs in pore waters were measured using SPME PDMS-fiber and ?PCB ranged from 41 to 1500 ng L?1. The resulting KPCBi ds were ~ 1 log unit lower in comparison to other reported values. A simple model for the KPCBi d consisted of the product of the organic carbon fraction and the octanol-water partition coefficient and provided an excellent prediction for the measured values, with a mean square error of 0.09 ± 0.06. Although black carbon content is very high in these sediments and was expected to play an important role in the distribution of PCBs, no improvement was obtained when a two-carbon model was used. PMID:23974165

MARTINEZ, ANDRES; O'SULLIVAN, COLIN; REIBLE, DANNY; HORNBUCKLE, KERI C.

2013-01-01

64

Toxicity of silicon carbide nanowires to sediment-dwelling invertebrates in water or sediment exposures.  

PubMed

Silicon carbide nanowires (SiCNW) are insoluble in water. When released into an aquatic environment, SiCNW would likely accumulate in sediment. The objective of this study was to assess the toxicity of SiCNW to four freshwater sediment-dwelling organisms: amphipods (Hyalella azteca), midges (Chironomus dilutus), oligochaetes (Lumbriculus variegatus), and mussels (Lampsilis siliquoidea). Amphipods were exposed to either sonicated or nonsonicated SiCNW in water (1.0?g/L) for 48?h. Midges, mussels, and oligochaetes were exposed only to sonicated SiCNW in water for 96?h. In addition, amphipods were exposed to sonicated SiCNW in whole sediment for 10 d (44% SiCNW on dry wt basis). Mean 48-h survival of amphipods exposed to nonsonicated SiCNW in water was not significantly different from the control, whereas mean survival of amphipods exposed to sonicated SiCNW in two 48-h exposures (0 or 15% survival) was significantly different from the control (90 or 98% survival). In contrast, no effect of sonicated SiCNW was observed on survival of midges, mussels, or oligochaetes. Survival of amphipods was not significantly reduced in 10-d exposures to sonicated SiCNW either mixed in the sediment or layered on the sediment surface. However, significant reduction in amphipod biomass was observed with the SiCNW either mixed in sediment or layered on the sediment surface, and the reduction was more pronounced for SiCNW layered on the sediment. These results indicated that, under the experimental conditions, nonsonicated SiCNW in water were not acutely toxic to amphipods, sonicated SiCNW in water were acutely toxic to the amphipods, but not to other organisms tested, and sonicated SiCNW in sediment affected the growth but not the survival of amphipods. PMID:21305577

Mwangi, Joseph N; Wang, Ning; Ritts, Andrew; Kunz, James L; Ingersoll, Christopher G; Li, Hao; Deng, Baolin

2011-04-01

65

Water and sediment chemistry of Lake Pumayum Co, South Tibet, China: implications for interpreting sediment carbonate  

Microsoft Academic Search

A combination of water and sediment chemistry was used to investigate carbonate production and preservation in Lake Pumayum\\u000a Co (altitude 5,030 m a.s.l.), south Tibet, China. We compared the chemical composition of lake water in various parts of the\\u000a lake with that of input rivers and found that the loss of Ca2+ results from calcite sedimentation induced by evaporation and biogenic precipitation.

Jianting Ju; Li-ping Zhu; Junbo Wang; Manping Xie; Xiaolin Zhen; Yong Wang; Ping Peng

2010-01-01

66

Interstitial water chemistry of the Santa Barbara Basin sediments  

Microsoft Academic Search

The interstitial water composition (SO 4 2- , alkalinity, sulfide, Ca 2+ , Mg 2+ , K + , Si(OH) 4 , phosphate, NO 2 - , NO 3 - , NH 4 + , and Cl%.) of both the `basin' sediment in the center of the Santa Barbara Basin and the `slope' sediment shallower than the basin sill is

Edward Sholkovitz

1973-01-01

67

Water and Sediment Quality in the Yukon River Basin, Alaska, During Water Year 2001  

E-print Network

Water and Sediment Quality in the Yukon River Basin, Alaska, During Water Year 2001 Open by Paul F. Schuster, 2003. #12;WATER AND SEDIMENT QUALITY IN THE YUKON RIVER BASIN, ALASKA, DURING WATER............................................................................................................ 3 CHAPTER 3 - Dissolved Organic Carbon (DOC) Characterization................................ 23

68

Water and Sediment Quality in the Yukon River Basin, Alaska, During Water Year 2002  

E-print Network

Water and Sediment Quality in the Yukon River Basin, Alaska, During Water Year 2002 Open at Eagle, Alaska. #12;Water and Sediment Quality in the Yukon River Basin, Alaska, During Water Year 2002................................................................................................ 4 CHAPTER 3 - Dissolved Organic Carbon (DOC) Characterization

69

The use of helical heat exchanger for heat recovery domestic water-cooled air-conditioners  

Microsoft Academic Search

An experimental study on the performance of a domestic water-cooled air-conditioner (WAC) using tube-in-tube helical heat exchanger for preheating of domestic hot water was carried out. The main aims are to identify the comprehensive energy performance (space cooling and hot water preheating) of the WAC and the optimum design of the helical heat exchanger taking into account the variation in

Yi Xiaowen; W. L. Lee

2009-01-01

70

Domestic wash water reclamation for reuse as commode water supply using filtration: Reverse-osmosis separation technique  

NASA Technical Reports Server (NTRS)

A combined filtration-reverse-osmosis water recovery system has been evaluated to determine its capability to reclaim domestic wash water for reuse as a commode water supply. The system produced water that met all chemical and physical requirements established by the U.S. Public Health Service for drinking water with the exception of carbon chloroform extractables, methylene blue active substances, and phenols. It is thought that this water is of sufficient quality to be reused as commode supply water. The feasibility of using a combined filtration and reverse-osmosis technique for reclaiming domestic wash water has been established. The use of such a technique for wash-water recovery will require a maintenance filter to remove solid materials including those less than 1 micron in size from the wash water. The reverse-osmosis module, if sufficiently protected from plugging, is an attractive low-energy technique for removing contaminants from domestic wash water.

Hall, J. B., Jr.; Batten, C. E.; Wilkins, J. R.

1974-01-01

71

Sediment–water interactions of thallium under simulated estuarine conditions  

Microsoft Academic Search

Thallium(I) has been added to estuarine sediment suspended in various natural and artificial aqueous samples in order to examine its reactivity under simulated estuarine conditions. In river water and sea water, adsorption of Tl to sediment was so rapid that a period of desorption–relaxation succeeded instantaneous adsorption. Entire time-courses could not be fitted with a conventional kinetic model, but pseudo-first-order

Andrew Turner; Amelie Cabon; Gillian A. Glegg; Andrew S. Fisher

2010-01-01

72

Degradation of sulfonamides antibiotics in lake water and sediment.  

PubMed

Degradation of three sulfonamides (SAs), namely sulfamethoxazole (SMX), sulfamethazine (SMZ), and sulfadimethoxine (SDM) in surface water and sediments collected from Taihu Lake and Dianchi Lake, China was investigated in this study. The surface water (5-10 cm) was collected from the east region of Taihu Lake, China. Two sets of degradation experiments were conducted in 3-L glass bottles containing 2 L of fresh lake water and 100 ?g/L of individual SAs aerated by bubbling air at a rate of approximately 1.2 L/min, one of which was sterilized by the addition of NaN3 (0.1%). Sediment samples were taken from Taihu Lake and Dianchi Lake, China. For the sediment experiment, 5 g of sediment were weighed into a 50-mL glass tube, with 10 mg/kg of individual SAs. Different experimental conditions including the sediment types, sterilization, light exposure, and redox condition were also considered in the experiments. The three SAs degraded in lake water with half-lives (t 1/2) of 10.5-12.9 days, and the half-lives increased significantly to 31.9-49.8 days in the sterilized water. SMZ and SDM were degraded by abiotic processes in Taihu and Dianchi sediments, and the different experimental conditions and sediments characteristics had no significant effect on their declines. SMX, however, was mainly transformed by facultative anaerobes in Taihu and Dianchi sediments under anaerobic conditions, and the degradation rate of SMX in non-sterile sediment (t 1/2 of 9.6-16.7 days) were higher than in sterilized sediment (t 1/2 of 18.7-135.9 days). Under abiotic conditions, degradation of SMX in Dianchi sediment was faster than in Taihu sediment, probably due to the higher organic matter content and inorganic photosensitizers concentrations in Dianchi sediment. High initial SAs concentration inhibited the SAs degradation, which was likely related to the inhibition of microorganism activities by high SAs levels in sediments. Results from this study could provide information on the persistence of commonly used sulfanomides antibiotics in lake environment. PMID:22903812

Zhang, Yuan; Xu, Jian; Zhong, Zhenxing; Guo, Changsheng; Li, Lei; He, Yan; Fan, Wenhong; Chen, Yucheng

2013-04-01

73

The effects of the water management framework and the role of domestic consumers on urban water conservation in Botswana  

Microsoft Academic Search

This article examines the adverse effects of a fragmented water management framework and the role of domestic water users on water conservation in Gaborone, the rapidly growing capital city of Botswana. There was a major drought in Botswana in 2004, which recurred in 2007. The drought seriously affected water availability in Gaborone, re-igniting the water conservation debate. Most urban households

Elisha N. Toteng

2008-01-01

74

Measurements on suspension water of different natural lake sediments  

SciTech Connect

Suspension water of sediment suspensions contains considerable amounts of non-separable parts of the sediment. These parts, often referred to as the third phase, may consist of non-settling particles, dissolved organic materials and various macromolecules. Although the nature and composition of third phase material is unknown, the amount in suspension water and the composition is dependent on the nature of the bulk sediment. In the present study suspension water, originating from three different lake sediments, was analyzed by measuring (1) Dry Weight (DW), (2) Dissolved Organic Carbon (DOC) and (3) the apparent enhanced solubility of three chlorinated benzenes. The latter was measured in a new developed method, in which the chemicals were added to the suspension water by air in an airbridge-system. This method seems to be a suitable method for measuring enhanced solubilities in suspension water of relatively volatile compounds. DW and DOC concentrations and apparent enhanced solubilities vary considerably between the three sediments. However, the results of the three analyses are not in parallel, i.e. enhanced solubilities can not be predicted by the DW or DOC concentration of the suspension water. This means that DW or DOC do not give a good description of the suspension water concerning the sorption behavior of chemicals in suspension water.

Schrap, S.M.; Londo, M.; Bakker, M. [Univ. of Utrecht (Netherlands)

1994-12-31

75

Microbiological Evaluation of Water Quality from Urban Watersheds for Domestic Water Supply Improvement  

PubMed Central

Agricultural and urban runoffs may be major sources of pollution of water bodies and major sources of bacteria affecting the quality of drinking water. Of the different pathways by which bacterial pathogens can enter drinking water, this one has received little attention to date; that is, because soils are often considered to be near perfect filters for the transport of bacterial pathogens through the subsoil to groundwater. The goals of this study were to determine the distribution, diversity, and antimicrobial resistance of pathogenic Escherichia coli isolates from low flowing river water and sediment with inputs from different sources before water is discharged into ground water and to compare microbial contamination in water and sediment at different sampling sites. Water and sediment samples were collected from 19 locations throughout the watershed for the isolation of pathogenic E. coli. Heterotrophic plate counts and E. coli were also determined after running tertiary treated water through two tanks containing aquifer sand material. Presumptive pathogenic E. coli isolates were obtained and characterized for virulent factors and antimicrobial resistance. None of the isolates was confirmed as Shiga toxin E. coli (STEC), but as others, such as enterotoxigenic E. coli (ETEC). Pulsed field gel electrophoresis (PFGE) was used to show the diversity E. coli populations from different sources throughout the watershed. Seventy six percent of the isolates from urban sources exhibited resistance to more than one antimicrobial agent. A subsequent filtration experiment after water has gone through filtration tanks containing aquifer sand material showed that there was a 1 to 2 log reduction in E. coli in aquifer sand tank. Our data showed multiple strains of E. coli without virulence attributes, but with high distribution of resistant phenotypes. Therefore, the occurrence of E. coli with multiple resistances in the environment is a matter of great concern due to possible transfer of resistant genes from nonpathogenic to pathogenic strains that may result in increased duration and severity of morbidity. PMID:22408583

Ibekwe, A. Mark; Murinda, Shelton E.; Graves, Alexandria K.

2011-01-01

76

Microbiological evaluation of water quality from urban watersheds for domestic water supply improvement.  

PubMed

Agricultural and urban runoffs may be major sources of pollution of water bodies and major sources of bacteria affecting the quality of drinking water. Of the different pathways by which bacterial pathogens can enter drinking water, this one has received little attention to date; that is, because soils are often considered to be near perfect filters for the transport of bacterial pathogens through the subsoil to groundwater. The goals of this study were to determine the distribution, diversity, and antimicrobial resistance of pathogenic Escherichia coli isolates from low flowing river water and sediment with inputs from different sources before water is discharged into ground water and to compare microbial contamination in water and sediment at different sampling sites. Water and sediment samples were collected from 19 locations throughout the watershed for the isolation of pathogenic E. coli. Heterotrophic plate counts and E. coli were also determined after running tertiary treated water through two tanks containing aquifer sand material. Presumptive pathogenic E. coli isolates were obtained and characterized for virulent factors and antimicrobial resistance. None of the isolates was confirmed as Shiga toxin E. coli (STEC), but as others, such as enterotoxigenic E. coli (ETEC). Pulsed field gel electrophoresis (PFGE) was used to show the diversity E. coli populations from different sources throughout the watershed. Seventy six percent of the isolates from urban sources exhibited resistance to more than one antimicrobial agent. A subsequent filtration experiment after water has gone through filtration tanks containing aquifer sand material showed that there was a 1 to 2 log reduction in E. coli in aquifer sand tank. Our data showed multiple strains of E. coli without virulence attributes, but with high distribution of resistant phenotypes. Therefore, the occurrence of E. coli with multiple resistances in the environment is a matter of great concern due to possible transfer of resistant genes from nonpathogenic to pathogenic strains that may result in increased duration and severity of morbidity. PMID:22408583

Ibekwe, A Mark; Murinda, Shelton E; Graves, Alexandria K

2011-12-01

77

Geochemistry of molybdenum in some stream sediments and waters  

NASA Astrophysics Data System (ADS)

Elevated concentrations of Mo are present in both the waters and sediments of Tenmile Creek, downstream from the large Mo deposit at Climax. Colorado. Concentrations of Mo reach a maximum of 10mg/1 in the water and 384?/g in the (-) 80 mesh fraction of the sediment. The Mo anomaly extends for more than 80 km downstream from Climax, and results from the mining and milling at Climax. Background Mo concentrations in the nearby mountainous area are < 10?g/l (water) and < 5?g/g (sediment). Immediately below three small unmined Mo-rich orebodies elsewhere in Colorado < 3?g/l Mo are present in the waters and 20-30?g/g Mo in the fine fraction of the sediments. The Mo in the sediment of Tenmile Creek is chiefly adsorbed on coatings of amorphous Fe oxyhydroxide. and is similar to its form below two small, unmined Mo deposits. Mining has not changed the character of the chemical processes responsible for Mo dispersion from the Climax site. A modified version of the WATEQF computer program ( PLUMMERet al., 1976) predicts that Tenmile Creek is undersaturated with respect to ferrimolybdite. molybdenite, powellite, and ilsemannite. The Mo in the stream water occurs as the molybdate ion which can be adsorbed on amorphous Fe oxyhydroxides. These predictions are supported by the absence of Mo minerals in the sediment of Tenmile Creek.

Kaback, Dawn S.; Runnells, Donald D.

1980-03-01

78

Modelling water availability, sediment export and reservoir sedimentation in drylands with the WASA-SED Model  

Microsoft Academic Search

The process-based, spatially semi-distributed modelling framework WASA-SED for water and sediment transport in large dryland catchments is presented. The WASA-SED model simulates the runoff and erosion processes at the hillslope scale, the transport processes of suspended and bedload fluxes in the river reaches and the retention and remobilisation processes of sediments in reservoirs. The modelling tool enables the evaluation of

E. N. Mueller; A. Güntner; T. Francke; G. Mamede

2008-01-01

79

Domestic water uses: characterization of daily cycles in the north region of Portugal.  

PubMed

Nowadays, there is an increasing discussion among specialists about water use efficiency and the best measures to improve it. In Portugal, there have been a few attempts to expand the implementation of in situ water reuse projects. However, there is a lack of information about indoor water uses and how they are influenced by sociodemographic characteristics. There are several studies that investigate per capita global water usage, but the partitioning of this volume per domestic device and daily cycles is yet unknown. Identified as one of the key questions in sustainable building design, the water end-use is of primary importance to the design of hydraulic networks in buildings. In order to overcome this lack, a quantitative characterization of daily water uses for each domestic device was performed, based on a weekly monitoring program in fifty-two different dwellings in the northern region of Portugal (Vila Real, Valpaços and Oporto). For forty of them, each water usage of different domestic devices of each dwelling was recorded. At the same time, the remaining twelve dwellings were also monitored in order to register the volume of water consumed in each utilization of each domestic device. This paper presents the results of this complete monitoring program, using collected data to establish indoor water use patterns for each domestic device, aiming to support a more realistic approach to residential water use. The daily cycles in the different cities, where the monitoring program was performed, are also presented, in order to evaluate possible influences of sociodemographic characteristics. PMID:23685370

Matos, Cristina; Teixeira, Carlos A; Duarte, A A L S; Bentes, I

2013-08-01

80

Antifouling biocides in water and sediments from California marinas.  

PubMed

Irgarol 1051 is a common antifouling biocide and is highly toxic to non-target plant species at low ng/L concentrations. We measured up to 254 ng/L Irgarol in water and up to 9 ng/g dry weight Irgarol in sediments from Southern California recreational marinas. Irgarol's metabolite, M1, concentrations were up to 62 ng/L in water and 5 ng/g dry weight in sediments. Another antifouling biocide, diuron, reached up to 68 ng/L in water and 4 ng/g dry weight in sediments. The maximum Irgarol concentrations in water were greater than the Irgarol concentration recommended as the plant toxicity benchmark (136 ng/L), suggesting that Irgarol concentrations may be high enough to cause changes in phytoplankton communities in the sampled marinas. Irgarol concentrations measured in sediments were greater than calculated Environmental Risk Limits (ERLs) for Irgarol in sediments (1.4 ng/g). Antifouling pesticide accumulation in sediments may present a potential undetermined risk for benthic organisms. PMID:23453818

Sapozhnikova, Yelena; Wirth, Edward; Schiff, Kenneth; Fulton, Michael

2013-04-15

81

Solar hot water manual for electric utilities: Domestic hot water systems: Final report  

SciTech Connect

This manual is a consolidation of research quantifying the potential of solar domestic hot water (DHW) systems to satisfy electric utility load management objectives, especially peak clipping. Performance data on solar, heat pump, and utility-controlled DHW systems were collected and analyzed; computer simulations were also performed to obtain hour-by-hour demand curves during typical summer and winter days in seven geographic regions. The results show promise for solar and heat pump water heaters in all parts of the country when compared with conventional electric water heaters. Demand reduction by solar DHW systems during the peak period ranges from 12 to 78% in summer and 0 to 36% in winter, depending on geographic location. Demand reduction by heat pump water heaters during the peak period averages around 50% in both summer and winter in all locations. Load management of solar DHW systems can shift demand to evening hours, but provides only limited energy savings to homeowners.

Ahmed, S.F.; Estoque, J.

1986-12-01

82

Health improvement of domestic hot tap water supply Gusev, Kaliningrad Region, Russia. Make-up water tank project. Final report.  

National Technical Information Service (NTIS)

This report describes the project 'Health Improvement of Domestic Hot Tap Water Supply, Gusev, Kaliningrad, Russia', which was carried out in the autumn of 1996 and financed by the Danish Environmental Protection Agency, the Danish Energy Agency and Gusev...

J. Aagaard

1998-01-01

83

Fish interactions with the sediment-water interface  

Microsoft Academic Search

In two mesocosm experiments of cross-classified design, using sixteen 900-liter containers, we measured how benthivorous, omnivorous, and planktivorous fish interact with the sediment-water interface to influence planktonic and benthic production. Experiment 1 used three fish treatments (Ictalurus punctatus, Notemigonus crysoleucas, Lepomis macrochirus) and a fishless control in the presence or absence of a natural pond sediment layer. The benthivorous Ictalurus

Joanne M. Cline; Therese L. East; Stephen T. Threlkeld

1994-01-01

84

Water recovery and solid waste processing for aerospace and domestic applications  

NASA Technical Reports Server (NTRS)

The work is described accomplished in compiling information needed to establish the current water supply and waste water processing requirements for dwellings, and for developing a preliminary design for a waste water to potable water management system. Data generated was used in formulation of design criteria for the preliminary design of the waste water to potable water recycling system. The system as defined was sized for a group of 500 dwelling units. Study tasks summarized include: water consumption, nature of domestic water, consumer appliances for low water consumption, water quality monitoring, baseline concept, and current and projected costs.

Murawczyk, C.

1973-01-01

85

Estimate of self-supplied domestic water use in Oklahoma during 1980  

USGS Publications Warehouse

Reported or measured water-use data for the domestic self-supplied user were not available for Oklahoma; therefore estimates of water use within this classification were derived. The total self-supplied population in Oklahoma during 1980 was estimated to be 343,615, which was 11.4 percent of the total 1980 State population. The rate of water use by this group was estimated to be 56 gallons per capita per day. The estimated annual domestic self-supplied water use by county ranged from 10 to 1,180 acre-feet, with a total statewide use of 21,610 acre-feet.

Stoner, J. D.

1984-01-01

86

Spectroscopic analyses of pollutants in water, sediment and fish  

NASA Astrophysics Data System (ADS)

Water ways in Egypt is suffering from continual discharge without adequate treatment especially in the Delta and greater Cairo area. Accordingly water, sediments and catfishes were collected from El Mouheet El Youmna drain in Giza. Cd, Cr, Pb and Zn were determined furthermore the molecular structure of sediment and catfish were conducted with FTIR spectroscopy. Although studied metals were lower in water, higher values are recorded in sediment and catfish samples. FTIR shows possible interaction among metals and organic structures mainly proteins. The bioaccumulation of Pb and Cd proportion was significantly increased in the liver tissues of catfish. A correlation coefficient among sediment and fish liver metals accumulation exist. This infers that the waste assimilation capacity for the drain is high, a phenomena that could be ascribed to dilution, sedimentation and continual water exchange. Furthermore, the genotoxicity affect in catfish genomic corroborates the genus diagnostic markers which attributed to long pollution. This is an indication that agriculture and industrial wastes discharged into the drain has badly a significant effect on the ecological balance.

Abdel-Gawad, Fagr Kh.; Ibrahim, Hanan S.; Ammar, Nabila S.; Ibrahim, Medhat

2012-11-01

87

A model for sulfur accumulation in soft water lake sediments  

SciTech Connect

A geochemical model for sulfur in soft water lake sediments of the Adirondack Mountains, New York, is developed to gain insight into the timing and magnitude of historical changes in sulfur loading. Surficial sulfur concentrations range from 3500 to 10,000 {mu}g g{minus}{sup 1}, increase to 6000 to >20,000 {mu}g g{minus}{sup 1} at a depth of 2-6 cm, and then decrease downcore to background levels of 2500-7500 {mu}g g{minus}{sup 1}. Sulfate concentrations are about 50-80 {mu}M in the overlying water and decrease rapidly below the sediment-water interface. A mathematical model is constructed assuming sulfur is incorporated into sediments by burial of detrital organic matter and by diffusion of dissolved sulfate from the overlying water with subsequent fixation into the sediment solids. Several scenarios of historical sulfate deposition were examined as model boundary conditions. The observed sediment sulfur profiles are best modeled using boundary conditions showing loading increases of about a factor of 8 since about 1940. Assuming as much as a decade of retention of sulfate within the terrestrial portion of the ecosystem, this suggests that significant increases in sulfate deposition rates began sometime about 1930 in this area. 34 refs., 7 figs., 2 tabs.

Matisoff, G. [Case Western Reserve Univ., Cleveland, OH (United States)] [Case Western Reserve Univ., Cleveland, OH (United States); Holdren, G.R. Jr. [Battelle Pacific Northwest Labs., Richland, WA (United States)] [Battelle Pacific Northwest Labs., Richland, WA (United States)

1995-07-01

88

Seasonal variations in pore water and sediment geochemistry of littoral lake sediments (Asylum Lake, MI, USA)  

PubMed Central

Background Seasonal changes in pore water and sediment redox geochemistry have been observed in many near-surface sediments. Such changes have the potential to strongly influence trace metal distribution and thus create seasonal fluctuations in metal mobility and bioavailability. Results Seasonal trends in pore water and sediment geochemistry are assessed in the upper 50 cm of littoral kettle lake sediments. Pore waters are always redox stratified, with the least compressed redox stratification observed during fall and the most compressed redox stratification observed during summer. A 2-step sequential sediment extraction yields much more Fe in the first step, targeted at amorphous Fe(III) (hydr)oxides (AEF), then in the second step, which targets Fe(II) monosulfides. Fe extracted in the second step is relatively invariant with depth or season. In contrast, AEF decreases with sediment depth, and is seasonally variable, in agreement with changes in redox stratification inferred from pore water profiles. A 5-step Tessier extraction scheme was used to assess metal association with operationally-defined exchangeable, carbonate, iron and manganese oxide (FMO), organic/sulfide and microwave-digestible residual fractions in cores collected during winter and spring. Distribution of metals in these two seasons is similar. Co, As, Cd, and U concentrations approach detection limits. Fe, Cu and Pb are mostly associated with the organics/sulfides fraction. Cr and Zn are mostly associated with FMO. Mn is primarily associated with carbonates, and Co is nearly equally distributed between the FMO and organics/sulfide fractions. Conclusion This study clearly demonstrates that near-surface lake sediment pore water redox stratification and associated solid phase geochemistry vary significantly with season. This has important ramifications for seasonal changes in the bioavailability and mobility of trace elements. Without rate measurements, it is not possible to quantify the contribution of various processes to natural organic matter degradation. However, the pore water and solid phase data suggest that iron reduction and sulfate reduction are the dominant pathways in the upper 50 cm of these sediments. PMID:17181862

Koretsky, Carla M; Haas, Johnson R; Miller, Douglas; Ndenga, Noah T

2006-01-01

89

The effectiveness of a magnetic physical water treatment device on scaling in domestic hot-water storage tanks  

Microsoft Academic Search

In this paper the effectiveness of a permanent magnet for the prevention of scale was investigated. Experiments were conducted on two electrically heated domestic hot-water storage tanks. Ten experiments were conducted, each over a period of 28 d in which 8 000 l of water was heated to 75°C, while the quality of the feed water and mass precipitation of

C Smith; PP Coetzee

90

Tributary Sediment Yield, Water Yield and Sediment Composition as Controls of Habitat Heterogeneity in River Networks  

NASA Astrophysics Data System (ADS)

There is growing evidence that the delivery of water and sediment from tributaries can, via changes in habitat, elicit biological responses in the recipient channel. In particular, greater habitat heterogeneity near confluences may support biodiversity "hotspots" of broad, ecosystem significance. However, our understanding of what controls tributary impacts is very limited. This hinders effective consideration of confluences in river management practice; a problem that is pressing because of recognition that lotic ecosystems involve bio-physical interactions across networks, rather than along simple drainage lines. To date, field data have been used to specify empirical rules relating the probability of a tributary's impact to basin properties such as relative area. This approach has the advantage that it is easily applied at landscape scales, but because basin characteristics are used as gross surrogates for sediment flux, water flux, and sediment composition, little has been learned about the operation and interaction of these primary controls. We therefore used a 1-D sediment routing model with multiple grain-size fractions to investigate mainstream responses to inputs of water and sediment at confluences. Simulations were performed for different initial conditions, using many combinations of values of three independent parameters: the ratios of tributary to mainstream water flux (QR), sediment flux (FR) and characteristic bed load grain size (DR). A primary distinction can be made between confluences that exhibit aggradation (DR > 2) and those that exhibit degradation (DR < 1 or FR = 0), but in the real world post-confluence degradation is rare and we therefore focus here on aggrading tributaries. We describe the impact of QR, FR and DR on the longitudinal spatial heterogeneity of three indicative characteristics of physical habitat: mainstream grain size, percentage sand and Froude number. To apply our results at broader scales requires specification of relations between QR, FR, DR and easily measured network or basin parameters. This issue is considered, and tentative inferences about the network-scale implications of our results are made.

Rice, S.; Ferguson, R.; Hoey, T.

2005-05-01

91

Water and protein dynamics in sedimented systems: a relaxometric investigation.  

PubMed

Sedimented proteins have recently been shown to provide solid-state NMR spectra of high quality, suitable for structural investigation. This is ascribed to the strong self-crowding effect, which apparently increases the reorientation time up to the point that the protein can be considered immobile on the NMR timescale. Herein, a relaxometric investigation of sedimented bovine serum albumin is performed to obtain information on the dynamics of the system. The measurement of the proton longitudinal relaxation rates as a function of the applied magnetic field indicates that the sedimented protein has relaxation properties very different from those of the protein in concentrated water solutions, even in the presence of glycerol, and similar to those of slightly rehydrated lyophilized systems. This study confirms the hypothesis that the reorientation of the protein molecules is largely abolished in sediments. PMID:23671018

Luchinat, Claudio; Parigi, Giacomo; Ravera, Enrico

2013-09-16

92

Bacterial Mercury Methylation At The Sediment-Water Interface Of Mercury Contaminated Sediments  

EPA Science Inventory

Bench scale experiments were conducted to improve our understanding of bacterial mediation of mercury transformation (methylation), specifically those factors which govern the production of methyl mercury (MeHg) at the sediment-water interface. The greatest cause for concern re...

93

Effects of sediment type and water level on biomass production of wetland plant species  

Microsoft Academic Search

We investigated how water level and different sediment types affect the growth of wetland plant species. Twelve different species were grown in drained and waterlogged sediments, which represented types normally encountered in wetlands: a mineral sediment from exposed sites, a sediment from a sheltered site rich in labile organic matter and an organic sediment with decomposing litter of Phragmites australis

John P. M. Lenssen; Frank B. J. Menting; Wim H. van der Putten; Cornelis W. P. M. Blom

1999-01-01

94

Measure Guideline: Combination Forced-Air Space and Tankless Domestic Hot Water Heating Systems  

SciTech Connect

This document describes design and application guidance for combination space and tankless domestic hot water heating systems (combination systems) used in residential buildings, based on field evaluation, testing, and industry meetings conducted by Building Science Corporation. As residential building enclosure improvements continue to drive heating loads down, using the same water heating equipment for both space heating and domestic water heating becomes attractive from an initial cost and space-saving perspective. This topic is applicable to single- and multi-family residential buildings, both new and retrofitted.

Rudd, A.

2012-08-01

95

Contaminated marine sediments: Water column and interstitial toxic effects  

SciTech Connect

The toxicity that contaminated sediments may introduce into the water column has not been measured extensively. In order to quantify this potential toxicity, the seawater overlying two uncontaminated and three contaminated marine sediments was evaluated in the laboratory with the sea urchin Arbacia punctulata fertilization test. Concentration of polychlorinated biphenyls (PCBs) and copper, as representative contaminants, were also measured. To characterize sources of toxicity, samples were chemically manipulated using reversed-phase chromatography, cation exchange, and chelation. Water column toxicity and contaminant concentrations were higher in the suspended exposures than in bedded exposures. Interstitial water toxicity and contaminant concentrations were generally greater than either bedded or suspended exposures. Chemical manipulation indicated that the observed toxicity in water column exposures was probably caused by metallic and/or nonionic organic contaminants. Conversely, manipulation of interstitial water did not result in significantly reduced toxicity, suggesting that other toxicants such as ammonia and hydrogen sulfide may be active.

Burgess, R.M.; McKinney, R.A. (Science Applications International Corp., Narragansett, RI (United States)); Schweitzer, K.A. (Chemical Waste Management, Inc., Dartmouth, MA (United States)); Phelps, D.K. (Environmental Protection Agency, Narragansett, RI (United States))

1993-01-01

96

Contaminated marine sediments: Water column and interstitial toxic effects  

SciTech Connect

The toxicity that contaminated sediments may introduce into the water column has not been measured extensively. In order to quantify this potential toxicity, the seawater overlying two uncontaminated and three contaminated marine sediments was evaluated in the laboratory with the sea urchin Arbacia punctulata fertilization test. Concentrations of polychlorinated biphenyls (PCBs) and copper, as representative contaminants, were also measured. To characterize sources of toxicity, samples were chemically manipulated using reversed-phase chromatography, cation exchange, and chelation. Water column toxicity and contaminant concentrations were higher in the suspended exposures than in bedded exposures. Interstitial water toxicity and contaminant concentrations were generally greater than either bedded or suspended exposures. Chemical manipulation indicated that the observed toxicity in water column exposures was probably caused by metallic and/or nonionic organic contaminants. Conversely, manipulation of interstitial waters did not result in significantly reduced toxicity, suggesting that other toxicants such as ammonia and hydrogen sulfide may be active.

Burgess, R.M.; Schweitzer, K.A.; McKinney, R.A.; Phelps, D.K.

1993-01-01

97

Water and bed-sediment quality in the vicinity of Berlin Lake, Ohio, 2001  

USGS Publications Warehouse

Berlin Lake, in northeast Ohio, was created by the U.S. Army Corps of Engineers in 1943 and is used primarily for flood control for the upper reaches of the Mahoning River. The area surrounding and under the lake has been tapped for oil and natural gas production. One of the by-products of oil and gas production is concentrated salt water or brine, which might have an effect on the chemical quality of area potable-water sources. This report presents the results of a U.S. Geological Survey baseline study to collect current (2001) water and sediment-quality data and to characterize water quality in the Berlin Lake watershed. Chloride-to-bromide ratios were used to detect the presence of brine in water samples and to indicate possible adverse effects on water quality. Analyses of ground-water samples from domestic wells in the area indicate a source of chloride and bromide, but defining the source would require more data collection. Analyses of specific conductance and dissolved solids indicate that 78 percent (14 of 18) of the ground-water samples exceeded the Secondary Maximum Contaminant Level for dissolved solids in public water supplies of 500 milligrams per liter (mg/L), compared to 6 percent of samples exceeding 500 mg/L in two nearby studies. Surface water was analyzed twice, once each during low-flow and surface runoff conditions. A comparison of the 2001 data to historical chloride concentrations, accounting for seasonal changes, does not indicate an increase in chloride loads for surface water in the area of Berlin Lake. Polycyclic aromatic hydrocarbons were found in bed-sediment samples collected from the mouths of major tributaries to Berlin Lake. Polycyclic aromatic hydrocarbons are produced during the incomplete combustion of organic carbon materials such as wood and fossil fuels, and they are components of petroleum products.

Darner, Robert A.

2002-01-01

98

Sediment-water fluxes of mercury in Lavaca Bay, Texas  

SciTech Connect

The aqueous flux of inorganic Hg and monomethyl Hg from sediments to the water column was determined at several sites in Lavaca Bay, an estuary along the Texas Coast, historically impacted by Hg discharges. Diffusive fluxes were calculated at 15 sites using interstitial pore water gradients and compared to direct flux measurements obtained at two sites using benthic flux chambers. The diffusive flux of monomethyl mercury (MMHg), when modeled as a chloride species, varied over 3 orders /of magnitude from 0.2 to 1500 ng m{sup {minus}2} day{sup {minus}1}. Diffusive fluxes determined at a single site revealed that MMHg fluxes varied seasonally; maximal fluxes occurred in late winter to early spring. Flux chamber deployments at an impacted site revealed t hat MMHg was the Hg species entering the water column from sediments and the flux was not in steady-state; there was a strong diurnal signal with most of the MMHg flux occurring during dark periods. The flux of inorganic Hg was smaller and not as easily discernible by this method. The MMHg flux during the dark period was about 6 times greater than the estimated diffusional flux for MMHgCl, suggesting that biological and/or chemical processes near the sediment-water interface were strongly mediating the sediment-water exchange of MMHg.

Gill, G.A. [Texas A and M Univ., Galveston, TX (United States)] [Texas A and M Univ., Galveston, TX (United States); Bloom, N.S. [Frontier Geosciences Inc., Seattle, WA (United States)] [Frontier Geosciences Inc., Seattle, WA (United States); Cappellino, S. [Parametrix, Inc., Houston, TX (United States)] [Parametrix, Inc., Houston, TX (United States); Driscoll, C.T. [Syracuse Univ., NY (United States). Dept. of Civil and Environmental Engineering] [Syracuse Univ., NY (United States). Dept. of Civil and Environmental Engineering; Dobbs, C.; McShea, L. [Aluminum Co. of America, Point Comfort, TX (United States)] [Aluminum Co. of America, Point Comfort, TX (United States); Mason, R. [Univ. of Maryland, Solomons, MD (United States). Chesapeake Biological Lab.] [Univ. of Maryland, Solomons, MD (United States). Chesapeake Biological Lab.; Rudd, J.W.M. [Dept. of Fisheries and Oceans, Winnipeg, Manitoba (Canada). Freshwater Inst.] [Dept. of Fisheries and Oceans, Winnipeg, Manitoba (Canada). Freshwater Inst.

1999-03-01

99

Evaluation of Simultaneous Demands for Water Supply for Domestic Washroom Appliances  

Microsoft Academic Search

This study examines the probable maximum simultaneous demands of water supply facilities at an acceptable level of reliability for some high-rise residential buildings in crowded cities. In particular, the probable maximum simultaneous water demands of domestic washrooms are derived for some usage patterns that the appliances in the same washroom would not operate simultaneously. The model parameters including usage patterns

K. W. Mui; L. T. Wong

2007-01-01

100

An agent-based model for domestic water management in Valladolid metropolitan area  

Microsoft Academic Search

In this work we demonstrate that the combination of agent-based modeling and simulation constitutes a useful methodological approach to dealing with the complexity derived from multiple factors with influence in the domestic water management in emergent metropolitan areas. In particular, we adapt and integrate different social submodels, models of urban dynamics, water consumption, and technological and opinion diffusion, in an

José M. Galán; Adolfo López-Paredes; Ricardo del Olmo

2009-01-01

101

Water and Sediment Yields for Wala Dam Catchment Area  

NASA Astrophysics Data System (ADS)

Wala Watershed occupies the upper part of Al-Mujib Basin, Jordan, with Mediterranean climate, sparse inhabitants and moderate agriculture. The area, in spite of its limited water resources, is considered as an important water supply as it encompasses Al-Heidan springs and pumping wells, which supply Amman city with a considerable amount of water, it also includes Wala Dam that has been constructed for groundwater recharge purposes. Recognizing the threats of water and soil loss with the consequent sedimentation problems, and the benefits of watershed modeling techniques in studying such topics, this study comprised an application of the Soil and Water Assessment Tool (SWAT), associated with the Geographic Information System (GIS) to simulate the hydrology, soil erosion and sedimentation of Wala Dam Catchment Area. A set of hydrological techniques was utilized to simulate various components such as the Curve Number Method, the Rational Method and the Universal Soil Loss Equation (USLE) and modified USLE models. The use of such techniques in a GIS environment required certain types of data, which were collected and prepared either as database files such as the daily rainfall records, or as analytical GIS layers of soil, landuse/cover, drainage pattern and Digital Elevation Model (DEM). A weather generator was incorporated to generate any missed weather data. The area was discretized into 43 subbasins and 82 hydrologic response units. Two simulation series were performed using annual and monthly printout frequency. Several results were obtained including water and sediment yields at Wala Dam location with the respective delivery ratios, and spatial representation of precipitation, surface runoff, soil erosion, sediment and water yield on subbasin level. Model calibration and verification were carried out using flow rate and sediment yield data observed at Wala flow station and the results were satisfactory, indicating that this model can represent well the climatic and physical conditions of the area. Two prediction scenarios were performed, both indicated that the western and northern subbasins yield more water to the dam and are more susceptible to soil erosion and sediment generation. The study resulted in some recommendations to enhance the built model and suggest soil conservation and sediment reduction measures to control soil loss and maintain storage in Wala Dam reservoir, in addition to protecting its bottom against clogging through which the process of groundwater recharge might malfunction.

Tarawneh, E.

2009-04-01

102

Development of the sediment and water quality management strategies for the Salt-water River, Taiwan.  

PubMed

The Salt-water River watershed is one of the major river watersheds in the Kaohsiung City, Taiwan. Water quality and sediment investigation results show that the river water contained high concentrations of organics and ammonia-nitrogen, and sediments contained high concentrations of heavy metals and organic contaminants. The main pollution sources were municipal and industrial wastewaters. Results from the enrichment factor (EF) and geo-accumulation index (Igeo) analyses imply that the sediments can be characterized as heavily polluted in regard to Cd, Cr, Pb, Zn, and Cu. The water quality analysis simulation program (WASP) model was applied for water quality evaluation and carrying capacity calculation. Modeling results show that the daily pollutant inputs were much higher than the calculated carrying capacity (1050 kg day(-1) for biochemical oxygen demand and 420 kg day(-1) for ammonia-nitrogen). The proposed watershed management strategies included river water dilution, intercepting sewer system construction and sediment dredging. PMID:21392809

Lin, C E; Chen, C T; Kao, C M; Hong, A; Wu, C Y

2011-01-01

103

Wave propagation in marine sediments and water saturated soils  

Microsoft Academic Search

Summary A unification of the theories of Biot and Weiskopf has been made to form the suitable equations of motion for porous water saturated soils and marine sediments. It has been shown that the velocities of the body waves depend on the direction of propagation. In the vertical direction there are three, one distortional and two dilatational waves. In the

S. K. Bose

1962-01-01

104

Wave propagation in marine sediments and water saturated soils  

Microsoft Academic Search

A unification of the theories of Biot and Weiskopf has been made to form the suitable equations of motion for porous water saturated soils and marine sediments. It has been shown that the velocities of the body waves depend on the direction of propagation. In the vertical direction there are three, one distortional and two dilatational waves. In the horizontal

S. K. Bose

1962-01-01

105

Measuring low concentrations of 234 Th in water and sediment  

E-print Network

Measuring low concentrations of 234 Th in water and sediment James T. Waplesa,*, Kent A. Orlandinib October 2002 Abstract 234 Th/238 U disequilibria have been used extensively in studies of particle methods for the analysis of 234 Th inadequate. The application of this radionuclide tracer technique

NOAA Great Lakes Environmental Research Laboratory, Episodic Events

106

Comparative greenhouse emissions analysis of domestic solar hot water systems  

Microsoft Academic Search

It is commonly assumed that solar hot water systems save energy and reduce greenhouse emissions relative to conventional fossil fuel-powered systems. Very rarely has the life-cycle greenhouse emissions (including the embodied greenhouse emissions of manufacture) of solar hot water systems been analysed. The extent to which solar hot water systems can reduce emissions compared with conventional systems can be shown

Robert H Crawford; Graham John Treloar; B. D. Ilozor; Peter Love

2003-01-01

107

Availability of Irrigation Water for Domestic Use in Pakistan: Its Impact on Prevalence of Diarrhoea and Nutritional Status of Children  

Microsoft Academic Search

This study assessed whether availability of water for domestic use had any impact on nutritional status of children in an area where people depend on irrigation water for all their domestic water needs. During May 1998-April 1999, data on the occurrence of diarrhoea among 167 children aged less than five years were collected from 10 villages in the command area

Wim van der Hoek; Sabiena G. Feenstra; Flemming Konradsen

108

Water and sediment for plot and field studies  

Microsoft Academic Search

The design and performance characteristics of a flush-type sampling device for plot and field studies are described. The sampler is weld-constructed and requires excavation and water conveyance for installation. It operates with no external power supply and collects consistently a known fraction of water and sediment passing through it. In laboratory tests, the sampler collected 2.65% (number of data points

S. A. Dressing; J. Spooner; J. M. Kreglow; E. O. Beasley; P. W. Westerman

2009-01-01

109

Relationship between oxygen consumption and sediment-water fluxes of heavy metals in coastal marine sediments  

SciTech Connect

The relationship between benthic oxygen demand and the sediment-water flux of six heavy metals (cobalt [Co], nickel [Ni], copper [Cu], zinc [Zn], cadmium [Cd], and lead [Pb]) was examined at two locations: New Bedford Harbor and Buzzards Bay, Massachusetts, USA. Dissolved metal fluxes were measured in laboratory microcosms incubated in the dark at in situ temperatures, and microcosms were collected over different seasons to examine temporal and spatial variability in the fluxes. The net flux of all metals was generally out of the sediments. However, at low rates of benthic oxygen demand, net flux of Pb and Co was into the sediments. When data from the two sites are combined, regression of metal fluxes against benthic oxygen demand was significant for all metals, with all slopes significantly different from zero. The flux values ranged from {minus}1.4 (mmole/m{sup 2}/d)/(mole/mole C){sub sediment} for Zn during winter to 42 (mmole/m{sup 2}/d)/(mole/mole C){sub sediment} for Cd during summer months. The magnitude of the fluxes generally showed the following relationship: Cd > Zn > Co, Ni, Cu > Pb, indicating higher relative mobility for Cd and lower mobility for Pb. The estimated annual fluxes of metals to New Bedford Harbor and Buzzards Bay amount to {approximately}0.06% (Pb) to 25% (Cd) of the inventory of metals in the top 2 cm of sediments and can equal the inventory of metals in the water column on a time scale as short as 7 d for Zn.

Shine, J.P.; Ika, R.; Ford, T.E. [Harvard School of Public Health, Boston, Massachusetts (United States). Dept. of Environmental Health

1998-11-01

110

Mercury, Methylmercury, and Other Constituents in Sediment and Water from Seasonal and Permanent  

E-print Network

Mercury, Methylmercury, and Other Constituents in Sediment and Water from Seasonal and Permanent, the Sacramento River Watershed Program, and the United States Environmental Protection Agency Mercury A., 2009, Mercury, methylmercury, and other constituents in sediment and water from seasonal

111

Domestic air-conditioner and integrated water heater for subtropical climate  

Microsoft Academic Search

The technology of using a heat pump for space conditioning and domestic hot water heating in residences has been developed for half a century. The earlier air-to-water heat pumps and water-heating heat pumps suffered from drawbacks like high costs, unreliable operation, and inflexible applications. They were not well positioned in the market to attract customers. This paper introduces a novel

Jie Ji; Tin-tai Chow; Gang Pei; Jun Dong; Wei He

2003-01-01

112

Water recovery and solid waste processing for aerospace and domestic applications. Volume 1: Final report  

NASA Technical Reports Server (NTRS)

A comprehensive study of advanced water recovery and solid waste processing techniques employed in both aerospace and domestic or commercial applications is reported. A systems approach was used to synthesize a prototype system design of an advanced water treatment/waste processing system. Household water use characteristics were studied and modified through the use of low water use devices and a limited amount of water reuse. This modified household system was then used as a baseline system for development of several water treatment waste processing systems employing advanced techniques. A hybrid of these systems was next developed and a preliminary design was generated to define system and hardware functions.

Murray, R. W.

1973-01-01

113

Preliminary design package for Sunspot Domestic Hot Water Heating System  

NASA Technical Reports Server (NTRS)

The design review includes a drawing list, auto-control logic, measurement definitions, and other document pertaining to the solar heated prototype hot water systems and two heat exchangers. The hot water systems consist of the following subsystems: collector, storage, control transport, auxiliary energy, and site data acquisition.

1976-01-01

114

Rainwater Harvesting Potential for Domestic Water Supply in Edo State  

Microsoft Academic Search

In the face of increasing scarcity of water resources, there is a need for communities to undertake audits of their current rainwater harvesting potential as a practical and promising alternative solution for water shortage. Despite the importance of rainwater harvest in socio-economic development of communities, very little information exists in the literature concerning it. This paper is an attempt to

S. I. Oni; Emmanuel Ege

2008-01-01

115

California buyer's guide for solar domestic hot water systems  

Microsoft Academic Search

Energy required for water heating and space conditioning accounts for 75% of the energy demand of the typical California home and 25% of the nation's total energy demand. As fuel costs continue to rise, an increasing percentage of consumer income will be spent on these essentials. This document describes how solar water heating equipment can be used to lower the

D. Ware; R. Johnson

1985-01-01

116

Estimate of self-supplied domestic water use in Nebraska during 1980  

USGS Publications Warehouse

No data base of actual measurements exists for self-supplied, domestic water use in Nebraska, because Nebraska laws do not require drilling permits, well registration, or reporting of volumes withdrawn from domestic wells. Self-supplied, domestic water use of 31,280 acre-ft in Nebraska during 1980 was computed from estimates of gal/day/capita use for each county. This represents an average of 95 gal/day/capita. During 1980, county use volumes ranged from 30 acre-ft in Hooker and Pawnee Counties to 1,380 acre-ft in Douglas County, and Hydrologic Unit use volumes ranged from < 5 acre-ft to 2,270 acre-ft. Natural Resources Districts ' (NRD) use volumes ranged from 360 acre-ft in Middle Niobrara NRD to 3,530 acre-feet in the Lower Elkhorn NRD for the same period. (Author 's abstract)

Steele, E. K.

1985-01-01

117

Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corp. , Columbus, Ohio. Final report  

SciTech Connect

The Solar Energy System located at the Columbia Gas Corporation, Columbus, Ohio, has 2978 ft/sup 2/ of Honeywell single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/h Bryan water-tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton Arkla hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts are included from the site files, specification references, drawings, installation, operation and maintenance instructions.

None

1980-11-01

118

Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio  

NASA Technical Reports Server (NTRS)

The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

1980-01-01

119

30 CFR 77.216-3 - Water, sediment, or slurry impoundments and impounding structures; inspection requirements...  

...2014-07-01 2014-07-01 false Water, sediment, or slurry impoundments...Installations § 77.216-3 Water, sediment, or slurry impoundments...program requirements. (a) All water, sediment, or slurry impoundments...operator based on the hazard potential and performance of the...

2014-07-01

120

30 CFR 77.216-3 - Water, sediment, or slurry impoundments and impounding structures; inspection requirements...  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Water, sediment, or slurry impoundments...Installations § 77.216-3 Water, sediment, or slurry impoundments...program requirements. (a) All water, sediment, or slurry impoundments...operator based on the hazard potential and performance of the...

2010-07-01

121

30 CFR 77.216-3 - Water, sediment, or slurry impoundments and impounding structures; inspection requirements...  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Water, sediment, or slurry impoundments...Installations § 77.216-3 Water, sediment, or slurry impoundments...program requirements. (a) All water, sediment, or slurry impoundments...operator based on the hazard potential and performance of the...

2012-07-01

122

30 CFR 77.216-3 - Water, sediment, or slurry impoundments and impounding structures; inspection requirements...  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Water, sediment, or slurry impoundments...Installations § 77.216-3 Water, sediment, or slurry impoundments...program requirements. (a) All water, sediment, or slurry impoundments...operator based on the hazard potential and performance of the...

2011-07-01

123

Ecotoxicological Assessment of Water and Sediment Pollution of the Iskar River bellow Samokov  

Microsoft Academic Search

A system of integral ecological indices has been worked out to assess the level of polution of water and sediments with hazardous substances. A model for the dynamics of the inegral index for water and sediments polution is proposed. This index was applied for ecotoxicological assessment of water and sediments polution of the Iskar river bellow Samokov. A modification method

Ivan Diadovski; Yana Raykovska; Niels De Pauw; Diederik Rousseau

124

Electrochemical Flocculation and Chlorination for Domestic Water Supplies  

E-print Network

Three electrochemical chlorinators were developed, tested and evaluated. The first used natural chlorides in the water to produce a chlorine residual; the second and third produced chlorine residuals by electrolysis of brine solution. Brine feed...

Dillion Jr., R. C.; Hiler, E. A.; Peters, J. L.

125

A load model to support demand management decisions on domestic storage water heater control strategy  

Microsoft Academic Search

Load control of domestic water heaters is a well known demand side management activity. A model capable of simulating the effect of various control parameters which affect the control strategy is presented in this paper. These parameters include the tariff structure, the number of control blocks, the maximum demand set point and the maximum duration for which any block may

J. C. van Tonder

1996-01-01

126

Thermosiphon solar domestic water heating systems: long-term performance prediction using artificial neural networks  

Microsoft Academic Search

The objective of this work is to use artificial neural networks (ANN) for the long-term performance prediction of thermosiphonic type solar domestic water heating (SDWH) systems. Thirty SDWH systems have been tested and modelled according to the procedures outlined in the standard ISO 9459-2 at three locations in Greece. From these, data from 27 of the systems were used for

Soteris A Kalogirou; Sofia Panteliou

2000-01-01

127

System design optimization for large building integrated solar heating systems for domestic hot water  

Microsoft Academic Search

Performance and economy for building integrated solar domestic hot water (DHW) heating systems have been calculated as a function of installed solar collector area per housing unit, and benefits from having a high summer solar fraction are calculated and discussed. A presentation of new Danish solar heating DHW demonstration projects, where a high solar fraction is combined with heat loss

P PEDERSEN

1993-01-01

128

Remote Sensing of Suspended Sediments and Shallow Coastal Waters  

NASA Technical Reports Server (NTRS)

Ocean color sensors were designed mainly for remote sensing of chlorophyll concentrations over the clear open oceanic areas (case 1 water) using channels between 0.4 and 0.86 micrometers. The Moderate Resolution Imaging Spectroradiometer (MODIS) launched on the NASA Terra and Aqua Spacecrafts is equipped with narrow channels located within a wider wavelength range between 0.4 and 2.5 micrometers for a variety of remote sensing applications. The wide spectral range can provide improved capabilities for remote sensing of the more complex and turbid coastal waters (case 2 water) and for improved atmospheric corrections for Ocean scenes. In this article, we describe an empirical algorithm that uses this wide spectral range to identifying areas with suspended sediments in turbid waters and shallow waters with bottom reflections. The algorithm takes advantage of the strong water absorption at wavelengths longer than 1 micrometer that does not allow illumination of sediments in the water or a shallow ocean floor. MODIS data acquired over the east coast of China, west coast of Africa, Arabian Sea, Mississippi Delta, and west coast of Florida are used in this study.

Li, Rong-Rong; Kaufman, Yoram J.; Gao, Bo-Cai; Davis, Curtiss O.

2002-01-01

129

Preliminary assessment of heavy metal contamination in surface water and sediments from Honghu Lake, East Central China  

NASA Astrophysics Data System (ADS)

Heavy metal concentrations in surface water and sediments collected from Honghu Lake in Hubei Province, China were analyzed, and ecological risks were evaluated according to the sediment quality guidelines. The results showed that the average concentrations of heavy metals in surface water were ranked as: As>Zn> Cu>Cr>Pb>Ni>Cd>Hg. In comparison with results reported in other rivers and the background values, The Honghu Lake was polluted by As, Cr, Pb, Cu and Ni. Most of metals might be mainly from fertilizers, industrial effluent and domestic wastewater around the lake. Heavy metals concentrations were relatively higher in the inlet area than in other areas. Negative correlations were observed between most heavy metals and pH, while a significant positive correlation was present between Zn, Cd and Pb. In the sediment core, Cu, Zn, Cr and Ni showed a decreasing trend while Cd present an increasing trend. The decrease of As, Cu, Zn, Cr and Ni in the 1990s might due to the flood event in 1998. The analysis of ecological risk assessment based on sediment quality guidelines suggested that heavy metals in most sediments from the Honghu Lake had moderate toxicity, with Cr being the highest priority pollutant.

Hu, Ying; Qi, Shihua; Wu, Chenxi; Ke, Yanping; Chen, Jing; Chen, Wei; Gong, Xiangyi

2012-03-01

130

Solar domestic hot water system installed at Texas City, Texas  

NASA Astrophysics Data System (ADS)

This is the final technical report of the solar energy system located at LaQuinta Motor Inn, Texas City, Texas. The system was designed to supply 63 percent of the total hot water load for a new 98 unit motor inn. The solar energy system consists of a 2100 square feet Raypack liquid flat plate collector subsystem and a 2500 gallon storage subsystem circulating hot water producing 3.67 x 10 to the 8th power Btu/year. Abstracts from the site files, specification references, drawings, installation, operation, and maintenance instructions are included.

1980-12-01

131

Solar domestic hot water system installed at Texas City, Texas  

NASA Technical Reports Server (NTRS)

This is the final technical report of the solar energy system located at LaQuinta Motor Inn, Texas City, Texas. The system was designed to supply 63 percent of the total hot water load for a new 98 unit motor inn. The solar energy system consists of a 2100 square feet Raypack liquid flat plate collector subsystem and a 2500 gallon storage subsystem circulating hot water producing 3.67 x 10 to the 8th power Btu/year. Abstracts from the site files, specification references, drawings, installation, operation, and maintenance instructions are included.

1980-01-01

132

Influence of Sediment Condition on Water Quality in the Izarigawa Dam Reservoir  

Microsoft Academic Search

The water environment of dam reservoirs is greatly influenced by sediment inflow from upstream, weather, and hydrological conditions. The Izarigawa Dam was completed in 1980, and sedimentation has been progressing yearly. The volume of accumulated sediment was 840,000 m 3 as of 2002. A sediment shelf formed in the dam reservoir has been advancing and it became conspicuous in 1993,

Tetsuya YABIKI; Makoto NAKATSUGAWA; Yasuhiro MURAKAMI

133

Can control of soil erosion mitigate water pollution by sediments?  

PubMed

The detrimental impact of sediment and associated pollutants on water quality is widely acknowledged, with many watercourses in the UK failing to meet the standard of 'good ecological status'. Catchment sediment budgets show that hill slope erosion processes can be significant sources of waterborne sediment, with rates of erosion likely to increase given predicted future weather patterns. However, linking on-site erosion rates with off-site impacts is complicated because of the limited data on soil erosion rates in the UK and the dynamic nature of the source-pathway-receptor continuum over space and time. Even so, soil erosion control measures are designed to reduce sediment production (source) and mobilisation/transport (pathway) on hill slopes, with consequent mitigation of pollution incidents in watercourses (receptors). The purpose of this paper is to review the scientific evidence of the effectiveness of erosion control measures used in the UK to reduce sediment loads of hill slope origin in watercourses. Although over 73 soil erosion mitigation measures have been identified from the literature, empirical data on erosion control effectiveness are limited. Baseline comparisons for the 18 measures where data do exist reveal erosion control effectiveness is highly variable over time and between study locations. Given the limitations of the evidence base in terms of geographical coverage and duration of monitoring, performance of the different measures cannot be extrapolated to other areas. This uncertainty in effectiveness has implications for implementing erosion/sediment risk reduction policies, where quantified targets are stipulated, as is the case in the EU Freshwater Fish and draft Soil Framework Directives. Also, demonstrating technical effectiveness of erosion control measures alone will not encourage uptake by land managers: quantifying the costs and benefits of adopting erosion mitigation is equally important, but these are uncertain and difficult to express in monetary terms. PMID:23815978

Rickson, R J

2014-01-15

134

Solar heat pump systems for domestic hot water  

Microsoft Academic Search

Vapour compression heat pumps can upgrade ambient heat sources to match the desired heating load temperature. They can offer considerable increase in operational energy efficiency compared to current water heating systems. Solar heat pumps collect energy not only from solar radiation but also from the ambient air. They can operate even at night or in totally overcast conditions. Since the

Lu Aye; W. W. S Charters; C Chaichana

2002-01-01

135

PII S0016-7037(99)00084-8 Dissolved sulfide distributions in the water column and sediment pore waters  

E-print Network

sites (550 and 590 m) with low ( 10 M) bottom-water dissolved-oxygen concentrations. Pore-water profilesPII S0016-7037(99)00084-8 Dissolved sulfide distributions in the water column and sediment pore) Abstract--Dissolved sulfide concentrations in the water column and in sediment pore waters were measured

van Geen, Alexander

136

Extraction of tricyclazole from soil and sediment with subcritical water.  

PubMed

The use of subcritical water to extract tricyclazole from soils and sediments was examined. Extraction efficiency and kinetics were determined as a function of temperature, sample age, sample matrix, sample size, and flow rate. Extraction temperature was the most influential experimental factor affecting extraction efficiency and kinetics, with increasing temperature (up to 150 degrees C) yielding faster and higher efficiency extractions. Higher extraction temperatures were also important for quantitative recovery of tricyclazole from aged samples. Extraction at 50 degrees C yielded 97% recoveries from samples aged 1 day but only 30% recoveries for samples aged 202 days, whereas extraction at 150 degrees C yielded recoveries of 85-100% that were independent of incubation time and sample matrix, with the exception of one sediment that contained a large amount of organic matter. Sample extracts from subcritical water extraction were generally a pale yellow color, contrasted with a dark brown color from organic solvent extractions of the same matrixes. Less sample cleanup was therefore required prior to analysis, with the total time for the extraction and analysis of a single sample being approximately 2 h. Subcritical water extraction is an effective technique for the rapid and quantitative extraction of tricyclazole from soils and sediments. PMID:10888518

Krieger, M S; Cook, W L; Kennard, L M

2000-06-01

137

A sediment resuspension and water quality model of Lake Okeechobee  

USGS Publications Warehouse

The influence of sediment resuspension on the water quality of shallow lakes is well documented. However, a search of the literature reveals no deterministic mass-balance eutrophication models that explicitly include resuspension. We modified the Lake Okeeehobee water quality model - which uses the Water Analysis Simulation Package (WASP) to simulate algal dynamics and phosphorus, nitrogen, and oxygen cycles - to include inorganic suspended solids and algorithms that: (1) define changes in depth with changes in volume; (2) compute sediment resuspension based on bottom shear stress; (3) compute partition coefficients for ammonia and ortho-phosphorus to solids; and (4) relate light attenuation to solids concentrations. The model calibration and validation were successful with the exception of dissolved inorganic nitrogen species which did not correspond well to observed data in the validation phase. This could be attributed to an inaccurate formulation of algal nitrogen preference and/or the absence of nitrogen fixation in the model. The model correctly predicted that the lake is lightlimited from resuspended solids, and algae are primarily nitrogen limited. The model simulation suggested that biological fluxes greatly exceed external loads of dissolved nutrients; and sedimentwater interactions of organic nitrogen and phosphorus far exceed external loads. A sensitivity analysis demonstrated that parameters affecting resuspension, settling, sediment nutrient and solids concentrations, mineralization, algal productivity, and algal stoichiometry are factors requiring further study to improve our understanding of the Lake Okeechobee ecosystem.

James, R. T.; Martin, J.; Wool, T.; Wang, P. F.

1997-01-01

138

Arsenic Treatment for Small Water Delivery and Domestic Systems  

Microsoft Academic Search

Inorganic arsenic has been linked to several types of cancer, as well as numerous non-cancerous health risks. Because of this, the EPA's Maximum Contaminant Level (MCL) for arsenic in drinking water was recently been reduced from 50 µg\\/L to 10 µg\\/L, with compliance scheduled for February of 2006. For small, rural communities the cost for current treatment options may be

Andrew Baker; Paul Dimick; Jenna Cellini; Amanda Eggleston; Catherine Herchenroder; Melissa Korpela; Erik Person; Katrin Przyuski; Ebony Sterling; Lee Vanzler

139

A longitudinal study of domestic water conservation behavior  

Microsoft Academic Search

A 1988 study of a school-linked sample in a metropolitan and a regional urban area established baseline data for knowledge, attitudes, intentions, and behavior with regard to water management and conservation (Murphy, Watson, & Moore, 1991). This paper reports on a 1991 follow-up, utilising both longitudinal and cross-sectional samples of students, teachers and parents, which aimed at identifying changes within

Susan Moore; Margot Murphy; Ray Watson

1994-01-01

140

Domestic Water Conservation Technologies: Federal Energy Management Program (FEMP) Federal Technology Alert (Booklet)  

SciTech Connect

Executive Order 13123 calls for the Federal government to conserve water as well as energy in its 500,000 facilities. To help set priorities among water-saving measures, the Federal Energy Management Program conducted a study of Federal water use in 1997. The study indicated that the government consumes more than 50% of its water in just three types of Federal facilities: housing, hospitals, and office buildings. These facilities have enough kitchens, rest rooms, and laundry areas to provide facility managers with many opportunities to begin reducing their water use (and utility costs) with appropriate water-saving fixtures and products. Therefore, this Federal Technology Alert focuses on domestic technologies, products, and appliances such as water-efficient faucets, showerheads, toilets, urinals, washing machines, and dishwashers. Conserving water also saves the energy needed to treat, pump, and heat that water in homes, businesses, and other buildings.

Not Available

2002-10-01

141

Contrasting water quality from paired domestic/public supply wells, central High Plains  

USGS Publications Warehouse

Closely located domestic and public supply wells were sampled using identical sampling procedures to allow comparison of water quality associated with well type. Water samples from 15 pairs of wells with similar screened intervals completed in the central High Plains regional aquifer in parts of Kansas, Oklahoma, and Texas were analyzed for more than 200 water quality constituents. No statistically significant differences were observed between the concentrations of naturally-derived constituents (major ions, trace elements, and radon) in paired wells. However, differences in water quality between paired wells were observed for selected anthrepogenic compounds (pesticides and tritium), in that some public supply wells produced water that was more recently recharged and contained constituents derived from surface activities. The presence of recently recharged water and compounds indicative of anthrepogenic activities in some public supply wells was likely due to operational variations (pumping rate and pumping cycles), as demonstrated in a particle tracking simulation. Water containing surface-derived anthropogenic compounds from near the water table was more quickly drawn to high volume public supply wells (less than five years) than domestic wells (greater than 120 years) with small pumping rates. These findings indicate that water quality samples collected from different well types in the same area are not necessarily directly comparable. Sampling domestic wells provides the best broad-scale assessment of water quality in this aquifer setting because they are less susceptible to localized contamination from near the water table. However, sampiing public supply wells better represents the quality of the used resource because of the population served.

Bruce, B.W.; Oelsner, G.P.

2001-01-01

142

Removal of sediment and bacteria from water using green chemistry.  

PubMed

Although nearly all newly derived water purification methods have improved the water quality in developing countries, few have been accepted and maintained for long-term use. Field studies indicate that the most beneficial methods use indigenous resources, as they are both accessible and accepted by communities they help. In an effort to implement a material that will meet community needs, two fractions of mucilage gum were extracted from the Opuntia ficus-indica cactus and tested as flocculation agents against sediment and bacterial contamination. As diatomic ions are known to affect both mucilage and promote cell aggregation, CaCl(2) was studied in conjunction and compared with mucilage as a bacteria removal method. To evaluate performance, ion-rich waters that mimic natural water bodies were prepared. Column tests containing suspensions of the sediment kaolin exhibited particle flocculation and settling rates up to 13.2 cm/min with mucilage versus control settling rates of 0.5 cm/min. Bacillus cereus tests displayed flocculation and improved settling times with mucilage concentrations lower than 5 ppm and removal rates between 97 and 98% were observed for high bacteria concentration tests (>10(8) cells/ml). This natural material not only displays water purification abilities, but it is also affordable, renewable and readily available. PMID:20369814

Buttice, Audrey L; Stroot, Joyce M; Lim, Daniel V; Stroot, Peter G; Alcantar, Norma A

2010-05-01

143

Bacteriological quality and risk assessment of the imported and domestic bottled mineral water sold in Fiji.  

PubMed

Considering the popularity of bottled mineral water among indigenous Fijians and tourists alike, a study was carried out to determine the bacteriological quality of different bottled waters. A risk assessment was also carried out. Seventy-five samples of bottled mineral water belonging to three domestic brands and 25 samples of one imported brand were analysed for heterotrophic plate count (HPC) bacteria and faecal coliforms. HPC counts were determined at 22 degrees C and 37 degrees C using R2A medium and a membrane filtration technique was used to determine the faecal coliform (FC) load in 100 ml of water on mFC agar. Between 28 and 68% of the samples of the various domestic brands failed to meet the WHO standard of 100 colony forming units (cfu) per 100 ml at 22 degrees C and 7% of these also tested positive for faecal coliforms. All imported bottled mineral water samples were within WHO standards. A risk assessment of the HPC bacteria was carried out in terms of beta haemolytic activity and antibiotic resistance. More than 50% of the isolates showed beta haemolytic activity and were multi-drug resistant. While the overall quality of the product was generally good, there is a need to enforce stringent quality standards for the domestic bottlers to ensure the safety of consumers. PMID:19590131

Zeenat, A; Hatha, A A M; Viola, L; Vipra, K

2009-12-01

144

Sediment export by water from an agricultural catchment in the Loam Belt of central Belgium  

Microsoft Academic Search

An agricultural drainage basin of 250 ha was selected in the Belgian Loam Belt to evaluate sediment export by water. Water discharge was continuously measured at the outlet of the catchment and suspended sediment samples were taken proportional with discharge during rainfall events. From these samples supended sediment concentration and grain-size distribution were determined. Within the catchment, regular surveys were

A. Steegen; Gerard Govers; Jeroen Nachtergaele; Ingrid Takken; Laurent Beuselinck; Jean Poesen

2000-01-01

145

Estimating suspended sediment concentrations in surface waters of the Amazon River wetlands from Landsat images  

Microsoft Academic Search

A method has been developed, based on spectral mixture analysis, to estimate the concentration of suspended sediment in surface waters of the Amazon River wetlands from Landsat MSS and TM images. Endmembers were derived from laboratory reflectance measurements of water-sediment mixtures with a range of sediment concentrations. Using these references spectra, the authors applied a linear mixture analysis to multispectral

L. A. K. Mertes; M. O. Smith; J. B. Adams

1993-01-01

146

Methane in the water and bottom sediments of the mouth area of the Severnaya Dvina River (White Sea)  

NASA Astrophysics Data System (ADS)

The mouth area of the Severnaya Dvina River is characterized by a high level of methane in the water (from 1.0 to 165.4 ?l/l) and in the bottom sediments (from 14 to 65000 ?l/kg), being quite comparable to the productive mouth areas of the rivers in the temperate zone. The maximum methane concentrations in the water and sediments were registered in the delta in the segments of channels and branches with low rates of tidal and runoff currents to which domestic and industrial wastewaters are supplied. In the riverine and marine water mixing zone with its upper boundary situated far into the delta and displaced depending on the phase of the tidal cycle, a decrease of the methane amount with the salinity increase was observed. The prevailing role in the formation of the methane content level in the water of the mouth area pertains to the bottom sediments, which is testified to by the close correlation between the gas concentrations in these two media. The existence of periodicity in the variations of the methane content level in the water of the river downstream caused by the tidal effects was found.

Gar'kusha, D. N.; Fedorov, Yu. A.; Khromov, M. I.

2010-08-01

147

Chemical composition of sediments, suspended matter, river water and ground water of the Nile (Aswan-Sohag traverse)  

Microsoft Academic Search

Sediment, suspended matter, river water and ground water samples were collected at twelve sites in the drainage valley of the Nile River, around Sohag (Central Egypt) and close to the Aswan High Dam. Elemental composition of the river water (27 elements), ground water (eight elements), suspended matter (12 elements) and sediments (12 elements) was studied. Aswan High Dam construction, agricultural

V. M. Dekov; Z. Komy; F. Araújo; A. Van Put; R. Van Grieken

1997-01-01

148

INTERACTION OF METALS AND ORGAINIC CARBON COLLOIDS IN ANOXIC INTERSTITIAL WATERS OF MARINE SEDIMENTS  

EPA Science Inventory

Marine colloids are an important component of natural water geochemistry critical to the cycling, speciation and bioavailability of metals in marine sediments. In sediment, metals exist in three phases: particulate, colloidal and dissolved. Dissolved metal concentrations have bee...

149

Dynamics of particle clouds in ambient currents with application to open-water sediment disposal  

E-print Network

Open-water sediment disposal is used in many applications around the world, including land reclamation, dredging, and contaminated sediment isolation. Timely examples include the land reclamation campaign currently underway ...

Gensheimer, Robert James, III

2010-01-01

150

THE RELATIONSHIP OF BIOACCUMULATIVE CHEMICALS IN WATER AND SEDIMENT TO RESIDUES IN FISH: A VISUALIZATION APPROACH  

EPA Science Inventory

A visualization approach is developed and presented for depicting and interpreting bioaccumulation relationships and data, i.e., bioaccumulation factors (BAFs), biota-sediment accumulation factors (BSAFs) and chemical residues in fish, using water-sediment chemical concentration ...

151

Surface water transport and distribution of uranium in contaminated sediments near a nuclear weapons processing facility  

E-print Network

sediments was assessed by an eight-step sequential extraction procedure to gauge U chemical lability and its propensity for transport. Comparisons were drawn between the easily dispersible, or water dispersible clay fraction (WDC) of the floodplain sediments...

Batson, Vicky Lynn

2012-06-07

152

Assessing the fate of dredged sediments placed in open-water sites, Northern Chesapeake Bay  

USGS Publications Warehouse

An integrated series of field studies and experiments have been carried out on dredged sediments placed in open water sites in Northern Chesapeake Bay. The studies include: (1) examination of the potential for fluidized sediment flow, (2) quantifying the volumetric changes that the sediments undergo during dredging process and subsequent to deposition, (3) estimating parameters for cohesive sediment erosion models from field data on currents and suspended sediment concentrations, and (4) incorporating the erosion model parameters and sediment transport equation into a 3-D hydrodynamic model for the upper Chesapeake Bay to predict transport directions and setting sites of eroded sediments under a variety of seasonal weather and river flow conditions.

Halka, Jeffrey; Panageotou, William; Sanford, Lawrence; Yu-Chou, Shenn

1994-01-01

153

Environmental assessment for the domestic water supply upgrades and consolidation on the Savannah River Site  

SciTech Connect

The domestic water systems on the Savannah River Site (SRS) are currently in need of upgrading to ensure compliance with the Safe Drinking Water Act and South Carolina Department of Health and Environmental Control (SCDHEC) Drinking Water Regulations. The SRS has 28 separate goundwater-based drinking water systems in use across the site. These aging systems were designed and constructed in the 1950s and are now facing increasing difficulties in meeting cur-rent regulations. Audits of the systems conducted by SCDHEC in 1986, 1988, 1991, and 1993 identified shortfalls in meeting the requirements for secondary maximum containment levels (MCLS) and SCDHEC design standards. Secondary MCLs are those items, such as odor or appearance, that do not pose a direct health impact. SRS has committed to SCDHEC to correct the drinking water discrepancies and construct two new consolidated inter-area drinking water systems. Upgrading the SRS drinking water systems would be necessary to support site activities regardless of the makeup or the mission at SRS. As such, the proposed upgrade and consolidation of SRS domestic water systems is treated as part of the ``No Action`` alternative for the Programmatic Environmental Impact Statement for Reconfiguration of the Nuclear Weapons Complex .

Not Available

1994-06-01

154

Pore-water chemistry in mangrove sediments: relationship with species composition and  

E-print Network

in accumulation of sedimentary organic matter and promotes low Ehs and the reduction of pore-water sulphate. NearPore-water chemistry in mangrove sediments: relationship with species composition and developmental communities and variable surface water inputs strongly impact sediment and ground water properties

Boyer, Edmond

155

Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri  

NASA Astrophysics Data System (ADS)

The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

1980-07-01

156

Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri  

NASA Technical Reports Server (NTRS)

The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

1980-01-01

157

Concentrations of Elements in Sediments and Selective Fractions of Sediments, and in Natural Waters in Contact with Sediments from Lake Roosevelt, Washington, September 2004  

USGS Publications Warehouse

Twenty-eight composite and replicate sediment samples from 8 Lake Roosevelt sites were collected and analyzed for 10 alkali and alkaline earth elements, 2 non-metals, 20 metals, and 4 lanthanide and actinide elements. All elements were detected in all sediment samples except for silver (95 percent of the elements detected for 1,008 analyses), which was detected only in 4 samples. Sequential selective extraction procedures were performed on single composite samples from the eight sites. The percentage of detections for the 31 elements analyzed ranged from 76 percent for the first extraction fraction using a weak extractant to 93 percent for the four-acid dissolution of the sediments remaining after the third sequential selective extraction. Water samples in various degrees of contact with the sediment were analyzed for 10 alkali and alkaline earth elements, 5 non-metals, 25 metals, and 16 lanthanide and actinide elements. The filtered water samples included 10 samples from the reservoir water column at 8 sites, 32 samples of porewater, 55 samples from reservoir water overlying sediments in 8 cores from the site incubated in a field laboratory, and 24 water samples that were filtered after being tumbled with sediments from 8 sites. Overall, the concentrations of only 37 percent of the 6,776 analyses of the 121 water samples were greater than the reporting limit. Selenium, bismuth, chromium, niobium, silver, and zirconium were not detected in any water samples. The percentage of concentrations for the water samples that were above the reporting limit ranged from 14 percent for the lanthanide and actinide elements to 77 percent for the alkali and alkaline earth elements. Concentrations were greater than reporting limits in only 23 percent of the analyses of reservoir water and 29 percent of the analyses of reservoir water overlying incubation cores. In contrast, 47 and 48 percent of the concentrations of porewater and water samples tumbled with sediments, respectively, were greater than the reporting limit.

Paulson, Anthony J.; Wagner, Richard J.; Sanzolone, Richard F.; Cox, Steven E.

2006-01-01

158

Chapter 3 Down the gurgler: Historical influences on Australian domestic water consumption  

Microsoft Academic Search

Australian city-dwellers are a thirsty people. Between the mid-nineteenth century and the present, the average daily consumption of water in Melbourne and Sydney has nearly trebled, from around 100 litres per head to around 300 litres per head. Industrial and other non-domestic users absorb about one-third of the flow but most is consumed in the bathrooms, laundries, kitchens, gardens and

Graeme Davison

159

Simulation of an unglazed collector system for domestic hot water and space heating and cooling  

Microsoft Academic Search

This paper details modeling assumptions and simulation results for an unglazed collector system supplying domestic hot water, space heating, and space cooling loads. Collectors are modeled using unglazed collector test results. Variation of savings with collector area, storage volume, heat exchanger size, and wind for the Albuquerque, NM climate are shown. Over the storage-to-collector ratio range of 40–640 l\\/m2collector, annual

Jay Burch; Craig Christensen; Jim Salasovich; Jeff Thornton

2004-01-01

160

Evaluating the exchange of DDTs between sediment and water in a major lake in North China.  

PubMed

A large-scale sampling program was conducted to simultaneously collect surface water, overlying water, pore water, and sediment samples at monthly intervals between March and December 2010 from Baiyangdian Lake, North China to assess the distribution of DDTs and determine the net direction of sediment-water exchange. Total DDT concentrations ranged 2.36-22.4 ng/L, 0.72-21.9 ng/L, 2.25-33.7 ng/L, and 4.42-7.29 ng/g in surface water, overlying water, pore water, and sediments, respectively, which were at the intermediate levels compared to those of other area around the world. Seasonal variations of DDTs were featured by higher concentration in summer. This was likely associated with (a) the increase of land runoff in the summer and (b) application of dicofol and DDT-containing antifouling paints for ships in summer. Sediment-water fugacity ratios of the DDT isomers were used to predict the direction of the sediment-water exchange of these isomers. The sediment-surface water, sediment-overlying water, and sediment-pore water fugacity ratios of DDT isomers averaged 0.34, 0.44, and 0.1, which are significantly lower than the equilibrium status (1.0), suggesting that the net flux direction were from the water to sediment and the sediment acted as a sink for the DDTs. The difference of DDT concentrations between sediment and water samples was found to be an important factor affecting the diffusion of DDT from the water to sediment. PMID:24337993

Dai, Guo-Hua; Liu, Xin-Hui; Liang, Gang; Gong, Wen-Wen

2014-03-01

161

A memory model of sedimentation in water reservoirs  

NASA Astrophysics Data System (ADS)

SummaryWe consider a one-dimensional model of water reservoir, where the sediment is diffusing according to the Fourier law modified with the introduction of a derivative of fractional distributed orders as memory formalism. The fractional order is equivalent to a time-varying diffusivity and the distributed orders represent a variety of memory mechanisms to model a sediment with a varied distribution of grain sizes. Using the Laplace transform (LT), we find the solution in the case when the flux is constant at the source and is arbitrarily given at the output. Then, the time-domain solution is obtained by means of a numerical Fourier transform. We apply a one-dimensional simplified model, with the diffusion governed by two parameters, to the Quarto Nuovo (Italy) reservoir, where the flux of sediment at the output is obtained from observed data. It is found that the flux increases when one of the parameters defining the diffusion model, the pseudo-diffusivity, is increasing or when the other parameter defining the diffusion, the order of fractional differentiation, is decreasing. When the latter parameter is nil, one obtains the classic diffusion with maximum flux.

Caputo, Michele; Carcione, José M.

2013-01-01

162

EARTHQUAKE HAZARDS TO DOMESTIC WATER DISTRIBUTION SYSTEMS IN SALT LAKE COUNTY, UTAH.  

USGS Publications Warehouse

A magnitude-7. 5 earthquake occurring along the central portion of the Wasatch Fault, Utah, may cause significant damage to Salt Lake County's domestic water system. This system is composed of water treatment plants, aqueducts, distribution mains, and other facilities that are vulnerable to ground shaking, liquefaction, fault movement, and slope failures. Recent investigations into surface faulting, landslide potential, and earthquake intensity provide basic data for evaluating the potential earthquake hazards to water-distribution systems in the event of a large earthquake. Water supply system components may be vulnerable to one or more earthquake-related effects, depending on site geology and topography. Case studies of water-system damage by recent large earthquakes in Utah and in other regions of the United States offer valuable insights in evaluating water system vulnerability to earthquakes.

Highland, Lynn, M.

1985-01-01

163

Scattering of sound by gas bubbles in water and sediments  

SciTech Connect

In this paper, a self-consistent multiple scattering approach with suitable pair-correlation function is employed to study acoustic wave propagation through water and sediments containing gas bubbles. The effects of surface tension, shear viscosity of the liquid and thermal conduction in the gas bubbles are considered in the analysis. In the Rayleigh limit, closed form expressions are given as a function of concentration of bubbles. Numerical results are presented for both phase velocity and coherent attenuation as a function of frequency near the fundamental resonance of the bubble for various values of concentration of bubbles.

Ma, Y.; Varadan, V.K.; Varadan, V.V.

1983-05-01

164

Risk factors for contamination of domestic hot water systems by Legionellae  

SciTech Connect

To assess risk factors associated with the contamination of the domestic environment by legionellae, 211 houses in the Quebec City area were randomly selected and water samples were collected from the hot water tank, the shower heads, and the most frequently used faucet. After centrifugation, concentrated samples were seeded in triplicate on BCYE and GPV media. Data on the characteristics of the hot water system and plumbing in the house and on the personal habils of the occupants were collected for each house. Among these 211 houses, hot water was provided by either an oil or gas heater in 33 and by an electric heater in 178. Legionellae were isolated from none of the samples from houses with oil or gas heaters and from 39% (69 of 178) of those with electric water heaters. This association remained highly significant after control for water temperature and other variables in a stratified analysis. In the 178 houses with an electric heater, 12% of the faucets, 15% of the shower heads, and 37% of the water heaters were contaminated. Legionella pneumophila serogroups 2 and 4 were the most frequently isolated strains. Logistic regression showed that factors associated with electric water heater contamination were (1) location of the house in older districts of the city (2) old age of the water heater, and (3) low water temperature. Contamination of the water heater was the only factor significantly associated with the contamination of peripheral outlets. This study shows that the presence of an electric heater is strongly associated with contamination of domestic hot water systems by Legionellae. The public health importance of this contamination is still unknown.

Alary, M.; Joly, J.R. (Univ. Laval, Quebec (Canada))

1991-08-01

165

Subcritical water extraction of polychlorinated biphenyls from soil and sediment  

SciTech Connect

Two certified reference materials, an industrial soil (CRM 481) and a river sediment (NIST 1939), were extracted by subcritical water at 50 atm and temperatures ranging from 50 to 300{degree}C. The extraction efficiency of PCBs is extremely dependent on water temperature, since the polarity (dielectric constant) of water can be dramatically lowered by raising the water temperature. While only traces of PCBs were extracted at 50 and 100{degree}C, quantitative PCB removal was reached at 250 and 300{degree}C. The extraction rate of subcritical water extraction is fast. For example, the largest quantities of all of the PCBs were extracted during the first 15 min at 250 or 300{degree}C (at liquid conditions). However, when the pressure was reduced to 50 atm at 300{degree}C (steam), the extraction was completed in less than 5 min. The recoveries reached by water extraction at 250-300{degree}C and 50 atm compare favorably to the certified values for both samples. The construction of an extraction/ collection system that allows quantitative extraction of PCBs with collection in a few milliliters of organic solvent is described. 41 refs., 4 figs., 4 tabs.

Yang, Y.; Bewadt, S.; Hawthorne, S.B.; Miller, D.J. [Univ. of North Dakota, Grand Forks, ND (United States)

1995-12-15

166

Hexachlorobenzene uptake by fathead minnows and macroinvertebrates in recirculating sediment/water systems.  

PubMed

Fathead minnows (Pimephales promelas), the worm, Lumbriculus variegatus, and the amphipods Hyalella azteca and Gammarus lacustris were exposed to hexachlorobenzene (HCB) in water with and without a bed of HCB-spiked sediment. Water HCB concentrations were maintained by recirculation through HCB-packed columns. Recirculating HCB-bound particulates and possibly eroded HCB particulates were an added source of HCB in addition to the sediment bed. Significant bioaccumulation of HCB in animal tissues was observed in water-only and water-sediment exposures. The presence of the HCB-spiked sediment did not result in a significant increase in the uptake of HCB by the organisms, but there was a substantial increase in sediment HCB levels over time. Higher tissue HCB levels in aquaria without sediment suggest that the sediment was a more efficient sink for HCB than the organisms. PMID:2331142

Schuytema, G S; Krawczyk, D F; Griffis, W L; Nebeker, A V; Robideaux, M L

1990-01-01

167

Hexachlorobenzene uptake by fathead minnows and macroinvertebrates in recirculating sediment/water systems  

SciTech Connect

Fathead minnow (Pimephales promelas), the worm, Lumbriculus variegatus, and the amphipods Hyalella azteca and Gammarus lacustris were exposed to hexachlorobenzene (HCB) in water with and without a bed of HCB-spiked sediment. Water HCB concentrations were maintained by recirculation through HCB-packed columns. Recirculating HCB-bound particulates and possibly eroded HCB particulates were an added source of HCB in addition to the sediment bed. Significant bioaccumulation of HCB in animal tissues was observed in water-only and water-sediment exposures. The presence of the HCB-spiked sediment did not result in a significant increase in the uptake of HCB by the organisms, but there was a substantial increase in sediment HCB levels over time. Higher tissue HCB levels in aquaria without sediment suggest that the sediment was a more efficient sink for HCB than the organisms.

Schuytema, G.S.; Krawczyk, D.F.; Griffis, W.L.; Nebeker, A.V.; Robideaux, M.L.

1990-01-01

168

Sediments can be important in regulating stream water P concentrations, and this has implications for establishing  

E-print Network

concentrations at low discharge. Relationships between Benthic Sediments andWater Column Phosphorus in Illinois nitrogen (N) and phosphorus (P) additions to surface waters (Diaz, 2001). These nutrients can cause phosphatase activity; BLS, Black Slough; DDW, distilled- deionized water; DRP,

David, Mark B.

169

Heating of domestic water by waste heat recovery from household refrigerating equipment  

NASA Astrophysics Data System (ADS)

Heat from a 370 l deep freeze was used to heat water in a 250 l boiler. Both units were made from mass produced components. Tests show that the functions of cooling and deep freezing units can be effectively combined with one warm water boiler. The necessary expenditure for the appliance is, however, only economical with deep freezing units because with normal domestic refrigerators the amount of waste heat is too small. The economy of the unit could be considerably increased by the development of a mass produced motor compressor with a sufficiently large oil cooler to accomplish an optimum thermal insulation of the motor compressor surface area.

Reil, J.; Kaster, B.; Wegner, M.

1982-09-01

170

Tapping the sun. An Arizona homeowner's guide to buying a solar domestic hot water system  

SciTech Connect

After a brief review of the nation's energy problems, the nature of solar energy and its availability are briefly described. Some commonly asked technical, economic, and political questions concerning solar domestic hot water systems are addressed. Generic solar water heating systems are described, including diagrams of them and explanations of how they work. System sizing is discussed, and methods and worksheets are provided for estimating hot water usage and appropriate tank and collector sizes. A worksheet is provided and explained for calculating how much money can be saved by a solar water heating system. System warranties are reviewed, and the interpretation and use of performance standards and ratings are discussed. Points are reviewed of which the buyer must be aware before purchasing a solar water heating system. Information resources are listed. (LEW)

Anderson, M.R.; Kimball, J.A.

1981-08-01

171

Tidal effect on dynamics of pore water nitrate in intertidal sediment of a eutrophic Estuary  

Microsoft Academic Search

To evaluate the effect of the tidal cycle on the pore water nitrate dynamics in intertidal sediment, concentrations of inorganic\\u000a nitrogen in water and sediment were monitored during tidal cycles in the mud flat of Tama Estuary, Japan. During submergence,\\u000a nitrate concentration was highest in the overlying water and decreased monotonically with increasing depth in the sediment,\\u000a suggesting that the

Toshihiro Usui; Isao Koike; Norio Ogura

1998-01-01

172

Percentage land use in the watershed determines the water and sediment quality of  

E-print Network

Percentage land use in the watershed determines the water and sediment quality of 22 marshes determines the water and sediment quality of Great Lakes wetlands. The first three components the relationship between land use and water quality. PC3, driven by soluble reactive phosphorus and nitrate

McMaster University

173

Analysis of Heavy metals in Water, Sediments and Fish samples of Madivala Lakes of Bangalore, Karnataka  

Microsoft Academic Search

? Abstract : Heavy metal (Pb, Cd, Cr, Ni ) concentration in water sediments and fish was analysed from Madivala lake in the month of June 2008. There was an appreciable increase in metal concentrations in going from the water to the sediment samples.The Heavy metal concentration, in water was in the order Pb > Cr > Cd > Ni

Abida Begum; HariKrishna S; Irfanulla Khan

174

Sediment Inventory and Phosphorus Fractions for Water Conservation Area Canals in the Everglades  

Microsoft Academic Search

Nutrient loading from the Everglades Agricultural Area and nearby urban communities plus water flow rate and canal size have signif- icantly influenced the amount of sediment and phosphorus (P) pools stored in the Water Conservation Area (WCA) canals in the Ever- glades.A study was conducted to characterize the potential impact that sediments might have on the overlying water column by

O. A. Diaz; S. H. Daroub; J. D. Stuck; M. W. Clark; T. A. Lang; K. R. Reddy

2006-01-01

175

The Release of Phosphorus to Porewater and Surface Water from River Riparian Sediments  

Microsoft Academic Search

Sediments can be both a source and a sink of dissolved phosphorus (P) in surface water and shallow groundwater. Using laboratory mesocosms, we studied the infl uence of fl ooding with deionized water and simulated river water on P release to solution using sediment columns taken from a riparian wetland. Th e mesocosm incubation results showed that rather than retaining

Ben W. J. Surridge; A. L. Heathwaite; Andrew J. Baird

2007-01-01

176

Rapid, high-precision potentiometric titration of alkalinity in ocean and sediment pore waters  

Microsoft Academic Search

A system for rapid, high precision potentiometric determination of alkalinity in sea water and sediment pore water is presented. Two titration units were used: a 40 ml unit for seawater and a small volume unit for sediment pore water. Titration time was normally less than 10 minutes per sample, including sample exchange. With a 40 ml sample volume, the relative

Conny Haraldsson; Leif G. Anderson; Martin Hassellöv; Stefan Hulth; Kristina Olsson

1997-01-01

177

Investigating the influence of incomplete separation of sediment and water on experimental sorption coefficients of chlorinated benzenes  

Microsoft Academic Search

The influence of incomplete separation of water and sediment in batch sorption experiments was investigated with five chlorinated benzenes. Only the sorption coefficients of the most hydrophobic chemical, hexachlorobenzene, decreased with increasing sediment\\/water ratios. This decrease is assumed to be caused by an increasing amount of sediment that was not separated from the aqueous phase. To quantify this incomplete water\\/sediment

S. Marca Schrap; Manuela Haller; Antoon Opperhuizen

1995-01-01

178

Experiments To Determine Modes of Cohesive Sediment Transport in Salt Water  

Microsoft Academic Search

Laboratory measurements were made on properties of clay sediments from San Francisco Bay, in conjunction with field measurements, to ascertain the modes of transport and deposition existing in the bay. Laboratory measurements on sediment suspensions, settling rates, rheological properties, and deposition from flowing water showed a dependence of the mode of transport on the suspended sediment concentration and on fiocculation

H. A. Einstein; R. B. Krone

1962-01-01

179

Selenium in sediments, pore waters and benthic infauna of Lake Macquarie, New South Wales,  

E-print Network

Selenium in sediments, pore waters and benthic infauna of Lake Macquarie, New South Wales December 1998 Abstract Measurements of selenium in sediments and benthic infauna of Lake Macquarie, an estuary on the east coast of Australia, indicate that sediments are a signi®cant source of selenium

Canberra, University of

180

STAND, A DYNAMIC MODEL FOR SEDIMENT TRANSPORT AND WATER QUALITY. (R825758)  

EPA Science Inventory

We introduce a new model–STAND (Sediment-Transport-Associated Nutrient Dynamics)–for simulating stream flow, sediment transport, and the interactions of sediment with other attributes of water quality. In contrast to other models, STAND employs a fully dynamic ba...

181

Bioavailability of lambda-cyhalothrin to Chironomus riparius in sediment–water and water-only systems  

Microsoft Academic Search

The bioavailability of 14C-lambda-cyhalothrin and its bioconcentration by larvae of the aquatic insect Chironomus riparius was studied in laboratory sediment–water systems. Ten different sediments with a range of physico-chemical characteristics were investigated. The chemical was applied to sediment slurries and fourth instar C. riparius were exposed in the test system for 48h. The distribution of the chemical between the sediment,

M. J Hamer; U. M Goggin; K Muller; S. J Maund

1999-01-01

182

Review of alkenone calibrations (culture, water column, and sediments)  

NASA Astrophysics Data System (ADS)

I review the status of alkenone unsaturation parameters as proxies for growth temperature and the potential for pCO2 estimates using the carbon isotopic composition of alkenones. Culture studies allow investigators to manipulate parameters that could influence the relative proportions of C37 and C38 ketones in producing organisms and to assess the possible influence of genetic variability on the calibration of unsaturation to growth temperature. Culture studies suggest large variability in the relation of unsaturation indices to growth temperature and hint that growth rate may play a role along with temperature in controlling unsaturation. Water column studies match the unsaturation index measured in particulate matter to ambient temperature, providing a snapshot of unsaturation-temperature relationship. In comparison to culture work, assemblages of regional water column data sets give more consistent relations of the unsaturation index to temperature, although the argument can be made for regional rather than basin-wide or global calibrations. A much simpler picture emerges from analyzing a global array of core top sediments. Regressions show that the sedimentary unsaturation indices follow a linear trend that is best correlated to mean annual temperature in the upper 10 m of the overlying water column. The regression is indistinguishable from the original Prahl et al. [1988] culture calibration of the U37 k' index to growth temperature. Exceptions occur at high latitudes, where the effects of highly seasonal production and the possible influence of salinity may affect the unsaturation index in sediments. Core top analyses also fail to reveal the variability of other alkenone parameters (for example, the ratio of C37 to C38 ketones) which have been found in culture studies. Much of the variance that appears in culture and water column calibrations is thus apparently removed in sediments, perhaps by temporal averaging. The promising paleo-pCO2 approach based on the isotopic composition of alkenones awaits the arrival of a significant number of core top and stratigraphic studies that will determine the extent to which physiological factors compromise the alkenone paleobarometer.

Herbert, T. D.

2001-02-01

183

Review of alkenone calibrations (culture, water column, and sediments)  

NASA Astrophysics Data System (ADS)

I review the status of alkenone unsaturation parameters as proxies for growth temperature and the potential for pCO2 estimates using the carbon isotopic composition of alkenones. Culture studies allow investigators to manipulate parameters that could influence the relative proportions of C37 and C38 ketones in producing organisms and to assess the possible influence of genetic variability on the calibration of unsaturation to growth temperature. Culture studies suggest large variability in the relation of unsaturation indices to growth temperature and hint that growth rate may play a role along with temperature in controlling unsaturation. Water column studies match the unsaturation index measured in particulate matter to ambient temperature, providing a snapshot of unsaturation-temperature relationship. In comparison to culture work, assemblages of regional water column data sets give more consistent relations of the unsaturation index to temperature, although the argument can be made for regional rather than basin-wide or global calibrations. A much simpler picture emerges from analyzing a global array of core top sediments. Regressions show that the sedimentary unsaturation indices follow a linear trend that is best correlated to mean annual temperature in the upper 10 m of the overlying water column. The regression is indistinguishable from the original Prahl et al. [1988] culture calibration of the U37k' index to growth temperature. Exceptions occur at high latitudes, where the effects of highly seasonal production and the possible influence of salinity may affect the unsaturation index in sediments. Core top analyses also fail to reveal the variability of other alkenone parameters (for example, the ratio of C37 to C38 ketones) which have been found in culture studies. Much of the variance that appears in culture and water column calibrations is thus apparently removed in sediments, perhaps by temporal averaging. The promising paleo-pCO2 approach based on the isotopic composition of alkenones awaits the arrival of a significant number of core top and stratigraphic studies that will determine the extent to which physiological factors compromise the alkenone paleobarometer.

Herbert, T. D.

2001-02-01

184

Scaling Behavior of Sediment Transport Induced by Water Diversion in River Networks  

NASA Astrophysics Data System (ADS)

A sediment transport dynamic model, based on the consideration of streams confluence and/or diversion, is proposed to investigate the influence of water diversion on the mainstream. The simulated results accord qualitatively with the observed or experimental phenomenon in the Yellow River, that is, sedimentation will get more in the main channel as the water is diverted. Some interesting scaling laws describing the behavior of the erosion-sedimentation state in the process of sediment transport are observed, which may help us to get some understandings of sediment transport dynamics in a river network.

Wang, Xu-Ming; Huo, Jie; Cao, Shi-Feng; Hao, Rui

185

EUTROPHICATION AND WATER QUALITY OF LAKES: CONTROL BY WATER RESIDENCE TIME AND TRANSPORT TO SEDIMENTS  

Microsoft Academic Search

Steady-state concentration in lake water is determined by the rate of input, residence time of water, and rate of removal into lake floor sediments. For a given input (loading) rate, a steady-state concentration is a ‘warning sign’ or a limit to which the lake will tend. For 22 lakes in North America and Western Europe, the upper limits of steady-state

A. LERMAN

1974-01-01

186

Quantitative bacterial examination of domestic water supplies in the Lesotho Highlands: water quality, sanitation, and village health.  

PubMed

Reported are the results of an examination of domestic water supplies for microbial contamination in the Lesotho Highlands, the site of a 20-year-old hydroelectric project, as part of a regional epidemiological survey of baseline health, nutritional and environmental parameters. The population's hygiene and health behaviour were also studied. A total of 72 village water sources were classified as unimproved (n = 23), semi-improved (n = 37), or improved (n = 12). Based on the estimation of total coliforms, which is a nonspecific bacterial indicator of water quality, all unimproved and semi-improved water sources would be considered as not potable. Escherichia coli, a more precise indicator of faecal pollution, was absent (P < 0.001) in most of the improved water sources. Among 588 queried households, only 38% had access to an "improved" water supply. Sanitation was a serious problem, e.g. fewer than 5% of villagers used latrines and 18% of under-5-year-olds had suffered a recent diarrhoeal illness. The study demonstrates that protection of water sources can improve the hygienic quality of rural water supplies, where disinfection is not feasible. Our findings support the WHO recommendation that E. coli should be the principal microbial indicator for portability of untreated water. Strategies for developing safe water and sanitation systems must include public health education in hygiene and water source protection, practical methods and standards for water quality monitoring, and a resource centre for project information to facilitate programme evaluation and planning. PMID:10593031

Kravitz, J D; Nyaphisi, M; Mandel, R; Petersen, E

1999-01-01

187

Evolution of the earth's water mass and sedimentation  

SciTech Connect

The origin of the hydrosphere has been discussed repeatedly. It has become clear that one cannot explain the current mass of water on the earth without invoking the most modern cosmogenic hypotheses, on the one hand, and without reconstructing the processes of metamorphism, granitization, and basalt melting, on the other. As all these problems are still at the stage of scientific hypothesis, any treatment of the change in water volume through geologic time can only be a very crude approximation. Recently, it has become clear that there is a fairly complicated interaction between the different parts of the lithosphere and the ocean water. The formation of water bound in various crustal shells (basalt, granite, and sediment) is summarized. It is concluded that in the remote period (up to 2 billion years ago), shallow lake-type basins were the most abundant, while in the period from 2 billion years to 0.2 billion years, there were extensive shallow intercontinental and epicontinental seas with an average depth of 0.5-2 km; there probably were no oceans resembling modern ones at that time. The modern oceans were effectively formed at the boundary between the Mesozoic and Cenozoic, when the volume of the hydrosphere attained its maximum value, while relief contrast resulted in depressions 5-6 km deep. 15 references.

Timofeev, P.P.; Kholodov, V.N.; Zverev, V.P.

1986-05-01

188

Domestic water carrying and its implications for health: a review and mixed methods pilot study in Limpopo Province, South Africa  

Microsoft Academic Search

BACKGROUND: Lack of access to safe water remains a significant risk factor for poor health in developing countries. There has been little research into the health effects of frequently carrying containers of water. The aims of this study were to better understand how domestic water carrying is performed, identify potential health risk factors and gain insight into the possible health

Jo-Anne L Geere; Paul R Hunter; Paul Jagals

2010-01-01

189

Distributions of pesticides and organic contaminants between water and suspended sediment, San Francisco Bay, California  

USGS Publications Warehouse

Suspended-sediment and water samples were collected from San Francisco Bay in 1991 during low river discharge and after spring rains. All samples were analyzed for organophosphate, carbamate, and organochlorine pesticides; petroleum hydrocarbons; biomarkers; and polynuclear aromatic hydrocarbons. The objectives were to determine the concentrations of these contaminants in water and suspended sediment during two different hydrologic conditions and to determine partition coefficients of the contaminants between water and sediment. Concentrations of hydrophobic contaminants, such as polynuclear aromatic hydrocarbons, varied with location of sample collection, riverine discharge, and tidal cycle. Concentrations of hydrophobic contaminants in suspended sediments were highest during low river discharge but became diluted as agricultural soils entered the bay after spring rains. Polynuclear aromatic hydrocarbons defined as dissolved in the water column were not detected. The concentrations sorbed on suspended sediments were variable and were dependent on sediment transport patterns in the bay. In contrast, the relatively hydrophilic organophosphate pesticides, such as chlorpyrifos and diazinon, has a more uniform concentration in suspended sediment. These pesticides were detected only after spring rains. Most of the measured diazinon, at least 98% for all samples, was in the dissolved phase. Measured partition coefficients for diazinon generally were uniform, which suggests that suspended-sediment concentrations were close to equilibrium with dissolved concentrations. The concentration of diazinon sorbed to suspended sediments, at any given sampling site, was driven primarily by the more abundant solution concentration. The concentrations of diazinon sorbed to suspended sediments, therefore, were independent of the patterns of sediment movement. ?? 1993 Estuarine Research Federation.

Domagalski, J.L.; Kuivila, K.M.

1993-01-01

190

Estimating suspended sediment concentrations in surface waters of the Amazon River wetlands from Landsat images  

SciTech Connect

A method has been developed, based on spectral mixture analysis, to estimate the concentration of suspended sediment in surface waters of the Amazon River wetlands from Landsat MSS and TM images. Endmembers were derived from laboratory reflectance measurements of water-sediment mixtures with a range of sediment concentrations. Using these references spectra, the authors applied a linear mixture analysis to multispectral images after accounting for instrument and atmosphere gains and offsets. Sediment concentrations were estimated for individual pixels from the mixture analysis results based on a nonlinear calibration curve relating laboratory sediment concentrations and reflectance to endmember fractions. The uncertainty in the sediment concentrations derived from this analysis for three Amazon images is predicted to be within [plus minus] 20 mg/L, and the concentrations fall within a range of concentrations of suspended sediment that were measured at several times and places in the field over the past 15 years. The emphasis of their work is to use the patterns of sediment concentrations to compute the approximate volumes of sediment that are transferred between the main channel and floodplain of the Amazon River. However, the methodology can be applied universally if the optical properties of water and sediment at the site are known, and it is, therefore, useful for the study of suspended sediment concentrations in surface waters of wetlands elsewhere.

Mertes, L.A.K.; Smith, M.O.; Adams, J.B. (Univ. of Washington, Seattle (United States))

1993-03-01

191

Microbial Diversity in Water and Sediment of Lake Chaka, an Athalassohaline Lake in Northwestern China  

PubMed Central

We employed culture-dependent and -independent techniques to study microbial diversity in Lake Chaka, a unique hypersaline lake (32.5% salinity) in northwest China. It is situated at 3,214 m above sea level in a dry climate. The average water depth is 2 to 3 cm. Halophilic isolates were obtained from the lake water, and halotolerant isolates were obtained from the shallow sediment. The isolates exhibited resistance to UV and gamma radiation. Microbial abundance in the sediments ranged from 108 cells/g at the water-sediment interface to 107 cells/g at a sediment depth of 42 cm. A major change in the bacterial community composition was observed across the interface. In the lake water, clone sequences affiliated with the Bacteroidetes were the most abundant, whereas in the sediments, sequences related to low G+C gram-positive bacteria were predominant. A similar change was also present in the archaeal community. While all archaeal clone sequences in the lake water belonged to the Halobacteriales, the majority of the sequences in the sediments were related to those previously obtained from methanogenic soils and sediments. The observed changes in the microbial community structure across the water-sediment interface were correlated with a decrease in salinity from the lake water (32.5%) to the sediments (approximately 4%). Across the interface, the redox state also changed from oxic to anoxic and may also have contributed to the observed shift in the microbial community. PMID:16751487

Jiang, Hongchen; Dong, Hailiang; Zhang, Gengxin; Yu, Bingsong; Chapman, Leah R.; Fields, Matthew W.

2006-01-01

192

Influence of water solubility, phase equilibria, and capillary pressure on methane occurrence in sediments  

SciTech Connect

Microbial methane is generated in rapidly accumulating marine sediments (>40 m/my) where pore waters are deficient in dissolved oxygen and sulfate. Based on indirect geochemical evidence, microbial methane generation is largely confined to depths of between 10 and 1000 meters beneath the sea floor. Under shelf conditions (water depth <200 m), methane concentrations can exceed solubility in pore water and accumulate as free gas, or escape the sediment as bubbles, or be oxidized in surface sediments. Under some deeper-water conditions of continental slope and rise sediments, more of the methane can be retained and buried because of increased solubility, and because methane in excess of solubility can be stabilized as methane hydrate. Few direct measurements of methane concentration in subsurface pore waters have been made. However, methane-water phase transitions (gas-water contacts, base of gas hydrate reflector) on seismic records can be used with methane solubility relationships to estimate gas contents of sediments. Comparison of various environments shows a relatively narrow range of dissolved methane contents. In marine sediments, free gas (and methane hydrate) is stable only in contact with methane-saturated pore water. Finer-grained sediments can be supersaturated with respect to a gas (and gas hydrate ) phase because of capillary pressure inhibition of bubble (or hydrate ) formation. The amount of methane dissolved in marine sediment pore water is necessarily larger than that present as gas hydrate.

Claypool, G.E. (Mobil Technology Co., Dallas, TX (United States))

1996-01-01

193

Sorption of chlorobiphenyls in sediment-water systems containing nonionic surfactants  

Microsoft Academic Search

Nonionic surfactants may aid remediation of contaminated soils and sediments by increasing aqueous concentrations of poorly water-soluble organic contaminants. In order to explore the effects of non-ionic surfactants on the sediment-water distribution of PCBs, a series of batch experiments was performed using four commercial nonionic surfactants and Red Cedar River sediment. Sediment-water distributions of 4,4â²-dichlorobiphenyl (Di-CB), 2,2â²,4,4â²-tetrachlorobiphenyl (Tetra-CB), and 2,2â²,4,4â²,5,5â²-hexachlorobiphenyl

Jae-Woo Park; Stephen A. Boyd

1999-01-01

194

Distribution and composition of fahs in surface waters, porewater and sediments from Xiamen Western Bay  

NASA Astrophysics Data System (ADS)

Xiamen Westem Bay's water and sediment quality were studied by determining the levels of sixteen polycyclic aromatic hydrocarbons (PAHs) in water, porewater and sediment samples from nine locations in the bay. Total PAH concentrations varied from 106 to 945 ng/l in water, below detection to 3548 ng/l in porewater, and 247 to 480 ng/g dry weight in surface sediments. PAHs levels in porewater were higher than those in surface water, due to the preference of these hydrophobic compounds for sedimentary phase instead of water. Such a concentration gradient implies a potential flux of pollutants from sediments to overlying water. The PAHs levels in sediments were one to several orders of magnitude lower than those in 1993, suggesting their decreased input in recent years and possible degradation with time.

Khalid, Maskaoui; Hong, Hua-Sheng; Zhang, Zu-Lin; Chen, Wei-Qi; Zhou, Jun-Liang

2001-03-01

195

Water quality in a rural river environment: distribution of metals among water and sediment compartments  

NASA Astrophysics Data System (ADS)

Sediments have a significant influence on water quality, owing to their role both as a sink and a potential source of pollutants. In fluvial environments from mountainous catchments, the dynamics of sediment particles and particle-bound contaminants are still poorly understood. As stated by Symader et al. (2007), bottom sediments of small rivers in mountainous areas behave like a transport system of its own and show high temporal variation in their chemical composition. The transport of significant sedimentary loads, as suspended matter, in short periods of time, mainly in winter, poses some issues concerning monitoring and modelling approaches of the transport and fate of micro-pollutants at the catchment scale. On one hand, high stream-flow velocity peaks make it difficult or impossible to maintain suspended sediment samplers fixed in the river channel. On the other hand, the cycle of deposition and re-suspension of finer material, throughout the hydrological year, leads to temporal changes of sediment properties. Our contribution reports some results of an investigation on the water quality in a mountainous rural meso-scale catchment, located in the NE of Portugal. The study integrates the examination of metal contents in the sediments and the water body. The river-bottom sediments and water were simply collected in a planned sampling network, in two different periods of the hydrological year (high and low flow). The finer and most recently deposited sediment was preferentially sampled, and the <63µm granulometric class analysed for the potentially bioavailable fraction. Three metals were considered to illustrate the observations resulting from the combination of data on its dissolved and particulate contents. These are Cu, Pb and Zn, which show similar spatial and temporal distributions at the catchment scale. In the main streams a general increase of metal contents in the potentially bioavailable fraction is observed downstream. The residual fraction decreases in high-energetic sites of the drainage network. No simultaneous variation trends in the metal contents in the water and in the sediment fractions studied are observed. The transport mechanisms and the exchange of material exert a joint influence. Regarding the possible origin of the considered elements we observe peaks of contents in sites influenced by geological mineralisation and urban effluents. The influence of agricultural practices in the fluvial environment quality is more noticeable in the zones of the basin where small agricultural fields, in narrow terraces, are inter-related with urban settlements. In the valleys the impact is lower; the soil layer is thicker and the topography is smoother, attenuating the superficial transport and higher retention of these metals in soils. The results show that the pollutant dispersion and transport in mountainous fluvial environments is governed by multiple interrelated factors difficult to control over time, and predictive models still need better information about the processes governing the transport into and within the fluvial network. The regular monitoring of bed sediments in this kind of basins is important to give some insight into the micro-pollutant transport in small mountainous catchments with an impact on the quality of receiving waters. Symader, W.; Bierl R.; Kurtenbach, A.; Krein, A. (2007). Transport Indicators. In: Sediment Dynamics and Pollutant Mobility in Rivers (eds Westrich, B. & Forstner, U.), pp. 269-304, Springer.

Reis, A.; Parker, A.; Alencoao, A.

2009-04-01

196

Historical and Hypothetical Future Sedimentation and Water Storage in Kajakai Reservoir, Central Afghanistan  

USGS Publications Warehouse

SUMMARY Sedimentation has reduced water storage in Kajakai Reservoir. If current sedimentation rates continue, hypothetical future reservoir water volumes at the spillway elevation of 1,033.5 meters could be reduced about 22 percent from 2006 to 2057. Even if the spillway elevation is raised to 1,045 meters, a severe drought could result in large multiyear irrigation-supply deficits in which reservoir water levels remain below 1,022 meters for more than 4 years. Hypothetical climate change and sedimentation could result in greater water-supply deficits. The chance of having sufficient water supplies in Kajakai Reservoir during the worst month is about 47 percent.

Vining, Kevin C.; Vecchia, Aldo V.

2008-01-01

197

Distribution of polyfluoroalkyl compounds in water, suspended particulate matter and sediment from Tokyo Bay, Japan  

Microsoft Academic Search

This study examined the environmental behaviour and fate of polyfluoroalkyl compounds (PFCs) found in water, suspended particulate matter (SPM) and sediment. The sampling of the sediment was performed at two stations from Tokyo Bay, Japan, in 2008. In addition, a depth profile of seawater was collected at three water layers from both sampling stations. The ?PFC concentrations ranged from 16.7

Lutz Ahrens; Sachi Taniyasu; Leo W. Y. Yeung; Nobuyoshi Yamashita; Paul K. S. Lam; Ralf Ebinghaus

2010-01-01

198

PRIMARY RESEARCH PAPER Water column oxygen demand and sediment oxygen flux  

E-print Network

PRIMARY RESEARCH PAPER Water column oxygen demand and sediment oxygen flux: patterns of oxygen of the USA. We analyzed rates of oxygen loss as water-column biochemical oxygen demand (BOD5) and sediment, chemical and biological data were collected to identify factors related to oxygen loss. BOD5 rates ranged

Mallin, Michael

199

Trace metal concentrations in water, sediments and fish tissue from Lake Tanganyika  

Microsoft Academic Search

Trace metal (Cu, Pb, Fe, Mn, Zn, Cd) concentrations were determined in water, sediments, various fin fish species and a bivalve (Mutelaspekei) from Lake Tanganyika using an atomic absorption spectrophotometer. Integrated water samples to depths of 10 m were collected using a pre-rinsed flexible plastic pipe. Sediment samples were collected using a ponar mud sampler. Fish samples were obtained using

F. M. M. Chale

2002-01-01

200

Sediment-water fluxes of nutrients in an Antarctic coastal environment: influence of bioturbation  

Microsoft Academic Search

Rates of exchanges of nitrate and ammonium across the sediment-water interface were measured in an inshore marine environment at Signy Island, South Orkney Islands, Antarctica, over 6 months from August 1991 to February 1992. The sediment was a source of ammonium to the water column but a sink of nitrate, although nitrate exchange rates were very variable. Concentration profiles of

D. B. Nedwell; T. R. Walker

1995-01-01

201

Petroleum hydrocarbons in water and sediments of northwest Arabian Gulf 1980–2005  

Microsoft Academic Search

A survey has been conducted to evaluate pollution by petroleum hydrocarbons (PHC's) in water, sediments and living organisms of southern Iraqi sectors represented by Shatt Al-Arab River, Khor Al-Zubair, Umm Qasser, Khor Abdullah and the northwest Arabian Gulf. Petroleum hydrocarbons in water as dissolved and particulate, in sediments as exchangeable and residual and in the organs of living organisms were

Faris J. M. Al-Imarah; Abass A. Hantoosh; Ali M. Nasir

2007-01-01

202

Recent changes of water discharge and sediment load in the Zhujiang (Pearl River) Basin, China  

Microsoft Academic Search

The paper is concerned with identifying changes in the time series of water and sediment discharge of the Zhujiang (Pearl River), China. The gradual trend test (Mann–Kendall test), and abrupt change test (Pettitt test), have been employed on annual water discharge and sediment load series (from the 1950s–2004) at nine stations in the main channels and main tributaries of the

Shurong Zhang; Xi Xi Lu; David L. Higgitt; Chen-Tung Arthur Chen; Jingtai Han; Huiguo Sun

2008-01-01

203

Trace Organic Contaminants in Sediment and Water from Ulsan Bay and Its Vicinity, Korea  

Microsoft Academic Search

Sediment and water samples collected from 32 locations in Ulsan Bay and adjacent inland areas were analyzed for polycyclic aromatic hydrocabons (PAHs), nonylphenol (NP), octylphenol (OP), bisphenol A (BPA), organochlorine (OC) pesticides (HCB, HCHs, CHLs, and DDTs), and poly- chlorinated biphenyls (PCBs) to characterize their spatial dis- tribution and contamination status. PAHs were detected in nearly all sediment and water

J. S. Khim; K. T. Lee; K. Kannan; D. L. Villeneuve; J. P. Giesy; C. H. Koh

2001-01-01

204

Water and sediment quality at mussel (Unionidae) habitats in the Ochlockonee River of Florida and Georgia  

Microsoft Academic Search

Water chemical analyses, porewater and whole sediment chemical analyses, and pore- water and whole sediment toxicity testing were performed as part of a combined effort between the US Fish and Wildlife Service and the US Geological Survey. These analyses were used to predict impaired stream sites that may impede a healthy natural riverine community. The analyses also revealed differences between

Jon M. Hemming; Parley V. Winger; Steven J. Herrington; Wendy Gierhart; Holly Herod; Jerry Ziewitz

2006-01-01

205

Sediment Inventory and Phosphorus Fractions for Water Conservation Area Canals in the Everglades  

E-print Network

Sediment Inventory and Phosphorus Fractions for Water Conservation Area Canals in the Everglades O in the Water Conservation Area (WCA) canals in the Ever- glades. A study was conducted to characterize

Florida, University of

206

[Health risk induced by estrogens during unplanned indirect potable reuse of reclaimed water from domestic wastewater].  

PubMed

The estrogenic endocrine disruptors in reclaimed water from domestic wastewater may induce health risks to human being, when reclaimed water is used for augmentation of drinking water unplannedly and indirectly. This study investigated changes in concentrations of estrone, estradiol, 17alpha-ethinyl estradiol, bisphenol A, nonylphenol and octylphenol in reclaimed water during the reuse of reclaimed water for augmentation to water source such as lakes and reservoir via river. Thereafter, health risk induced by estrogens during the resue of reclaimed water was evaluated. The concentration of estrogen in secondary effluent ranged 0.1-100 ng x L(-1). The highest concentrations of bisphenol A and nonylphenol reached up to 1-10 microg x L(-1). During the indirect reuse of reclaimed water as potable water, the dilution and degradation in river and lake, and the removal by drinking water treatment process could change the concentrations of estrogen. The non-carcinogenic risks of estrone, estradiol, bisphenol A, nonylphenol and octylphenol were lower than 1. When the hydraulic retention time of 17alpha-ethinyl estradiol (EE2) in lakes and reservoir was higher than 30 days, the non-carcinogenic risk of EE2 was lower than 1 in most cases. When the hydraulic retention time of EE2 in lakes and reservoir was less than 30 days and the percentages of reclaimed water in drinking water were higher than 50%, the non-carcinogenic risk induced by EE2 was higher than 1 in 20%-50% samples. This indicated that the risks of EE2 should be concerned. PMID:24881395

Wu, Qian-Yuan; Shao, Yi-Ru; Wang, Chao; Sun, Yan; Hu, Hong-Ying

2014-03-01

207

Detection of Legionella spp. from Domestic Water in the Prefecture of Arta, Greece  

PubMed Central

The aim of this research was the isolation of Legionella spp. from domestic water supply networks in the Prefecture of Arta. A total of 100 water samples, from 25 houses, were collected. Half of the samples concerned the cold water and half the hot water supply. Purpose was to detect colonization of the water networks with Legionella spp. >500?cfu/L by using the method of filtration (ISO 11731). Out of 100 samples, 6 samples from 3 houses were positive for Legionella spp. Legionella pneumophila serogroup 2–14 was isolated in 5 of 6 samples, whereas in the sixth sample Legionella anisa was identified. Only three of the samples had residual chloride over 0.2?mg/L, rate which is necessary for potable water, according to the Greek hygienic practice. Concerning the temperature of hot water, the mean temperature of the negative for Legionella samples was higher compared to the mean temperature of the positive for Legionella samples (49.9°C versus 45.5°C). It is estimated that there is risk of infection through the use of showers. The low concentration of chloride and the temperature, which was found within the limits favorable to developing Legionella spp. (20–45°C), provide fertile ground for proliferation of the bacteria. PMID:24744922

Dimitriadi, Dimitra; Velonakis, Emmanuel

2014-01-01

208

Remobilization of polychlorinated biphenyls from sediment and its consequences for their transport in river waters.  

PubMed

A laboratory experiment was performed to examine the remobilization of indicator polychlorinated biphenyls (iPCBs) from sediments and its results were applied to the real-world data for explaining the transport of PCBs in river. Seven PCB concentrations were determined in three series of model water-sediment systems (3 g of river sediment, three different volumes of distilled water (0.5, 0.25, and 0.15 ml), and 5 mg of biocide) after 11 days of incubation. Solid-phase extraction was used for separation of analytes from the aqueous phase and solvent extraction for isolation of analytes from the sediments, respectively. The extracts were analyzed for individual iPCB congeners using gas chromatography-mass spectrometry method. For each series of the experiment, the concentrations of PCBs in aqueous phase were similar. The average sediment/water partition coefficient value was 10(4) l/kg. The solubility of individual PCB congeners in water did not influence the desorption of PCBs from the sediment. Although the dominant form of PCBs in a water-sediment system occurs as suspended and colloidal fractions, these compounds are transported mostly in a dissolved form. Suspended and colloidal matter is a major sink for PCBs in low-energy aquatic environments. In contrast, the dissolved PCBs are readily transported in running waters. The mobilization of PCBs from sediments to aqueous phase, with respect to their solubility in water, seems to be limited, thus reducing the risk of secondary pollution. PMID:23007800

Gdaniec-Pietryka, Monika; Mechli?ska, Agata; Wolska, Lidia; Ga?uszka, Agnieszka; Namie?nik, Jacek

2013-05-01

209

Risk factors for contamination of domestic hot water systems by legionellae.  

PubMed Central

To assess risk factors associated with the contamination of the domestic environment by legionellae, 211 houses in the Quebec City area were randomly selected and water samples were collected from the hot water tank, the shower heads, and the most frequently used faucet. After centrifugation, concentrated samples were seeded in triplicate on BCYE and GPV media. Data on the characteristics of the hot water system and plumbing in the house and on the personal habits of the occupants were collected for each house. Among these 211 houses, hot water was provided by either an oil or gas heater in 33 and by an electric heater in 178. Legionellae were isolated from none of the samples from houses with oil or gas heaters and from 39% (69 of 178) of those with electric water heaters (P less than 0.0001). This association remained highly significant after control for water temperature and other variables in a stratified analysis. In the 178 houses with an electric heater, 12% of the faucets, 15% of the shower heads, and 37% of the water heaters were contaminated. Legionella pneumophila serogroups 2 and 4 were the most frequently isolated strains. Logistic regression showed that factors associated with electric water heater contamination were (i) location of the house in older districts of the city (P less than 0.0001), (ii) old age of the water heater (P = 0.003), and (iii) low water temperature (P = 0.05). Contamination of the water heater was the only factor significantly associated with the contamination of peripheral outlets (P less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1768104

Alary, M; Joly, J R

1991-01-01

210

Sediment contact tests as a tool for the assessment of sediment quality in German waters.  

PubMed

A sediment contact test (SCT) battery consisting of five ecotoxicological test systems was applied to 21 native freshwater sediments characterized by a broad variety of geochemical properties and anthropogenic contamination. Higher plants (Myriophyllum aquaticum), nematodes (Caenorhabditis elegans), oligochaetes (Lumbriculus variegatus), zebrafish embryos (Danio rerio), and bacteria (Arthrobacter globiformis), representing various trophic levels and exposure pathways, were used as test organisms. The test battery detected sediment toxicity caused by anthropogenic pollution, whereas the various tests provided site-specific, nonredundant information to the overall toxicity assessment. Based on the toxicity pattern derived from the test battery, the sediments were classified according to a newly proposed classification system for sediment toxicity assessment. The SCT-derived classification generally agreed well with the application of consensus-based sediment quality guidelines (SQGs), especially with regard to sediments with high toxic potential. For sediments with low to medium toxic potential, the SQGs often underestimated the toxicity that was detected by the SCTs, underpinning the need for toxicity tests in sediment quality assessment. PMID:23027525

Feiler, Ute; Höss, Sebastian; Ahlf, Wolfgang; Gilberg, Daniel; Hammers-Wirtz, Monika; Hollert, Henner; Meller, Michael; Neumann-Hensel, Helga; Ottermanns, Richard; Seiler, Thomas-Benjamin; Spira, Denise; Heininger, Peter

2013-01-01

211

Sediment enzyme activities and microbial community diversity in an oligotrophic drinking water reservoir, eastern China.  

PubMed

Drinking water reservoir plays a vital role in the security of urban water supply, yet little is known about microbial community diversity harbored in the sediment of this oligotrophic freshwater environmental ecosystem. In the present study, integrating community level physiological profiles (CLPPs), nested polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and clone sequence technologies, we examined the sediment urease and protease activities, bacterial community functional diversity, genetic diversity of bacterial and fungal communities in sediments from six sampling sites of Zhou cun drinking water reservoir, eastern China. The results showed that sediment urease activity was markedly distinct along the sites, ranged from 2.48 to 11.81 mg NH?-N/(g·24 h). The highest average well color development (AWCD) was found in site C, indicating the highest metabolic activity of heterotrophic bacterial community. Principal component analysis (PCA) revealed tremendous differences in the functional (metabolic) diversity patterns of the sediment bacterial communities from different sites. Meanwhile, DGGE fingerprints also indicated spatial changes of genetic diversity of sediment bacterial and fungal communities. The sequence BLAST analysis of all the sediment samples found that Comamonas sp. was the dominant bacterial species harbored in site A. Alternaria alternate, Allomyces macrogynus and Rhizophydium sp. were most commonly detected fungal species in sediments of the Zhou cun drinking water reservoir. The results from this work provide new insights about the heterogeneity of sediment microbial community metabolic activity and genetic diversity in the oligotrophic drinking water reservoir. PMID:24205265

Zhang, Haihan; Huang, Tinglin; Liu, Tingting

2013-01-01

212

Sediment Enzyme Activities and Microbial Community Diversity in an Oligotrophic Drinking Water Reservoir, Eastern China  

PubMed Central

Drinking water reservoir plays a vital role in the security of urban water supply, yet little is known about microbial community diversity harbored in the sediment of this oligotrophic freshwater environmental ecosystem. In the present study, integrating community level physiological profiles (CLPPs), nested polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and clone sequence technologies, we examined the sediment urease and protease activities, bacterial community functional diversity, genetic diversity of bacterial and fungal communities in sediments from six sampling sites of Zhou cun drinking water reservoir, eastern China. The results showed that sediment urease activity was markedly distinct along the sites, ranged from 2.48 to 11.81 mg NH3-N/(g·24h). The highest average well color development (AWCD) was found in site C, indicating the highest metabolic activity of heterotrophic bacterial community. Principal component analysis (PCA) revealed tremendous differences in the functional (metabolic) diversity patterns of the sediment bacterial communities from different sites. Meanwhile, DGGE fingerprints also indicated spatial changes of genetic diversity of sediment bacterial and fungal communities. The sequence BLAST analysis of all the sediment samples found that Comamonas sp. was the dominant bacterial species harbored in site A. Alternaria alternate, Allomyces macrogynus and Rhizophydium sp. were most commonly detected fungal species in sediments of the Zhou cun drinking water reservoir. The results from this work provide new insights about the heterogeneity of sediment microbial community metabolic activity and genetic diversity in the oligotrophic drinking water reservoir. PMID:24205265

Zhang, Haihan; Huang, Tinglin; Liu, Tingting

2013-01-01

213

The potential source of dissolved aluminum from resuspended sediments to the North Atlantic deep water  

SciTech Connect

Laboratory and field studies were conducted to investigate the significance of resuspended sediments as a source of dissolved Al to the deep northwest Atlantic. Sediment resuspension experiments demonstrate the effect on dissolved Al concentration (initially 11 nM) of adding natural suspended sediments (ca. 0.1-10 mg/L) to seawater. The concentration of dissolved Al increased by the resuspension of sediments; for example, addition of 0.15 mg/L sediments caused dissolved Al to increase by 10 nM. Distributions of dissolved and leachable particulate Al off the tail of the Grand Banks, near the high-energy western boundary current, show elevated levels in the near-bottom waters. The authors suggest that resuspended sediments associated with nepheloid layers along the western boundary of the North Atlantic are a source of dissolved Al. Strong western boundary currents provide the energy to resuspend and maintain intense nepheloid layers of sediments. Continued resuspension and deposition of sediments within the nepheloid layer promotes the release of Al from sediments to the overlying water. The Al-rich terrigenous sediments that predominate along the deep boundary of the Denmark Strait, Labrador Sea, Newfoundland and off Nova Scotia constitute a potentially significant source of dissolved Al. Release of Al from resuspended sediments associated with nepheloid layers at a more northern location (e.g., Denmark Strait) may contribute to the near-linear increase in dissolved Al with depth observed in the deep northwest Atlantic.

Moran, S.B.; Moore, R.M. (Dalhousie Univ., Halifax, Nova Scotia (Canada))

1991-10-01

214

Ecological impacts of lead mining on Ozark streams: Toxicity of sediment and pore water  

USGS Publications Warehouse

We studied the toxicity of sediments downstream of lead-zinc mining areas in southeast Missouri, using chronic sediment toxicity tests with the amphipod, Hyalella azteca, and pore-water toxicity tests with the daphnid, Ceriodaphnia dubia. Tests conducted in 2002 documented reduced survival of amphipods in stream sediments collected near mining areas and reduced survival and reproduction of daphnids in most pore waters tested. Additional amphipod tests conducted in 2004 documented significant toxic effects of sediments from three streams downstream of mining areas: Strother Creek, West Fork Black River, and Bee Fork. Greatest toxicity occurred in sediments from a 6-km reach of upper Strother Creek, but significant toxic effects occurred in sediments collected at least 14 km downstream of mining in all three watersheds. Toxic effects were significantly correlated with metal concentrations (nickel, zinc, cadmium, and lead) in sediments and pore waters and were generally consistent with predictions of metal toxicity risks based on sediment quality guidelines, although ammonia and manganese may also have contributed to toxicity at a few sites. Responses of amphipods in sediment toxicity tests were significantly correlated with characteristics of benthic invertebrate communities in study streams. These results indicate that toxicity of metals associated with sediments contributes to adverse ecological effects in streams draining the Viburnum Trend mining district.

Besser, J.M.; Brumbaugh, W.G.; Allert, A.L.; Poulton, B.C.; Schmitt, C.J.; Ingersoll, C.G.

2009-01-01

215

Control of water erosion and sediment in open cut coal mines in tropical areas  

SciTech Connect

The purpose is to reduce the environmental impacts from open cut mining in tropical areas, such as Indonesia and Vietnam. Research conducted on methods for the control of water erosion and sediment from open cut coal mines is described. Data were collected on climate and weathering in tropical areas, mechanism of water erosion and sedimentation, characteristics of rocks in coal measures under wet conditions, water management at pits and haul roads and ramps, and construction of waste dumps and water management. The results will be applied to the optimum control and management of erosion and sediments in open cut mining. 6 refs., 8 figs.

Ueda, T.; Nugraha, C.; Matsui, K.; Shimada, H.; Ichinose, M.; Gottfried, J. [Kyushu University, Fukuoka (Japan). Department of Earth Resources Engineering

2005-07-01

216

Water and Sediment Quality in the Yukon River Basin, Alaska, During Water Year 2003  

E-print Network

.......................................................................................................................51 CHAPTER 9 - Sediment Mineralogy)..................................70 CHAPTER 13 - Uranium Isotopes

217

Water and Sediment Quality in the Yukon River Basin, Alaska, During Water Year 2005  

E-print Network

........................................................................................................................46 CHAPTER 8 - Sediment Mineralogy...............................................60 CHAPTER 12 - Uranium Isotopes

218

Water and Sediment Quality in the Yukon River Basin, Alaska, During Water Year 2004  

E-print Network

........................................................................................................................47 CHAPTER 8 - Sediment Mineralogy)..................................62 CHAPTER 12 - Uranium Isotopes

219

234U and 238U isotopes in water and sediments of the southern Baltic.  

PubMed

The aim of this work was to determine the concentration of 234U and 238U and calculate the values of the 234U/238U activity ratio in waters and sediments from the various regions of the southern Baltic Sea: Gda?sk Deep, S?upsk Narrow and Bornholm Deep. The concentration of uranium in analysed sediments from southern Baltic increase with core depth to what probably is connected with diffusion from sediments to water through interstitial water, where uranium concentration is much higher than in bottom water. The highest concentrations of uranium were observed in sediments of S?upsk Narrow (0.66-7.11 mg kg(-1) d.w.) and S?upsk Bank (0.61-6.93 mg kg(-1) d.w.), the lowest in sediments from Bornholm Deep (0.54-3.77 mg kg(-1) d.w.). The 234U/238U activity ratio results indicated that the sedimentation of terrigenic material and Vistula River transport are the general sources of uranium in the southern Baltic sediments. The value of 234U/238U activity ratio in sediments from reduction areas from southern Baltic (Gda?sk Deep and Bornholm Deep) indicated that reduction process of U(VI) to U(IV) and removing of anthropogenic uranium from seawater to sediments constitutes a small part only in Gda?sk Deep. PMID:14689997

Skwarzec, B; Bory?o, A; Strumi?ska, D

2002-01-01

220

224Ra:228Th disequilibrium in coastal sediments: Implications for solute transfer across the sediment-water interface  

NASA Astrophysics Data System (ADS)

We utilized 224Ra/228Th disequilibrium in the sediment to investigate processes that regulate solute transfer across the sediment-water interface. Depth profiles of dissolved and surface-bound 224Ra and 228Th in the upper 0-20 cm sediment column were measured using a delayed coincidence counter during a cruise to the Yangtze estuary from 15 to 24 August 2011. Along with 224Ra and 228Th, depth profiles of 234Th were collected to determine the bioturbation rate in the sediment. At most study sites, a significant deficit of 224Ra relative to 228Th was observed in the upper 0-10 cm. In contrast, 224Ra was in excess with respect to 228Th in the upper 0-5 cm at the river mouth, possibly due to redistribution of 224Ra from the mid-salinity region. By modeling the 224Ra depth profiles in the sediment using the general diagenetic equation, we demonstrated that in most cases molecular diffusion and bioturbation together can account for only ?20-30% of the measured flux of 224Ra. We concluded that other mechanisms, especially irrigation, must be invoked to explain the remnant 70% of the observed deviation of 224Ra relative to 228Th. On the basis of the 224Ra/228Th disequilibrium in the sediment and a concept of increased surface area for exchange by irrigation as developed by early investigators, we proposed a new approach - the 224Ra/228Th disequilibrium approach to quantify the transfer rate of other dissolved species across the sediment-water interface. We have utilized this new approach to determine the benthic consumption rate of dissolved O2. The result reveals that benthic consumption is an important loss term of dissolved O2 in the Yangtze estuary and must be considered as one of the mechanisms that lead to hypoxia in this area.

Cai, Pinghe; Shi, Xiangming; Moore, Williard S.; Peng, Shiyun; Wang, Guizhi; Dai, Minhan

2014-01-01

221

Biogeochemical malfunctioning in sediments beneath a deep-water fish farm.  

PubMed

We investigated the environmental impact of a deep water fish farm (190 m). Despite deep water and low water currents, sediments underneath the farm were heavily enriched with organic matter, resulting in stimulated biogeochemical cycling. During the first 7 months of the production cycle benthic fluxes were stimulated >29 times for CO(2) and O(2) and >2000 times for NH(4)(+), when compared to the reference site. During the final 11 months, however, benthic fluxes decreased despite increasing sedimentation. Investigations of microbial mineralization revealed that the sediment metabolic capacity was exceeded, which resulted in inhibited microbial mineralization due to negative feed-backs from accumulation of various solutes in pore water. Conclusions are that (1) deep water sediments at 8 °C can metabolize fish farm waste corresponding to 407 and 29 mmol m(-2) d(-1) POC and TN, respectively, and (2) siting fish farms at deep water sites is not a universal solution for reducing benthic impacts. PMID:22763326

Valdemarsen, Thomas; Bannister, Raymond J; Hansen, Pia K; Holmer, Marianne; Ervik, Arne

2012-11-01

222

Domestic rainwater harvesting to improve water supply in rural South Africa  

NASA Astrophysics Data System (ADS)

Halving the proportion of people without sustainable access to safe drinking water and basic sanitation, is one of the targets of the 7th Millennium Development Goals (MDGs). In South Africa, with its mix of developed and developing regions, 9.7 million (20%) of the people do not have access to adequate water supply and 16 million (33%) lack proper sanitation services. Domestic Rainwater Harvesting (DRWH), which provides water directly to households enables a number of small-scale productive activities, has the potential to supply water even in rural and peri-urban areas that conventional technologies cannot supply. As part of the effort to achieve the MDGs, the South African government has committed itself to provide financial assistance to poor households for the capital cost of rainwater storage tanks and related works in the rural areas. Despite this financial assistance, the legal status of DRWH remains unclear and DRWH is in fact illegal by strict application of the water legislations. Beyond the cost of installation, maintenance and proper use of the DRWH system to ensure its sustainability, there is risk of waterborne diseases. This paper explores challenges to sustainable implementation of DRWH and proposes some interventions which the South African government could implement to overcome them.

Mwenge Kahinda, Jean-marc; Taigbenu, Akpofure E.; Boroto, Jean R.

223

Sudden clearing of estuarine waters upon crossing the threshold from transport to supply regulation of sediment transport as an erodible sediment pool is depleted: San Francisco Bay, 1999  

USGS Publications Warehouse

The quantity of suspended sediment in an estuary is regulated either by transport, where energy or time needed to suspend sediment is limiting, or by supply, where the quantity of erodible sediment is limiting. This paper presents a hypothesis that suspended-sediment concentration (SSC) in estuaries can suddenly decrease when the threshold from transport to supply regulation is crossed as an erodible sediment pool is depleted. This study was motivated by a statistically significant 36% step decrease in SSC in San Francisco Bay from water years 1991–1998 to 1999–2007. A quantitative conceptual model of an estuary with an erodible sediment pool and transport or supply regulation of sediment transport is developed. Model results confirm that, if the regulation threshold was crossed in 1999, SSC would decrease rapidly after water year 1999 as observed. Estuaries with a similar history of a depositional sediment pulse followed by erosion may experience sudden clearing.

Schoellhamer, David H.

2011-01-01

224

Observations on microbial percent respiration values in arctic and subarctic marine waters and sediments  

Microsoft Academic Search

Percent respiration was measured in over 1,100 arctic and subarctic marine water and sediment samples using14C-labeled glucose and glutamate. These measurements were made at different times of the year in 4 regions. Percent respiration values were typically lower in regions where the waters of large rivers mixed with seawater. They were also lower in sediments and in waters collected near

R. P. Griffiths; B. A. Caldwell; R. Y. Morita

1984-01-01

225

Nutritional value of sediments for macroinvertebrate communities in shallow eutrophic waters  

Microsoft Academic Search

The role of the nutritional quality of non-polluted soft-bottom sediments as a factor structuring in situ macroinvertebrate communities was studied in shallow eutrophic waters in The Netherlands. Sediments from clean sites were collected and analyzed for general characteristics (e.g. grain-size distribution) and nutritional value (e.g. C, N, P, polyunsaturated fatty acids). Also, macroinvertebrates were collected from these sediments and identified.

Vos de J. H; E. T. H. M. Peeters; R. Gylstra; M. H. S. Kraak; W. Admiraal

2004-01-01

226

Phytoremediation facilitates removal of nitrogen and phosphorus from eutrophicated water and release from sediment  

Microsoft Academic Search

Phosphorus (P) fractions and the effect of phytoremediation on nitrogen and phosphorus removal from eutrophicated water and\\u000a release from sediment were investigated in the eco-remediation experiment enclosures installed in the Hua-jia-chi pond (Hangzhou\\u000a city, Zhejiang province, China). The main P fraction in the sediment was inorganic phosphorus (IP). For the mesotrophic sediments,\\u000a IP mainly consisted of HCl-extractable P (Ca-P). The

Wu Xiang; Yang Xiao-E; Zed Rengel

2009-01-01

227

Sedimentation in Lake Biel, an eutrophic, hard-water lake in northwestern Switzerland  

Microsoft Academic Search

A 2-year study of sedimentation in Lake Biel reveals that three major factors can account for the spatial and temporal patterns\\u000a of tripton sedimentation. Allochthonous inputs of particulate matter mostly derived from the Aare river during spring snowmelt\\u000a and other high-water periods, provide about 50% of the carbonate and 50% of the siliceous matter collected in sediment traps.\\u000a Phytoplankton activity

Richard F. Wrightt; Albert Matter; Marc Schweingruber; Ulrich Siegenthaler

1980-01-01

228

Parameterization of biogeochemical sediment-water fluxes using in-situ measurements and a steady-state diagenetic model  

NASA Astrophysics Data System (ADS)

Sediment biogeochemical processes are important drivers of water column biogeochemistry in coastal areas. For example, sediment oxygen consumption can be an important driver of bottom water oxygen depletion in hypoxic systems, and sediment-water nutrient fluxes support primary productivity in the overlying water column. Yet, biogeochemical sediment-water fluxes are often parameterized crudely and only poorly constrained in coupled physical-biogeochemical models. Here, we present a method for parameterizing biogeochemical sediment-water fluxes realistically and efficiently, using in-situ measurements and a steady state diagenetic model. We apply this method to the Louisiana Shelf where high primary production induced by excess nutrient loads from the Mississippi-Atchafalaya River system promotes the development of hypoxic bottom waters in summer. The implementation of the parameterizations in a coupled circulation-biogeochemical model of the northern Gulf of Mexico results in realistic sediment-water fluxes that enable a sediment-water column feedback at low bottom oxygen concentrations.

Laurent, Arnaud; Fennel, Katja; Wilson, Robin; Lehrter, John; Devereux, Richard

2014-05-01

229

ECO: A Generic Eutrophication Model Including Comprehensive Sediment-Water Interaction  

PubMed Central

The content and calibration of the comprehensive generic 3D eutrophication model ECO for water and sediment quality is presented. Based on a computational grid for water and sediment, ECO is used as a tool for water quality management to simulate concentrations and mass fluxes of nutrients (N, P, Si), phytoplankton species, detrital organic matter, electron acceptors and related substances. ECO combines integral simulation of water and sediment quality with sediment diagenesis and closed mass balances. Its advanced process formulations for substances in the water column and the bed sediment were developed to allow for a much more dynamic calculation of the sediment-water exchange fluxes of nutrients as resulting from steep concentration gradients across the sediment-water interface than is possible with other eutrophication models. ECO is to more accurately calculate the accumulation of organic matter and nutrients in the sediment, and to allow for more accurate prediction of phytoplankton biomass and water quality in response to mitigative measures such as nutrient load reduction. ECO was calibrated for shallow Lake Veluwe (The Netherlands). Due to restoration measures this lake underwent a transition from hypertrophic conditions to moderately eutrophic conditions, leading to the extensive colonization by submerged macrophytes. ECO reproduces observed water quality well for the transition period of ten years. The values of its process coefficients are in line with ranges derived from literature. ECO’s calculation results underline the importance of redox processes and phosphate speciation for the nutrient return fluxes. Among other things, the results suggest that authigenic formation of a stable apatite-like mineral in the sediment can contribute significantly to oligotrophication of a lake after a phosphorus load reduction. PMID:23844160

Smits, Johannes G. C.; van Beek, Jan K. L.

2013-01-01

230

Levels of PAHs in the Waters, Sediments, and Shrimps of Estero de Urias, an Estuary in Mexico, and Their Toxicological Effects  

PubMed Central

PAHs were measured in water, sediment, and shrimps of Estero de Urias, an estuary in Sinaloa, Mexico, during the rainy and dry seasons, and analyzed for eleven PAHs routinely detected in samples. Phenanthrene was the most dominant congener in the water, sediment, and shrimp samples comprising about 38, 24, and 25%, respectively, of the eleven PAHs detected, followed by pyrene and naphthalene in water and sediment samples, and pyrene and fluorine in the shrimp samples. Total PAH concentrations ranged from 9 to 347?ng/L in water, 27 to 418?ng/g in sediments, and 36 to 498?ng/g in shrimps. The sources of contamination are closely related to human activities such as domestic and industrial discharge, automobile exhausts, and street runoff. High concentrations were also measured during the rainy season and during the first quarter of the year. Toxicity tests were also carried out, exposing fish embryos and juvenile shrimps to some of these PAHs. Fish embryos exposed to PAHs showed exogastrulation, while juvenile shrimps showed significantly lower growth rates than controls. DNA and protein alterations were also observed. These toxicity tests indicate that PAH concentrations measured could be dangerous to some aquatic organisms, particularly during early stages of development. PMID:22997501

Jaward, Foday M.; Alegria, Henry A.; Galindo Reyes, Jose G.; Hoare, Armando

2012-01-01

231

Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2001  

USGS Publications Warehouse

Suspended-sediment concentration data were collected in San Francisco Bay during water year 2001 (October 1, 2000-September 30, 2001). Optical backscatterance sensors and water samples were used to monitor suspended sediment at two sites in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two depths at most sites. Water samples were collected periodically and were analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the electrical output of the optical backscatterance sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes the suspended-sediment concentration data collected from October 2000 through September 2001. Calibration curves and plots of edited data for each sensor also are presented.

Buchanan, Paul A.; Ganju, Neil K.

2003-01-01

232

Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2002  

USGS Publications Warehouse

Suspended-sediment concentration data were collected in San Francisco Bay during water year 2002 (October 1, 2001-September 30, 2002). Optical backscatterance sensors and water samples were used to monitor suspended sediment at two sites in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two depths at most sites. Water samples were collected periodically and were analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the electrical output of the optical backscatterance sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes the suspended-sediment concentration data collected from October 2001 through September 2002. Calibration curves and plots of edited data for each sensor also are presented.

Buchanan, Paul A.; Ganju, Neil K.

2004-01-01

233

Integration of Pseudomonas aeruginosa and Legionella pneumophila in drinking water biofilms grown on domestic plumbing materials.  

PubMed

Drinking water biofilms were grown on coupons of plumbing materials, including ethylene-propylene-diene-monomer (EPDM) rubber, silane cross-linked polyethylene (PE-X b), electron-ray cross-linked PE (PE-X c) and copper under constant flow-through of cold tap water. After 14 days, the biofilms were spiked with Pseudomonas aeruginosa, Legionella pneumophila and Enterobacter nimipressuralis (10(6) cells/mL each). The test bacteria were environmental isolates from contamination events in drinking water systems. After static incubation for 24 h, water flow was resumed and continued for 4 weeks. Total cell count and heterotrophic plate count (HPC) of biofilms were monitored, and P. aeruginosa, L. pneumophila and E. nimipressuralis were quantified, using standard culture-based methods or culture-independent fluorescence in situ hybridization (FISH). After 14 days total cell counts and HPC values were highest on EPDM followed by the plastic materials and copper. P. aeruginosa and L. pneumophila became incorporated into drinking water biofilms and were capable to persist in biofilms on EPDM and PE-X materials for several weeks, while copper biofilms were colonized only by L. pneumophila in low culturable numbers. E. nimipressuralis was not detected in any of the biofilms. Application of the FISH method often yielded orders of magnitude higher levels of P. aeruginosa and L. pneumophila than culture methods. These observations indicate that drinking water biofilms grown under cold water conditions on domestic plumbing materials, especially EPDM and PE-X in the present study, can be a reservoir for P. aeruginosa and L. pneumophila that persist in these habitats mostly in a viable but non-culturable state. PMID:20556878

Moritz, Miriam M; Flemming, Hans-Curt; Wingender, Jost

2010-06-01

234

Assessing the occurrence and distribution of pyrethroids in water and suspended sediments  

USGS Publications Warehouse

The distribution of pyrethroid insecticides in the environment was assessed by separately measuring concentrations in the dissolved and suspended sediment phases of surface water samples. Filtered water was extracted by HLB solid-phase extraction cartridges, while the sediment on the filter was sonicated and cleaned up using carbon and aluminum cartridges. Detection limits for the 13 pyrethroids analyzed by gas chromatography-tandem mass spectrometry were 0.5 to 1 ng L-1 for water and 2 to 6 ng g for the suspended sediments. Seven pyrethroids were detected in six water samples collected from either urban or agricultural creeks, with bifenthrin detected the most frequently and at the highest concentrations. In spiked water samples and field samples, the majority of the pyrethroids were associated with the suspended sediments.

Hladik, M.L.; Kuivila, K.M.

2009-01-01

235

A vacuum-operated pore-water extractor for estuarine and freshwater sediments  

USGS Publications Warehouse

A vacuum-operated pore-water extractor for estuarine and freshwater sediments was developed and constructed from a fused-glass air stone attached with aquarium airline tubing to a 30 or 60 cc polypropylene syringe. Pore water is extracted by inserting the air stone into the sediment and creating a vacuum by retracting and bracing the syringe plunger. A hand-operated vacuum pump attached to a filtration flask was also evaluated as an alternative vacuum source. The volume and time to extract pore water varies with the number of devices and the sediment particle size. Extraction time is longer for fine sediments than for sandy sediments. Four liters of sediment generally yield between 500 and 1,500 mL of pore water. The sediment that surrounds and accumulates on the air stone acts as a filter, and, except for the first few milliliters, the collected pore water is clear. Because there is no exposure to air or avenue for escape, volatile compounds andin situ characteristics are retained in the extracted pore water.

Winger, P.V.; Lasier, P.J.

1991-01-01

236

Ecological risk assessment of urban creek sediments contaminated by untreated domestic wastewater: potential contribution of antimicrobials and a musk fragrance.  

PubMed

Despite the fact that some hydrophobic pharmaceuticals and personal care products (PPCPs) have been found to accumulate in river sediments, little is known about the contribution of these compounds to the toxicity of the whole sediment. We sampled river sediments from two urban creeks with an unsewered drainage area to investigate the toxicity for a benthic organism, Chironomus yoshimatsui. The concentrations of selected hydrophobic PPCPs, triclosan (TCS), triclocarban (TCC) and galaxolide (HHCB) were analysed using gas chromatographic mass spectroscopy or liquid chromatographic mass spectroscopy and were found to lie within the range 50 to 200 ng g(-1). The toxicity of the three individual contaminants for the chironomid was also determined. The toxicity of TCC was found to be the strongest, with an NOEC value of 2.5 microg g(-1). Combining the toxicity and measured environmental concentration, the ecological risk was assessed and the contribution of these contaminants to the whole sediment toxicity estimated, assuming additivity. The hazard quotient of all three compounds, determined without assessment factor, ranged between 0.01 and 0.1. The combined contribution of the three compounds to total sediment toxicity was as high as 8.2%, but other unknown factors may also make an important contribution. PMID:24191491

Tamura, Ikumi; Kimura, Kumiko; Kameda, Yutaka; Nakada, Norihide; Yamamoto, Hiroshi

2013-01-01

237

Heavy metals in the bed and suspended sediments of Anyang River, Korea: implications for water quality.  

PubMed

The objective of this study is to compare Anyang River bed sediments with water chemical composition and to assess the anthropogenic chemical inputs into the river system. Eight sampling locations were chosen along the river channel. Bed and suspended river sediments and water samples were collected, and analyzed for their chemical and physical composition. Data revealed that trace element concentrations in the river water were generally below world average, except for As, Mn, Ni and Cr. Among the three phases: water, bed and suspended sediment, more than 99% of the trace elements was associated with the bed sediment. Concentrations of trace elements in the sediment were a function a particle size distribution and organic content. The calculated degrees of enrichment based on the least influenced sample (ASD 1) indicated the river sediments were enriched with respect to background. The enrichment factors for Pb, Zn and As were relatively lower than for Cr, Co, Ni and Zn. The difference in the enrichment seems to reflect the human activities influence in the basin, and specially for Cd. Speciation of the elements in the five different chemical forms in the sediment by sequential extraction indicated that the reducible fraction was predominant for Fe, Zinc and Cu showed an irregular variation among the different fractions; whereas, Cd and Pb were more regular. Zinc and Cu highly existed mostly in exchangeable forms. Acid soluble and reducible forms were also important for most metals. The speciation implies that the metals associated with the sediment are subject to release into water bodies as goechemical variables (pH and Eh) change. Currently, the introduced metals are deposited near the source area and are mostly associated with the sediment, implying that the river bed sediment acts mainly as a sink, rather than a pool. The accumulated and enriched toxic trace elements can pose a potential pollution of river water. PMID:14740987

Lee, Sanghoon; Moon, Ji-Won; Moon, Hi-Soo

2003-12-01

238

Exergetic modeling and assessment of solar assisted domestic hot water tank integrated ground-source heat pump systems for residences  

Microsoft Academic Search

The present study deals with the exergetic modeling and performance evaluation of solar assisted domestic hot water tank integrated ground-source heat pump (GSHP) systems for residences for the first time to the best of the author's knowledge. The model is applied to a system, which mainly consists of (i) a water-to-water heat pump unit (ii) a ground heat exchanger system

Arif Hepbasli

2007-01-01

239

Physiological Response of Rainbow Trout to Sediment Released during Open-Cut Pipeline Water Crossing Construction  

Microsoft Academic Search

The physiological response of rainbow trout exposed to elevated suspended sediment concentrations downstream of two open-cut pipeline water crossings was investigated. Trout held in cages downstream of construction had increased respiration rates and shorter times till loss of equilibrium during sealed jar bioassays. Differences in blood hematocrit levels between experiments and transects is attributed to sediment concentration and particle size.

SCOTT M. REID; GLENN ISAAC; SERGE METIKOSH; JIM EVANS

2003-01-01

240

THE EFFECT OF LAKE ERIE WATER LEVEL VARIATIONS ON SEDIMENT RESUSPENSION  

E-print Network

THE EFFECT OF LAKE ERIE WATER LEVEL VARIATIONS ON SEDIMENT RESUSPENSION A Thesis Presented level on Lake Erie may result in increased applied fluid forces at the lake bed. In places where the previously deposited sediments have been exposed to toxic pollutants, it is important to identify possible

Foster, Diane

241

Distribution of trace metals in the Odra River system: Water–suspended matter–sediments  

Microsoft Academic Search

Extensive investigations of trace metals concentrations in water, suspended particulate matter (SPM) and bottom sediments of the whole Odra River system were carried out over the years 1997–2000. The vertical distribution of selected metals and their mobility were also studied in the sediment cores from upper and middle river sections. Significant levels of metal contamination were found. Median concentrations (Cd,

Edeltrauda Helios Rybicka; Ewa Adamiec; Urszula Aleksander-Kwaterczak

2005-01-01

242

The Salmon Disturbance Regime: Effects on Biofilm, Sediment and Water Sam J. Albers  

E-print Network

The Salmon Disturbance Regime: Effects on Biofilm, Sediment and Water by Sam J. Albers BSc biofilms suggesting a po- tential floc trapping mechanism that drives biofilm growth. Using the Horsefly spawning channel, the role of biofilms in trapping fine sediment was evaluated as a mechanism of salmon

Northern British Columbia, University of

243

STUDIES OF BENZIDINE-BASED DYES IN SEDIMENT-WATER SYSTEMS  

EPA Science Inventory

The sorption and degradation of several benzidine-based dyes were studied in sediment-water systems. tudies in resaturated sediment demonstrated that sorption was strongly dependent on pH and the nature and concentration of the inorganic salt in solution. egradation of the dyes i...

244

DEGRATION OF SELECTED HALOGENATED ETHANES IN ANOXIC SEDIMENT-WATER SYSTEMS  

EPA Science Inventory

The degradation of selected halogenated ethanes was studied in anoxic sediment-water suspensions at 1 to 20% sediment concentrations. Batch kinetic experiments were used to quantify decay. Eh measurements of all suspensions were below -100mV (vs SHE), indicating reduced environme...

245

Organic pollutants in mussels and sediments of the coastal waters off Perth, Western Australia  

Microsoft Academic Search

The results of a survey of organic pollutants in the marine sediments and the common mussel, Mytilus edulis, from the southern metropolitan coastal waters off Perth are presented. Organophosphorus and organochlorine pesticides, polychlorinated biphenyls, aliphatic and polycyclic aromatic hydrocarbons and organotin compounds were analysed in surficial (top 20 mm) sediments from 175 sites and in mussel tissue from 35 sites

James S. Burt; Geoff F. Ebell

1995-01-01

246

Phosphorus in sediments and pore waters of selected Polish dam reservoirs  

Microsoft Academic Search

This study aimed to examine and explain the spatial distribution of total phosphorus in sediments and orthophosphates in interstitial water in four Polish dam reservoirs with varying hydrological and geochemical characteristics. The results are linked to physicochemical parameters of sediments: organic matter and calcium carbonates content, pH, redox potential and conductivity. In two of the studied reservoirs hydrological dynamics were

Adriana Trojanowska; Piotr Jezierski

2011-01-01

247

SURVIVAL OF 'DAPHNIA MAGNA' AND 'HYALELLA AZTECA' IN CADMIUM-SPIKED WATER AND SEDIMENT  

EPA Science Inventory

Freshwater sediments and water were spiked with cadmium (Cd) in the laboratory, and toxicity tests were conducted with the cladoceran Daphnia magna and the amphipod Hyalella azteca to determine if Cd in the sediment would cause increased toxicity. The 48-h LC50 values for Daphnia...

248

Partitioning of Cs137 Between Sediment and Water From the Black Sea  

Microsoft Academic Search

As part of a joint USA\\/USSR Environmental Agreement to determine the distribution and concentration of Chernobyl radioactivity in the northwest Black Sea area, the sediment from eight stations was collected and analyzed to assess the ability of this material to adsorb radiocaesium. Batch tests were conducted in which Cs-137 tracer was added to mixtures of sediment and bottom water, with

M. Fuhrmann; R. Pietrzak; J. Neiheisel; R. Dyer

1992-01-01

249

A reservoir operating method for riverine ecosystem protection, reservoir sedimentation control and water supply  

NASA Astrophysics Data System (ADS)

Riverine ecosystem protection requires the maintenance of natural flow and sediment regimes downstream from dams. In reservoir management schedules this requirement should be integrated with sedimentation control and human water supply. However, traditional eco-friendly reservoir operating methods have usually only considered the natural flow regime. This paper seeks to develop a reservoir operating method that accounts for both the natural flow and sediment regimes as well as optimizing the water supply allocations. Herein, reservoir water level (RWL), sediment-occupied ratio of reservoir volume (SOR) and rate of change of SOR (RCSOR) are adopted as three triggers of a drawdown-flushing-based sediment management policy. Two different groups of reservoir operating rule curves (RORCs) are designed for sediment-flushing and non-sediment-flushing years, and the three triggers, RWL, SOR and RCSOR, are used to change the “static” RORCs to “dynamic” ones. The approach is applied to the Wangkuai Reservoir, China to test its effectiveness. This shows that the approach can improve the flexibility of reservoir operators to balance the reservoir management, water supply management and the flow and sediment needs of the downstream riverine ecosystem.

Yin, Xin-An; Yang, Zhi-Feng; Petts, Geoffrey E.; Kondolf, G. Mathias

2014-05-01

250

A probe for sampling interstitial waters of stream sediments and bog soils  

USGS Publications Warehouse

A probe for sampling interstitial waters of stream sediments and bog soils is described. Samples can be obtained within a stratigraphic interval of 2-3 cm, to a depth of 60-80 cm, and with little or no contamination of the samples by sediment or air. ?? 1974.

Nowlan, G.A.; Carollo, C.

1974-01-01

251

AUTOMATED LONG-TERM REMOTE MONITORING OF SEDIMENT-WATER INTERFACIAL FLUX  

EPA Science Inventory

Advective flux across the sediment-water interface is temporally and spatially heterogeneous in nature. For contaminated sediment sites, monitoring spatial as well as temporal variation of advective flux is of importance to proper risk management. This project was conducted to ...

252

Factors regulating recruitment from the sediment to the water column in the bloom-forming cyanobacterium Gloeotrichia echinulata  

Microsoft Academic Search

SUMMARY 1. The influence of light, temperature, sediment mixing and sediment origin (water depth) on the recruitment of the cyanobacterium Gloeotrichia echinulata was examined in the laboratory. 2. Light and temperature were the most important factors initiating germination in G. echinulata. 3. The extent of germination (recruited biovolume) was mainly regulated by temperature and sediment mixing. Furthermore, sediment mixing significantly

IRENE K ARLSSON-ELFGREN; K ARIN R ENGEFORS; S USANNE G USTAFSSON

253

Towards the development of a combined Norovirus and sediment transport model for coastal waters  

NASA Astrophysics Data System (ADS)

Sewage effluent in coastal waters used for oyster culture poses a risk to human health. The primary pathogen in outbreaks of gastroenteritis following consumption of raw oysters is the Norovirus or "winter vomiting bug". The Norovirus is a highly infectious RNA virus of the Caliciviridae taxonomic family. It has a long survival time in coastal waters (T90 = 30 days in winter). Oysters selectively concentrate Norovirus in their digestive ducts. The virus cannot be removed by conventional depuration. The primary goal of the research is to quantify the risk of Norovirus infection in coastal waters through physically-based high-resolution numerical modelling. Cork Harbour and Clew Bay in Ireland provide case studies for the research. The models simulate a number of complex physical, chemical and biological processes which influence the transport and decay of the virus as well as its bioaccumulation in oyster tissue. The current phase of the research is concerned with the adsorption of the virus to suspended sediment in the water column. Adsorbed viruses may be taken out of the water column when sedimentation occurs and, subsequently, be added to it with resuspension of the bed sediment. Preliminary simulations of the Norovirus-sediment model indicate that suspended sediment can influence the transport of the virus in coastal waters when a high sediment-water partitioning coefficient is used and the model is run under calm environmental conditions. In this instance a certain fraction of the adsorbed viruses are taken out of the water column by sedimentation and end up locked in the bed sediment. Subsequently, under storm conditions, a large number of viruses in the bed are released into the water column by erosion of the bed and a risk of contamination occurs at a time different to when the viruses were initially released into the body of water.

Barry, K.; O'Kane, J. P. J.

2009-04-01

254

Evaluation of natural radioactivity in soil, sediment and water samples of Niger Delta (Biseni) flood plain lakes, Nigeria.  

PubMed

This paper presents the findings of a baseline study undertaken to evaluate the natural radioactivity levels in soil, sediment and water samples in four flood plain lakes of the Niger Delta using a hyper pure germanium (HPGe) detector. The activity profile of radionuclides shows low activity across the study area. The mean activity level of the natural radionuclides (226)Ra, (232)Th and (40)K is 20 ± 3, 20 ± 3 and 180 ± 50 Bq kg(-1), respectively. These values are well within values reported elsewhere in the country and in other countries with similar environments. The study also examined some radiation hazard indices. The mean values obtained are, 76 ± 14 Bq kg(-1), 30 ± 5.5 ?Gy h(-1), 37 ± 6.8 ?Sv y(-1), 0.17 and 0.23 for Radium Equivalent Activity (Ra(eq)), Absorbed Dose Rates (D), Annual Effective Dose Rates (E(ff) Dose), External Hazard Index (H(ex)) and Internal Hazard Index (H(in)) respectively. All the health hazard indices are well below their recommended limits. The soil and sediments from the study area provide no excessive exposures for inhabitants and can be used as construction materials without posing any significant radiological threat to the population. The water is radiologically safe for domestic and industrial use. The paper recommends further studies to estimate internal and external doses from other suspected radiological sources to the population of the Biseni kingdom. PMID:21514983

Agbalagba, E O; Onoja, R A

2011-07-01

255

Contamination of nonylphenolic compounds in creek water, wastewater treatment plant effluents, and sediments from Lake Shihwa and vicinity, Korea: Comparison with fecal pollution  

USGS Publications Warehouse

Nonylphenolic compounds (NPs), coprostanol (COP), and cholestanol, major contaminants in industrial and domestic wastewaters, were analyzed in creek water, wastewater treatment plant (WWTP) effluent, and sediment samples from artificial Lake Shihwa and its vicinity, one of the most industrialized regions in Korea. We also determined mass discharge of NPs and COP, a fecal sterol, into the lake, to understand the linkage between discharge and sediment contamination. Total NP (the sum of nonylphenol, and nonylphenol mono- and di-ethoxylates) were 0.32–875 ?g L-1 in creeks, 0.61–87.0 ?g L-1 in WWTP effluents, and 29.3–230 ?g g-1 TOC in sediments. Concentrations of COP were 0.09–19.0 ?g L-1 in creeks, 0.11–44.0 ?g L-1 in WWTP effluents, and 2.51–438 ?g g-1 TOC in sediments. The spatial distributions of NPs in creeks and sediments from the inshore region were different from those of COP, suggesting that Lake Shihwa contamination patterns from industrial effluents differ from those from domestic effluents. The mass discharge from the combined outfall of the WWTPs, located in the offshore region, was 2.27 kg d-1 for NPs and 1.00 kg d-1 for COP, accounting for 91% and 95% of the total discharge into Lake Shihwa, respectively. The highest concentrations of NPs and COP in sediments were found in samples at sites near the submarine outfall of the WWTPs, indicating that the submarine outfall is an important point source of wastewater pollution in Lake Shihwa.

Choi, Minkyu; Furlong, Edward T.; Moon, Hyo-Bang; Yu, Jun; Choi, Hee-Gu

2011-01-01

256

Contamination of nonylphenolic compounds in creek water, wastewater treatment plant effluents, and sediments from Lake Shihwa and vicinity, Korea: comparison with fecal pollution.  

PubMed

Nonylphenolic compounds (NPs), coprostanol (COP), and cholestanol, major contaminants in industrial and domestic wastewaters, were analyzed in creek water, wastewater treatment plant (WWTP) effluent, and sediment samples from artificial Lake Shihwa and its vicinity, one of the most industrialized regions in Korea. We also determined mass discharge of NPs and COP, a fecal sterol, into the lake, to understand the linkage between discharge and sediment contamination. Total NP (the sum of nonylphenol, and nonylphenol mono- and di-ethoxylates) were 0.32-875 ?g L(-1) in creeks, 0.61-87.0 ?g L(-1) in WWTP effluents, and 29.3-230 ?g g(-1) TOC in sediments. Concentrations of COP were 0.09-19.0 ?g L(-1) in creeks, 0.11-44.0 ?g L(-1) in WWTP effluents, and 2.51-438 ?g g(-1) TOC in sediments. The spatial distributions of NPs in creeks and sediments from the inshore region were different from those of COP, suggesting that Lake Shihwa contamination patterns from industrial effluents differ from those from domestic effluents. The mass discharge from the combined outfall of the WWTPs, located in the offshore region, was 2.27 kg d(-1) for NPs and 1.00 kg d(-1) for COP, accounting for 91% and 95% of the total discharge into Lake Shihwa, respectively. The highest concentrations of NPs and COP in sediments were found in samples at sites near the submarine outfall of the WWTPs, indicating that the submarine outfall is an important point source of wastewater pollution in Lake Shihwa. PMID:21890169

Choi, Minkyu; Furlong, Edward T; Moon, Hyo-Bang; Yu, Jun; Choi, Hee-Gu

2011-11-01

257

Remote sensing of suspended sediment water research: principles, methods, and progress  

NASA Astrophysics Data System (ADS)

In this paper, we reviewed the principle, data, methods and steps in suspended sediment research by using remote sensing, summed up some representative models and methods, and analyzes the deficiencies of existing methods. Combined with the recent progress of remote sensing theory and application in water suspended sediment research, we introduced in some data processing methods such as atmospheric correction method, adjacent effect correction, and some intelligence algorithms such as neural networks, genetic algorithms, support vector machines into the suspended sediment inversion research, combined with other geographic information, based on Bayesian theory, we improved the suspended sediment inversion precision, and aim to give references to the related researchers.

Shen, Ping; Zhang, Jing

2011-12-01

258

Spatial Variability of Metals in Surface Water and Sediment in the Langat River and Geochemical Factors That Influence Their Water-Sediment Interactions  

PubMed Central

This paper determines the controlling factors that influence the metals' behavior water-sediment interaction facies and distribution of elemental content (75As, 111Cd, 59Co, 52Cr, 60Ni, and 208Pb) in water and sediment samples in order to assess the metal pollution status in the Langat River. A total of 90 water and sediment samples were collected simultaneously in triplicate at 30 sampling stations. Selected metals were analyzed using ICP-MS, and the metals' concentration varied among stations. Metal concentrations of water ranged between 0.08–24.71??g/L for As, <0.01–0.53??g/L for Cd, 0.06–6.22??g/L for Co, 0.32–4.67??g/L for Cr, 0.80–24.72??g/L for Ni, and <0.005–6.99??g/L for Pb. Meanwhile, for sediment, it ranged between 4.47–30.04?mg/kg for As, 0.02–0.18?mg/kg for Cd, 0.87–4.66?mg/kg for Co, 4.31–29.04?mg/kg for Cr, 2.33–8.25?mg/kg for Ni and 5.57–55.71?mg/kg for Pb. The average concentration of studied metals in the water was lower than the Malaysian National Standard for Drinking Water Quality proposed by the Ministry of Health. The average concentration for As in sediment was exceeding ISQG standards as proposed by the Canadian Sediment Quality Guidelines. Statistical analyses revealed that certain metals (As, Co, Ni, and Pb) were generally influenced by pH and conductivity. These results are important when making crucial decisions in determining potential hazardous levels of these metals toward humans. PMID:22919346

Lim, Wan Ying; Aris, Ahmad Zaharin; Zakaria, Mohamad Pauzi

2012-01-01

259

Application of multi-objective technique in modeling water and sediment flow in river reaches  

NASA Astrophysics Data System (ADS)

Usually water resources problems consist of multiple objectives that may be conflicting and competing in nature. To evaluate optimal water resources system performances often it is required to obtain a compromise solution satisfying several goals and objectives. For example, in the case of multipurpose reservoir operations, a number of conflicting and competing purposes such as supply of water for conservation uses, downstream flood control, hydropower generation and related environmental objectives are to be optimally satisfied. It may be noted that for deriving maximum benefit from conservation uses reservoir storage should be as high as possible; on the other hand to achieve maximum flood control benefits the storage should be kept as low as possible. Since flood control and conservation objectives are conflicting in nature, higher achievement in flood control objective results in lower attainment of the conservation objectives. In other areas of water resources such as, rainfall runoff modeling, water quality problems, watershed management etc often a number of objectives are required to be satisfied to derive optimal system performances. It is known that one prominent cause of soil erosion and runoff generation from a catchment is related to the effect of rainfall over the catchment and thus water and the sediment discharge at a river station are mainly depended on rainfall and the catchment characteristics. Water and sediment discharge for a river section can be considered as two outputs due to a rainfall input over the catchment. To describe sediment and water flow through river reaches usually separate models are used and the model parameters are estimated using single/multiple optimization routines. Since water and sediment flow are effects with a common cause, a new model can be obtained that can quantify and explain both the effects that is, flow of sediment and water in a river course. In the present study, application of multiple objective optimization technique has described in obtaining parameters of the integrated water-sediment flow model. The integrated model needs to be calibrated using both water and sediment data for a river reach and requires separate objective functions to independently match water and sediment flow variations for a station. The integrated model describing two hydrological variables is highly nonlinear with exponential model form and requires efficient algorithm to identify model parameters. Multiple objectives were framed to calibrate the model using water and sediment data and the model parameters were estimated applying non-dominated sorting genetic algorithm (NSGA-II). The proposed model formulations are demonstrated for simulating suspended sediment load and water discharge in the Mississippi River Basin, USA. Results obtained show that an integrated model having multiple objectives can be developed to describe two hydrological variables with satisfactory performances.

Sil, Briti Sundar; Choudhury, Parthasarathi

2010-10-01

260

Metal leaching in drinking water domestic distribution system: an Italian case study.  

PubMed

The objective of this study was to evaluate metal contamination of tap water in seven public buildings in Brescia (Italy). Two monitoring periods were performed using three different sampling methods (overnight stagnation, 30-min stagnation, and random daytime). The results show that the water parameters exceeding the international standards (Directive 98/83/EC) at the tap were lead (max = 363??g/L), nickel (max = 184??g/L), zinc (max = 4900??g/L), and iron (max = 393??g/L). Compared to the total number of tap water samples analyzed (122), the values higher than limits of Directive 98/83/EC were 17?% for lead, 11?% for nickel, 14?% for zinc, and 7?% for iron. Three buildings exceeded iron standard while five buildings exceeded the standard for nickel, lead, and zinc. Moreover, there is no evident correlation between the leaching of contaminants in the domestic distribution system and the age of the pipes while a significant influence is shown by the sampling methods. PMID:24382119

Sorlini, Sabrina; Gialdini, Francesca; Collivignarelli, Carlo

2014-12-01

261

Partition of nonpolar organic pollutants from water to soil and sediment organic matters  

USGS Publications Warehouse

The partition coefficients (Koc) of carbon tetrachloride and 1,2-dichlorobenzene between normal soil/sediment organic matter and water have been determined for a large set of soils, bed sediments, and suspended solids from the United States and the People's Republic of China. The Koc values for both solutes are quite invariant either for the soils or for the bed sediments; the values on bed sediments are about twice those on soils. The similarity of Koc values between normal soils and between normal bed sediments suggests that natural organic matters in soils (or sediments) of different geographic origins exhibit comparable polarities and possibly comparable compositions. The results also suggest that the process that converts eroded soils into bed sediments brings about a change in the organic matter property. The difference between soil and sediment Koc values provides a basis for identifying the source of suspended solids in river waters. The very high Koc values observed for some special soils and sediments are diagnostic of severe anthropogenic contamination.

Chiou, C.T.

1995-01-01

262

Three-dimensional acoustic propagation through shallow water internal, surface gravity and bottom sediment waves  

E-print Network

This thesis describes the physics of fully three-dimensional low frequency acoustic interaction with internal waves, bottom sediment waves and surface swell waves that are often observed in shallow waters and on continental ...

Shmelev, Alexey Alexandrovich

2011-01-01

263

30 CFR 77.216-5 - Water, sediment or slurry impoundments and impounding structures; abandonment.  

This plan shall provide for major slope stability, include a schedule for the plan's implementation and, except as provided in paragraph (b) of this section, contain provisions to preclude the probability of future impoundment of water, sediment, or...

2014-07-01

264

30 CFR 77.216-5 - Water, sediment or slurry impoundments and impounding structures; abandonment.  

Code of Federal Regulations, 2013 CFR

This plan shall provide for major slope stability, include a schedule for the plan's implementation and, except as provided in paragraph (b) of this section, contain provisions to preclude the probability of future impoundment of water, sediment, or...

2013-07-01

265

30 CFR 77.216-5 - Water, sediment or slurry impoundments and impounding structures; abandonment.  

Code of Federal Regulations, 2012 CFR

This plan shall provide for major slope stability, include a schedule for the plan's implementation and, except as provided in paragraph (b) of this section, contain provisions to preclude the probability of future impoundment of water, sediment, or...

2012-07-01

266

VISUALIZING THE RELATIONSHIP OF PBTS IN WATER AND SEDIMENT TO RESIDUES IN FISH  

EPA Science Inventory

Bioaccumulation of persistent bioaccumulative toxicants (PBTs) in aquatic organisms results from uptake of the chemicals through several different exposure routes associated with water, sediment, and biota. This paper presents an approach for depicting and interpreting bioaccumul...

267

Distribution of Bdellovibrio bacteriovorus in sewage works, river water, and sediments.  

PubMed Central

Bdellovibrio was found in all liquid phases of the sewage works examined. The predator was also found in all the river sediments and sewage-polluted river waters examined but could not be found in some unpolluted river waters. Bdellovibrio was able to multiply on the high numbers of bacteria present in the aerobic percolating filter film but could not survive in anaerobic sludge. Similarly, the predator was present in the aerobic surface layers of river sediments but not in the anaerobic bottom layers. The major source of Bdellovibrio in the polluted rivers examined were sewage works effluents, and numbers in both river water and sediment were correlated with river water quality. It was unlikely that Bdellovibrio was important in reducing numbers of other bacteria in either sewage or river sediment. PMID:1267445

Fry, J C; Staples, D G

1976-01-01

268

Water and Sediment Quality in the Yukon River and its Tributaries Between Atlin, British  

E-print Network

Water and Sediment Quality in the Yukon River and its Tributaries Between Atlin, British Columbia in the Yukon River and its tributaries between Atlin, British Columbia, Canada, and Eagle, Alaska, USA, 2004: U ................................................................................................................................. 19 Big Salmon River

269

The influence of lagoon on neighboring rivers by water and sediment quality.  

PubMed

Canonical discriminant analysis (CDA) was applied in order to distinguish the water-quality and the sediment-quality parameters from neighboring rivers, and to recognize similarities of water and sediment properties between a lagoon and neighboring rivers. Two set of constructed discriminant functions showed a marked contribution to most of the discriminant variables. In water, the significant parameters - the total nitrogen, algae, dissolved oxygen and total phosphate - were combined as the nutrient effect factor. The recognition capacities of the two discriminant functions were 95.6 and 4.4%, respectively; the Kaoping River showed the most similarities with the water quality in Dapeng Bay; in sediment, the significant parameters porosity, Cd, Cr, Al, and Pb were combined as the heavy metal effect factor. The recognition capacities were 82.6 and 17.4%, respectively, but the sediment properties in these three rivers had no significant similarity with the Dapeng Bay. PMID:20453320

Lai, W L; Chen, J J; Chung, C Y; Lee, C G; Liao, S W

2010-01-01

270

Sediment-water distribution of perfluorooctane sulfonate (PFOS) in Yangtze River Estuary.  

PubMed

Analysis of Perfluorooctane sulfonate (PFOS) distribution in water and sediment in Yangtze River Estuary showed that the estuary was a sink for PFOS. Salinity was an important parameter in controlling the sediment-water interactions and the fate or transport of PFOS in the aquatic environment. As the salinity (S per thousand) increased from 0.18 to 3.31, the distribution coefficient (K(d)) between sediment and water linearly increased from 0.76 to 4.70 L g(-1). The study suggests that PFOS may be carried with the river water and transported for long distances before it reaches to the sea and largely scavenged to the sediment in the estuaries due to the dramatic change in salinity. PMID:20170997

Pan, Gang; You, Chun

2010-05-01

271

PRECISION OF DIALYSIS (PEEPER) SAMPLING OF CADMIUM IN MARINE SEDIMENT INTERSTITIAL WATER  

EPA Science Inventory

Isolating and analyzing interstitial water (IW) during sediment toxicity tests enables researchers to relate concentrations of contaminants to responses of organisms, particularly when IW is a primary route of exposure to bioavailable contaminants by benthic dwelling organisms. W...

272

The role of sediments in the phosphorus cycle in Lake Lugano. II. Seasonal and spatial variability of microbiological processes at the sediment-water interface  

Microsoft Academic Search

P, Fe, Mn, and S species were analyzed in water samples from the sediment-water interface collected at four seasonally different times during the course of a year at two sampling sites in the southern basin of Lake Lugano (Lago di Lugano). The results reveal the strong influence of the biogeochemical processes in the sediment on the chemical composition of the

Maja A. Lazzaretti; Kurt W. Hanselmann; Helmut Brandl; Daniel Span; Reinhard Bachofen

1992-01-01

273

ENTRAINMENT OF SEDIMENTS AND DREDGED MATERIALS IN SHALLOW LAKE WATERS  

EPA Science Inventory

Results of recent laboratory experiments concerned with the ntrainment and deposition of sediment is in lakes are reported. rom these experiments and other recent work, quantitative descriptions and parameterizations of entrainment and deposition processes are made. n the interpr...

274

Superficial deep-water sediments of the Eastern Marmara Basin  

NASA Astrophysics Data System (ADS)

Superficial sediments (top ˜ Im) of the Eastern Mediterranean Basin, Sea of Marmara, Turkey accumulated rapidly (0.087 ± 0.012 g/cm2 · y) by hemipelagic sedimentation with only limited amounts of gravity flow or bottom current action under low oxygenated but not anoxic conditions. They have restricted faunas, relatively higher organic carbon (1 1.8%) and lower calcium carbonate (14 20%) contents than other Eastern Mediterranean Basin sediments. Sedimentation shows little change over the last millenium except for an increase in Cu, Zn, Pb, Cr, and P over the last few centuries. The increase was most likely caused by increased metallurgical activities since the eighteenth century but are not at sufficient levels for the area to be regarded as polluted.

Evans, G.; Erten, H.; Alavi, S. N.; von Gunten, H. R.; Ergin, M.

1989-03-01

275

Hydrothermal sediments are a source of water column Fe and Mn in the Bransfield Strait, Antarctica  

NASA Astrophysics Data System (ADS)

Short sediment cores were collected from ?1100 m water depth at the top of Hook Ridge, a submarine volcanic edifice in the Central Basin of the Bransfield Strait, Antarctica, to assess Fe and Mn supply to the water column. Low-temperature hydrothermal fluids advect through these sediments and, in places, subsurface H2S is present at high enough concentrations to support abundant Sclerolinum sp., an infaunal tubeworm that hosts symbiotic thiotrophic bacteria. The water column is fully oxic, and oxygen penetration depths at all sites are 2-5 cmbsf. Pore water Fe and Mn content is high within the subsurface ferruginous zone (max. 565 ?mol Fe L-1, >3-7 cmbsf)-14-18 times higher than values measured at a nearby, background site of equivalent water depth. Diffusion and advection of pore waters supply significant Fe and Mn to the surface sediment. Sequential extraction of the sediment demonstrates that there is a significant enrichment in a suite of reactive, authigenic Fe minerals in the upper 0-5 cm of sediment at one site characterised by weathered crusts at the seafloor. At a site with only minor authigenic mineral surface enrichment we infer that leakage of pore water Fe and Mn from the sediment leads to enriched total dissolvable Fe and Mn in bottom waters. An Eh sensor mounted on a towed package mapped a distinct Eh signature above this coring site which is dispersed over several km at the depth of Hook Ridge. We hypothesise that the main mechanism for Fe and Mn efflux from the sediment is breach of the surface oxic layer by the abundant Sclerolinum sp., along with episodic enhancements by physical mixing and resuspension of sediment in this dynamic volcanic environment. We propose that Hook Ridge sediments are an important source of Fe and Mn to the deep waters of the Central Basin in the Bransfield Strait, where concentrations are sustained by the benthic flux, and Fe is stabilised in the water column as either colloidal phases or ligand-bound dissolved species. Entrainment of this water mass into the Drake Passage and thereby the Antarctic Circumpolar Current could provide a significant metal source to this HNLC region of the Southern Ocean if mixing and upwelling occurs before removal of this metal pool to underlying sediments. Sediment-covered volcanic ridges are common within rifted margins and may play a previously overlooked role in the global Fe cycle.

Aquilina, Alfred; Homoky, William B.; Hawkes, Jeffrey A.; Lyons, Timothy W.; Mills, Rachel A.

2014-07-01

276

Effects of sediment transport and seepage direction on hydraulic properties at the sediment-water interface of hyporheic settings  

USGS Publications Warehouse

Relations between seepage flux and hydraulic properties are difficult to quantify in fluvial settings because of the difficulty in measuring these variables in situ. Tests conducted in a 1.5-m diameter by 1.5-m tall sediment-filled tank indicate that hydraulic gradient increased and hydraulic conductivity (K) decreased following the onset of downward seepage but both parameters were little changed following the onset of upward seepage. Reductions in K during downward seepage were more pronounced when surface-water current was sufficient to mobilize sediment on the bed. Averaged ratios of K determined during upward seepage to K determined during downward seepage (Kup/Kdown) through a sand-and-gravel bed increased from 1.4 to 1.7 with increasing surface-water velocity, and decreased to slightly greater than 1 when the sediment bed became fully mobile. Kup/Kdown for tests conducted with a silt veneer on the bed surface was greater than 2 for all but the fastest surface-water velocities. Substantial reductions in K also were associated with a silt floc that formed on the bed surface during and following test runs. Although the silt floc was typically less than 0.5 mm in thickness, most of the hydraulic gradient was distributed across this thin layer. K of the thin silt floc was reduced by two to three orders of magnitude relative to the underlying sediment. Directional bias in K and relation between K and surface-water velocity require the presence or absence of a layer of lower-K sediment at or near the bed surface, without which no reduction in K and corresponding increase in hydraulic gradient can occur at the bed surface. The lack of prior observation of the consistent bias in K associated with seepage direction is somewhat surprising given the numerous studies where K has been measured in fluvial settings, but may be explained by the small value of the bias relative to the typical uncertainty associated with field determinations of K. If shown to exist in field settings, this bias and its relation to fluvial processes will be relevant to many studies conducted in hyporheic settings that require determination of fluxes across the sediment-water interface.

Rosenberry, D. O.; Pitlick, J.

2009-01-01

277

Effects of sediment transport and seepage direction on hydraulic properties at the sediment-water interface of hyporheic settings  

NASA Astrophysics Data System (ADS)

SummaryRelations between seepage flux and hydraulic properties are difficult to quantify in fluvial settings because of the difficulty in measuring these variables in situ. Tests conducted in a 1.5-m diameter by 1.5-m tall sediment-filled tank indicate that hydraulic gradient increased and hydraulic conductivity ( K) decreased following the onset of downward seepage but both parameters were little changed following the onset of upward seepage. Reductions in K during downward seepage were more pronounced when surface-water current was sufficient to mobilize sediment on the bed. Averaged ratios of K determined during upward seepage to K determined during downward seepage ( K up/K down) through a sand-and-gravel bed increased from 1.4 to 1.7 with increasing surface-water velocity, and decreased to slightly greater than 1 when the sediment bed became fully mobile. K up/K down for tests conducted with a silt veneer on the bed surface was greater than 2 for all but the fastest surface-water velocities. Substantial reductions in K also were associated with a silt floc that formed on the bed surface during and following test runs. Although the silt floc was typically less than 0.5 mm in thickness, most of the hydraulic gradient was distributed across this thin layer. K of the thin silt floc was reduced by two to three orders of magnitude relative to the underlying sediment. Directional bias in K and relation between K and surface-water velocity require the presence or absence of a layer of lower- K sediment at or near the bed surface, without which no reduction in K and corresponding increase in hydraulic gradient can occur at the bed surface. The lack of prior observation of the consistent bias in K associated with seepage direction is somewhat surprising given the numerous studies where K has been measured in fluvial settings, but may be explained by the small value of the bias relative to the typical uncertainty associated with field determinations of K. If shown to exist in field settings, this bias and its relation to fluvial processes will be relevant to many studies conducted in hyporheic settings that require determination of fluxes across the sediment-water interface.

Rosenberry, Donald O.; Pitlick, John

2009-07-01

278

Distribution of heavy metals in water, particulate matter and sediments of Gediz River (Eastern Aegean)  

Microsoft Academic Search

The present paper is the first document of heavy metal levels in surficial sediment, water and particulate matter of the Gediz\\u000a River collected from five different sites in August, October 1998, February, June 1999. The present work attempts to establish\\u000a the status of distribution and environmental implications of metals in the sediment, water and particulate matter and their\\u000a possible sources

F. Kucuksezgin; E. Uluturhan; H. Batki

2008-01-01

279

Universal scaling of dissolved oxygen distribution at the sediment-water interface: A power law  

Microsoft Academic Search

Dissolved oxygen (DO) distribution at the sediment-water interface of a flow over a smooth bed is investigated for Reynolds numbers .360 and ,4,090. These conditions are commonly encountered in streams, wetlands, and lakes. A power-law scaling of DO distribution is derived and compared with experimental data. The scaling analysis is based on DO flux at the sediment-water interface in a

Miki Hondzo; Tom Feyaerts; Richard Donovan; Ben L. O'Connor

2005-01-01

280

Determination of pentachlorophenol in water and aquifer sediments by high-performance liquid chromatography  

USGS Publications Warehouse

Methods for the determination of pentachlorophenol (PCP) in water and aquifer sediments are presented. Reverse-phase high-performance liquid chromotography employing ion suppression and gradient elution is used. PCP can be determined directly in water at a lower limit of detection Of 0.2 micrograms per liter. For extracts of sediment, PCP can be determined to a lower limit of 1.0 micrograms per kilogram.

Goerlitz, D. F.

1981-01-01

281

Exchange of polychlorinated biphenyls between sediment and water in the Hudson River estuary  

Microsoft Academic Search

Sediment-bound polychlorinated biphenyls (PCBs) measured at several sites in the lower Hudson River Estuary are above equilibrium\\u000a with the overlying water, providing a thermodynamic driving force for exchange from sediment to water. The fluxes of PCB congeners\\u000a are estimated for a number potential processes: diffusive release of dissolved and colloidal PCBs from the bed, resuspension\\u000a and subsequent desorption from resuspended

Diane R. Achman; Bruce J. Brownawell; Lianchu Zhang

1996-01-01

282

Estrogenic Activity in Water and Sediments of a French River: Contribution of Alkylphenols  

Microsoft Academic Search

Alkylphenols, known to possess estrogenic activity, have been found in the aquatic environment. In this study, we focused\\u000a on the contribution of alkylphenols to total estrogenic activity in sediment and water extracts of French rivers. Four sites\\u000a representing rural, agricultural, urban, and industrial watersheds were studied. The concentrations of alkylphenols in water\\u000a and sediment were quantified by GC\\/MS. Estrogen-responsive reporter

H. Fenet; E. Gomez; A. Pillon; D. Rosain; J.-C. Nicolas; C. Casellas; P. Balaguer

2003-01-01

283

Dissolved sulfide distributions in the water column and sediment pore waters of the Santa Barbara Basin  

USGS Publications Warehouse

Dissolved sulfide concentrations in the water column and in sediment pore waters were measured by square-wave voltammetry (nanomolar detection limit) during three cruises to the Santa Barbara Basin in February 1995, November-December 1995, and April 1997. In the water column, sulfide concentrations measured outside the basin averaged 3 ?? 1 nM (n = 28) in the 0 to 600 m depth range. Inside the basin, dissolved sulfides increased to reach values of up to 15 nM at depths >400 m. A suite of box cores and multicores collected at four sites along the northeastern flank of the basin showed considerable range in surficial (400 ??M at 10 cm. Decreases in water-column nitrate below the sill depth indicate nitrate consumption (-55 to -137 ??mole m-2 h-1) similar to nearby Santa Monica Basin. Peaks in pore-water iron concentrations were generally observed between 2 and 5 cm depth with shallowest peaks at the 590 m site. These observations, including observations of the benthic microfauna, suggest that the extent to which the sulfide flux, sustained by elevated pore-water concentrations, reaches the water column may be modulated by the abundance of sulfide-oxidizing bacteria in addition to iron redox and precipitation reactions.

Kuwabara, J. S.; Van Geen, A.; McCorkle, D. C.; Bernhard, J. M.

1999-01-01

284

Analytical and experimental analysis of procedures for testing solar domestic hot-water systems. NBS Building Science Series 140  

Microsoft Academic Search

A repeatable test method independent of outdoor environmental conditions and laboratory geographical location is required in order to provide a means by which solar domestic hot water systems may be rated and compared. Three experimental techniques which allow the net thermal output of an irradiated solar collector array to be reproduced indoors without the use of a solar simulator are

A. H. Fanney; W. C. Thomas; C. A. Scarbrough; C. P. Terlizzi

1982-01-01

285

Domestic hot water consumption and efficiency: Researching consumption and demand in New York City multifamily apartment buildings. Final report  

Microsoft Academic Search

This report combines the results of two research projects sponsored by the New York State Energy Research and Development Authority and conducted by EME Group to study domestic hot water (DHW) in multifamily buildings. Part 1 of the report focuses on DHW consumption and demand in 50 New York City multifamily buildings ranging in size from 20 to 248 units.

W. Loss; E. Neumann; M. McNamara; T. Sahagian; J. Winterson

1997-01-01

286

[Effects of sediment dredging on benthos community structure and water quality in Zhushan Bay].  

PubMed

We surveyed the changes of macro-benthos community composition and nutrients concentration in water in Zhushan Bay after it had been dredged 6 months, which aimed to remove the polluted surface sediments. The results showed that the main benthos in the dredged and un-dredged sediments were Limodrilus hoffmeisteri, Pelopia and Bellamya aeruginosa; compared to the un-dredged sediments, the bio-diversity of dredged areas became lower. However, its biomass became higher than that in un-dredged areas. Concentration range changes of TN and TP in overlying water was 1.64-4.45 mg/L and 0.133-0.258 mg/L, respectively. The post-dredged sediments were still in a higher state of nutrients for the higher concentration nutrients in overlying water, macro-benthos were the species that lived in a serious polluted water environment. Using Shannon-Weaver, Simpson, and Goodnight benthic index to evaluate the results show that the dredged area is in the moderately polluted level, but un-dredged area is in the middle-heavily polluted level. According to the benthos fauna surveys and water quality monitoring results, the effective of sediment dredging could play its role only the strict control on the external pollution resources have been made and reduces the effects of polluted water on the sediments. PMID:21250446

Liu, Guo-Feng; Zhang, Zhi-Yong; Liu, Hai-Qin; Zhong, Ji-Cheng; Yan, Shao-Hua; Fan, Cheng-Xin

2010-11-01

287

Spatial variability of sediment ecotoxicity in a large storm water detention basin.  

PubMed

Detention basins are valuable facilities for urban storm water management, from both the standpoint of flood control and the trapping of pollutants. Studies performed on storm water have shown that suspended solids often constitute the main vector of pollutants (heavy metals, polycyclic aromatic hydrocarbon (PAH), etc.). In order to characterise the ecotoxicity of urban sediments from storm water detention basins, the sediments accumulated over a 6-year period were sampled at five different points through the surface of a large detention basin localised in the east of Lyon, France. A specific ecotoxicological test battery was implemented on the solid phase (raw sediment) and the liquid phase (interstitial water of sediments). The results of the study validated the method formulated for the ecotoxicological characterization of urban sediments. They show that the ecotoxicological effect of the sediments over the basin is heterogeneous and greater in areas often flooded. They also show the relationship between, on one hand, the physical and chemical characteristics of the sediments and, on the other hand, their ecotoxicity. Lastly, they contribute to a better understanding of the dynamics of the pollution close to the bottom of detention basins, which can be useful for improving their design. The results of this research raise particularly the issue of using oil separators on the surface of detention basins. PMID:24243265

Merchan, Carolina Gonzalez; Perrodin, Yves; Barraud, Sylvie; Sébastian, Christel; Becouze-Lareure, Céline; Bazin, Christine; Kouyi, Gislain Lipeme

2014-04-01

288

Heavy metals in water, sediment and tissues of Leuciscus cephalus from a stream in southwestern Turkey  

Microsoft Academic Search

Concentrations of heavy metals (Cd, Cr, Cu, Pb and Zn) were measured in water, bottom sediment and tissues (muscle and gills) of Leuciscus cephalus from the Dipsiz stream in the Yatagan basin (southwestern Turkey), the site of a thermal power plant. Results for levels in water were compared with national and international water quality guidelines, as well as literature values

Ahmet Demirak; Fevzi Yilmaz; A. Levent Tuna; Nedim Ozdemir

2006-01-01

289

Sediment pore water collection methods for trace metal analysis: A review  

Microsoft Academic Search

Collection and analysis of pore water has become an important aspect of many environmental programs. Pore water analyses are used for toxicity identification, sediment quality assessment and diagenetic studies. This paper reviews the four commonly used methods for collection of pore water and potential artifacts from their use, particularly in the preparation of samples for trace metal analysis. Two of

Steven E. Bufflap; Herbert E. Allen

1995-01-01

290

Analysis of national water-pollution-control policies. 2. Agricultural sediment control  

Microsoft Academic Search

A national water network model is used to analyze the likely effects of agricultural sediment-control policies on the quality of the nation's waters. This analysis is believed superior to previous assessments based mainly on erosion estimates without accounting for the characteristics of the receiving water or the contribution of pollutants from nonagricultural activities. Specifically, while the earlier assessments concluded that

Leonard P. Gianessi; Henry M. Peskin

1981-01-01

291

Chloride/bromide and chloride/fluoride ratios of domestic sewage effluents and associated contaminated ground water  

SciTech Connect

To establish geochemical tools for tracing the origin of ground water contamination, the authors examined the variations of Cl/Br and Cl/F (weight) ratios in (1) domestic waste water from the Dan Region Sewage Reclamation Project and from reservoirs in the central coast of Israel; (2) associated contaminated ground water; and (3) pristine ground water from the Mediterranean coastal aquifer of Israel. The data show that supply water, anthropogenic NaCl and fluoridation control the Cl/Br and Cl/F ratios of domestic waste water, and conventional sewage treatment does not affect the anthropogenic inorganic signals. The Cl/Br ratios of ground water contaminated with sewage effluent reflect conservative mixing proportions of sewage and regional ground water components. Sensitivity tests demonstrate that it is possible to detect and distinguish sewage contamination from marine ratios after a sewage contribution of 5 to 15% is mixed with regional ground water. Mixing with Br-enriched fresh water however, would reduce this sensitivity. Since the high Cl/Br signal of sewage effluents is distinguishable from other anthropogenic sources with low Cl/Br ratios and from natural contamination sources, Cl/Br ratios can therefore be a useful inorganic tracer for identification of the origin of contaminated ground water. The Cl/F ratios of sewage-contaminated ground water were higher than those in the original sewage effluent, which suggests retention of fluoride into the aquifer solid phase.

Vengosh, A.; Pankratov, I. [Hydrological Service, Jerusalem (Israel)

1998-09-01

292

Impacts of ocean acidification on sediment processes in shallow waters of the Arctic Ocean.  

PubMed

Despite the important roles of shallow-water sediments in global biogeochemical cycling, the effects of ocean acidification on sedimentary processes have received relatively little attention. As high-latitude cold waters can absorb more CO2 and usually have a lower buffering capacity than warmer waters, acidification rates in these areas are faster than those in sub-tropical regions. The present study investigates the effects of ocean acidification on sediment composition, processes and sediment-water fluxes in an Arctic coastal system. Undisturbed sediment cores, exempt of large dwelling organisms, were collected, incubated for a period of 14 days, and subject to a gradient of pCO2 covering the range of values projected for the end of the century. On five occasions during the experimental period, the sediment cores were isolated for flux measurements (oxygen, alkalinity, dissolved inorganic carbon, ammonium, nitrate, nitrite, phosphate and silicate). At the end of the experimental period, denitrification rates were measured and sediment samples were taken at several depth intervals for solid-phase analyses. Most of the parameters and processes (i.e. mineralization, denitrification) investigated showed no relationship with the overlying seawater pH, suggesting that ocean acidification will have limited impacts on the microbial activity and associated sediment-water fluxes on Arctic shelves, in the absence of active bio-irrigating organisms. Only following a pH decrease of 1 pH unit, not foreseen in the coming 300 years, significant enhancements of calcium carbonate dissolution and anammox rates were observed. Longer-term experiments on different sediment types are still required to confirm the limited impact of ocean acidification on shallow Arctic sediment processes as observed in this study. PMID:24718610

Gazeau, Frédéric; van Rijswijk, Pieter; Pozzato, Lara; Middelburg, Jack J

2014-01-01

293

Impacts of Ocean Acidification on Sediment Processes in Shallow Waters of the Arctic Ocean  

PubMed Central

Despite the important roles of shallow-water sediments in global biogeochemical cycling, the effects of ocean acidification on sedimentary processes have received relatively little attention. As high-latitude cold waters can absorb more CO2 and usually have a lower buffering capacity than warmer waters, acidification rates in these areas are faster than those in sub-tropical regions. The present study investigates the effects of ocean acidification on sediment composition, processes and sediment-water fluxes in an Arctic coastal system. Undisturbed sediment cores, exempt of large dwelling organisms, were collected, incubated for a period of 14 days, and subject to a gradient of pCO2 covering the range of values projected for the end of the century. On five occasions during the experimental period, the sediment cores were isolated for flux measurements (oxygen, alkalinity, dissolved inorganic carbon, ammonium, nitrate, nitrite, phosphate and silicate). At the end of the experimental period, denitrification rates were measured and sediment samples were taken at several depth intervals for solid-phase analyses. Most of the parameters and processes (i.e. mineralization, denitrification) investigated showed no relationship with the overlying seawater pH, suggesting that ocean acidification will have limited impacts on the microbial activity and associated sediment-water fluxes on Arctic shelves, in the absence of active bio-irrigating organisms. Only following a pH decrease of 1 pH unit, not foreseen in the coming 300 years, significant enhancements of calcium carbonate dissolution and anammox rates were observed. Longer-term experiments on different sediment types are still required to confirm the limited impact of ocean acidification on shallow Arctic sediment processes as observed in this study. PMID:24718610

Gazeau, Frederic; van Rijswijk, Pieter; Pozzato, Lara; Middelburg, Jack J.

2014-01-01

294

Effect of sediment settling on controlling golden mussel invasion in water transfer project  

NASA Astrophysics Data System (ADS)

Inter-basin water transfer projects have been widely used to solve uneven distribution of water resources and water shortage in China. Along with the transferring of water resources, golden mussel (Limnoperna fortunei), the filter-collector macro-invertebrate species originating from southern China has also been inadvertently transferred to new aquatic environment, resulting in quick and uncontrolled spread of the species. The golden mussels are invasive by nature and endowed with a strong byssus for attaching onto their habitat, allowing them to easily invade natural and artificial aquatic systems, which was resulted in high-density golden mussel attachment that causes serious bio-fouling. Invasion and bio-fouling by golden mussels in water transfer systems has drawn attention widely because it has resulted in high resistance to water flow, corrosion of pipe walls and even clogging of tunnels, as well as causing water pollution and ecological imbalance in the regions that receive water infested with golden mussels. Field investigation was conducted along the East River, which is the main drinking water resource for Cantong province and Hongkong, China, to study the natural habitats of golden mussels. Surveys of water transfer tunnels which carry water from the East River to several big cities in Cantong province were done to study golden mussel invasion and attachment in tunnels. It is found that in the natural habitat, golden mussels mainly attach to bedrock and bank stones and solid surfaces facing upstream, while no golden mussels are attached on the surfaces facing downstream and suffering sediment deposition. In the water transfer tunnels, golden mussel attachment densities of 40,000 individuals/m2 mainly occurred on the portion of tunnel walls which face downwards and thus avoid sedimentation. An experiment was designed to study the effect of sediment settling on golden mussel attachment. The results showed that settling of fine sediment particles affects golden mussels by preventing them from filtering food and oxygen from water, and in this way killing them. The attachment density decreased with increased sediment deposition. Golden mussel density decreased by about 70-90% when the sedimentation rate increased by 3-6 times. Therefore, spraying with fine sediment or creating hyper-concentration of sediment water to treat golden mussels before they enter tunnels is recommended as an effective strategy for controlling golden mussel invasion and high-density bio-fouling. Key words: golden mussel invasion; bio-fouling; sediment settling; habitat; controlling strategy

Xu, Mengzhen; Wang, Zhaoyin; Bogen, Jim; Pan, Baozhu

2013-04-01

295

A generic method for projecting and valuing domestic water uses, application to the Mediterranean basin at the 2050 horizon.  

NASA Astrophysics Data System (ADS)

The aim is to be able to assess future domestic water demands in a region with heterogeneous levels of economic development. This work offers an original combination of a quantitative projection of demands (similar to WaterGAP methodology) and an estimation of the marginal benefit of water. This method is applicable to different levels of economic development and usable for large-scale hydroeconomic modelling. The global method consists in building demand functions taking into account the impact of both the price of water and the level of equipment, proxied by economic development, on domestic water demand. Our basis is a 3-blocks inverse demand function: the first block consists of essential water requirements for food and hygiene; the second block matches intermediate needs; and the last block corresponds to additional water consumption, such as outdoor uses, which are the least valued. The volume of the first block is fixed to match recommended basic water requirements from the literature, but we assume that the volume limits of blocks 2 and 3 depend on the level of household equipment and therefore evolve with the level of GDP per capita (structural change), with a saturation. For blocks 1 and 2 we determine the value of water from elasticity, price and quantity data from the literature, using the point-extension method. For block 3, we use a hypothetical zero-cost demand and maximal demand with actual water costs to linearly interpolate the inverse demand function. These functions are calibrated on the 24 countries part of the Mediterranean basin using data from SIMEDD, and are used for the projection and valuation of domestic water demands at the 2050 horizon. They enable to project total water demand, and also the respective shares of the different categories of demand (basic demand, intermediate demand and additional uses). These projections are performed under different combined scenarios of population, GDP and water costs.

Neverre, Noémie; Dumas, Patrice

2014-05-01

296

Occurrence of perfluorinated compounds in the aquatic environment as found in science park effluent, river water, rainwater, sediments, and biotissues.  

PubMed

The current article maps perfluoroalkyl acids (PFAAs) contamination in the largest Science Park of Taiwan. The occurrence of ten target PFAAs in the effluent of an industrial wastewater treatment plant (IWWTP), its receiving rivers, rainwater, sediment, and the muscles and livers of fish was investigated. All target PFAAs were found in effluent of IWWTP, in which perfluorooctane sulfonate (PFOS) (6,930 ng/L), perfluorohexyl sulfonate (PFHxS) (2,662 ng/L) and perfluorooctanoic acid (PFOA) (3,298 ng/L) were the major constituents. Concentrations of PFBS and PFOS in the IWWTP downstream areas have exceeded safe concentration levels of avian and aquatic life, indicating a potential risk to wildlife in those areas. In sediment samples, predominant contaminants were PFOS (1.5-78 ng/g), PFOA (0.5-5.6 ng/g), and perfluorododecanoic acid (PFDoA) (nd-5.4 ng/g). In biological tissue samples, concentrations as high as 28,933 ng/g of PFOS were detected in tilapia and catfish liver samples. A positive correlation for log (C sediment/C water) and log (C tissue/C water) was found. The concentration and proportion (percentage of all PFAAs) of PFOS found in biotissue samples from the Keya River (which receives industrial wastewater) were found to be much greater (200 times) than those of samples from the Keelung River (which receives mainly domestic wastewater). These findings suggest that the receiving aquatic environments and, in turn, the human food chain can be significantly influenced by industrial discharges. PMID:24464397

Lin, Angela Yu-Chen; Panchangam, Sri Chandana; Tsai, Yu-Ting; Yu, Tsung-Hsien

2014-05-01

297

Metal cycling during sediment early diagenesis in a water reservoir affected by acid mine drainage.  

PubMed

The discharge of acid mine drainage (AMD) into a reservoir may seriously affect the water quality. To investigate the metal transfer between the water and the sediment, three cores were collected from the Sancho Reservoir (Iberian Pyrite Belt, SW Spain) during different seasons: turnover event; oxic, stratified period; anoxic and under shallow perennially oxic conditions. The cores were sliced in an oxygen-free atmosphere, after which pore water was extracted by centrifugation and analyzed. A sequential extraction was then applied to the sediments to extract the water-soluble, monosulfide, low crystallinity Fe(III)-oxyhydroxide, crystalline Fe(III)-oxide, organic, pyrite and residual phases. The results showed that, despite the acidic chemistry of the water column (pH<4), the reservoir accumulated a high amount of autochthonous organic matter (up to 12 wt.%). Oxygen was consumed in 1mm of sediment due to organic matter and sulfide oxidation. Below the oxic layer, Fe(III) and sulfate reduction peaks developed concomitantly and the resulting Fe(II) and S(II) were removed as sulfides and probably as S linked to organic matter. During the oxic season, schwertmannite precipitated in the water column and was redissolved in the organic-rich sediment, after which iron and arsenic diffused upwards again to the water column. The flux of precipitates was found to be two orders of magnitude higher than the aqueous one, and therefore the sediment acted as a sink for As and Fe. Trace metals (Cu, Zn, Cd, Pb, Ni, Co) and Al always diffused from the reservoir water and were incorporated into the sediments as sulfides and oxyhydroxides, respectively. In spite of the fact that the benthic fluxes estimated for trace metal and Al were much higher than those reported for lake and marine sediments, they only accounted for less than 10% of their total inventory dissolved in the column water. PMID:23747557

Torres, E; Ayora, C; Canovas, C R; García-Robledo, E; Galván, L; Sarmiento, A M

2013-09-01

298

System simulation and verification of a storage-type heat exchanger used in a solar domestic hot water system  

Microsoft Academic Search

A storage-type heat exchanger (bare copper tubing or finned copper tubing placed inside the water storage tank) has been used widely in solar domestic hot water systems. This type of heat exchanger has been frequently adopted into solar system design, especially in residential and small-scale commercial applications. However, to analyze the heat transfer phenomenon of a storage-type heat exchanger in

J. G. Cherng; E. Lumsdaine; E. Thacher

1980-01-01

299

Biogeochemistry of PCBs in interstitial waters of a coastal marine sediment  

NASA Astrophysics Data System (ADS)

Polychlorinated biphenyls (PCBs) were measured in interstitial waters and sediments at a site in New Bedford Harbor, Massachusetts, to study partitioning processes of hydrophobic organic compounds in marine sediments. Pore water concentrations of total PCBs, expressed as Aroclor 1254, increased with depth in the sediments with a maximum concentration of 17.1 ?g/L at 9-11 cm. Apparent distribution coefficients of individual chlorobiphenyls decreased with depth and were related to dissolved organic carbon levels. Results from this site suggest that most of the PCBs in interstitial waters are sorbed to organic colloids. A simple three-phase equilibrium sorption model can explain many features of the data. Changes in the composition of individual chlorobiphenyls in the sediments were also apparent. Microbial degradation appears to be responsible for large relative depletions of several chlorobiphenyls with depth in the core.

Brownawell, Bruce J.; Farrington, John W.

1986-01-01

300

Summary of suspended-sediment concentration data, San Francisco Bay, California, water year 2000  

USGS Publications Warehouse

Suspended-sediment concentration data were collected in San Francisco Bay during water year 2000 (October 1, 1999?September 30, 2000). Optical backscatterance sensors and water samples were used to monitor suspended sediment at one site in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two depths at most sites. Water samples were collected periodically and were analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the electrical output of the optical backscatterance sensors. This report presents the data-collection methods and summarizes the suspended-sediment concentration data collected from October 1999 through September 2000. Calibration plots and plots of edited data for each sensor also are presented.

Buchanan, Paul A.; Ganju, Neil K.

2002-01-01

301

Diffusive Release of Uranium from Contaminated Sediments into Capillary Fringe Pore Water  

SciTech Connect

We investigated the dynamics of U release between pore water fractions, during river stage changes from two contaminated capillary fringe sediments. Samples were from 7.0 m and 7.6 m below ground surface (bgs) in the Hanford 300 area. Sediments were packed into columns and saturated with Hanford groundwater for three to 84 days. After specified times, > 48 µm radius (calculated) sediment pores were drained, followed by draining pores to 15 µm radius. U release in the first two weeks was similar between sediments and pore sizes with a range of 4.4 to 5.6 µM U in the 14 day sample. The 7.0 m bgs sediment U declined in the larger pores to 0.22 µM at day 84, whereas the small pores released U to 6.7 µM at day 84. The 7.6 m bgs sediment released 1.4 µM on day 84, in the large pores, but continuously released U from the smaller pores (13.2 uM on day 84). The continuous release of U has resulted in a diffusion gradient from the smaller to larger pores. The observed differences in U pore-water concentrations between the two sediment samples were attributed to co-precipitation of U with carbonates. A mineral phase in the sediments was also identified as an U-carbonate species, similar to rutherfordine [UO2(CO3)].

Rod, Kenton A.; Wellman, Dawn M.; Flury, Markus; Pierce, Eric M.; Harsh, James B.

2012-09-13

302

A conceptual model for river water and sediment dispersal in the Santa Barbara Channel, California  

USGS Publications Warehouse

The ephemeral Santa Clara River delivers large amounts of freshwater and sediment to the eastern Santa Barbara Channel during brief, episodic discharge events. This discharge into the channel was characterized here with shipboard measurements during floods of 1997 and 1998. Within approximately 1-km of the river mouth, the river discharge quickly stratifies into a freshened, turbid surface plume and a bottom nephloid layer. Observations immediately off the Santa Clara River mouth on a peak day of river discharge revealed that sediment rapidly settled from the freshened surface waters, as suspended sediment in the freshened surface plume contained only ???6% of the sediment mass expected if the sediment mixed conservatively. On the two subsequent days the reduction of sediment mass in the surface plume continued at ???50% per day. These observations suggest that river sediment undergoes rapid initial settling within ???1-km of the river mouth, followed by somewhat slower rates of settling. Although we did not measure sedimentation or bottom boundary layer processes, our mass balance results suggest that almost all of the river sediment either escapes along or deposits upon the inner shelf seabed.

Warrick, J. A.; A. k. , Mertes, L.; Washburn, L.; A. , Siegel, D.

2004-01-01

303

Contamination of estuarine water, biota, and sediment by halogenated organic compounds: A field study  

USGS Publications Warehouse

Studies conducted in the vicinity of an industrial outfall in the Calcasieu River estuary, Louisiana, have shown that water, bottom and suspended sediment, and four different species of biota are contaminated with halogenated organic compounds (HOC) including haloarenes. A "salting-out" effect in the estuary moderately enhanced the partitioning tendency of the contaminants into biota and sediments. Contaminant concentrations in water, suspended sediments, and biota were found to be far below the values predicted on the basis of the assumption of phase equilibria with respect to concentrations in bottom sediment. Relative concentration factors of HOC between biota (catfish) and bottom sediment increased with increasing octanol/estuarine water partition coefficients (Kow*), maximizing at log Kow* of about 5, although these ratios were considerably less than equilibrium values. In contrast, contaminant concentrations in water, biota, and suspended sediments were much closer to equilibrium values. Bioconcentration factors of HOC determined on the basis of lipid content for four different biotic species correlated reasonably well with equilibrium triolein/water partition coefficients (Ktw).

Pereira, W.E.; Rostad, C.E.; Chiou, C.T.; Brinton, T.I.; Barber, L.B., II; Demcheck, D.K.; Demas, C.R.

1988-01-01

304

Soil, Groundwater, Surface Water, and Sediments of Kennedy Space Center, Florida: Background Chemical and Physical Characteristics  

NASA Technical Reports Server (NTRS)

This study documented background chemical composition of soils, groundwater, surface; water, and sediments of Kennedy Space Center. Two hundred soil samples were collected, 20 each in 10 soil classes. Fifty-one groundwater wells were installed in 4 subaquifers of the Surficial Aquifer and sampled; there were 24 shallow, 16 intermediate, and 11 deep wells. Forty surface water and sediment samples were collected in major watershed basins. All samples were away from sites of known contamination. Samples were analyzed for organochlorine pesticides, aroclors, chlorinated herbicides, polycyclic aromatic hydrocarbons (PAH), total metals, and other parameters. All aroclors (6) were below detection in all media. Some organochlorine pesticides were detected at very low frequencies in soil, sediment, and surface water. Chlorinated herbicides were detected at very low frequencies in soil and sediments. PAH occurred in low frequencies in soiL, shallow groundwater, surface water, and sediments. Concentrations of some metals differed among soil classes, with subaquifers and depths, and among watershed basins for surface water but not sediments. Most of the variation in metal concentrations was natural, but agriculture had increased Cr, Cu, Mn, and Zn.

Shmalzer, Paul A.; Hensley, Melissa A.; Mota, Mario; Hall, Carlton R.; Dunlevy, Colleen A.

2000-01-01

305

Analytical Methods for Measuring Mercury in Water, Sediment and Biota  

SciTech Connect

Mercury (Hg) exists in a large number of physical and chemical forms with a wide range of properties. Conversion between these different forms provides the basis for mercury's complex distribution pattern in local and global cycles and for its biological enrichment and effects. Since the 1960’s, the growing awareness of environmental mercury pollution has stimulated the development of more accurate, precise and efficient methods of determining mercury and its compounds in a wide variety of matrices. During recent years new analytical techniques have become available that have contributed significantly to the understanding of mercury chemistry in natural systems. In particular, these include ultra sensitive and specific analytical equipment and contamination-free methodologies. These improvements allow for the determination of total mercury as well as major species of mercury to be made in water, sediments and soils, and biota. Analytical methods are selected depending on the nature of the sample, the concentration levels of mercury, and what species or fraction is to be quantified. The terms “speciation” and “fractionation” in analytical chemistry were addressed by the International Union for Pure and Applied Chemistry (IUPAC) which published guidelines (Templeton et al., 2000) or recommendations for the definition of speciation analysis. "Speciation analysis is the analytical activity of identifying and/or measuring the quantities of one or more individual chemical species in a sample. The chemical species are specific forms of an element defined as to isotopic composition, electronic or oxidation state, and/or complex or molecular structure. The speciation of an element is the distribution of an element amongst defined chemical species in a system. In case that it is not possible to determine the concentration of the different individual chemical species that sum up the total concentration of an element in a given matrix, meaning it is impossible to determine the speciation, it is a useful practice to do fractionation instead. Fractionation is the process of classification of an analyte or a group of analytes from a certain sample according to physical (e.g. size, solubility) or chemical (e.g. bonding, reactivity) properties."

Lasorsa, Brenda K.; Gill, Gary A.; Horvat, Milena

2012-06-07

306

Water Velocity and Bioturbation Alter Sediment Resuspension and Biogeochemistry in an Experimental Freshwater Mesocosm System  

NASA Astrophysics Data System (ADS)

Processes such as bioturbation and resuspension can affect organic matter decomposition by altering sediment redox conditions. Increased oxygen availability may, in turn, affect remineralization rates and larger scale processes such as benthic-pelagic coupling. However, relatively few studies have explicitly tested the simultaneous effects of bioturbation and water velocity on benthic biogeochemistry and sediment resuspension. Using a mesocosm system we conducted two experiments testing the effects of bioturbator identity on particulate and dissolved nutrient dynamics before and after a resuspension event (i.e. water velocity held constant at 0.12 m s-1 for 2 hr; Expt. 1) and rates of sediment resuspension with increasing water velocity (0.00 - 0.20 m s-1; Expt. 2). We manipulated bioturbator identity across four levels as sediments were undisturbed (control), manually punctured (2% of surface area), or disturbed by one of two fish species, either bluegill or catfish. For Expt. 1, the bioturbation treatments were applied for several days and measurements were made before and after the resuspension event. Initially, water column chlorophyll and total suspended sediment (TSS) concentrations were highest in the catfish treatments. Bioturbator identity did not affect the stoichiometry of TSS as strongly; C:N was unaffected by our treatments while N:P was lowest in the disturbed treatments. After the resuspension event, there was no difference in TSS concentrations or stoichiometric ratios across the bioturbation treatments. Dissolved nutrient flux rates were insensitive to the bioturbation treatments and were more strongly influenced by the resuspension event. For instance, sediment NO3- fluxes were negative (i.e. net flux into sediments) until after the resuspension event when they became positive. In Expt. 2, we gradually increased water velocity from 0.00 - 0.20 m s-1 and measured TSS concentrations only. TSS was initially highest in catfish treatments and lowest in the control treatments. However, once the water velocity was greater than 0.08 m s-1 there was no difference in TSS concentrations across the bioturbation treatments. Sediment resuspension rates were highest in control and manually disturbed treatments, possibly because these treatments had the lowest initial TSS concentrations. Overall, our results indicate that bioturbation and water velocity affect sediment nutrient dynamics and resuspension. By extension, disturbances that affect surficial sediments may also impact algal growth rates by altering nutrient and light levels. Thus it is important to consider how benthic animal communities and species identity interact with water velocity to influence sediment biogeochemical processes.

Spivak, A.; Vanni, M. J.

2010-12-01

307

Recent changes of water discharge and sediment load in the Zhujiang (Pearl River) Basin, China  

NASA Astrophysics Data System (ADS)

The paper is concerned with identifying changes in the time series of water and sediment discharge of the Zhujiang (Pearl River), China. The gradual trend test (Mann-Kendall test), and abrupt change test (Pettitt test), have been employed on annual water discharge and sediment load series (from the 1950s-2004) at nine stations in the main channels and main tributaries of the Zhujiang. Both the Mann-Kendall and Pettitt tests indicate that water discharge at all stations in the Zhujiang Basin showed no significant trend or abrupt shift. Annual water discharges are mainly influenced by precipitation variability, while the construction of reservoirs/dams in the Zhujiang Basin had little influence on water discharge. Sediment load, however, showed significant decreasing trends at some stations in the main channel of the Xijiang and Dongjiang. More stations have seen significantly decreasing trends since the 1990s. The decreasing sediment load in the Zhujiang reflects the impacts of reservoir construction in the basin. In contrast, the Liujiang, the second largest tributary of the Xijiang, has experienced a significant upward shift of sediment load around 1991 likely caused by exacerbated rock desertification in the karst regions. The annual sediment load from the Zhujiang (excluding the delta region) to the estuary has declined from 80.4 × 10 6 t averaged for the period 1957-1995 to 54.0 × 10 6 t for the period 1996-2004. More specifically, the sediment load declined steadily since the early 1990s so that in 2004 it was about one-third of the mean level of pre-90s. Water discharge and sediment load of the Zhujiang would be more affected by human activities in the future with the further reservoir developments, especially the completion of the Datengxia hydroelectric project, and an intensification of the afforestation policy in the drainage basin.

Zhang, Shurong; Lu, Xi Xi; Higgitt, David L.; Chen, Chen-Tung Arthur; Han, Jingtai; Sun, Huiguo

2008-02-01

308

Extending the analytical window for water-soluble organic matter in sediments by aqueous Soxhlet extraction  

NASA Astrophysics Data System (ADS)

Dissolved organic matter (DOM) in marine sediments is a complex mixture of thousands of individual constituents that participate in biogeochemical reactions and serve as substrates for benthic microbes. Knowledge of the molecular composition of DOM is a prerequisite for a comprehensive understanding of the biogeochemical processes in sediments. In this study, interstitial water DOM was extracted with Rhizon samplers from a sediment core from the Black Sea and compared to the corresponding water-extractable organic matter fraction (<0.4 ?m) obtained by Soxhlet extraction, which mobilizes labile particulate organic matter and DOM. After solid phase extraction (SPE) of DOM, samples were analyzed for the molecular composition by Fourier Transform Ion-Cyclotron Resonance Mass Spectrometry (FT-ICR MS) with electrospray ionization in negative ion mode. The average SPE extraction yield of the dissolved organic carbon (DOC) in interstitial water was 63%, whereas less than 30% of the DOC in Soxhlet-extracted organic matter was recovered. Nevertheless, Soxhlet extraction yielded up to 4.35% of the total sedimentary organic carbon, which is more than 30-times the organic carbon content of the interstitial water. While interstitial water DOM consisted primarily of carbon-, hydrogen- and oxygen-bearing compounds, Soxhlet extracts yielded more complex FT-ICR mass spectra with more peaks and higher abundances of nitrogen- and sulfur-bearing compounds. The molecular composition of both sample types was affected by the geochemical conditions in the sediment; elevated concentrations of HS- promoted the early diagenetic sulfurization of organic matter. The Soxhlet extracts from shallow sediment contained specific three- and four-nitrogen-bearing molecular formulas that were also detected in bacterial cell extracts and presumably represent proteinaceous molecules. These compounds decreased with increasing sediment depth while one- and two-nitrogen-bearing molecules increased, resulting in a higher similarity of both sample types in the deep sediment. In summary, Soxhlet extraction of sediments accessed a larger and more complex pool of organic matter than present in interstitial water DOM.

Schmidt, Frauke; Koch, Boris P.; Witt, Matthias; Hinrichs, Kai-Uwe

2014-09-01

309

Authigenic molybdenum formation in marine sediments: a link to pore water sulfide in the Santa Barbara Basin  

Microsoft Academic Search

Pore water and sediment Mo concentrations were measured in a suite of multicores collected at four sites along the northeastern flank of the Santa Barbara Basin to examine the connection between authigenic Mo formation and pore water sulfide concentration. Only at the deepest site (580 m), where pore water sulfide concentrations rise to >0.1 ?M right below the sediment water

Yan Zheng; Robert F. Anderson; Alexander van Geen; James Kuwabara

2000-01-01

310

Microbial transformations of arsenic: mobilization from glauconitic sediments to water.  

PubMed

In the Inner Coastal Plain of New Jersey, arsenic (As) is released from glauconitic sediment to carbon- and nutrient-rich shallow groundwater. This As-rich groundwater discharges to a major area stream. We hypothesize that microbes play an active role in the mobilization of As from glauconitic subsurface sediments into groundwater in the Inner Coastal Plain of New Jersey. We have examined the potential impact of microbial activity on the mobilization of arsenic from subsurface sediments into the groundwater at a site on Crosswicks Creek in southern New Jersey. The As contents of sediments 33-90 cm below the streambed were found to range from 15 to 26.4 mg/kg, with siderite forming at depth. Groundwater beneath the streambed contains As at concentrations up to 89 ?g/L. Microcosms developed from site sediments released 23 ?g/L of As, and active microbial reduction of As(V) was observed in microcosms developed from site groundwater. DNA extracted from site sediments was amplified with primers for the 16S rRNA gene and the arsenate respiratory reductase gene, arrA, and indicated the presence of a diverse anaerobic microbial community, as well as the presence of potential arsenic-reducing bacteria. In addition, high iron (Fe) concentrations in groundwater and the presence of iron-reducing microbial genera suggests that Fe reduction in minerals may provide an additional mechanism for release of associated As, while arsenic-reducing microorganisms may serve to enhance the mobility of As in groundwater at this site. PMID:22494492

Mumford, Adam C; Barringer, Julia L; Benzel, William M; Reilly, Pamela A; Young, L Y

2012-06-01

311

Microbial transformations of arsenic: Mobilization from glauconitic sediments to water  

USGS Publications Warehouse

In the Inner Coastal Plain of New Jersey, arsenic (As) is released from glauconitic sediment to carbon- and nutrient-rich shallow groundwater. This As-rich groundwater discharges to a major area stream. We hypothesize that microbes play an active role in the mobilization of As from glauconitic subsurface sediments into groundwater in the Inner Coastal Plain of New Jersey. We have examined the potential impact of microbial activity on the mobilization of arsenic from subsurface sediments into the groundwater at a site on Crosswicks Creek in southern New Jersey. The As contents of sediments 33–90 cm below the streambed were found to range from 15 to 26.4 mg/kg, with siderite forming at depth. Groundwater beneath the streambed contains As at concentrations up to 89 ?g/L. Microcosms developed from site sediments released 23 ?g/L of As, and active microbial reduction of As(V) was observed in microcosms developed from site groundwater. DNA extracted from site sediments was amplified with primers for the 16S rRNA gene and the arsenate respiratory reductase gene, arrA, and indicated the presence of a diverse anaerobic microbial community, as well as the presence of potential arsenic-reducing bacteria. In addition, high iron (Fe) concentrations in groundwater and the presence of iron-reducing microbial genera suggests that Fe reduction in minerals may provide an additional mechanism for release of associated As, while arsenic-reducing microorganisms may serve to enhance the mobility of As in groundwater at this site.

Mumford, Adam C.; Barringer, Julia L.; Benzel, William M.; Reilly, Pamela A.; Young, L.Y.

2012-01-01

312

Heat and dissolved oxygen exchanges between the sediment and water column in a shallow salty lagoon  

NASA Astrophysics Data System (ADS)

oxygen (DO) and heat exchanges across the water-sediment interface (WSI) of a shallow lagoon are controlled by processes occurring on both sides of the WSI, particularly volumetric source and sink on the sediment side and turbulent transport on the waterside. This article presents and analyzes measurements of DO (Js) and heat (Hg) fluxes across the WSI in the extremely shallow lagoon of Salar del Huasco (20.274°S, 68.883°W, 3800 m above sea level), where volumetric source of DO and heat exists in the sediment layer, related to benthic primary production and absorption of solar radiation, respectively. Microprofiles of temperature and DO were measured, and they were used for measuring Js and Hg, and volumetric source/sink terms in the sediments. This information was used to propose and validate the simple theoretical framework to predict both the magnitude and direction of Js and Hg. On the one hand, Js can be predicted with a simple algebraic expression, where the diffusional mass transfer coefficient defines the magnitude of Js while the direction is controlled by the balance between DO production and consumption in the sediments. On the other hand, solar radiation is absorbed in the upper sediments, and this heat diffuses toward the water column and the sediments. The heat flux toward the water column also induces unstable convection that promotes vertical transport across the WSI. The theoretical framework proposed here will help to understand DO and heat budgets of shallow aquatic systems in which solar radiation reaches the WSI.

Fuente, Alberto

2014-04-01

313

A review of surface-water sediment fractions and their interactions with persistent manmade organic compounds  

USGS Publications Warehouse

This paper reviews the suspended and surficial sediment fractions and their interactions with manmade organic compounds. The objective of this review is to isolate and describe those contaminant and sediment properties that contribute to the persistence of organic compounds in surface-water systems. Most persistent, nonionic organic contaminants, such as the chlorinated insecticides and polychlorinated biphenyls (PCBs), are characterized by low water solubilities and high octanol-water partition coefficients. Consequently, sorptive interactions are the primary transformation processes that control their environmental behavior. For nonionic organic compounds, sorption is primarily attributed to the partitioning of an organic contaminant between a water phase and an organic phase. Partitioning processes play a central role in the uptake and release of contaminants by sediment organic matter and in the bioconcentration of contaminants by aquatic organisms. Chemically isolated sediment fractions show that organic matter is the primary determinant of the sorptive capacity exhibited by sediment. Humic substances, as dissolved organic matter, contribute a number of functions to the processes cycling organic contaminants. They alter the rate of transformation of contaminants, enhance apparent water solubility, and increase the carrying capacity of the water column beyond the solubility limits of the contaminant. As a component of sediment particles, humic substances, through sorptive interactions, serve as vectors for the hydrodynamic transport of organic contaminants. The capabilities of the humic substances stem in part from their polyfunctional chemical composition and also from their ability to exist in solution as dissolved species, flocculated aggregates, surface coatings, and colloidal organomineral and organometal complexes. The transport properties of manmade organic compounds have been investigated by field studies and laboratory experiments that examine the sorption of contaminants by different sediment size fractions. Field studies indicate that organic contaminants tend to sorb more to fine-grained sediment, and this correlates significantly with sediment organic matter content. Laboratory experiments have extended the field studies to a wider spectrum of natural particulates and anthropogenic compounds. Quantitation of isotherm results allows the comparison of different sediment sorbents as well as the estimation of field partition coefficients from laboratory-measured sediment and contaminant properties. Detailed analyses made on the basis of particle-size classes show that all sediment fractions need to be considered in evaluating the fate and distribution of manmade organic compounds. This conclusion is based on observations from field studies and on the variety of natural organic sorbents that demonstrate sorptive capabilities in laboratory isotherm experiments.

Witkowski, P. J.; Smith, J. A.; Fusillo, T. V.; Chiou, C. T.

1987-01-01

314

Ecotoxicological characterisation of sedimentation in the Kis-Balaton Water Protection System.  

PubMed

The main function of the Kis-Balaton Water Protection System is to retain nutrients and total suspended solids, thus protecting the water quality of Lake Balaton. In this paper, the toxic nature of the sediment in the 2nd reservoir of the KBWPS has been characterised, using a battery of tests: Vibrio fischeri acute bioassay on whole sediment samples, and V. fischeri bioassay on pore water and elutriate samples. The latest version of the V. fischeri bioluminescence inhibition was applied, the Flash assay which uses a kinetic mode and is able to detect the toxicity of solid, turbid/coloured samples. Whole sediment toxicity showed a clear spatial distribution of toxicity, in parallel with elutriate toxicity. However, no pore water toxicity was detected, leading to the conclusion that contaminants are not water soluble. PMID:22695524

Paulovits, G; Kováts, Nóra; Acs, Á; Ferincz, Á; Kovács, Anikó; Kakasi, B; Nagy, Sz; Kiss, Gy

2012-06-01

315

Heavy Metals in Water and Sediment: A Case Study of Tembi River  

PubMed Central

This study was carried out to examine heavy metals concentration in water and sediment of upstream and downstream of the entry of the sewage to the Tembi River, Iran. Samples were collected from upstream and downstream and were analyzed for Cd, Cr, Cu, Fe, Pb, Ni, and Zn by atomic absorption spectrophotometer. The results indicated that the average concentration of the metals in water and sediment on downstream was more than that of upstream. The comparison of the mean concentrations of heavy metals in water of the Tembi River with drinking water standards and those in the water used for agriculture suggests that the mean concentration of Cu and Zn lies within the standard range for drinking water and the mean concentration of Mn, Zn, and Pb lies within the standard range of agricultural water. The highest average concentration on downstream for Pb in water and for Mn in sediment was 1.95 and 820.5?ppm, respectively. Also, the lowest average concentration on upstream was identified for Cd in water and sediment 0.07 and 10?ppm, respectively. With regard to the results, it gets clear that using the water for recreational purposes, washing, and fishing is detrimental to human health and the environment. PMID:24616738

Shanbehzadeh, Saeed; Vahid Dastjerdi, Marzieh; Hassanzadeh, Akbar; Kiyanizadeh, Toba

2014-01-01

316

The Characterization of Organic Matter in Abyssal Sediments, Pore Waters and Sediment Traps  

Microsoft Academic Search

\\u000a Substantial information regarding the history, source and transfer of both carbon and nitrogen to and within the deep sea\\u000a lies in the chemical and isotopic signals of organic materials. Isotopic and chemical characterization of sediment trap samples\\u000a indicate that the captured particulate materials are an organic rich food source for abyssal organisms which become highly\\u000a altered at or just below

Stephen A. Macko

317

Accumulation of Nitrogen in the Pore Water of Anoxic Lake Sediments  

NASA Astrophysics Data System (ADS)

The impact of soil runoff nitrogen on the Silver Lake of Iowa was assessed in this study. Currently, the lake cannot support its designated uses as a recreational water body. Extensive algal blooms characterize the lake in late summer, lowering the dissolved oxygen content in water (< 2.0 mg/L). The goal of this study was to map the buildup of nitrogen in the pore water of lake sediments and come up with recommendations for restoration strategies. Sediment cores were taken from 20 sites along 5 transects in the lake. In the top 5 cm of the sediments, the pore water nitrogen ranges between 1.8 and 733.1 micro-gm of nitrate per gm of sediments. The average concentration is 94 micro-g/gm. Vertically, nitrate concentrations were measured at 90 micro-g/gm at 0-10 cm, 95 micro-g/gm at 10-20 cm, and 19 micro-g/gm at 20-30 cm. The sharp decline in nitrate below the 20 cm depth in the sediment is attributed to biochemical reduction of nitrate through denitrification in relatively older, much anoxic sediments. The above results indicate that sediments in Silver Lake are heavily contaminated with N trapped in the pore water. The primary sources of N are the surrounding croplands and an active hog lot on the southeastern lakeshore. The average rate of sedimentation in the lake has been 1 cm/year in the last 32 years. Upon sedimentation, the pore water N is slowly released to the lake water, thereby dramatically limiting the lake's capability to process incoming nutrients. The mass distribution of N in the lake was estimated as 3.66 x 103 kg (65%) in bottom sediments, 172 kg (3%) in suspended particulates, and 1.83 x 103 kg (32%) in the dissolved phase. Some of the recommendations made through this study include dredging the top 25 cm of lake sediments, applying buffer strips along the lake's northern and eastern shorelines, and reducing the application of N and P-based fertilizers.

Iqbal, M. Z.; Fields, C. L.

2005-05-01

318

Grazing Land Management Strongly Controls Water Quality, Sediment and Channel Dynamics in Tallgrass Prairie Headwater Networks  

NASA Astrophysics Data System (ADS)

In the prairie remnants of North America, watershed sediment regimes are heavily influenced by livestock grazing practices. Despite dramatic declines in stream water quality and ecosystem function concomitant with increasing gazing pressures, there have been no studies to quantitatively assess the relationship between various grazing treatments and sediment production in natural grassland ecosystems. In this study, we evaluate suspended sediment transport and channel morphology in the Flint Hills physiographic province using a paired whole-watershed approach, including 2 replicates of high density cattle grazing, 2 replicates of low density cattle grazing, 3 replicates of bison grazing and 3 replicates of no grazing. As expected, results demonstrate that cattle grazing operations increase e-coli, sediment concentrations and increase channel width. However, no significant differences in e-coli, suspended sediment dynamics or channel geomorphology were found between bison grazed and ungrazed watersheds.

Grudzinski, B. G.; Daniels, M. D.

2013-12-01

319

WATER AND SEDIMENT MANAGEMENT FOR THE BLUE NILE BASIN  

Microsoft Academic Search

The sediment yield of rivers is often sensitive to changes in catchments land use and human activities. Such an impact is most likely to be demonstrated at a restricted spatial scale, particularly in headwater catchments. In large river basins such as Nile River Basin, there are needs to study, understand, and quantify the impacts of these modifications on the hydrologic

Tarek Mohamed Abdel-Aziz

2009-01-01

320

ATRAZINE DESORPTION KINETICS FROM A FRESH-WATER SEDIMENT  

EPA Science Inventory

Research has shown that the sorption and desorption of neutral organic compounds to soils and sediments occurs in two stages, with an initial rapid sorption/desorption phase (usually less than an hour) followed by a slower phase that can last for several months to years for very ...

321

Heat transport near sediment-water interfaces with bedforms  

Microsoft Academic Search

The mechanical and thermal energy balance of streams, underlying sediments, and adjacent aquifers controls the distribution of lotic organisms. Thus, the energy transport within and between these systems is an issue of utmost importance in terms of understanding their ecology and biogeochemistry. In fast-flow systems, heat advection is equally important as, or more important than, heat conduction. In recent years,

M. B. Cardenas; J. L. Wilson

2005-01-01

322

Threshold events in spring discharge: Evidence from sediment and continuous water level measurement  

NASA Astrophysics Data System (ADS)

SummaryIn September 2004, three major hurricanes, Frances, Ivan, and Jeanne, traveled up the eastern United States from the Gulf Coast bringing large amounts of rain to Central Pennsylvania. Monitoring equipment in place at Arch Spring, Blair County, PA captured the effects of these storms on the karstic spring flow. Together these storms revealed a quantitative limit for the carrying capacity of the conduit system. Ivan was a much more devastating storm to the area because rain fell on ground already saturated by Frances, but the net stage increase at the spring was greater during the earlier Frances storm, a 74 cm stage increase versus a 54 cm increase. Storm water not transported through the Arch Spring system was diverted into surface channels during these storms. Suspended sediment collected by an automatic sampler during Frances reveals another threshold crossed. Concurrent with increasing stage and high conductance water, maximum sediment concentrations (933 mg/L) exceed previous fluxes by up to an order of magnitude. The timing of the sediment pulse indicates that high sediment concentrations occur not only when the storm water reaches the spring, but also when stored water is being flushed out of the karst spring system. Sediment previously deposited in the conduit system is flushed only when adequate flows occur, indicating that sediment transport in karst is marked by thresholds and is a strongly non-linear process.

Herman, Ellen K.; Toran, Laura; White, William B.

2008-03-01

323

Sediment microbial communities in Great Boiling Spring are controlled by temperature and distinct from water communities.  

PubMed

Great Boiling Spring is a large, circumneutral, geothermal spring in the US Great Basin. Twelve samples were collected from water and four different sediment sites on four different dates. Microbial community composition and diversity were assessed by PCR amplification of a portion of the small subunit rRNA gene using a universal primer set followed by pyrosequencing of the V8 region. Analysis of 164 178 quality-filtered pyrotags clearly distinguished sediment and water microbial communities. Water communities were extremely uneven and dominated by the bacterium Thermocrinis. Sediment microbial communities grouped according to temperature and sampling location, with a strong, negative, linear relationship between temperature and richness at all taxonomic levels. Two sediment locations, Site A (87-80 °C) and Site B (79 °C), were predominantly composed of single phylotypes of the bacterial lineage GAL35 (\\[pmacr]=36.1%), Aeropyrum (\\[pmacr]=16.6%), the archaeal lineage pSL4 (\\[pmacr]=15.9%), the archaeal lineage NAG1 (\\[pmacr]=10.6%) and Thermocrinis (\\[pmacr]=7.6%). The ammonia-oxidizing archaeon 'Candidatus Nitrosocaldus' was relatively abundant in all sediment samples <82 °C (\\[pmacr]=9.51%), delineating the upper temperature limit for chemolithotrophic ammonia oxidation in this spring. This study underscores the distinctness of water and sediment communities in GBS and the importance of temperature in driving microbial diversity, composition and, ultimately, the functioning of biogeochemical cycles. PMID:23235293

Cole, Jessica K; Peacock, Joseph P; Dodsworth, Jeremy A; Williams, Amanda J; Thompson, Daniel B; Dong, Hailiang; Wu, Geng; Hedlund, Brian P

2013-04-01

324

Sediment microbial communities in Great Boiling Spring are controlled by temperature and distinct from water communities  

PubMed Central

Great Boiling Spring is a large, circumneutral, geothermal spring in the US Great Basin. Twelve samples were collected from water and four different sediment sites on four different dates. Microbial community composition and diversity were assessed by PCR amplification of a portion of the small subunit rRNA gene using a universal primer set followed by pyrosequencing of the V8 region. Analysis of 164?178 quality-filtered pyrotags clearly distinguished sediment and water microbial communities. Water communities were extremely uneven and dominated by the bacterium Thermocrinis. Sediment microbial communities grouped according to temperature and sampling location, with a strong, negative, linear relationship between temperature and richness at all taxonomic levels. Two sediment locations, Site A (87–80?°C) and Site B (79?°C), were predominantly composed of single phylotypes of the bacterial lineage GAL35 (p?=36.1%), Aeropyrum (p?=16.6%), the archaeal lineage pSL4 (p?=15.9%), the archaeal lineage NAG1 (p?=10.6%) and Thermocrinis (p?=7.6%). The ammonia-oxidizing archaeon ‘Candidatus Nitrosocaldus' was relatively abundant in all sediment samples <82?°C (p?=9.51%), delineating the upper temperature limit for chemolithotrophic ammonia oxidation in this spring. This study underscores the distinctness of water and sediment communities in GBS and the importance of temperature in driving microbial diversity, composition and, ultimately, the functioning of biogeochemical cycles. PMID:23235293

Cole, Jessica K; Peacock, Joseph P; Dodsworth, Jeremy A; Williams, Amanda J; Thompson, Daniel B; Dong, Hailiang; Wu, Geng; Hedlund, Brian P

2013-01-01

325

Sedimentation on the cold-water coral Lophelia pertusa: cleaning efficiency from natural sediments and drill cuttings.  

PubMed

Anthropogenic threats to cold-water coral reefs are trawling and hydrocarbon drilling, with both activities causing increased levels of suspended particles. The efficiency of Lophelia pertusa in rejecting local sediments and drill cuttings from the coral surface was evaluated and found not to differ between sediment types. Further results showed that the coral efficiently removed deposited material even after repeated exposures, indicating an efficient cleaning mechanism. In an experiment focusing on burial, fine-fraction drill cuttings were deposited on corals over time. Drill cutting covered coral area increased with repeated depositions, with accumulation mainly occurring on and adjacent to regions of the coral skeleton lacking tissue cover. Tissue was smothered and polyp mortality occurred where polyps became wholly covered by material. Burial of coral by drill cuttings to the current threshold level used in environmental risk assessment models by the offshore industry (6.3mm) may result in damage to L. pertusa colonies. PMID:21529851

Larsson, Ann I; Purser, Autun

2011-06-01

326

Organic matter diagenesis in shallow water carbonate sediments  

NASA Astrophysics Data System (ADS)

Muddy carbonate deposits near the Dry Tortugas, Florida, are characterized by high organic carbon remineralization rates. However, approximately half of the total sedimentary organic matter potentially supporting remineralization is occluded in CaCO 3 minerals (intracrystalline). While a portion of nonintracrystalline organic matter appears to cycle rapidly, intracrystalline organic matter has an approximately constant concentration with depth, suggesting that as long as its protective mineral matrix is intact, it is not readily remineralized. Organic matter in excess of intracrystalline organic matter that is preserved may have a variety of mineral associations (e.g., intercrystalline, adsorbed or detrital). In surface sediment, aspartic acid contributed ˜22 mole % and ˜50 mole % to nonintracrystalline and intracrystalline pools, respectively. In deeper sediment (1.6-1.7m), the composition of hydrolyzable amino acids in both pools was similar (aspartic acid ˜40 mole %). Like amino acids, intracrystalline and nonintracrystalline fatty acids have different compositions in surface sediments, but are indistinguishable at depth. These data suggest that preserved organic matter in the nonintracrystalline pool is stabilized by its interactions with CaCO 3. Neutral lipids are present in very low abundances in the intracrystalline pool and are extensively degraded in both the intracrystalline and nonintracrystalline pools, suggesting that mineral interactions do not protect these compounds from degradation. The presence of chlorophyll- a, but absence of phytol, in the intracrystalline lipid pool demonstrates that chloropigments are present only in the nonintracrystalline pool. Sedimentary chloropigments decrease with depth at similar rates in Dry Tortugas sediments as found in alumino-silicate sediments from the Long Island Sound, suggesting that chloropigment degradation is largely unaffected by mineral interactions. Overall, however, inclusion and protection of organic matter by biominerals is a major pathway for organic matter preservation in this low-organic carbon, biomineral-rich regime.

Ingalls, Anitra E.; Aller, Robert C.; Lee, Cindy; Wakeham, Stuart G.

2004-11-01

327

Phytoremediation of mercury- and methyl mercury-contaminated sediments by water hyacinth (Eichhornia crassipes).  

PubMed

Phytoremediation has the potential for implementation at mercury- (Hg) and methylHg (MeHg)-contaminated sites. Water hyacinths (Eichhornia crassipes) were investigated for their ability to assimilate Hg and MeHg into plant biomass, in both aquatic and sediment-associated forms, over a 68-day hydroponic study. The suitability of E. crassipes to assimilate both Hg and MeHg was evaluated under differing phosphate (PO4) concentrations, light intensities, and sediment:aqueous phase contamination ratios. Because aquatic rhizospheres have the ability to enhance MeHg formation, the level of MeHg in water, sediment, and water hyacinth was also measured. Hg and MeHg were found to concentrate preferentially in the roots of E. crassipes with little translocation to the shoots or leaves of the plant, a result consistent with studies from similar macrophytes. Sediments were found to be the major sink for Hg as they were able to sequester Hg, making it non-bioavailable for water hyacinth uptake. An optimum PO4 concentration was observed for Hg and MeHg uptake. Increasing light intensity served to enhance the translocation of both Hg and MeHg from roots to shoots. Assimilation of Hg and MeHg into the biomass of water hyacinths represents a potential means for sustainable remediation of contaminated waters and sediments under the appropriate conditions. PMID:22567701

Chattopadhyay, Sandip; Fimmen, Ryan L; Yates, Brian J; Lal, Vivek; Randall, Paul

2012-02-01

328

Metal ions in water and sediments of the Pom-Atasta Lagoon, Mexico  

SciTech Connect

Temperature, salinity, turbidity, total suspended solids (TSS), pH, and dissolved oxygen were measured in the surface water of the Pom-Atasta Lagoon at 15 stations during 5 sampling events from September 1996--May 1997. Concentrations of Cu, Cd, Ni, Zn, Pb, Cr, Ag, Fe, Co, and Ba were also determined in the water and sediments at 15 stations during the study period. The values of salinity, turbidity, and TSS were related to the inputs of river water into the lagoon. Metals in the water and sediments showed no spatial variation. Seasonality in the concentrations of Cu, Zn, Ag, and Ba in the water was found and may be related to the resuspension of sediments in the lagoon. The concentrations of metals in sediments did not give significant seasonal variation. Metals in sediments were not correlated with the iron, suggesting an anthropogenic source of metals in the Pom-Atasta Lagoon. The concentrations of dissolved Pb were above the value recommended by the National Water Commission of Mexico.

Vazquez, G.F.; Enciso, G.; Morales, J.W. [UNAM, Distrito Federal (Mexico). Instituto de Ciencias Del Mar y Limnologia] [UNAM, Distrito Federal (Mexico). Instituto de Ciencias Del Mar y Limnologia; Sharma, V.K. [Texas A and M Univ., Corpus Christi, TX (United States). Dept. of Chemistry] [Texas A and M Univ., Corpus Christi, TX (United States). Dept. of Chemistry; Nischt, S.L.; Domingo, G.L. [PEMEX, Campeche (Mexico)] [PEMEX, Campeche (Mexico)

1999-07-01

329

Pore-water and epibenthic exposures in contaminated sediments using embryos of two estuarine fish species  

SciTech Connect

The authors` objectives were to determine the feasibility of using embryos of two fish species, Menidia beryllina and Atherinops affinis, in estuarine sediment toxicity tests at ambient temperatures and salinities, and to compare pore-water and sediment water interface corer (SWIC) exposure techniques using these same species. The ultimate goal is to determine whether these pore-water and SWIC methods can be used in in situ exposure studies. Sediment samples were collected at both a reference and contaminated site at the Mare Island Naval Shipyard in San Francisco Bay. Pore-water testes were conducted using methods developed in the laboratory, and SWIC tests were conducted using a modification of B. Anderson et al. Salinity and temperature tolerance experiments revealed that M. beryllina embryos can tolerate temperatures between 160 C and 240 C and salinities of 10 ppt to 25 ppt, whereas A. affinis has a temperature range between 160 C and 200 C. Comparisons between pore-water and SWIC exposures at a reference site within MINSY showed no significant difference in hatching success. However, hatching success in SWIC exposures was significantly lower than pore-water exposures at a previously characterized contaminated site. In conclusion, both M. beryllina and A. affinis embryos may be useful for sediment and in situ toxicity testing in estuarine environments. Their wide temperature and salinity tolerances allow for minimal test manipulations, and M. beryllina showed excellent hatching success in reference sediments for both types of exposures.

Jelinski, J.A.; Anderson, S.L. [Lawrence Berkeley National Lab., CA (United States)

1995-12-31

330

Domestic wastewater treatment by peatlands in a northern climate: a water quality study  

SciTech Connect

The use of peatlands as the main form of wastewater treatment in a northern climate was studied for the James Bay Energy Society. The Fontanges campsite (70/sub 0/ 17' 30'' W, 54/sup 0/ 34' 00'' N) was chosen as the study site. In less than 1.5 km from the point of discharge BOD/sub 5/, COD, total hardness, inorganic carbon, orthophosphates, total phosphorus, ammonia and total nitrogen were reduced by at least 90%. The peatland treatment system studied is divided into four components, each having a specific function. The first part combines the action of microorganisms and adsorption on peat, thus reducing the organic content while increasing the inorganic constituents. The second part uses peat to adsorb the inorganic elements already present in the wastewater and those produced in the first part of the system. The third component acts as an aerator, increasing the dissolved oxygen and decreasing the BOD/sub 5/ levels of the water. The fourth part removes most of the remaining nutrients, thus acting like a tertiary treatment. Overall, peatlands seemed to be effective in treating domestic settled wastewater in a cold climate.

Dubuc, Y.; Janneteau, P.; Labonte, R.; Roy, C.; Briere, F.

1986-04-01

331

Testing and analysis of load-side immersed heat exchangers for solar domestic hot water systems  

SciTech Connect

This report describes work to determine the performance of load-side heat exchangers for use in residential solar domestic hot water systems. We measured the performance of four heat exchangers: a smooth coil and a finned coil having heat transfer areas of 2.5 m/sup 2/ (26 ft/sup 2/) and those having areas of 1.7 m/sup 2/ (19 ft/sup 2/). A numerical model using the thermal network program MITAS was constructed, and results were compared to the experimental results. Research showed a smooth coil with only 70% of the surface area of a finned coil performed better than the finned coil. Also, load-side heat exchangers can maintain and enhance stratification in storage tanks, permitting the use of control strategies that take advantage of stratified storage tanks to increase system performance. The analytical model, which agreed reasonably well with the experimental results, was used to vary heat exchanger flow rate and area and initial tank temperature for both a smooth- and a finned-coil heat exchanger. Increasing the heat exchanger flow rate and area results in higher heat transfer rates but not necessarily optimal performance. Lower initial tank temperatures resulted in reduced tank stratification. The smooth heat exchanger outperformed the finned heat exchanger with the same outside surface area. 15 refs., 37 figs., 9 tabs.

Farrington, R.B.; Bingham, C.E.

1987-10-01

332

Eutrophication in the northern Adriatic Sea: Pore water and sediment studies  

SciTech Connect

The northern Adriatic Sea has been plagued by problems of eutrophication. This area is relatively shallow (maximum depth = 60m), becoming stratified during the summer months which inhibits oxygen transport to bottom waters. Anthropogenic nutrient loading in rivers entering the northern Adriatic (Po River being the largest) has increased nutrient input to this system and stimulated algal growth. Cores were collected for studies of pore water and solid phase chemistry at 6 stations in this region. [sup 210]Pb was used to constrain sediment accumulation rates and a range of 0-0.5 cm/yr was determined at different stations. Excess [sup 234]Th was only found in the upper 1-2 cm, suggesting that bioturbation is largely restricted to shallow depths. Pore water profiles show evidence of irrigation, and mean diffusive fluxes for oxygen, silica phosphate and ammonia are generally 20-90% of the fluxes obtained from benthic chamber measurements. This is consistent with previous work in this area in which studies of radon fluxes indicated that irrigation plays an important role in sediment-water exchange. Pore water profiles in the northern portion of the study area (near the Po River Delta) were markedly different than profiles in the south; sediments in the north are substantially more acidic and have high concentrations of dissolved iron and phosphate. From the alkalinity vs. TCO[sub 2] relationship in sediment pore waters it appears that differences in reactions involving the reduction of iron oxides and the exchange of magnesium for iron in clays are responsible for this regional difference in pore water properties. Sediments close to the Po apparently undergo more iron-magnesium exchange, while more distal sediments are limited in their ability to do so. Other pore water observations are limited in their ability to do so. Other pore water observations and trends regarding the shape of the silica profiles (which show shallow maxima) will be discussed.

Hammond, D.E.; Berelson, W.M. (Univ. of Southern California, Los Angeles (United States)); Giordani, P.; Langone, L.; Frignani, M.; Ravaioli, M. (Inst. di Geologia Marina, CNR, Bologna (Italy))

1990-01-09

333

Exchange of nutrients across the sediment-water interface in intertidal ria systems (SW Europe)  

NASA Astrophysics Data System (ADS)

Concentrations of nitrate, nitrite, ammonium, phosphate and silicate were determined in river water, tidal water that floods the intertidal sediment (flooding water) and pore water of those sediments in the Northern Galician Rias of Ortigueira and Viveiro (NW Iberian Peninsula). The field surveys were done in the productive seasons of spring and summer 2008. Short-sediment cores and tidal flooding water were sampled at the intertidal area during the first 20 min that the tide inundates the sampling site. Nutrient fluxes of rivers (Lourido and Landro) flowing into the rias were in the order of H4SiO4 > NO3- > NH4+ > HPO42 Nutrients input from those rivers were low relative to the nutrient discharge of the entire coastal area. Striking changes of nutrient concentrations in flooding and pore waters of intertidal sediments were observed in the short periods of tidal inundation. Nutrient fluxes driven by molecular diffusion and tide-induced transport across the sediment-water interface were quantified and compared to the nutrient river contribution. Diffusive fluxes ranged from 9.3 to 13.7 nmol·cm- 2·d- 1 for nitrate and nitrite, - 1.32 to 30.1 nmol·cm- 2·d- 1 for ammonium, - 0.01 to 0.49 nmol·cm- 2·d- 1 for phosphate, and - 13.2 to 0.2 nmol·cm- 2·d- 1 for silicate. Tide-induced transport always exceeded diffusive fluxes, with differences reaching up to four orders of magnitude for silicate. The overall results of this study emphasize the relevance of tidal water movement in promoting the sediment-water exchange of nutrients in intertidal sub-ecosystems.

Ospina-Alvarez, N.; Caetano, M.; Vale, C.; Santos-Echeandía, J.; Bernárdez, P.; Prego, R.

2014-01-01

334

Field Evaluation Of Arsenic Transport Across The Ground Water/Surface Water Interface: Speciation In Sediment Material  

EPA Science Inventory

The solubility and mobility of arsenic in ground water are influenced by a variety of processes in the northeastern US subjective to geogenic and anthropogenic sources. This presentation will discuss the speciation of arsenic in sediment profiles resulting from ground water disc...

335

Enzyme activities in the water column and in shallow permeable sediments from the northeastern Gulf of Mexico  

NASA Astrophysics Data System (ADS)

The activities of extracellular enzymes that initiate the microbial remineralization of high molecular weight organic matter were investigated in the water column and sandy surface sediments at two sites in the northeastern Gulf of Mexico. Six fluorescently labeled polysaccharides were hydrolyzed rapidly in the water column as well as in permeable sediments. This result contrasts with previous studies carried out in environments dominated by fine-grained muds, in which the spectrum of enzymes active in the water column is quite limited compared to that of the underlying sediments. Extracts of Spirulina, Isochrysis, and Thalassiosira were also used to measure hydrolysis rates in water from one of the sites. Rates of hydrolysis of the three plankton extracts were comparable to those of the purified polysaccharides. The broad spectrum and rapid rates of hydrolysis observed in the water column at both sites in the northeastern Gulf of Mexico may be due to the permeable nature of the sediments. Fluid flux through the sediments is sufficiently high that the entire 1.5 m deep water column could filter though the sediments on timescales of a few days to two weeks. Movement of water through sediments may also transport dissolved enzymes from the sediment into the water column, enhancing the spectrum as well as the rate of water column enzymatic activities. Such interaction between the sediments and water column would permit water column microbial communities to access high molecular weight substrates that might otherwise remain unavailable as substrates.

Arnosti, C.; Ziervogel, K.; Ocampo, L.; Ghobrial, S.

2009-09-01

336

Sorption and desorption behavior of organotin compounds in sediment-pore water systems.  

PubMed

Sediments contaminated with organotin compounds (OTs), in particular triorganotins (TOTs), are abundant in areas with high shipping activities. To assess the possible remobilization of these highly toxic compounds from such sediments, a profound understanding of their sorption/desorption behavior is necessary. In this work the extent and reversibility of sorption of OTs to sediments has been investigated using contaminated freshwater harbor sediments and two certified OT containing marine sediments. Experiments conducted with perdeuterated OTs showed that sorption of OTs to sediments is a fast and reversible process involving primarily particulate organic matter (POM) constituents as sorbents. The organic carbon-normalized sediment-water distribution ratios (DOC, expressed in L/kgOC) determined in the laboratory were consistent with in-situ DOCs obtained from OT concentrations measured in sediment and pore water samples from two dated sediment cores. For both butyl- and phenyltin compounds the log DOC values were in the range of 4.7-6.1, and the following sequence was observed: DOC (tri-OT) > or = DOC (di-OT) > or = DOC (mono-OT). However, the differences were much less pronounced than would have been expected for hydrophobic partitioning of the corresponding compounds into POM. These results support our hypothesis from earlier work with dissolved humic acids that OT sorption to sediments occurs primarily by reversible formation of (innerspere) complexes between the tin atom and carboxylate and phenolate ligands present in POM. Because of the high DOC values (i.e. log DOC > or = 4) the diffusion of OTs from deeper sediments to the surface will be rather slow, and thus a major release from undisturbed sediments is not expected. However, because OTs readily desorb, any resuspension of contaminated sediments (e.g., by the tide, storms or dredging activities) will lead to enhanced OT concentrations in the overlaying water column. Furthermore, in contrastto polycyclic aromatic hydrocarbons (PAH) where large fractions may be tightly bound (in)to soot or other carbonaceous materials, OTs will be more readily bioavailable due to the fast and reversible sorption/desorption behavior. PMID:11505992

Berg, M; Arnold, C G; Müller, S R; Mühlemann, J; Schwarzenbach, R P

2001-08-01

337

Laboratory measurements of physical, chemical, and optical characteristics of Lake Chicot sediment waters  

NASA Technical Reports Server (NTRS)

Reflectance, chromaticity, diffuse attenuation, beam attenuation, and several other physical and chemical properties were measured for various water mixtures of lake bottom sediment. Mixture concentrations range from 5 ppm to 700 ppm by weight of total suspended solids in filtered deionized tap water. Upwelled reflectance is a nonlinear function of remote sensing wave lengths. Near-infrared wavelengths are useful for monitoring highly turbid waters with sediment concentrations above 100 ppm. It is found that both visible and near infrared wavelengths, beam attenuation correlates well with total suspended solids ranging over two orders of magnitude.

Witte, W. G.; Whitlock, C. H.; Usry, J. W.; Morris, W. D.; Gurganus, E. A.

1981-01-01

338

Concentration of arsenic in water, sediments and fish species from naturally contaminated rivers.  

PubMed

Arsenic (As) may occur in surface freshwater ecosystems as a consequence of both natural contamination and anthropogenic activities. In this paper, As concentrations in muscle samples of 10 fish species, sediments and surface water from three naturally contaminated rivers in a central region of Argentina are reported. The study area is one of the largest regions in the world with high As concentrations in groundwater. However, information of As in freshwater ecosystems and associated biota is scarce. An extensive spatial variability of As concentrations in water and sediments of sampled ecosystems was observed. Geochemical indices indicated that sediments ranged from mostly unpolluted to strongly polluted. The concentration of As in sediments averaged 6.58 ?g/g ranging from 0.23 to 59.53 ?g/g. Arsenic in sediments barely followed (r = 0.361; p = 0.118) the level of contamination of water. All rivers showed high concentrations of As in surface waters, ranging from 55 to 195 ?g/L. The average concentration of As in fish was 1.76 ?g/g. The level of contamination with As differed significantly between species. Moreover, the level of bioaccumulation of As in fish species related to the concentration of As in water and sediments also differed between species. Whilst some fish species seemed to be able to regulate the uptake of this metalloid, the concentration of As in the large catfish Rhamdia quelen mostly followed the concentration of As in abiotic compartments. The erratic pattern of As concentrations in fish and sediments regardless of the invariable high levels in surface waters suggests the existence of complex biogeochemical processes behind the distribution patterns of As in these naturally contaminated ecosystems. PMID:23179469

Rosso, Juan José; Schenone, Nahuel F; Pérez Carrera, Alejo; Fernández Cirelli, Alicia

2013-04-01

339

A new device for collection of interstitial water from wetland sediments  

USGS Publications Warehouse

A sampler for collection of interstitial water from wetland sediments is described. It differs from other sampling devices because it does not have to be filled with solution to facilitate diffusion, it does not have to be removed from the wetland to collect samples, and it can be used to draw repeated samples over time from identical locations. The device facilitates 'in situ' measurement of a wide range of abiotic parameters such as electrical conductivity, redox potential, and pH in wetland sediments. The device has application in ecological investigations of sediment-borne wildlife diseases, studies of benthic invertebrates, measurement of nutrient exchange, and other aspects of wetland ecology.

Euliss, N.H., Jr.; Barnes, R.K.

1992-01-01

340

Energy use and domestic hot water consumption - Phase 1. Final report  

SciTech Connect

New York State Energy Research & Development Authority has sponsored a project to develop comprehensive operating data on combined domestic hot water (DHW) and heating systems to be used in system design and specifications. The new, more precise DHW flow data (broken down on a per capita basis) result in a better foundation for sizing decisions. Thirty New York City multifamily buildings with combined steam heating and DHW plants were instrumented to monitor apartment, outdoor, boiler and DHW temperatures, and burner on-off times. In nine buildings, which had been upgraded, additional data collected were: stack temperature, DHW flow in 15-minute increments, oil and boiler make-up water flows, and DHW temperature before and after the mixing valve and on the return line. The data set collected for 14 months amounts to a data base of over 110 megabytes. This report presents DHW demand patterns, seasonal variations, weekday vs. weekend consumption, consumption vs. occupancy levels, coincidence of 15-, 60-, 120-, and 180- minute demand periods, and average vs. peak demand levels, as well as figures for energy to generate DHW. The format of guidelines presented in this report differs from those currently in use. The {open_quotes}Low - Medium - High{close_quotes} (LMH) users set of guidelines provide a range, rather than a specific, singular gallonage standard. By providing LMH tables and guidelines for their application the design engineer or contractor can then use these as a tool from which to select the appropriate level that matches the site being served. Values are presented for both New York sizing guidelines (developed from this study), as well as a set of {open_quote}National{close_quote} figures (derived from a compilation of studies conducted in other cities). The LMH approach and {open_quote}National{close_quote} guidelines were adopted for inclusion in the 1995 ASHRAE Handbook revision.

Goldner, F.S. [Energy Management & Research Associates, Brooklyn, NY (United States)

1994-11-01

341

NITROGEN DYNAMICS IN SEDIMENT DURING WATER LEVEL MANIPULATION ON THE UPPER MISSISSIPPI RIVER  

Microsoft Academic Search

Nitrogen (N) has been linked to increasing eutrophication in the Gulf of Mexico and as a result there is increased interest in managing and improving water quality in the Mississippi River system. Water level reductions, or 'drawdowns', are being used more frequently in large river impoundments to improve vegetation growth and sediment compaction. We selected two areas of the Upper

JENNIFER C. CAVANAUGH; WILLIAM B. RICHARDSON; ERIC A. STRAUSSb; LYNN A. BARTSCHa

342

Dynamic modelling of passive margin salt tectonics: effects of water loading, sediment properties and  

E-print Network

Dynamic modelling of passive margin salt tectonics: effects of water loading, sediment properties by Couette £ow in the underlying salt.The e¡ects of water: (i) increase solid and £uid pressures that contain salt through two-dimensional (2D) analytical failure analysis and plane-strain ¢nite

Beaumont, Christopher

343

TOXICITY OF CADMIUM IN WATER AND SEDIMENT SLURRIES TO 'DAPHNIA MAGNA'  

EPA Science Inventory

Daphnia magna Straus were exposed to cadmium for 48 h in water and in equilibrated water sediment slurries using breakers and recirculating test chambers. Differences in toxicity based on dissolved and free cadmium (Cd(2+)) between the two levels of tested total solids 100 and 10...

344

WATER RESERVOIRS, IRRIGATION AND SEDIMENTATION IN CENTRAL ASIA: A FIRST-CUT ASSESSMENT FOR UZBEKISTAN  

E-print Network

1 WATER RESERVOIRS, IRRIGATION AND SEDIMENTATION IN CENTRAL ASIA: A FIRST-CUT ASSESSMENT-HEINO4 , Masharif BAKIEV1 1 Tashkent Institute of Irrigation and Melioration, Hydraulic Engineering-distributed later for different purposes. Irrigation is primarily a major water consumer in arid countries

Boyer, Edmond

345

Comparisons of deep-sea sediments and overlying water collected using Multiple Corer and Box Corer  

Microsoft Academic Search

Sediments and overlying water collected using Multiple Corer (MC) and Box Corer (BC) at three stations in Suruga Bay were compared from the view points of meiobenthic and chemical characteristics. Dissolved oxygen, pH, ammonium and nitrite concentrations of the overlying waters were lower, whereas nitrate and phosphate concentrations were higher constantly in the samples collected by MC than those by

Yoshihisa Shirayama; Tomohiko Fukushima

1995-01-01

346

DEVELOPMENT AND DEMONSTRATION OF A BIDIRECTIONAL ADVECTIVE FLUX METER FOR SEDIMENT-WATER INTERFACE  

EPA Science Inventory

A bidirectional advective flux meter for measuring water transport across the sediment-water interface has been successfully developed and field tested. The flow sensor employs a heat-pulse technique combined with a flow collection funnel for the flow measurement. Because the dir...

347

SPATIAL AND TEMPORAL ANALYSES OF THE BACTERIAL FAUNA AND WATER, SEDIMENT, AND AMPHIPOD TISSUE CHEMISTRY  

E-print Network

levels in water samples, especially in the late spring, but were infrequently detected in sediment bioaccumulation of Pendemethalin and Dieldrin, and low levels of lead were detected in most tissue samples). The numerous sinkholes, springs, and caves of the Salem Plateau all play an important role in the flow of water

Taylor, Steven J.

348

Proposed development of Sediment Quality Guidelines under the European Water Framework Directive: a critique  

Microsoft Academic Search

The Water Framework Directive is the most important piece of water legislation in Europe for many years and will substantially influence the environmental regulation of chemicals, including human and veterinary pharmaceuticals. The development of Sediment Environmental Quality Standards (EQSs) is called for by the Directive, and proposals have been made for achieving this. However, these proposals are technically controversial and

Mark Crane

2003-01-01

349

ANALYSIS OF NATIONAL WATER POLLUTION CONTROL POLICIES. 2. AGRICULTURAL SEDIMENT CONTROL  

EPA Science Inventory

Application of a national water network model permits an analysis of the likely effects of agricultural sediment control policies on the quality of the nation's waters. This analysis is believed superior to previous assessments based mainly on erosion estimates without accounting...

350

COSOLVENT EFFECTS ON PHENANTHRENE SORPTION-DESORPTION ON A FRESH-WATER SEDIMENT  

EPA Science Inventory

This study evaluated the effects of the water-miscible cosolvent methanol on the sorption-desorption of phenanthrene by the natural organic matter (NOM) of a fresh-water sediment. A biphasic pattern was observed in the relationship between the log of the carbon-normalized sorpti...

351

Rare earth elements in the pore waters of reducing nearshore sediments  

Microsoft Academic Search

The REE are mobile during early diagenesis in reducing nearshore sediments of Buzzards Bay leading to greatly enhanced concentrations in pore waters, e.g. 815 pmol kg-1 Nd and 1910 pmol kg-1 Ce within 30 cm of the sediment-seawater interface, about 10-50 times local seawater values. Two principal diagenetic reactions have been identified. Preferential Ce enrichment (positive Ce anomalies) and preferential

H. Elderfield; E. R. Sholkovitz

1987-01-01

352

Natural and artificial radionuclides in the Suez Canal bottom sediments and stream water  

Microsoft Academic Search

Concentration of natural and artificial radionuclides in Suez Canal bottom sediments and stream water have been measured using gamma spectrometers based on a hyper-pure Ge detector. The activity concentrations of 238U series, 232Th series and 40K did not exceed 16.0, 15.5 and 500.0 Bq kg-1 dry weight for sediments. The activity concentration of 238U series and 40K did not exceed

M. S. El-Tahawy; M. A. Farouk; N. M. Ibrahiem; S. A. M. El-Mongey

1994-01-01

353

Linear Alkylbenzene Sulfonate tolerance in bacteria isolated from sediment of tropical water bodies polluted with detergents  

Microsoft Academic Search

The discharge of untreated detergent-bearing waste introduces linear alkylbenzene sulfonates (LAS) to the aquatic environment. The surfactant persists in some streams and rivers in Nigeria, some is adsorbed to suspended materials and end in the sediment of the receiving water bodies. In this study, bacteria isolated from sediments of some tropical detergent-effluent-polluted streams were tested for tolerance to LAS using

Kehinde I. T. Eniola; Albert B. Olayemi

354

Polychlorinated biphenyls in water, sediment and selected organisms of Galveston Bay, Texas: environmental levels and bioaccumulation  

E-print Network

Bay sampling sites . . . . . . . . . . . . . . . . 67 9. PCB concentrations in brain and liver tissue of laughing gull, Larus atricilla from Galveston Bay, Texas, during 1978-1979 10. Determination of the suspended material present in the water... of gull, Larus atricilla from Trinity Bay, Texas, 1978 73 4. Liver extract of gull, Larus atricilla from East Bay, Texas, 1978 5. Aroclor 1016 standard 82 6. Extract of unexposed West Bay sediment used in the uptake experiment 7. West Bay sediment...

Stahl, Ralph Garner

2012-06-07

355

Impacts of soil-water conservation in Jialing River on sedimentation of the Three Gorges Reservoir  

Microsoft Academic Search

The Jialing River is one of the main tributaries of the Yangtze River. The average annual runoff accounts for 16% and the\\u000a sediment load 26% of the total at Yichang therefore it's one of the main contributors of sediment to the Three Gorges Reservoir.\\u000a Ever since 1989, our country has implemented “Yangtze River soil and water conservation” project, Till the

Lei Xiaozhang; Cao Shuyou; Jiang Xiaohua

2006-01-01

356

Degradation of terbutryn in sediments and water under various redox conditions  

Microsoft Academic Search

A laboratory study was conducted to examine the degradation of terbutryn [2?(t?butylamino)?4?(ethylamino)?6?(methylthio)?s?triazine] in sediment and water under different redox conditions. Terbutryn degraded slowly in static aerobic systems (loosely capped flask, 25°C) with half?lives of 240 and 180 days in pond and river sediment, respectively. Degradation products, identified by co?chromatography on TLC and HPLC systems, included hydroxy?terbutryn, terbutryn?sulfoxide and N?deethyl terbutryn.

D. C. G. Muir; A. L. Yarechewski

1982-01-01

357

Mercury and methylmercury contents in mine-waste calcine, water, and sediment collected from the Palawan Quicksilver mine, Philippines  

USGS Publications Warehouse

The Palawan Quicksilver mine, Philippines, produced about 2,900 t of mercury during mining of cinnabar ore from 1953 to 1976. More than 2,000,000 t of mine-waste calcines (retorted ore) were produced during mining, much of which were used to construct a jetty in nearby Honda Bay. Since 1995, high Hg contents have been found in several people living near the mine, and 21 of these people were treated for mercury poisoning. Samples of mine-waste calcine contain high total Hg concentrations ranging from 43-660 ??g/g, whereas total Hg concentrations in sediment samples collected from a mine pit lake and local stream vary from 3.7-400 ??g/g. Mine water flowing through the calcines is acidic, pH 3.1-4.3, and total Hg concentrations ranging from 18-31 ??g/l in this water significantly exceed the 1.0-??g/l drinking water standard for Hg recommended by the World Health Organization (WHO). Total Hg contents are generally lower in water samples collected from surrounding domestic wells, the mine pit lake, Honda Bay, and the nearby stream, varying from 0.008-1.4 ??g/l. Methylmercury concentrations in water draining mine calcines range from <0.02-1.4 ng/l, but methylmercury is highest in the pit lake water, ranging from 1.7-3.1 ng/l. Mercury methylation at the Palawan mine is similar to or higher than that found in other mercury mines worldwide. Much of the methylmercury generated in Palawan mine-waste calcines and those in Honda Bay is transferred to water, and then to marine fish and seafood. A food source pathway of Hg to humans is most likely in this coastal, high fish-consuming population.

Gray, J.E.; Greaves, I.A.; Bustos, D.M.; Krabbenhoft, D.P.

2003-01-01

358

A comparison of solids collected in sediment traps and automated water samplers  

USGS Publications Warehouse

Sediment traps are being used in some pollution monitoring programs in the USA to sample suspended solids for contaminant analyses. This monitoring approach assumes that the characteristics of solids obtained in sediment traps are the same as those collected in whole-water sampling devices. We tested this assumption in the upper Mississippi River, based on the inorganic particle-size distribution (determined with a laser particle- analyzer) and volatile matter content of solids (a surrogate for organic matter). Cylindrical sediment traps (aspect ratio 3) were attached to a rigid mooring device and deployed in a flowing side channel in Navigation Pool 7 of the upper Mississippi River. On each side of the mooring device, a trap was situated adjacent to a port of an autosampler that collected raw water samples hourly to form 2-d composite samples. Paired samples (one trap and one raw water, composite sample) were removed from each end of the mooring device at 2-d intervals during the 30-d study period and compared. The relative particle collection efficiency of paired samplers did not vary temporally. Particle-size distributions of inorganic solids from sediment traps and water samples were not significantly different. The volatile matter content of solids was lesser in sediment traps (mean, 9.5%) than in corresponding water samples (mean, 22.7%). This bias may have been partly due to under-collection of phytoplankton (mainly cyanobacteria), which were abundant in the water column during the study. The positioning of water samplers and sediment traps in the mooring device did not influence the particle-size distribution or total solids of samples. We observed a small difference in the amount of organic matter collected by water samplers situated at opposite ends of the mooring device.

Bartsch, L.A.; Rada, R.G.; Sullivan, J.F.

1996-01-01

359

Significance of fine-grained sediment lofting from melt-water generated turbidity currents for the timing of glaciomarine sediment transport into the deep sea  

Microsoft Academic Search

Sediment lofting from turbidity currents is a process that occurs in density currents generated from fresh-water discharges into the sea and other gravity currents that can produce reversed buoyancy. Settling of suspended sediment from the top or deposition from the bottom of the flows may lower the density below that of ambient seawater causing the currents to lift up from

Reinhard Hesse; Saeed Khodabakhsh

2006-01-01

360

An Integrated Assessment of Sediment Remediation in a Midwestern U.S. Stream Using Sediment Chemistry, Water Quality, Bioassessment and Fish Biomarkers  

EPA Science Inventory

A comprehensive biological, sediment and water quality study of the lower Little Scioto River near Marion, Ohio, USA was undertaken in July 2007 to evaluate the effectiveness of removal of creosote-contaminated sediment. The study area covered 7.5 river miles (RMs) of the river, ...

361

Occurrence of macrophyte monocultures in drainage ditches relates to phosphorus in both sediment and water.  

PubMed

Monocultures of functional equivalent species often negatively affect nutrient cycling and overall biodiversity of aquatic ecosystems. The importance of water and sediment nutrients for the occurrence of monocultures was analysed using field data from drainage ditches. Ranges of nutrients were identified that best explained the occurrence of monocultures of Elodea nuttallii (Planch.) St. John (Waterweed type), monocultures of duckweed (Duckweed type) and the occurrence of a diverse submerged vegetation (Mixed type). Results indicated these three vegetation types occurred at distinctive ranges of phosphorus in water and sediment. Sediment phosphorus distinguished monocultures from the Mixed type, with the two monocultures occurring at two to four times higher concentrations. The Waterweed type occurred at higher sediment phosphorus levels than the mixed type, showed a higher degree of dominance and lower number of red list species. Phosphorus concentrations in water were four to six times higher in the Duckweed type compared to the Waterweed and Mixed type. The three vegetation types had comparable total biomass which was unexpected. This comparability was likely caused by duckweed only growing at the water surface at the highest nutrient levels and the limited space in drainage ditches for increased submerged biomass development at high nutrient availability. Possible measures to limit the occurrence of monocultures, and thereby increasing the ecological quality, are discussed with focus on lowering phosphorus concentrations in both water and sediment and on removal of plant species that develop into monocultures. PMID:24255858

van Zuidam, Jeroen P; Peeters, Edwin Thm

2013-01-01

362

Radium isotopes as a tracer of sediment-water column exchange in the North Sea  

NASA Astrophysics Data System (ADS)

column exchange plays an important role in coastal biogeochemistry. We utilize short-lived radium isotopes (224Ra and 223Ra) to understand and quantify the dominant processes governing sediment-water column exchange throughout the North Sea. Our comprehensive survey, conducted in September 2011, represents the first of its kind conducted in the North Sea. We find that two main sources regulate surface Ra distributions: minor coastal input from rivers and shallow mudflats and North Sea sediments as the dominant source. Pore waters show 100-fold larger activities than the water column. North Sea sediment characteristics such as porosity and mean grain size, as well as turbulence at the sediment-water interface, are the dominant factors contributing to variability of Ra efflux. Ra inventory and mass balance approaches consistently yield high benthic Ra effluxes in the southern North Sea, driven by strong tidal and wind mixing, which in turn cause high sediment irrigation rates. These results exceed incubation-based Ra flux estimates and the majority of previously reported Ra flux estimates for other regions. Ra-based estimates of benthic alkalinity fluxes compare well to observed values, and the high rates of Ra efflux imply a potentially significant exchange of other products of sedimentary reactions, including carbon and nutrient species. Passive tracer simulations lend strong support to the Ra source attribution and imply seasonal variation in the surface water Ra distribution depending on stratification conditions.

Burt, W. J.; Thomas, H.; Pätsch, J.; Omar, A. M.; Schrum, C.; Daewel, U.; Brenner, H.; Baar, H. J. W.

2014-08-01

363

Distribution, sources and composition of antibiotics in sediment, overlying water and pore water from Taihu Lake, China.  

PubMed

The occurrence of 15 antibiotics classified as sulphonamides, fluoroquinolones, macrolides, tetracyclines and trimethoprim in sediment, overlying water, and pore water matrices in Taihu Lake, China was studied. The total concentrations were from 4.1?g/kg to 731?g/kg, from 127ng/L to 1210ng/L, and from 1.5ng/L to 216ng/L in sediment, overlying water and pore water, respectively. Antibiotics in different locations originated from various sources, depending on human, agricultural and aquacultural activities. Composition analysis indicated that human-derived and animal-derived drugs significantly contributed to the total contamination of antibiotics in the lake, indicating the high complexity of contamination sources in Taihu Lake Basin. The in situ sediment-pore water partitioning coefficients were generally greater than sediment-overlying water partitioning coefficients, suggesting continuous inputs into the lake water. This study shows that antibiotics are ubiquitous in all compartments in Taihu Lake, and their potential hazards to the aquatic ecosystem need further investigation. PMID:25129162

Xu, Jian; Zhang, Yuan; Zhou, Changbo; Guo, Changsheng; Wang, Dingming; Du, Ping; Luo, Yi; Wan, Jun; Meng, Wei

2014-11-01

364

Surface water concentrations and loading budgets of pharmaceuticals and other domestic-use chemicals in an urban watershed (Washington, DC, USA).  

PubMed

Pharmaceuticals and domestic-use chemicals (PDCs) are classes of emerging chemical contaminants thought to enter the aquatic environment primarily through wastewater treatment plant (WTP) discharges. The intent of this study was to quantify loadings of PDCs in an urban watershed. The watershed has two major branches but with wastewater discharge occurring in only one of the two major branches. Surface water from the Anacostia River (Washington, DC) was collected in base-flow and storm-flow regimes. Surface water was filtered to separate water and particles, and the PDCs were extracted from water with Oasis HLB solid-phase extraction cartridges and extracted from sediments using microwave-assisted extraction. The PDCs in the extracts were quantified using gas chromatography-mass spectrometry in the form of the trimethylsilyl ether derivatives. The most frequently detected PDC with the highest concentration was bisphenol-A in both branches of the Anacostia River watershed and the least frequently detected PDC was diclofenac. The overall median concentrations for all measured PDCs in surface water ranged from nondetectable to 54.9 ng/l. Alternatively, in the collected WTPs samples, naproxen was observed, with the highest concentration and the median concentrations in WTP effluent ranging from nondetectable to 276 ng/l. Estimates of PDC loadings for February 2006 from WTP effluent showed that <2% of the downstream load in the NE Branch was derived from WTP discharge. PDC sources other than WTP effluent appear to influence surface water concentrations in the urban Anacostia River watershed. PMID:20098984

Shala, Lirije; Foster, Gregory D

2010-04-01

365

Effects of Three Gorges Reservoir (TGR) water storage in June 2003 on Yangtze River sediment entering the estuary  

Microsoft Academic Search

The world-greatest water conservancy project, Three Gorges Reservoir (TGR), stored water for the first time in June 2003, which provides an excellent opportunity to examine its effects on the sediment entering the Yangtze River estuary. A daily record dataset of water discharge and suspended sediment concentration (SSC) of the Yangtze River measured at Datong (the controlling hydrological gauging station into

Z. X. Chu; S. K. Zhai

2006-01-01

366

Sediment desiccation as a driver of phosphate availability in the water column of Mediterranean wetlands.  

PubMed

Sediment desiccation is expected to drastically affect nutrient cycling in Mediterranean wetlands as global climate change models predict that many areas will become significantly drier than they currently are. In this study, we selected two Mediterranean wetlands that clearly differ in their water chemical composition (Honda and Hituelo wetlands) in order to determine the impact of sediment desiccation on phosphate (PO?(3-)) adsorption and desorption properties. A decrease in PO?(3-) sorption properties was observed in transects from the littoral zone to dry land in both lakes concomitantly with a reduction in organic matter content, revealing a critical role of organic matter for sequestering P in the lake sediment. Our experiments designed to determine if drying events would lead to an enhanced P release upon re-wetting have shown that, simulating natural conditions of re-flooding (that is without adding sodium azide), PO?(3-) concentrations were notably higher in the overlying water than those initially measured in the lake water. These results highlight the impact of drying sediment and the subsequent re-wetting on increasing P concentrations in lake water and accordingly, affecting to lake trophic state. Finally, we aimed on determining the overall effect of biotic versus abiotic activity on P release patterns observed upon re-wetting. Our results have evidenced that while in Honda, biotic processes upon re-wetting are crucial for increasing P retention in the sediment; P exchange across sediment and water upon dry sediment re-wetting is basically mediated by abiotic processes in Hituelo. PMID:23988744

Gilbert, Juan Diego; Guerrero, Francisco; de Vicente, Inmaculada

2014-01-01

367

[Distribution of polycyclic aromatic hydrocarbons in water and sediment from Zhoushan coastal area, China].  

PubMed

The spatial and temporal distribution of 16 polycyclic aromatic hydrocarbons (PAHs) has been investigated in water and sediments of Zhoushan coastal area every two months in 2012. The concentrations of total PAHs ranged from 382.3 to 816.9 ng x L(-1), with the mean value of 552.5 ng x L(-1) in water; whereas it ranged from 1017.9 to 3047.1 ng x g(-1), with the mean value of 2 022.4 ng x g(-1) in sediment. Spatial distribution showed that Yangshan and Yanwoshan offshore area had the maximum and minimum of total PAHs contents in water, while the maximum and minimum occurred at Yangshan and Zhujiajian Nansha offshore area in sediment. Temporal distribution revealed that total PAHs contents in water reached the maximum and minimum values in October and June, however in sediments these values were found in August and June, respectively. The PAHs pollution was affected by oil emission, charcoal and coal combustion. Using the biological threshold and exceeded coefficient method to assess the ecological risk of PAHs in Zhoushan coastal area, the result showed that sigma PAHs had a lower probability of potential risk, while there was a higher probability of potential risk for acenaphthylene monomer, and there might be ecological risk for acenaphthene and fluorene. Distribution of PAHs between sediment and water showed that Zhoushan coastal sediment enriched a lot of PAHs, meanwhile the enrichment coefficient (K(d) value) of sediment in Daishan island was larger than that in Zhoushan main island. PMID:25244854

Jiang, Min; Tuan, Le Huy; Mei, Wei-Ping; Ruan, Hui-Hui; Wu, Hao

2014-07-01

368

Suspended-sediment and fresh-water discharges in the Ob and Yenisey rivers, 1960-1988  

Microsoft Academic Search

Of the world's great rivers, the Ob and Yenisey rank among the largest suppliers of fresh water and among the smallest suppliers of suspended sediment to the coastal ocean. Sediment in the middle reaches of the rivers is mobilized from bordering terraces and exchanged between channels and flood plains. Sediment in the lower reaches of these great rivers is deposited

R. H. Meade; N. N. Bobrovitskaya; V. I. Babkin

2000-01-01

369

Methods for determination of inorganic substances in water and fluvial sediments  

USGS Publications Warehouse

Chapter Al of the laboratory manual contains methods used by the U.S. Geological Survey to analyze samples of water, suspended sediments, and bottom material for their content of inorganic constituents. Included are methods for determining the concentration of dissolved constituents in water, the total recoverable and total of constituents in water-suspended sediment samples, and the recoverable and total concentrations of constituents in samples of bottom material. The introduction to the manual includes essential definitions and a brief discussion of the use of significant figures in calculating and reporting analytical results. Quality control in the water-analysis laboratory is discussed, including the accuracy and precision of analyses, the use of standard-reference water samples, and the operation of an effective quality-assurance program. Methods for sample preparation and pretreatment are given also. A brief discussion of the principles of the analytical techniques involved and their particular application to water and sediment analysis is presented. The analytical methods of these techniques are arranged alphabetically by constituent. For each method, the general topics covered are the application, the principle of the method, the interferences, the apparatus and reagents required, a detailed description of the analytical procedure, reporting results, units and significant figures, and analytical precision data, when available. More than 126 methods are given for the determination of 70 inorganic constituents and physical properties of water, suspended sediment, and bottom material.

Edited by Fishman, Marvin J.; Friedman, Linda C.

1989-01-01

370

Diffusive release of uranium from contaminated sediments into capillary fringe pore water  

SciTech Connect

Despite remediation efforts at the former nuclear weapons facility at the Hanford site (Washington State), leaching of uranium (U) from contaminated sediments to the ground water persists at the Hanford 300 Area. Flooding of contaminated capillary fringe sediments due to seasonal changes in the Columbia River stage has been identified as a reason of continued U supply to ground water. We investigated the release of U from Hanford capillary fringe sediments to pore water. Contaminated Hanford sediments were packed into reservoirs of centrifugal filter devices and saturated with Columbia River water for 3 to 84 days at varying solution-to-solid ratios (1:3, 1:1, 5:1, 10:1, 25:1 mL:g). After specified times, samples were centrifuged to a gravimetric water content of 0.11 ± 0.06 g g-1. Within the first three days, there was an initial rapid release of 6-9% of total U from the sediments into the pore water, independent of the solution-to-solid ratio. After 14 days of reaction, however, the experiments with the narrowest solution-to-solid ratios (1:3 and 1:1 mL:g) showed a decline in dissolved U concentrations. The removal of U from the solution phase was accompanied by removal of Ca and HCO3-. Geochemist workbench simulations, conducted using measured solution concentrations from experiments, indicated that calcite could precipitate in the 1:3 solution-to-solid ratio experiment. After the rapid initial release in the first three days for the 5:1, 10:1, and 25:1 solution-to-solid ratio experiments, there was sustained release of U into the pore water. Up to 22% of total U was released on day 84 for the 25:1 solution-to-solid ratio reaction. This sustained release of U from the sediments had diffusion-limited kinetics.

Rod, Kenton A.; Wellman, Dawn M.; Flury, Markus; Pierce, Eric M.; Harsh, James B.

2012-10-01

371

Enhancing the start-up of a UASB reactor treating domestic wastewater by adding a water extract of Moringa oleifera seeds  

Microsoft Academic Search

Water extract of Moringa oleifera seeds (WEMOS) was used to enhance the start-up of a self-inoculated upflow anaerobic sludge blanket (UASB) reactor treating raw domestic wastewater. Two reactors labelled control (RC) and WEMOS addition (RM) were started without special inoculum. Both reactors were fed continuously for 22 weeks with domestic wastewater containing an average total chemical oxygen demand (COD) of

Y. Kalogo; A. M'Bassiguié Séka; W. Verstraete

2001-01-01

372

Aquatic Sediments.  

ERIC Educational Resources Information Center

Presents a literature review of aquatic sediments and its effect upon water quality, covering publications of 1976-77. This review includes: (1) sediment water interchange; (2) chemical and physical characterization; and (3) heavy water in sediments. A list of 129 references is also presented. (HM)

Sanville, W. D.; And Others

1978-01-01

373

Water volume and sediment accumulation in Lake Linganore, Frederick County, Maryland, 2009  

USGS Publications Warehouse

To assist in understanding sediment and phosphorus loadings and the management of water resources, a bathymetric survey was conducted at Lake Linganore in Frederick County, Maryland in June 2009 by the U.S. Geological Survey, in cooperation with the City of Frederick and Frederick County, Maryland. Position data and water-depth data were collected using a survey grade echo sounder and a differentially corrected global positioning system. Data were compiled and edited using geographic information system software. A three-dimensional triangulated irregular network model of the lake bottom was created to calculate the volume of stored water in the reservoir. Large-scale topographic maps of the valley prior to inundation in 1972 were provided by the City of Frederick and digitized. The two surfaces were compared and a sediment volume was calculated. Cartographic representations of both water depth and sediment accumulation were produced along with an area/capacity table. An accuracy assessment was completed on the resulting bathymetric model. Vertical accuracy at the 95-percent confidence level for the collected data, the bathymetric surface model, and the bathymetric contour map was calculated to be 0.95 feet, 1.53 feet, and 3.63 feet, respectively. The water storage volume of Lake Linganore was calculated to be 1,860 acre-feet at full pool elevation. Water volume in the reservoir has decreased by 350 acre-feet (about 16 percent) in the 37 years since the dam was constructed. The total calculated volume of sediment deposited in the lake since 1972 is 313 acre-feet. This represents an average rate of sediment accumulation of 8.5 acre-feet per year since Linganore Creek was impounded. A sectional analysis of sediment distribution indicates that the most upstream third of Lake Linganore contains the largest volume of sediment whereas the section closest to the dam contains the largest amount of water. In comparison to other Maryland Piedmont reservoirs, Lake Linganore was found to have one of the lowest sedimentation rates at 0.26 cubic yards per year per acre of drainage area. Sedimentation rates in other comparable Maryland reservoirs were Prettyboy Reservoir (filling at a rate of 2.26 cubic yards per year per acre), Loch Raven Reservoir (filling at a rate of 0.88 cubic yards per year per acre) and Piney Run Reservoir (filling at a negligible rate).

Sekellick, Andrew J.; Banks, S. L.

2010-01-01

374

Laboratory upwelled radiance and reflectance spectra of Kerr reservoir sediment waters  

NASA Technical Reports Server (NTRS)

Reflectance, chromaticity, and several other physical and chemical properties were measured for various water mixtures of bottom sediments taken from two sites at Kerr Reservoir, Virginia. Mixture concentrations ranged from 5 to 1000 ppm by weight of total suspended solids (TSS) in filtered deionized tap water. The two sets of radiance and reflectance spectra obtained were similar in shape and magnitude for comparable values of TSS. Upwelled reflectance was observed to be a nonlinear function of TSS with the degree of curvature a function of wavelength. Sediment from the downstream site contained a greater amount of particulate organic carbon than from the upstream site. No strong conclusions can be made regarding the effects of this difference on the radiance and reflectance spectra. Near-infrared wavelengths appear useful for measuring highly turbid water with concentrations up to 1000 ppm or more. Chromaticity characteristics do not appear useful for monitoring sediment loads above 150 ppm.

Witte, W. G.; Whitlock, C. H.; Morris, W. D.; Gurganus, E. A.

1982-01-01

375

Can sediment data be used to predict alkalinity and base cation chemistry of surface waters?  

PubMed

We hypothesise that stream sediment elemental composition can predict mean and minimum concentrations of alkalinity, Ca and Mg in the river water throughout a river network. We tested this hypothesis for the River Derwent catchment in North Yorkshire, England, by using 6 years of water chemistry data from the Environment Agency and a digital elevation model to flow path-weight British Geological Survey (BGS) sediment element concentration data. The predictive models for mean concentrations were excellent for Ca and alkalinity, but less good for Mg, and did not require land use data inputs as stream water sediment composition seems to reflect all aspects of the riparian zone soil system. Predictive model forms were linear. Attempts to predict minimum values for Ca and alkalinity also were less satisfactory. This probably is due to variations in hydrological response times to individual precipitation events across the catchment. PMID:21051075

Begum, S; McClean, C J; Cresser, M S; Breward, N

2010-12-15

376

Investigation of heavy metal contaminations in the lower Sakarya river water and sediments.  

PubMed

In this work, water and sediment samples were collected from three different stations located along the Sakarya river between May and September 2003. Lead, copper, chromium, zinc, nickel and cadmium concentrations were determined by using solvent extraction and flame atomic absorption spectrometric method. The results show that differences based upon sampling times, regions, sediment and water samples were observed. The mean levels of copper, nickel, chromium, lead, cadmium, zinc for sediment samples are; 4.630 microg g(-1), 13.520 microg g(-1), 8.780 microg g(-1), 2.550 microg g(-1), 9.990 microg g(-1) and for water samples are; 0.851 microg g(-1), 1.050 microg g(-1), 0.027 microg g(-1), 1.786 microg g(-1), 0.236 microg g(-1), 0.173 microg g(-1), respectively. PMID:16897496

Dundar, Mustafa S; Altundag, Huseyin

2007-05-01

377

Identification of Water-Quality Trends Using Sediment Cores from Dillon Reservoir, Summit County, Colorado  

USGS Publications Warehouse

Since the construction of Dillon Reservoir, in Summit County, Colorado, in 1963, its drainage area has been the site of rapid urban development and the continued influence of historical mining. In an effort to assess changes in water quality within the drainage area, sediment cores were collected from Dillon Reservoir in 1997. The sediment cores were analyzed for pesticides, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and trace elements. Pesticides, PCBs, and PAHs were used to determine the effects of urban development, and trace elements were used to identify mining contributions. Water-quality and streambed-sediment samples, collected at the mouth of three streams that drain into Dillon Reservoir, were analyzed for trace elements. Of the 14 pesticides and 3 PCBs for which the sediment samples were analyzed, only 2 pesticides were detected. Low amounts of dichloro-diphenyldichloroethylene (DDE) and dichloro-diphenyldichloroethane (DDD), metabolites of dichlorodiphenyltrichloroethane (DDT), were found at core depths of 5 centimeters and below 15 centimeters in a core collected near the dam. The longest core, which was collected near the dam, spanned the entire sedimentation history of the reservoir. Concentrations of total combustion PAH and the ratio of fluoranthene to pyrene in the core sample decreased with core depth and increased over time. This relation is likely due to growth in residential and tourist populations in the region. Comparisons between core samples gathered in each arm of the reservoir showed the highest PAH concentrations were found in the Tenmile Creek arm, the only arm that has an urban area on its shores, the town of Frisco. All PAH concentrations, except the pyrene concentration in one segment in the core near the dam and acenaphthylene concentrations in the tops of three cores taken in the reservoir arms, were below Canadian interim freshwater sediment-quality guidelines. Concentrations of arsenic, cadmium, chromium, copper, lead, and zinc in sediment samples from Dillon Reservoir exceeded the Canadian interim freshwater sediment-quality guidelines. Copper, iron, lithium, nickel, scandium, titanium, and vanadium concentrations in sediment samples decreased over time. Other elements, while no trend was evident, displayed concentration spikes in the down-core profiles, indicating loads entering the reservoir may have been larger than they were in 1997. The highest concentrations of copper, lead, manganese, mercury, and zinc were detected during the late 1970's and early 1980's. Elevated concentrations of trace elements in sediment in Dillon Reservoir likely resulted from historical mining in the drainage area. The downward trend identified for copper, iron, lithium, nickel, scandium, titanium, and vanadium may be due in part to restoration efforts in mining-affected areas and a decrease in active mining in the Dillon Reservoir watershed. Although many trace-element core-sediment concentrations exceeded the Canadian probable effect level for freshwater lakes, under current limnological conditions, the high core-sediment concentrations do not adversely affect water quality in Dillon Reservoir. The trace-element concentrations in the reservoir water column meet the standards established by the Colorado Water Quality Control Commission. Although many trace-element core-sediment concentrations exceeded the Canadian probable effect level for freshwater lakes, under current limnological conditions, the high core-sediment concentrations do not adversely affect water quality in Dillon Reservoir. The trace-element concentrations in the reservoir water column meet the standards established by the Colorado Water Quality Control Commission.

Greve, Adrienne I.; Spahr, Norman E.; Van Metre, Peter C.; Wilson, Jennifer T.

2001-01-01

378

Analysis of heavy metals concentration in water and sediment in the Hara biosphere reserve, southern Iran.  

PubMed

This study determined the concentration of heavy metals (Al, Cr, Cu, and Zn) in water and sediments at nine sites in the Hara biosphere reserve of southern Iran during the summer and winter 2010. Determination of Al, Cr, Cu, and Zn in water was carried out by graphite furnace atomic absorption spectrometer (Shimadzu, AA 610s) and in sediment by flame atomic absorption spectrometer (Perkin Elmer, AA3030). Results showed that the heavy metal concentrations in the water samples decreased in the sequence of Zn > Al > Cu > Cr, while in sediment samples were Cr > Zn > Cu > Al. Data analysis indicated that with the exception of Al, there was a Pearson's correlation coefficient between pH and Cu, Zn, and Cr at ? = 0.01, 0.05, and 0.001 in sediment (in winter), respectively. There were also significant differences between heavy metals of Cr, Cu, and Zn during the two seasons (p < 0.001) in the water and sediment. PMID:22740619

Nowrouzi, Mohsen; Mansouri, Borhan; Nabizadeh, Sahar; Pourkhabbaz, Alireza

2014-02-01

379

Hg bioaccumulation in a contaminated flowing water system-sediment, macroinvertebrates, and fish interactions  

NASA Astrophysics Data System (ADS)

The Truckee River (TR) of Nevada/California USA has been and is impacted physically and chemically by human actions. Previous work has shown a significant difference in mercury (Hg) concentrations of fish and water collected above and below the confluence of Steamboat Creek (SBC) with the river. Steamboat Creek is contaminated with Hg due to legacy milling of gold and silver ore at Washoe Lake. We investigated the potential for Hg concentrations in water, sediments and macroinvertebrates to be latent indicators of potential sources of methylmercury (MeHg) for fish species. Sites below SBC showed significantly higher Hg concentrations in water, sediments, macroinvertebrates, and fish. Not only were MeHg concentrations in sediments associated with specific environmental conditions, but sediments from the shore versus the active channel appeared to be an important source of MeHg to waters during periods of high flow. Data showed that areas with high Hg concentrations in sediments were also locations of elevated Hg concentrations in some species of macroinvertebrates. Bioaccumulation was observed not only as a function of tropic stature for fish in the reach impacted by SBC, but also for macroinvertebrates with predator species having higher concentrations than collectors and omnivorous.

Pizarro-Barraza, C.; Gustin, M. S.; Peacock, M.

2010-12-01

380

Diffusive release of uranium from contaminated sediments into capillary fringe pore water  

SciTech Connect

Despite remediation efforts at the former nuclear weapons facility, leaching of uranium (U) from contaminated sediments to the ground water persists at the Hanford site 300 Area. Flooding of contaminated capillary fringe sediments due to seasonal changes in the Columbia River stage has been identified as a source for U supply to ground water. We investigated U release from Hanford capillary fringe sediments by packing sediments into reservoirs of centrifugal filter devices and saturated with Columbia River water for 3 to 84 days at varying solution-to-solid ratios. After specified times, samples were centrifuged. Within the first three days, there was an initial rapid release of 6-9% of total U, independent of the solution-to-solid ratio. After 14 days of reaction, however, the experiments with the narrowest solution-to-solid ratios showed a decline in dissolved U concentrations. The removal of U from the solution phase was accompanied by removal of Ca and HCO3-. Geochemical modeling indicated that calcite could precipitate in the narrowest solution-to-solid ratio experiment. After the rapid initial release in the first three days for the wide solution-to-solid ratio experiments, there was sustained release of U into the pore water. This sustained release of U from the sediments had diffusion-limited kinetics.

Rod, Kenton A. [Pacific Northwest National Laboratory (PNNL); Wellman, Dawn M. [Pacific Northwest National Laboratory (PNNL); Flury, Markus [Washington State University, Pullman; Pierce, Eric M [ORNL; Harsh, James B. [Washington State University, Pullman

2012-01-01

381

Diffusive release of uranium from contaminated sediments into capillary fringe pore water  

NASA Astrophysics Data System (ADS)

Despite remediation efforts at the former nuclear weapons facility, leaching of uranium (U) from contaminated sediments to the ground water persists at the Hanford site 300 Area. Flooding of contaminated capillary fringe sediments due to seasonal changes in the Columbia River stage has been identified as a source for U supply to ground water. We investigated U release from Hanford capillary fringe sediments by packing sediments into reservoirs of centrifugal filter devices and saturating them with Columbia River water for 3 to 84 days at varying solution-to-solid ratios. After specified times, samples were centrifuged. Within the first three days, there was an initial rapid release of 6-9% of total U, independent of the solution-to-solid ratio. After 14 days of reaction, however, the experiments with the narrowest solution-to-solid ratios showed a decline in dissolved U concentrations. The removal of U from the solution phase was accompanied by removal of Ca and HCO3-. Geochemical modeling indicated that calcite could precipitate in the narrowest solution-to-solid ratio experiment. After the rapid initial release in the first three days for the wide solution-to-solid ratio experiments, there was sustained release of U into the pore water. This sustained release of U from the sediments had diffusion-limited kinetics.

Rod, Kenton A.; Wellman, Dawn M.; Flury, Markus; Pierce, Eric M.; Harsh, James B.

2012-10-01

382

[Indication of Northern Caspian regions by biochemical (enzymatic) indices of water and bottom sediments].  

PubMed

We evaluated ecological status in the region of mixing of river and sea waters in the northern Caspian Sea with high anthropogenic pressure. We studied the regions of Volga River fore-delta, the water areas neighboring ancient hydrological transects, and the sea regions between the transects. The water areas were evaluated by biochemical degradation of organic compounds (proteinase and amylase activities) in water and bottom sediments as well as hydrochemical indices of water (salt composition and contents of dissolved oxygen and biogenic compounds). In conditions of active vegetation of phytoplankton and higher aquatic plants soon after the highest wave of the Volga flood, we studied distribution of hydrolytic enzyme activities involved in the global production/destruction cycle of high molecular weight organic compounds (proteins and polysaccharides). The data obtained with the trypsin-azocasein and alpha-amylase-modified starch tests indicates pollution of water and surface sediments in the lower reaches of Volga and the inflow sea regions. PMID:14735793

Korneeva, G A; Miroshnik, L Iu; Tsytsarin, A G

2003-01-01

383

Total and Methyl Mercury Distribution in Water, Sediment, and Fish tissue in New England Streams  

NASA Astrophysics Data System (ADS)

Conditions that are conducive to the methylation of mercury are of particular concern because methyl mercury (MeHg) is the most toxic mercury species and is rapidly bioaccumulated and biomagnified in wildlife and man. The New England Coastal Basins study unit, as part of the U.S. Geological Survey's National Water Quality Assessment program, has evaluated relations between concentrations of total mercury (HgT) and MeHg in stream water and bed sediment, and HgT in fish tissue at sites with a variety of watershed characteristics. Fifty-five stream sites from Rhode Island to Maine were sampled for water and bed sediment during 1998 - 2000. A subset of 27 sites was sampled for fish tissue. Sediment, water, and fish tissue samples were collected during summer low flow conditions within a week of each other to show patterns of MeHg accumulation and partitioning relative to site and watershed conditions. Concentrations of HgT in water and bed sediment ranged from 1 to 13 nanograms per liter (ng/L) and from 7 to 3,100 nanograms per gram (ng/g) dry weight, respectively. Concentrations of MeHg in water and sediment ranged from 0.04 to 1.8 ng/L and from 1 to 38 ng/g dry weight, respectively, and were positively correlated with concentrations of organic carbon. Methylation efficiency, as estimated by MeHg/HgT, ranged from 0.003 to 0.282 for sediment and water samples, with a median value of 0.071. Methylation efficiency was highest at sampling sites with low urbanization and high organic carbon concentrations. HgT concentrations in fish tissue (mixed sunfish species) ranged from 42 to 349 ng/g wet weight and were positively correlated with concentrations of MeHg in water and bed sediment. A positive relation was not observed between HgT concentrations in fish tissue and HgT concentrations in water and bed sediment. These preliminary results indicate a high potential for mercury bioaccumulation in aquatic organisms in New England streams.

Chalmers, A. T.; Krabbenhoft, D. P.

2001-05-01

384

Water and Sediment Yields for Wala Dam Catchment Area  

Microsoft Academic Search

Wala Watershed occupies the upper part of Al-Mujib Basin, Jordan, with Mediterranean climate, sparse inhabitants and moderate agriculture. The area, in spite of its limited water resources, is considered as an important water supply as it encompasses Al-Heidan springs and pumping wells, which supply Amman city with a considerable amount of water, it also includes Wala Dam that has been

E. Tarawneh

2009-01-01

385

Measured and modelled effects of temperature, dissolved oxygen and nutrient concentration on sediment-water nutrient exchange  

Microsoft Academic Search

Empirical models of sediment-water fluxes of NH4+, NO3- were and PO43- were formed based on published reports. The models were revised and parameters evaluated based on laboratory incubations of sediments collected from Gunston Cove, VA. Observed fluxes ranged from — 18 (sediments uptake) to 276 (sediment release) mg NH4+ m-2 day-1, -17 to -509 mg NO3- m-2 day-1, and -16.4

Carl F. Cerco

1989-01-01

386

Land subsidence in Yunlin, Taiwan, due to Agricultural and Domestic Water Use  

NASA Astrophysics Data System (ADS)

Subsidence in a layered aquifer is caused by groundwater excess extraction and results in complicated problems in Taiwan. Commonly, responsibility to subsidence for agricultural and domestic water users is difficulty to identify due to the lack of quantitative evidences. An integrated model was proposed to analyze subsidence problem. The flow field utilizes analytical solution for pumping in a layered system from Neuman and Witherspoon (1969) to calculate the head drawdown variation. The subsidence estimation applies Terzaghi (1943) one-dimensional consolidation theory to calculate the deformation in each layer. The proposed model was applied to estimate land subsidence and drawdown variation at the Yuanchang Township of Yunlin County in Taiwan. Groundwater data for dry-season periods were used for calibration and validation. Seasonal effect in groundwater variation was first filtered out. Dry-season pumping effect on land subsidence was analyzed. The results show that multi-layer pumping contributes more in subsidence than single-layer pumping on the response of drawdown and land subsidence in aquifer 2 with a contribution of 97% total change at Yuanchang station. Pumping in aquifer 2 contributes more significant than pumping in aquifer 3 to cause change in drawdown and land subsidence in aquifer 2 with a contribution of 70% total change at Yuanchang station. Larger area of subsidence in Yuanchang Township was attributed pumping at aquifer 2 while pumping at aquifer 3 results in significant subsidence near the well field. The single-layer user contributes most area of subsidence but the multi-layer user generates more serious subsidence.

Hsu, K.; Lin, P.; Lin, Z.

2013-12-01

387

Environmental pollution impact on water and sediments of Kumaun lakes, Lesser Himalaya, India: a comparative study  

NASA Astrophysics Data System (ADS)

A study of the water and sediment chemistry of the Nainital, Bhimtal, Naukuchiyatal and Sattal Lakes of Kumaun, has shown that the water of these lakes are alkaline and that electrical conductivity, total dissolved solid and bicarbonate HCO{3/-} are much higher in Nainital than in the other three lakes. The weathering of limestone lithology and anthropogenic pollution, the latter due to the very high density of population in the Nainital valley, are the primary sources of enhanced parameters. The low pH of Nainital Lake water is due to low photosynthesis and enhanced respiration, increasing CO2 in the water and the consequent enhancement of Ca2+ and HCO{3/-}. The dissolved oxygen in Nainital Lake is less compared to other lakes, indicating anoxic conditions developing at the mud water interface at depth. The PO{4/3-} content in Nainital is higher (124 ?g/l), showing an increasing trend over time leading to eutrophic conditions. The trace metals (Cu, Co, Zn, Ni, Mn, and Sr) are present in greater amounts in the water of Nainital Lake than in the other three lakes, though Fe and Cr are high in Bhimtal and Fe in Naukuchiyatal. The higher abundance is derived from the leaching of Fe Mg from metavolcanic and metabasic rocks. Most of the heavy metals (Cr, Ni, Cu, Mn, Fe, Sr, and Zn) significantly enrich the suspended sediments of the lakes compared to the bed sediments which due to their adsorption on finer particles and owing to multiple hydroxide coating and organic content, except for Fe, which is enriched in the bed sediments. The high rate of sedimentation, 11.5 mm/year in Nainital, compared to Bhimtal with 4.70 mm/year, Naukuchiyatal with 3.72 mm/year, and Sattal with 2.99 mm/year, has resulted in shorter residence time, poor sorting of grains, and lesser adsorption of heavy metals, leading consequently, their depletion in the bed sediments of Nainital Lake.

Das, Brijraj K.

2005-12-01

388

Estrogenic Compounds and Estrogenicity in Surface Water, Sediments, and Organisms from Yundang Lagoon in Xiamen, China  

Microsoft Academic Search

Seven estrogenic compounds—estrone (E1), 17?-estradiol (E2), 17?-ethynylestradiol (EE2), diethylstilbestrol (DES), nonylphenol\\u000a (NP), octylphenol (OP), and bisphenol A (BPA)—in sediments, surface water, pore water, and organisms were investigated and\\u000a estrogenic activities were estimated by examining estradiol equivalent (EEQ) concentrations in Yundang Lagoon of Xiamen. The\\u000a results showed that estrogenic compounds were present in all matrixes of interest: in surface water, ranging

Xian ZhangYajie; Yajie Gao; Qingzhao Li; Guoxin Li; Qinghai Guo; Changzhou Yan

2011-01-01

389

Study of photocatalytic degradation of tributyltin, dibutylin and monobutyltin in water and marine sediments.  

PubMed

This study reports on the first assessment of the treatment of sediments contaminated by organotin compounds using heterogeneous photocatalysis. Photocatalysis of organotins in water was carried out under realistic concentration conditions (?gL(-1)). Degradation compounds were analyzed by GC-ICP-MS; a quasi-complete degradation of tributyltin (TBT) in water (99.8%) was achieved after 30min of photocatalytic treatment. The degradation by photolysis was about (10%) in the same conditions. For the first time decontamination of highly polluted marine sediments (certified reference material and harbor sediments) by photocatalysis proves that the use of UV and the production of hydroxyl radicals are an efficient way to treat organotins adsorbed onto marine sediment despite the complexity of the matrix. In sediment, TBT degradation yield ranged from 32% to 37% after only 2h of irradiation (TiO2-UV) and the by-products: dibutyltin (DBT) and monobutyltin (MBT) were degraded very rapidly in comparison with TBT. It was shown that during photocatalysis of organotins in sediments, the hydroxyl radical attack and photolysis are the two ways for the degradation of adsorbed TBT. PMID:24613444

Brosillon, Stephan; Bancon-Montigny, Chrystelle; Mendret, Julie

2014-08-01

390

Sediment Mobilization From Reservoirs Can Cause Short Term Oxygen Depletion In Downstream Receiving Waters  

NASA Astrophysics Data System (ADS)

Reservoir management can cause incidences of short-term sediment mobilization, e.g. during dam removal or drawdown for maintenance or habitat purposes. Much of the associated planning focuses on predicting, quantifying, and mitigating the physical impacts of sediment mobilization, transport, and deposition. Sediment pulses can cause multiple regulatory and management concerns, such as turbidity or suspended sediment concentrations that may exceed State standards, geomorphic change and effects on property or infrastructure, or wildlife impacts such as stress to fish via gill abrasion or burial of critical habitat. Water-quality issues associated with sediment mobilization, including nutrient and contaminant transport, are often given less attention, presumably because their effects are less immediate or because of resource constraints. Recent experience with large pulses of sediment from several western reservoirs involving dam removals and temporary drawdowns indicates that oxygen demand, leading to depletion of downstream dissolved oxygen (DO), can also be a significant short-term concern. During the October 2011 Condit Dam removal on the White Salmon River in Washington, DO in receiving waters about 4.5 km downstream of the dam dropped to less than 1 mg/L within 2 hours of the demolition; in response, salmonids were observed to be in distress, apparently gulping for air at the water surface. DO remained low for at least 24 hours in this reach, and dead fish were observed. In December 2012, during a drawdown designed to aid juvenile-salmonid migration through Fall Creek Reservoir in Oregon, DO dropped precipitously about 1.5 km downstream as turbidity peaked, and a muted DO decrease was also observed approximately 14 miles further downstream despite a large dilution from unaffected sources. Laboratory experiments and modeling using sediments from reservoirs proposed for removal on the Klamath River, California, demonstrated the likelihood for downstream DO depletion stemming from a combination of chemical (< 2 hr) and biological (days-weeks) oxidation processes, depending on rates of sediment mobilization. Such depletion could contribute to fish stress or mortality for tens of kilometers downstream of the dams and for the duration of the sediment mobilization. Although modeling DO demand and measuring stream DO response during periods of elevated sediment concentration remains an area requiring further research, planning for large sediment mobilizing events could better anticipate and mitigate short-term, acute stresses on fish and aquatic life by recognizing the potential for transient, but significant, DO-related impacts.

Anderson, C.; Schenk, L.; Bragg, H.; Singer, M.; Hume, N.

2013-12-01

391

HPLC-PFD determination of priority pollutant PAHs in water, sediment, and semipermeable membrane devices  

USGS Publications Warehouse

High performance liquid chromatography coupled with programmable fluorescence detection was employed for the determination of 15 priority pollutant polycyclic aromatic hydrocarbons (PPPAHs) in water, sediment, and semipermeable membrane devices (SPMDs). Chromatographic separation using this analytical method facilitates selectivity, sensitivity (ppt levels), and can serve as a non-destructive technique for subsequent analysis by other chromatographic and spectroscopic techniques. Extraction and sample cleanup procedures were also developed for water, sediment, and SPMDs using various chromatographic and wet chemical methods. The focus of this publication is to examine the enrichment techniques and the analytical methodologies used in the isolation, characterization, and quantitation of 15 PPPAHs in different sample matrices.

Williamson, K.S.; Petty, J.D.; Huckins, J.N.; Lebo, J.A.; Kaiser, E.M.

2002-01-01

392

Natural and artificial radionuclides in the Suez Canal bottom sediments and stream water  

NASA Astrophysics Data System (ADS)

Concentration of natural and artificial radionuclides in Suez Canal bottom sediments and stream water have been measured using ? spectrometers based on a hyper-pure Ge detector. The activity concentrations of 238U series, 232Th series and 40K did not exceed 16.0, 15.5 and 500.0 Bq kg-1 dry weight for sediments. The activity concentration of 238U series and 40K did not exceed 0.6 and 18.0 Bq 1-1 for stream water.

El-Tahawy, M. S.; Farouk, M. A.; Ibrahiem, N. M.; El-Mongey, S. A. M.

1994-07-01

393

Effect of rainfall on settling velocity of sediment particles in quiescent water  

E-print Network

water level with rainfag 57 Oscilloscope signals for probe at 4 inches be- low water level with raiafsQ 58 CHAPTER I INTRODUCTION Sedimentation in rivers, canals, lakes, and reservoirs has be? come a menace of considerable concern to engineers... capacity. Of the 33. 6 million acre-feet oi initial stor- age available in reservoirs of the Upper Colorado River Basin, 17. 8 million acre~feet have been included for sediment storage pools (4). Brown (2) states that surveys from 5 percent of the 10...

Bhuiyan, A. F. M. Sadiqul Islam

2012-06-07

394

Occurrence and Potential Human-Health Relevance of Volatile Organic Compounds in Drinking Water from Domestic Wells in the United States  

E-print Network

Occurrence and Potential Human-Health Relevance of Volatile Organic Compounds in Drinking Water, USGS. Article descriptor: Exposure assessment Key words: domestic wells, drinking-water quality, human-Butyl Ether NAWQA, National Water-Quality Assessment Program NWQL, National Water Quality Laboratory P&T GC

395

Sediment and water discharge rates of Turkish Black Sea rivers before and after hydropower dam construction  

SciTech Connect

Presently, the water discharge rate to the Black Sea by Turkish rivers is approximately 41 km[sup 3]/yr. The sediment discharge rate of Turkish rivers to the Black Sea is 28 x 10[sup 6] t/yr. Before construction of the hydroelectric dams, the sediment discharge rate was approximately 70 x 10[sup 6] t/yr. The sharp reduction in sediment load is largely a result of the dams near the mouths of the Yesil Irmak and Kizil Irmak rivers. Before the construction of dams, Turkish rivers contributed approximately one third of the total amount of sediment received by the Black Sea from all surrounding rivers. The life-span of the major reservoirs varies from approximately only one century (Yesil Irmak river reservoirs) to several thousand years (Sakarya river reservoirs). Life-span for the large Altinkaya Dam reservoir is estimated with approximately 500 yr.

Hay, B.J. (Louis Berger Associates, Inc., Needham, MA (United States))

1994-06-01

396

Influence of an adjuvant on the distribution of herbicides in a sediment/water system.  

PubMed

This study concerned the influence of a mineral oil adjuvant used as tank-mix, on the sorption of commercially formulated compounds in soil using a laboratory-scale sediment/water system. The laboratory experiment was conducted with the adjuvant Atpolan 80 EC and the triazine herbicide atrazine and isoxaflutole which belong to the isoxazole class of herbicides. Ditch bed sediment was the medium. Pesticide distribution was measured in the aqueous phase, both in systems with and without the sediment. The proportion of pesticide moving into the sediment layer was depended on physicochemical properties of the compounds, but it was also influenced by the adjuvant in case of atrazine and only slightly in that of isoxaflutole. Atpolan 80 EC also caused an increase of Kd and Koc values of atrazine. PMID:17390786

Swarcewicz, M; Skórska, E

2006-01-01

397

Nutrient exchange across the sediment-water interface in the Potomac River estuary  

NASA Astrophysics Data System (ADS)

The flux of ammonia, phosphate, silica and radon-222 from Potomac tidal river and estuary sediments is controlled by processes occurring at the sediment-water interface and within surficial sediment. Calculated diffusive fluxes range between 0·6 and 6·5 mmol m -2 day -1 for ammonia, 0·020 and 0·30 mmol m -2 day -1 for phosphate, and 1·3 and 3·8 mmol m -2 day -1 for silica. Measured in situ fluxes range between 1 and 21 mmol m -2 day -1 for ammonia, 0·1 and 2·0 mmol m -2 day -1 for phosphate, and 2 and 19 mmol m -2 day -1 for silica. The ratio of in situ fluxes to diffusive fluxes (flux enhancement) varied between 1·6 and 5·2 in the tidal river, between 2·0 and 20 in the transition zone, and from 1·3 to 5·1 in the lower estuary. The large flux enhancements from transition zone sediments are attributed to macrofaunal irrigation. Nutrient flux enhancements are correlated with radon flux enhancements, suggesting that fluxes may originate from a common region and that nutrients are regenerated within the upper 10-20 cm of the sediment column. The low fluxes of phosphate from tidal viver sediments reflect the control benthic sediment exerts on phosphorus through sorption by sedimentary iron oxyhydroxides. In the tidal river, benthic fluxes of ammonia and phosphate equal one-half and one-third of the nutrient input of the Blue Plains sewage treatment plant. In the tidal Potomac River, benthic sediment regeneration supplies a significant fraction of the nutrients utilized by primary producers in the water column during the summer months.

Callender, Edward; Hammond, Douglas E.

1982-10-01

398

Assessment of arsenic concentrations in domestic well water, by town, in Maine 2005-09  

USGS Publications Warehouse

Prior studies have established that approximately 10 percent of domestic wells in Maine have arsenic levels greater than the U.S. Environmental Protection Agency maximum contaminant limit (10 micrograms per liter (ug/L)). Of even greater concern are multiple discoveries of wells with very high arsenic levels (> 500 ug/L) in several areas of the State. A study was initiated to assist the Maine Center for Disease Control and Prevention (ME-CDC) in developing a better understanding of the statewide spatial occurrence of wells with elevated arsenic levels at the individual town level, identify areas of the State that should be targeted for increased efforts to promote well-water testing, and generate data for potential use in predicting areas of the State likely to have very high levels of arsenic. The State's Health and Environmental and Testing Laboratory (HETL) annually analyzes samples from thousands of domestic wells for arsenic. Results of arsenic analyses of domestic well water submitted to the HETL from 2005 to 2009 were screened and organized, by town, in order to summarize the results for all towns with samples submitted to the HETL. In order to preserve the privacy of well owners, the screening and organization of samples was conducted in the offices of the ME-CDC, following applicable Maine and United States laws, rules, and privacy policies. After screening, the database contained samples from 531 towns in Maine and from 11,111 individual wells. Of those towns, 385 had samples from 5 or more individual wells, 174 towns had samples from 20 or more individual wells, and 49 towns had samples from 60 or more wells. These samples, because they were submitted by homeowners and were not part of a random sample, may not be representative of all wells in a given area. The minimum, maximum, and median arsenic values for the towns with five or more samples were calculated, and the maximum and median values were mapped for the State. The percentages of samples exceeding 10, 50, 100, and 500 ug/L were calculated for the 174 towns with 20 or more sampled wells, and statewide maps were prepared for each of these categories. More than 25 percent of the sampled wells in 44 towns exceeded 10 ug/L. Many fewer towns had wells with samples that exceeded the 50, 100, or 500 ug/L categories. For 19 towns, more than 10 percent of the sampled wells had arsenic concentrations that exceeded 50 ug/L, and in 45 towns, 1 percent or more exceeded 100 ug/L. Of these, Surry in Hancock County had 120 wells tested, and 23 percent of those wells had arsenic concentrations that exceeded 100 ug/L, which is a much higher rate than for other towns. In only four towns (Danforth in Washington County, Surry and Blue Hill in Hancock County, and Woolwich in Sagadahoc County), 1 percent or more of the sampled wells had arsenic concentrations greater than 500 ug/L during 2005-09. The distribution of high arsenic concentrations in wells follows some geographic patterns, which are generally geologically controlled. There are clusters or belts of towns with high arsenic concentrations (> 50 ug/L), such as in southern coastal areas, the Kennebec County area, and towns along the central coastal part of Maine. In contrast, there are areas of the State with low arsenic concentrations, such as the northernmost towns, as well as towns in the western and west-central areas. There appear to be three distinct large-scale areas of high concentrations of arsenic in groundwater-one in southern coastal areas, one in central Kennebec County, and one in the town of Ellsworth (Hancock County) and the surrounding areas. In addition, several smaller clusters of isolated high concentrations of arsenic in groundwater exist. Earlier testing has identified other clusters of very high arsenic concentrations in groundwater in the towns of Northport, Buxton/Hollis, and Waldoboro, but those samples were collected before 2005 and did not factor in this analysis.

Nielsen, M.G.; Lombard, P.J.; Schalk, L.F.

2010-01-01

399

Water and sediment dynamics at Saint Lawrence River mouth  

Microsoft Academic Search

The main features of the hydrological regime and morphological structure of the estuarine-type mouth area of the Saint Lawrence\\u000a River are considered. Data on the structure of water masses, thermal and ice regimes in the Gulf of Saint Lawrence, which\\u000a has a significant effect on the estuary, are given. The major attention is paid to water mixing processes, water and

E. N. Dolgopolova; M. V. Isupova

2011-01-01

400

Uranium diagenesis in sediments underlying bottom waters with high oxygen content  

NASA Astrophysics Data System (ADS)

We measured U in sediments (both pore waters and solid phase) from three locations on the middle Atlantic Bight (MAB) from the eastern margin of the United States: a northern location on the continental shelf off Massachusetts (OC426, 75 m water depth), and two southern locations off North Carolina (EN433-1, 647 m water depth and EN433-2, 2648 m water depth). These sediments underlie high oxygen bottom waters (250-270 ?M), but become reducing below the sediment-water interface due to the relatively high organic carbon oxidation rates in sediments (EN433-1: 212 ?mol C/cm 2/y; OC426: 120 ± 10 ?mol C/cm 2/y; EN433-2: 33 ?mol C/cm 2/y). Pore water oxygen goes to zero by 1.4-1.5 cm at EN433-1 and OC426 and slightly deeper oxygen penetration depths were measured at EN433-2 (˜4 cm). All of the pore water profiles show removal of U from pore waters. Calculated pore water fluxes are greatest at EN433-1 (0.66 ± 0.08 nmol/cm 2/y) and less at EN433-2 and OC426 (0.24 ± 0.05 and 0.13 ± 0.05 nmol/cm 2/y, respectively). Solid phase profiles show authigenic U enrichment in sediments from all three locations. The average authigenic U concentrations are greater at EN433-1 and OC426 (5.8 ± 0.7 nmol/g and 5.4 ± 0.2 nmol/g, respectively) relative to EN433-2 (4.1 ± 0.8 nmol/g). This progression is consistent with their relative ordering of 'reduction intensity', with greatest reducing conditions in sediments from EN433-1, less at OC426 and least at EN433-2. The authigenic U accumulation rate is largest at EN433-1 (0.47 ± 0.05 nmol/cm 2/y), but the average among the three sites on the MAB is ˜0.2 nmol/cm 2/y. Pore water profiles suggest diffusive fluxes across the sediment-water interface that are 1.4-1.7 times greater than authigenic accumulation rates at EN433-1 and EN433-2. These differences are consistent with oxidation and loss of U from the solid phase via irrigation and/or bioturbation, which may compromise the sequestration of U in continental margin sediments that underlie bottom waters with high oxygen concentrations. Previous literature compilations that include data exclusively from locations where [O 2] bw < 150 ?M suggest compelling correlations between authigenic U accumulation and organic carbon flux to sediments or organic carbon burial rate. Sediments that underlie waters with high [O 2] bw have lower authigenic U accumulation rates than would be predicted from relationships developed from results that include locations where [O 2] bw < 150 ?M.

Morford, Jennifer L.; Martin, William R.; Carney, Caitlin M.

2009-05-01

401

Impacts of sewage of a pulp and paper industry on the sediments of Vigozero water basin  

NASA Astrophysics Data System (ADS)

The studies of sediments of Vigozero reservoir with 1969 for 2009 are presented. Vigozero water basin belongs to pool of the White Sea. It's watershed area is 16 800 km2, water surface area is 1140 km2, volume of lake - 6,46 km3, average depth - 6,2 m, the maximum depth - 23 m, the water residence time -1,14 years. Northern part of Vigozero reservoir tests influence of sewage of Segeja pulp and paper mill, operating since 1938. Zones of pollution of a bottom are allocated: 1- solid waste; 2 - active silt, lignin, cellulose; 3 - transformed suspended solids. Distribution and stratification of deposits, their physical and chemical parameters is investigated. It is shown, that change of a chemical compound of sediments is connected with volume and qualitative of sewage. The tendency to the extension of polluted zones and to spreading of organic pollution all the bottom is considered. Maximum settling velocity was fixed in 1980 -1985. Accumulation of the organic compounds in sediments at that time resulted in the development of high internal loading. Change of an ecological situation in Vigozero water basin, connected with falling volumes of manufacture last 20 years, has affected sediment genesis processes, therefore the concentrations of organic substances and biogenic elements have decreased in a superficial layer of sediments, concentration of iron has increased. Now, transformation of the organic substances, which have been saved up earlier, demands significant amounts of oxygen. Variability of pH and Eh of sediments indicates unstable oxidation-reduction conditions. Ore formations on a redox-barrier interfere with transport of substances from deposits in water. The work was supported in part by Russian Foundation for Basic Research (grant ? 08-05-98811).

Natalia, Belkina

2010-05-01

402

Microbial diversity and composition of the sediment in the drinking water reservoir Saidenbach (Saxonia, Germany).  

PubMed

Sediments contain a huge number and diversity of microorganisms that are important for the flux of material and are pivotal to all major biogeochemical cycles. Sediments of reservoirs are affected by a wide spectrum of allochthous and autochthonous influences providing versatile environments along the flow of water within the reservoir. Here we report on the microbial diversity in sediments of the mesotrophic drinking water reservoir Saidenbach, Germany, featuring a pronounced longitudinal gradient in sediment composition in the reservoir system. Three sampling sites were selected along the gradient, and the microbial communities in two sediment depths were characterized using catalysed reporter deposition fluorescence in situ hybridization (CARD-FISH) and a bar-coded pyrosequencing approach. Multivariate statistic was used to reveal relationships between sequence diversity and the environmental conditions. The microbial communities were tremendously diverse with a Shannon index of diversity (H') ranging from 6.7 to 7.1. 18,986 sequences could be classified into 37 phyla including candidate divisions, but the full extent of genetic diversity was not captured. While CARD-FISH gave an overview about the community composition, more detailed information was gained by pyrosequencing. Bacteria were more abundant than Archaea. The dominating phylum in all samples was Proteobacteria, especially Betaproteobacteria and Deltaproteobacteria. Furthermore, sequences of Bacteroidetes, Verrucomicrobia, Acidobacteria, Chlorobi, Nitrospira, Spirochaetes, Gammaproteobacteria, Alphaproteobacteria, Chloroflexi, and Gemmatimonadetes were found. The site ammonium concentration, water content and organic matter content revealed to be strongest environmental predictors explaining the observed significant differences in the community composition between sampling sites. PMID:22154008

Röske, Kerstin; Sachse, René; Scheerer, Carola; Röske, Isolde

2012-02-01

403

Water and sediment transport of channel-flat systems in a mesotidal mudflat: Willapa Bay, Washington  

NASA Astrophysics Data System (ADS)

The muddy tidal flats of southern Willapa Bay, Washington are tidally dominated and receive little direct freshwater input. We use data from instruments deployed in channels of different size and on their adjacent flats to investigate the hydrodynamics and sediment dynamics of each morphological setting under a range of seasonal and meteorological conditions, including rain and wind events. Interaction between the morphology of the channel/flat complex and tidal water-level variations produces well-defined velocity pulses during both flooding and ebbing tides. These pulses represent about 27% of the total along-channel water transport and 35% of the suspended-sediment transport of the system. Maintenance of continuity produces the velocity pulse, and pulse magnitude is determined by tidal range. Wind alters the flow regime in channels and on the flat, enhancing over-flat ebb flow in this study location while decreasing ebb-pulse intensity. Wind speed was positively correlated with minimum suspended-sediment concentration. Precipitation falling directly on flats was found to erode flat sediment, which subsequently formed a temporary deposit in the adjacent channel. Residual along-channel water transport in channels and on nearby flats was flood dominant under all seasonal conditions sampled, and sediment flux was flood dominant during winter and spring deployments.

Nowacki, Daniel J.; Ogston, Andrea S.

2013-06-01

404

Ra isotopes as a tracer of sediment-water column exchange in the North Sea  

NASA Astrophysics Data System (ADS)

Quantifying the benthic flux of short-lived radium isotopes (224Ra and 223Ra) provides information regarding the extent, and the dominant processes governing sediment-water column exchange in the North Sea. For this purpose we employed three independent measurement techniques including sediment incubation chambers, water column inventories, and a surface mass-balance. Incubation results from 11 stations indicate significant spatial variability in Radium efflux throughout the North Sea, as well as a strong dependence on the stirring rate of the overlying water column. Both inventory and mass-balance methods yield consistently higher benthic fluxes for the Southern North Sea than incubation-based estimates due to the inability of the laboratory incubations to recreate the in-situ mixing conditions present in the well-mixed Southern North Sea. Furthermore, fluxes in the Southern North Sea are higher than those previously reported in other regions, likely due to high rates of sediment irrigation induced by strong tidal and wind mixing near the interface of permeable sandy sediments. The seasonality of distributions and the magnitudes of both benthic and coastal Ra fluxes are further examined by applying Ra as a passive tracer in the 3-dimensional hydrodynamics of the ECOSMO model. Finally, flux estimates combined with direct measurements of porewater Ra activities yield volume fluxes [L m-2 d-1], which when further applied to porewater concentrations of carbon or nutrient species, can provide important information regarding the role of sediments in North Sea biogeochemistry.

Burt, William; Thomas, Helmuth; Pätsch, Johannnes; Omar, Abdirahman; Schrum, Corinna; Daewel, Ute

2014-05-01

405

Widespread potential for microbial MTBE degradation in surface-water sediments  

USGS Publications Warehouse

Microorganisms indigenous to stream and lake bed sediments, collected from 11 sites throughout the United States, demonstrated significant mineralization of the fuel oxygenate, methyl-tert-butyl ether (MTBE). Mineralization of [U-14C]MTBE to 14CO2 ranged from 15 to 66% over 50 days and did not differ significantly between sediments collected from MTBE contaminated sites and from sites with no history of MTBE exposure. This result suggests that even the microbial communities indigenous to newly contaminated surface water systems will exhibit some innate ability to attenuate MTBE under aerobic conditions. The magnitude of MTBE mineralization was related to the sediment grain size distribution. A pronounced, inverse correlation (p < 0.001; r2 = 0.73) was observed between the final recovery of 14CO2 and the percentage content of silt and clay sized grains (grain diameter < 0.125 mm). The results of this study indicate that the microorganisms that inhabit the bed sediments of streams and lakes can degrade MTBE efficiently and that this capability is widespread in the environment. Thus aerobic bed sediment microbial processes may provide a significant environmental sink for MTBE in surface water systems throughout the United States and may contribute to the reported transience of MTBE in some surface waters.

Bradley, P. M.; Landmeyer, J. E.; Chapelle, F. H.

2001-01-01

406

Occurrence of arsenic in sediment pore waters in the central Kanto Plain, Japan  

NASA Astrophysics Data System (ADS)

The Kanto Plain is known as the largest plain in Japan, where marine sediments are widely developed because of cyclic iteration of global sea-level changes even 50 km or more inland from the present shoreline. In this area, dependence on groundwater for water requirements is relatively high; in particular, around 40 % of the municipal water supply is dependent on groundwater. Arsenic levels greater than that permitted by the environmental standards of Japan have been detected in groundwater in this area. Therefore, to evaluate occurrences of arsenic and other related elements in pore waters contained in natural sediment layers, we measured the levels of various inorganic chemical substances such as arsenic (As), iron (Fe), and sulfur (S) and major dissolved ions such as sulfate (SO42-), calcium (Ca2+), and sodium (Na+). Pore waters were collected from sediment samples that were obtained by a drilling from the river bottom down to 44 m depth; pore water samples were obtained immediately after extraction of sediments. The sedimentary facies in the vertical profile are continental, transitional, and marine, including two aquifers. The upper aquifer (15-20 m) contains fine to medium sand, whereas the lower aquifer (37-44 m) contains medium to coarse and gravelly sand. Arsenic and other inorganic elements were measured by an inductively coupled plasma mass spectrometer (ICP/MS) and an inductively coupled plasma atomic emission spectrometer (ICP/AES), and major dissolved ions were measured by an ion chromatograph analyzer. The total content of chemical elements was measured by X-ray fluorescence analysis using solid sediment samples. We obtained the following results. The arsenic concentrations in pore waters in marine silt and clay sediments (approximately 0.04 mg/L) were about five times higher than that in continental sediments (approximately 0.008 mg/L). The highest concentration of arsenic (0.074 mg/L) was detected at a depth of 13 m, which is immediately above the upper aquifer. Visual observations confirmed that this level is under oxidizing conditions. Thus, it regards that arsenic was adsorbed to iron hydroxide in the sediments. On the other hand, in the top part of the section, from the river bottom to a depth of approximately 3 m, arsenic concentrations in the pore waters were clearly high and decreased gradually and continuously with depth. This is considered to be the result of anthropogenic impact on the river.

Hachinohe, Shoichi; Hamamoto, Hideki; Ishiyama, Takashi; Hossain, Sushmita; Oguchi, Chiaki T.

2014-05-01

407

Sudden Clearing of Estuarine Waters upon Crossing the Threshold from Transport to Supply Regulation of Sediment Transport as an Erodible Sediment Pool is Depleted: San Francisco Bay, 1999  

USGS Publications Warehouse

The quantity of suspended sediment in an estuary is regulated either by transport, where energy or time needed to suspend sediment is limiting, or by supply, where the quantity of erodible sediment is limiting. This paper presents a hypothesis that suspended-sediment concentration (SSC) in estuaries can suddenly decrease when the threshold from transport to supply regulation is crossed as an erodible sediment pool is depleted. This study was motivated by a statistically significant 36% step decrease in SSC in San Francisco Bay from water years 1991-1998 to 1999-2007. A quantitative conceptual model of an estuary with an erodible sediment pool and transport or supply regulation of sediment transport is developed. Model results confirm that, if the regulation threshold was crossed in 1999, SSC would decrease rapidly after water year 1999 as observed. Estuaries with a similar history of a depositional sediment pulse followed by erosion may experience sudden clearing. ?? 2011 Coastal and Estuarine Research Federation (outside the USA).

Schoellhamer, D. H.

2011-01-01

408

Comparison of whole-sediment, elutriate and pore-water exposures for use in assessing sediment-associated organic contaminants in bioassays  

SciTech Connect

Bioassays have frequently been used as tools to simulate exposure of benthos to sediment-associated contaminants in hazard assessments. Due to the problems involved with estimating bioavailability in whole-sediment bioassays, aqueous fractions such as elutriates and pore water have been substituted for whole-sediment exposures. The objective of this research was to compare and evaluate the bioavailability of representative neutral hydrophobic contaminants in whole sediments and in aqueous extracts of whole sediment in simultaneous bioassays, using three representative indicator species, Diporeia spp., Chironomus riparius larvae, and Lumbriculus variegatus. Aqueous extracts of whole sediment did not accurately represent the exposure observed in whole sediment. Generally, the aqueous extracts underexposed organisms compared to whole sediment, even after adjusting accumulation to the fraction of organic carbon in the test media. Accumulation comparisons among whole-sediment, elutriate, and pore-water exposures depended on sampling time. At some sampling times for some contaminants, differences in accumulation between a particular aqueous extract and whole sediment were not significant; however, these similarities were not observed for all species at the particular sampling time. Bioaccumulation and contaminant clearance data suggest that a number of factors such as the indicator species, exposure media, and chemical/physical properties of individual contaminants are responsible for the accumulation differences observed among the tested media. Normalizing bioaccumulation to the amount of organic carbon in a source compartment adjusted for bioavailability differences of only some contaminants. The authors suggest that the bioavailability of contaminants such as those tested cannot be accurately predicted in bioassays that expose organisms to aqueous representations of whole sediment.

Harkey, G.A. (Great Lakes Environmental Research Lab., Ann Arbor, MI (United States) Clemson Univ., Pendleton, SC (United States)); Landrum, P.F. (Great Lakes Environmental Research Lab., Ann Arbor, MI (United States)); Klaine, S.J. (Clemson Univ., Pendleton, SC (United States))

1994-08-01

409

SEDIMENT INFLOWS AND WATER QUALITY IN AN URBANIZING WATERSHED  

Microsoft Academic Search

Lake Whatcom is a large, deep, monomictic lake in the Puget lowlands of Washington State. Expanding development from the city of Bellingham and a large diversion of water from the Nooksack River to the lake are two recent impacts. Bellingham depends on the lake as its sole drinking and industrial water supply. Additionally, the lake is an important recreational resource.

David F. Brakke

1984-01-01