Map showing abundance and distribution of copper in oxide residues of stream-sediment samples, Medford 1 degree by 2 degrees Quadrangle, Oregon-California

USGS Publications Warehouse

Whittington, Charles L.; Grimes, David J.; Leinz, Reinhard W.

1985-01-01

Stream-sediment sampling in the Medford 1o x 2o quadrangle was undertaken to provide to aid in assessment of the mineral resource potential of the quadrangle. This map presents data on the abundance and distribution of copper in the oxide residues (oxalic-acid leachates) of stream sediments and in the minus-0.18-mm sieve fraction of selected stream sediments collected in the quadrangle. 

Map showing abundance and distribution of arsenic in oxide residues of stream-sediment samples, Medford 1 degree by 2 degrees Quadrangle, Oregon-California

USGS Publications Warehouse

Whittington, Charles L.; Leinz, Reinhard W.; Grimes, David J.

1985-01-01

Stream-sediment sampling in the Medford 1o x 2o quadrangle was undertaken to provide to aid in assessment of the mineral resource potential of the quadrangle. This map presents data on the abundance and distribution of copper in the oxide residues (oxalic-acid leachates) of stream sediments and in the minus-0.18-mm sieve fraction of selected stream sediments collected in the quadrangle. 

Sediment source fingerprinting to quantify fine sediment sources in forested catchments, Chile.

NASA Astrophysics Data System (ADS)

Schuller, P.; Walling, D. E.; Iroume, A.; Castillo, A.; Quilodran, C.

2012-04-01

A study to improve the understanding of the primary sediment sources and transfer pathways in catchments disturbed following forest plantation harvesting is being undertaken in South-Central Chile. The study focuses on two sets of paired experimental catchments (treatment and control), located about 400 km apart, with similar soil type but contrasting mean annual rainfall: Nacimiento (1,200 mm year-1) and Los Ulmos (2,500 mm year-1). Sediment source fingerprinting techniques are being used to document the primary fine sediment sources. In each catchment, three potential sediment sources were defined: clearcut slopes (Z1), forest roads (Z2) and the stream channel (Z3). In each catchment, multiple representative composite samples of the different potential source materials were collected before harvest operations from the upper 1 cm layer in Z1, Z2, and from the channel bank and bed for Z3. A time-integrating trap sampler installed in the discharge monitoring station constructed at the outlet of each catchment has been used to collect samples of the suspended sediment and these have been supplemented by sediment collected from the weir pools. Total suspended sediment load is been quantified in the monitoring stations using discharge records and integrated water sampling. Caesium-137 (137Cs), excess lead-210 (210Pbex) and other sediment properties are being used as fingerprints. After air-drying, oven-drying at 40°C and disaggregation, both the source material samples and the sediment samples collected in the discharge monitoring stations were sieved through a 63-μm sieve and the <63-μm fractions were used for subsequent analyses. For radionuclide assay, the samples were sealed in Petri dishes and after 4 weeks the mass activity density (activity concentration) of 137Cs and 210Pbex was determined by gamma analysis, using an ORTEC extended range Ge detector of 53% relative efficiency. The 137Cs and 210Pbex activity and organic carbon (Corg) concentration associated with potential source materials and the target sediment show that the two radionuclides used in combination with the Corg property provide effective source fingerprints. Additional work using a mixing model taking account of particle size effects is required to establish the relative contributions of the three sources to the fine sediment loads of the study catchments. This research is supported by the Chilean Government through FONDECYT Project 1090574 and by the IAEA through CRP D1.20.11 (Contract CHI-15531 and Technical Contract 15478) and the RLA 05/051 Project.

Standard operating procedures for collection of soil and sediment samples for the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study

USGS Publications Warehouse

Fisher, Shawn C.; Reilly, Timothy J.; Jones, Daniel K.; Benzel, William M.; Griffin, Dale W.; Loftin, Keith A.; Iwanowicz, Luke R.; Cohl, Jonathan A.

2015-12-17

An understanding of the effects on human and ecological health brought by major coastal storms or flooding events is typically limited because of a lack of regionally consistent baseline and trends data in locations proximal to potential contaminant sources and mitigation activities, sensitive ecosystems, and recreational facilities where exposures are probable. In an attempt to close this gap, the U.S. Geological Survey (USGS) has implemented the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study to collect regional sediment-quality data prior to and in response to future coastal storms. The standard operating procedure (SOP) detailed in this document serves as the sample-collection protocol for the SCoRR strategy by providing step-by-step instructions for site preparation, sample collection and processing, and shipping of soil and surficial sediment (for example, bed sediment, marsh sediment, or beach material). The objectives of the SCoRR strategy pilot study are (1) to create a baseline of soil-, sand-, marsh sediment-, and bed-sediment-quality data from sites located in the coastal counties from Maine to Virginia based on their potential risk of being contaminated in the event of a major coastal storm or flooding (defined as Resiliency mode); and (2) respond to major coastal storms and flooding by reoccupying select baseline sites and sampling within days of the event (defined as Response mode). For both modes, samples are collected in a consistent manner to minimize bias and maximize quality control by ensuring that all sampling personnel across the region collect, document, and process soil and sediment samples following the procedures outlined in this SOP. Samples are analyzed using four USGS-developed screening methods—inorganic geochemistry, organic geochemistry, pathogens, and biological assays—which are also outlined in this SOP. Because the SCoRR strategy employs a multi-metric approach for sample analyses, this protocol expands upon and reconciles differences in the sample collection protocols outlined in the USGS “National Field Manual for the Collection of Water-Quality Data,” which should be used in conjunction with this SOP. A new data entry and sample tracking system also is presented to ensure all relevant data and metadata are gathered at the sample locations and in the laboratories.

Ecological evaluation of proposed dredged material from St. Andrew Bay, Florida

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayhew, H.L.; Word, J.Q.; Kohn, N.P.

1993-10-01

The US Army Corps of Engineers (USACE), Mobile District, requested that the Battelle/Marine Sciences Laboratory (MSL) conduct field sampling and chemical and biological testing to determine the suitability of potential dredged material for open ocean disposal. Sediment from St. Andrew Bay was chemically characterized and evaluated for biological toxicity and bioaccumulation of contaminants. The Tier III guidance for ocean disposal testing requires tests of water column effects (following dredged material disposal), deposited sediment toxicity, and bioaccumulation of contaminants from deposited sediment (dredged material). To meet these requirements, the MSL conducted suspended-particulate-phase (SPP) toxicity tests, solid-phase toxicity tests, and bioaccumulation testingmore » on sediment representing potential dredged material from Panama City Harbor. Physical and chemical characterization of sediment to support toxicity and bioaccumulation results was also conducted on both the test and reference sediments. The MSL collected sediment samples from five sites in St. Andrew Bay and one reference site near Lands End Peninsula. The five test sediments and the reference sediment were analyzed for physical and chemical sediment characteristics, SPP chemical contaminants, solid-phase toxicity, SPP toxicity, and bioaccumulation of contaminants.« less

Investigating the sources of sediment in a Canadian agricultural watershed using a colour-based fingerprinting technique

NASA Astrophysics Data System (ADS)

Barthod, Louise; Lobb, David; Owens, Philip; Martinez-Carreras, Nuria; Koiter, Alexander; Petticrew, Ellen; McCullough, Gregory

2014-05-01

The development of beneficial management practises to minimize adverse impacts of agriculture on soil and water quality requires information on the sources of sediment at the watershed scale. Sediment fingerprinting allows for the determination of sediment sources and apportionment of their contribution within a watershed, using unique physical, radiochemical or biogeochemical properties, or fingerprints, of the potential sediment sources. The use of sediment colour as a fingerprint is an emerging technique that can provide a rapid and inexpensive means of investigating sediment sources. This technique is currently being utilized to determine sediment sources within the South Tobacco Creek Watershed, an agricultural watershed located in the Canadian prairies (south-central Manitoba). Suspended sediment and potential source (topsoil, channel bank and shale bedrock material) samples were collected between 2009 and 2011 at six locations along the main stem of the creek. Sample colour was quantified from diffuse reflectance spectrometry measurements over the visible wavelength range using a spectroradiometer (ASD Field Spec Pro, 400-2500 nm). Sixteen colour coefficients were derived from several colour space models (CIE XYZ, CIE xyY, CIE Lab, CIE Luv, CIE Lch, Landsat RGB, Redness Index). The individual discrimination power of the colour coefficients, after passing several prerequisite tests (e.g., linearly additive behaviour), was assessed using discriminant function analysis. A stepwise discriminant analysis, based on the Wilk's lambda criterion, was then performed in order to determine the best-suited colour coefficient fingerprints which maximized the discrimination between the potential sources. The selected fingerprints classified the source samples in the correct category 86% of the time. The misclassification is due to intra-source variability and source overlap which can lead to higher uncertainty in sediment source apportionment. The selected fingerprints were then included in a Bayesian mixing model using Monte-Carlo simulation (Stable Isotope Analysis in R, SIAR) in order to apportion the contribution of the different sources to the sediment collected at each location. A switch in the dominant sediment source between the headwaters and the outlet of the watershed is observed. Sediment is enriched with shale bedrock and depleted of topsoil sources as the stream crosses and down-cuts through the Manitoba Escarpment. The switch in sources highlights the importance of the sampling location in relation to the scale and geomorphic connectivity of the watershed. Although the results include considerable uncertainty, they are consistent with the findings from a classical fingerprinting approach undertaken in the same watershed (i.e., geochemical and radionuclide fingerprints), and confirm the potential of sediment colour parameters as suitable fingerprints.

An Investigation into Heavy Metal Contamination and Mobilization in the Lower Rouge River, Michigan

NASA Astrophysics Data System (ADS)

Shihadeh, M.; Forrester, J.; Napieralski, J. A.

2010-12-01

Similar to many densely populated watersheds in the Great Lakes Basin, the Rouge River in Michigan drains a heavily urbanized watershed, which, over time, has accumulated a substantial amount of contamination due to decades of manufacturing and refining industries. Statistically significant levels of heavy metals have been found in the bed sediment of the Rouge; however, little is known about the mobilization of these contaminated bed sediments. The goal of this study was to ascertain the extent to which these potentially contaminated sediments are mobilized and transported downstream. Suspended sediment samples were collected at four sites along the lower Rouge River using composite depth integrated sediment samples three times per week, resulting in a total of twenty samples from each site. Turbidity was measured simultaneously using a YSI datalogger at all sampling locations. Sediment was also extracted from floodplain soil pits and silted vegetation, as well as river bed sediment cores along stream channel cross-sections. Heavy metal concentrations (As, Cd, Cr, Cu, Fe, Pb, Hg, Ni, Se, Zn) were analyzed using ICP-MS and compared against both background characteristics for Michigan soils and EPA Hazardous Criteria Limits. As expected, a positive correlation exists between turbidity and heavy metal concentrations. Even in the sampling sites furthest upstream, heavy metal concentrations exceeded background soil characteristics, with a few also exceeding hazardous criteria limits. The heavy metal concentrations found in the Lower Rouge affirm the elevated pollution classification of the river, depict the overall influence of industrialization on stream health, and verify that contaminated sediments are being deposited in aquatic and floodplain environments during variable flow or high discharge events. Results from this study emphasize the need to remediate bed sediments in the Rouge and suggest that there may be significant bioaccumulation potential for organisms inhabiting the floodplain corridor.

Anaerobic oxidation of methane in sediments of two boreal lakes

NASA Astrophysics Data System (ADS)

Rissanen, Antti J.; Karvinen, Anu; Nykänen, Hannu; Mpamah, Promise; Peura, Sari; Tiirola, Marja; Kankaala, Paula

2014-05-01

Anaerobic oxidation of methane (AOM) is a considerable sink for methane (CH4) in marine systems, but very little is known about the occurrence and importance of the process in freshwater systems. In addition, much about the microbial communities involved in AOM is unclear. AOM coupled with sulfate reduction is the dominant AOM process in marine systems but the scarce existing data suggest that, in freshwater systems, AOM coupled with reduction of alternative electron acceptors (nitrate/nitrite, manganese, iron) is more important. In this study, potential for AOM coupled with metal reduction was studied in boreal lake sediments. Slurries of sediment samples collected from two sites in southeastern Finland, i.e. from Lake Orivesi, Heposelkä, an vegetated littoral site, dominated by Phragmites australis (Sample Sa, sediment layer 0 - 25 cm) and from the profundal zone of a mesotrophic Lake Ätäskö (Aa, 0 - 10 cm; Ab, 10 - 30 cm; Ac, 90 - 130 cm), were incubated in laboratory in anaerobic conditions at in situ temperatures for up to 5 months. The samples were amended either 1) with 13CH4, 2) 13CH4 + manganese(II) oxide (MnO) or 3) 13CH4 + iron(III) hydroxide (Fe(OH)3), and the processes were measured by following the 13C transfer to the carbon dioxide (CO2) pool and by concentration measurements of CH4 and CO2. Changes in microbial communities were studied from DNA extracted from sediment samples before and after incubation period by next-generation sequencing (Ion Torrent) of polymerase chain reaction (PCR) - amplified bacterial and archaeal 16S rRNA and methyl coenzyme-M reductase gene (mcrA) amplicons. Increase in 13C of CO2 gas confirmed that AOM took place in sediments of both study lakes. In general, 13CO2 - production was significant both at the beginning (0 - 21 days) and at the end (84 - 151 days) of incubation period. Potential AOM rates (calculated based on 13CO2 - production) varied considerably and were much lower in deep sediment (Sample Ac), 0.1 - 0.2 nmol CH4 d-1gwetsediment-1, than in surface sediment samples (Samples Aa, Ab and Sa), 0.2 - 12.3 nmol CH4 d-1gwetsediment-1. AOM took place without metal additions in every sample type. Addition of MnO increased potential AOM rates in surface sediment samples but not in deep sediment samples. Addition of Fe(OH)3increased AOM significantly only in Aa samples. Molecular microbiological analyses are currently in progress and the results will be shown in the poster presentation.

The distribution of phosphorus in Popes Creek, VA, and in the Pocomoke River, MD: Two watersheds with different land management practices in the Chesapeake Bay Basin

USGS Publications Warehouse

Simon, N.S.; Bricker, O.P.; Newell, W.; McCoy, J.; Morawe, R.

2005-01-01

This paper compares phosphorus (P) concentrations in sediments from two watersheds, one with, and one without, intensive animal agriculture. The watersheds are in the coastal plain of the Chesapeake Bay and have similar physiographic characteristics. Agriculture in the Pocomoke River, MD, watershed supplied 2.7 percent of all broiler chickens produced in the USA in 1997. Poultry litter is an abundant, local source of manure for crops. Broiler chickens are not produced in the Popes Creek, VA, watershed and poultry manure is, therefore, not a major source of fertilizer. The largest concentrations of P in sediment samples are found in floodplain and main-stem bottom sediment in both watersheds. Concentrations of total P and P extracted with 1N HCl are significantly larger in main-stem bottom sediments from the Pocomoke River than in main-stem bottom sediments from Popes Creek. Larger concentrations of P are associated with what are potentially redox sensitive iron oxyhydroxides in sediment samples from the Pocomoke River watershed than are associated with what are potentially redox sensitive iron oxyhydroxides in sediment samples from the Popes Creek watershed. Data for P and iron (Fe) concentrations in sediments from the Popes Creek watershed provide a numerical framework (baseline) with which to compare P and Fe concentrations in sediment from the Pocomoke River watershed. ?? Springer 2005.

Large-scale risk assessment of polycyclic aromatic hydrocarbons in shoreline sediments from Saudi Arabia: environmental legacy after twelve years of the Gulf war oil spill.

PubMed

Bejarano, Adriana C; Michel, Jacqueline

2010-05-01

A large-scale assessment of polycyclic aromatic hydrocarbons (PAHs) from the 1991 Gulf War oil spill was performed for 2002-2003 sediment samples (n = 1679) collected from habitats along the shoreline of Saudi Arabia. Benthic sediment toxicity was characterized using the Equilibrium Partitioning Sediment Benchmark Toxic Unit approach for 43 PAHs (ESBTU(FCV,43)). Samples were assigned to risk categories according to ESBTU(FCV,43) values: no-risk (< or = 1), low (>1 - < or = 2), low-medium (>2 - < or = 3), medium (>3 - < or = 5) and high-risk (>5). Sixty seven percent of samples had ESBTU(FCV,43) > 1 indicating potential adverse ecological effects. Sediments from the 0-30 cm layer from tidal flats, and the >30 - <60 cm layer from heavily oiled halophytes and mangroves had high frequency of high-risk samples. No-risk samples were characterized by chrysene enrichment and depletion of lighter molecular weight PAHs, while high-risk samples showed little oil weathering and PAH patterns similar to 1993 samples. North of Safaniya sediments were not likely to pose adverse ecological effects contrary to sediments south of Tanaqib. Landscape and geomorphology has played a role on the distribution and persistence in sediments of oil from the Gulf War. Copyright 2009 Elsevier Ltd. All rights reserved.

Sediment quantity and quality in three impoundments in Massachusetts

USGS Publications Warehouse

Zimmerman, Marc James; Breault, Robert F.

2003-01-01

As part of a study with an overriding goal of providing information that would assist State and Federal agencies in developing screening protocols for managing sediments impounded behind dams that are potential candidates for removal, the U.S Geological Survey determined sediment quantity and quality at three locations: one on the French River and two on Yokum Brook, a tributary to the west branch of the Westfield River. Data collected with a global positioning system, a geographic information system, and sediment-thickness data aided in the creation of sediment maps and the calculation of sediment volumes at Perryville Pond on the French River in Webster, Massachusetts, and at the Silk Mill and Ballou Dams on Yokum Brook in Becket, Massachusetts. From these data the following sediment volumes were determined: Perryville Pond, 71,000 cubic yards, Silk Mill, 1,600 cubic yards, and Ballou, 800 cubic yards. Sediment characteristics were assessed in terms of grain size and concentrations of potentially hazardous organic compounds and metals. Assessment of the approaches and methods used at study sites indicated that ground-penetrating radar produced data that were extremely difficult and time-consuming to interpret for the three study sites. Because of these difficulties, a steel probe was ultimately used to determine sediment depth and extent for inclusion in the sediment maps. Use of these methods showed that, where sampling sites were accessible, a machine-driven coring device would be preferable to the physically exhausting, manual sediment-coring methods used in this investigation. Enzyme-linked immunosorbent assays were an effective tool for screening large numbers of samples for a range of organic contaminant compounds. An example calculation of the number of samples needed to characterize mean concentrations of contaminants indicated that the number of samples collected for most analytes was adequate; however, additional analyses for lead, copper, silver, arsenic, total petroleum hydrocarbons, and chlordane are needed to meet the criteria determined from the calculations. Particle-size analysis did not reveal a clear spatial distribution pattern at Perryville Pond. On average, less than 65 percent of each sample was greater in size than very fine sand. The sample with the highest percentage of clay-sized particles (24.3 percent) was collected just upstream from the dam and generally had the highest concentrations of contaminants determined here. In contrast, more than 90 percent of the sediment samples in the Becket impoundments had grain sizes larger than very fine sand; as determined by direct observation, rocks, cobbles, and boulders constituted a substantial amount of the material impounded at Becket. In general, the highest percentages of the finest particles, clays, occurred in association with the highest concentrations of contaminants. Enzyme-linked immunosorbent assays of the Perryville samples showed the widespread presence of petroleum hydrocarbons (16 out of 26 samples), polycyclic aromatic hydrocarbons (23 out of 26 samples), and chlordane (18 out of 26 samples); polychlorinated biphenyls were detected in five samples from four locations. Neither petroleum hydrocarbons nor polychlorinated biphenyls were detected at Becket, and chlordane was detected in only one sample. All 14 Becket samples contained polycyclic aromatic hydrocarbons. Replicate quality-control analyses revealed consistent results between paired samples. Samples from throughout Perryville Pond contained a number of metals at potentially toxic concentrations. These metals included arsenic, cadmium, copper, lead, nickel, and zinc. At Becket, no metals were found in elevated concentrations. In general, most of the concentrations of organic compounds and metals detected in Perryville Pond exceeded standards for benthic organisms, but only rarely exceeded standards for human contact. The most highly contaminated samples were

From streets to streams: assessing the toxicity potential of urban sediment by particle size

USGS Publications Warehouse

Corsi, Steven R.; Selbig, William R.; Roger T. Bannerman,; ,

2013-01-01

Urban sediment can act as a transport mechanism for a variety of pollutants to move towards a receiving water body. The concentrations of these pollutants oftentimes exceed levels that are toxic to aquatic organisms. Many treatment structures are designed to capture coarse sediment but do not work well to similarly capture the fines. This study measured concentrations of select trace metals and PAHs in both the silt and sand fractions of urban sediment from four sources: stormwater bed, stormwater suspended, street dirt, and streambed. Concentrations were used to assess the toxic potential of sediment based on published sediment quality guidelines. All sources of sediment showed some level of toxic potential with stormwater bed sediment the highest followed by stormwater suspended, street dirt, and streambed. Both metal and PAH concentration distributions were highly correlated between the four sampling locations suggesting the presence of one or perhaps only a few sources of these pollutants which remain persistent as sediment is transported from street to stream. Comparison to other forms of combustion- and vehicle-related sources of PAHs revealed coal tar sealants to have the strongest correlation, in both the silt and sand fractions, at all four sampling sites. This information is important for environmental managers when selecting the most appropriate Best Management Practice (BMP) as a way to mitigate pollution conveyed in urban stormwater from source to sink.

Determining the sources of suspended sediment in a Mediterranean groundwater-dominated river: the Na Borges basin (Mallorca, Spain).

NASA Astrophysics Data System (ADS)

Estrany, Joan; Martinez-Carreras, Nuria

2013-04-01

Tracers have been acknowledged as a useful tool to identify sediment sources, based upon a variety of techniques and chemical and physical sediment properties. Sediment fingerprinting supports the notion that changes in sedimentation rates are not just related to increased/reduced erosion and transport in the same areas, but also to the establishment of different pathways increasing sediment connectivity. The Na Borges is a Mediterranean lowland agricultural river basin (319 km2) where traditional soil and water conservation practices have been applied over millennia to provide effective protection of cultivated land. During the twentieth century, industrialisation and pressure from tourism activities have increased urbanised surfaces, which have impacts on the processes that control streamflow. Within this context, source material sampling was focused in Na Borges on obtaining representative samples from potential sediment sources (comprised topsoil; i.e., 0-2 cm) susceptible to mobilisation by water and subsequent routing to the river channel network, while those representing channel bank sources were collected from actively eroding channel margins and ditches. Samples of road dust and of solids from sewage treatment plants were also collected. During two hydrological years (2004-2006), representative suspended sediment samples for use in source fingerprinting studies were collected at four flow gauging stations and at eight secondary sampling points using time-integrating sampling samplers. Likewise, representative bed-channel sediment samples were obtained using the resuspension approach at eight sampling points in the main stem of the Na Borges River. These deposits represent the fine sediment temporarily stored in the bed-channel and were also used for tracing source contributions. A total of 102 individual time-integrated sediment samples, 40 bulk samples and 48 bed-sediment samples were collected. Upon return to the laboratory, source material samples were oven-dried at 40° C, disaggregated using a pestle and mortar, and dry sieved to

Primary sources and toxicity of PAHs in Milwaukee-area streambed sediment

USGS Publications Warehouse

Baldwin, Austin K.; Corsi, Steven R.; Lutz, Michelle A.; Ingersoll, Christopher G.; Dorman, Rebecca A.; Magruder, Christopher; Magruder, Matthew

2017-01-01

High concentrations of polycyclic aromatic hydrocarbons (PAHs) in streams can be a significant stressor to aquatic organisms. To understand the likely sources and toxicity of PAHs in Milwaukee-area streams, streambed sediment samples from 40 sites and parking lot dust samples from 6 sites were analyzed for 38 parent PAHs and 25 alkylated PAHs. Diagnostic ratios, profile correlations, principal components analysis, source-receptor modeling, and mass fractions analysis were used to identify potential PAH sources to streambed sediment samples, and land-use analysis was used to relate streambed sediment PAH concentrations to different urban-related land uses. On the basis of this multiple lines-of-evidence approach, coal-tar pavement sealant was indicated as the primary source of PAHs in a majority of streambed sediment samples, contributing an estimated 77% of total PAHs to samples, on average. Comparison to the Probable Effect Concentrations and (or) the Equilibrium Partitioning Sediment Benchmark indicates that 78% of stream sediment samples are likely to cause adverse effects to benthic organisms. Laboratory toxicity tests on a 16-sample subset of the streambed sites using the amphipod Hyalella azteca (28-day) and the midge Chironomus dilutus (10-day) measured significant reductions in one or more biological endpoints, including survival, in 75% of samples, with H. azteca more responsive than C. dilutus.

Heavy metals in surface sediments of the Jialu River, China: their relations to environmental factors.

PubMed

Fu, Jie; Zhao, Changpo; Luo, Yupeng; Liu, Chunsheng; Kyzas, George Z; Luo, Yin; Zhao, Dongye; An, Shuqing; Zhu, Hailiang

2014-04-15

This work investigated heavy metal pollution in surface sediments of the Jialu River, China. Sediment samples were collected at 19 sites along the river in connection with field surveys and the total concentrations were determined using atomic fluorescence spectrometer and inductively coupled plasma optical emission spectrometer. Sediment samples with higher metal concentrations were collected from the upper reach of the river, while sediments in the middle and lower reaches had relatively lower metal concentrations. Multivariate techniques including Pearson correlation, hierarchical cluster and principal components analysis were used to evaluate the metal sources. The ecological risk associated with the heavy metals in sediments was rated as moderate based on the assessments using methods of consensus-based Sediment Quality Guidelines, Potential Ecological Risk Index and Geo-accumulation Index. The relations between heavy metals and various environmental factors (i.e., chemical properties of sediments, water quality indices and aquatic organism indices) were also studied. Nitrate nitrogen, total nitrogen, and total polycyclic aromatic hydrocarbons concentrations in sediments showed a co-release behavior with heavy metals. Ammonia nitrogen, total nitrogen, orthophosphate, total phosphate and permanganate index in water were found to be related to metal sedimentation. Heavy metals in sediments posed a potential impact on the benthos community. Copyright © 2014 Elsevier B.V. All rights reserved.

Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

USGS Publications Warehouse

Nowell, Lisa H.; Norman, Julia E.; Ingersoll, Christopher G.; Moran, Patrick W.

2016-01-01

Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical/chemical characteristics of sediment, and uncertainty in TEB values. Additional evaluations of benchmarks in relation to sediment chemistry and toxicity are ongoing.

Some potential hazardous trace elements contamination and their ecological risk in sediments of western Chaohu Lake, China.

PubMed

Zheng, Liu-Gen; Liu, Gui-Jian; Kang, Yu; Yang, Ren-Kang

2010-07-01

The Chaohu is one of the largest five freshwater lakes in China. It provides freshwater for agriculture, life, and part of industry. The quality of water becomes worst and worst due to the toxic matter. In this study, we collected the samples from the sedimentary mud in the lake. The distribution of some potential hazardous trace elements (Cu, Ni, Cr, As, Pb, Cd, and Hg) in the sediments of western Chaohu Lake, has been determined and studied, and the enrichment factors, the index of geoaccumulation, and potential ecological risk were analyzed and calculated. The results show that: the levels of selected potential hazardous trace element vary from different sampling sites and significant anthropogenic impact of Pb and Cd occur in sediments. The contamination rank of Pb and Cd are moderate, and Pb has a light potential ecological risk, but Cd is heavy. The total potential ecological risk of the selected hazardous trace elements in this study in Chaohu Lake is moderate. Cluster and correlation analysis indicate that the selected potential hazardous trace element pollutant has different source and co-contamination also occur in sediments.

Assessment of trace metals contamination level, bioavailability and toxicity in sediments from Dakar coast and Saint Louis estuary in Senegal, West Africa.

PubMed

Diop, Cheikh; Dewaelé, Dorothée; Cazier, Fabrice; Diouf, Amadou; Ouddane, Baghdad

2015-11-01

Trace metals have the potential to associate with sediments that have been recognised as significant source of contamination for the benthic environment. The current study aims assessing the trace metals contamination level in sediments from Dakar coast and Saint Louis estuary, and to examine their bioavailability to predict potential toxicity of sediments. Surface sediment samples were collected between June 2012 and January 2013 in three sampling periods from eight stations. Trace metals were analysed using inductively coupled plasma-optical emission spectrometer. Geoaccumulation indexes (Igeo) showed strong pollution by Cd, Cr, Cu and Pb confirmed by enrichment factor (EF) suggesting that these metals derived from anthropogenic sources. Toxicity indexes exceeded one in several sites suggesting the potential effects on sediment-dwelling organisms, which may constitute a risk to populations' health. However, seasonal variability of metal bioavailability was noted, revealing the best period to monitor metal contamination. From an ecotoxicological point of view, concentrations of Cd, Cr, Cu and Pb were above the effects range low threshold limit of the sediment quality guidelines for adverse biological effects. In addition, with Pb concentrations above the effect range medium values in some sites, biological effects may occur. Copyright © 2014 Elsevier Ltd. All rights reserved.

The role of large wood in retaining fine sediment, organic matter and plant propagules in a small, single-thread forest river

NASA Astrophysics Data System (ADS)

Osei, Nana A.; Gurnell, Angela M.; Harvey, Gemma L.

2015-04-01

This paper investigates associations among large wood accumulations, retained sediment, and organic matter and the establishment of a viable propagule bank within a forested reach of a lowland river, the Highland Water, UK. A wood survey within the 2-km study reach, illustrates that the quantity of wood retained within the channel is typical of relatively unmanaged river channels bordered by deciduous woodland and that the wood accumulations (jams) that are present are well developed, typically spanning the river channel and comprised of wood that is well decayed. Sediment samples were obtained in a stratified random design focusing on nine subreaches within which samples were aggregated from five different types of sampling location. Two of these locations were wood-associated (within and on bank faces immediately adjacent to wood jams), and the other three locations represented the broader river environment (gravel bars, bank faces, floodplain). The samples were analysed to establish their calibre, organic, and viable plant propagule content. The gravel bar sampling locations retained significantly coarser sediment containing a lower proportion of organic matter and viable propagules than the other four sampling locations. The two wood-related sampling locations retained sediment of intermediate calibre between the gravel bar and the bank-floodplain samples but they retained significantly more organic matter and viable propagules than were found in the other three sampling locations. In particular, the jam bank samples (areas of sediment accumulation against bank faces adjacent to wood jams) contained the highest number of propagules and the largest number of propagule species. These results suggest that retention of propagules, organic matter and relatively fine sediment in and around wood jams has the potential to support vegetation regeneration, further sediment retention, and as a consequence, landform development within woodland streams, although this process is arrested by grazing at the study site. These results also suggest that self-restoration using wood is a potentially cost-effective and far-reaching river restoration strategy but that its full effects develop gradually and require the establishment of a functioning wood budget coupled with grazing levels that are in balance with vegetation growth.

Geo-accumulation index and contamination factors of heavy metals (Zn and Pb) in urban river sediment.

PubMed

Haris, Hazzeman; Looi, Ley Juen; Aris, Ahmad Zaharin; Mokhtar, Nor Farhanna; Ayob, Nur Ain Ayunie; Yusoff, Fatimah Md; Salleh, Abu Bakar; Praveena, Sarva Mangala

2017-12-01

The aim of the present study was to appraise the levels of heavy metal contamination (Zn and Pb) in sediment of the Langat River (Selangor, Malaysia). Samples were collected randomly from 15 sampling stations located along the Langat River. The parameters measured were pH, redox potential, salinity, electrical conductivity, loss of ignition, cation exchanges capacity (Na, Mg, Ca, K), and metal ions (Zn and Pb). The geo-accumulation index (I geo ) and contamination factor (C f ) were applied to determine and classify the magnitude of heavy metal pollution in this urban river sediment. Results revealed that the I geo of Pb indicated unpolluted to moderately polluted sediment at most of the sampling stations, whereas Zn was considered to be within background concentration. The I geo results were refined by the C f values, which showed Pb with very high C f at 12 stations. Zinc, on the other hand, had low to moderate C f values. These findings indicated that the sediment of the Langat River is severely polluted with Pb. The Zn concentration at most sampling points was well below most sediment quality guidelines. However, 40% of the sampling points were found to have a Pb concentration higher than the consensus-based probable effect concentration of 128 mg/kg (concentrations above this value are likely to cause harmful effects). This result not only highlights the severity of Pb pollution in the sediment of the Langat River, but also the potential risk it poses to the environment.

Toxicity of sediment cores collected from the Ashtabula River in northeastern Ohio, USA, to the amphipod Hyalella azteca

USGS Publications Warehouse

Ingersoll, C.G.; Kemble, N.E.; Kunz, J.L.; Brumbaugh, W.G.; MacDonald, D.D.; Smorong, D.

2009-01-01

This study was conducted to support a Natural Resource Damage Assessment and Restoration project associated with the Ashtabula River in Ohio. The objective of the study was to evaluate the chemistry and toxicity of 50 sediment samples obtained from five cores collected from the Ashtabula River (10 samples/core, with each 10-cm-diameter core collected to a total depth of about 150 cm). Effects of chemicals of potential concern (COPCs) measured in the sediment samples were evaluated by measuring whole-sediment chemistry and whole-sediment toxicity in the sediment samples (including polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], organochlorine pesticides, and metals). Effects on the amphipod Hyalella azteca at the end of a 28-day sediment toxicity test were determined by comparing survival or length of amphipods in individual sediment samples in the cores to the range of responses of amphipods exposed to selected reference sediments that were also collected from the cores. Mean survival or length of amphipods was below the lower limit of the reference envelope in 56% of the sediment samples. Concentrations of total PCBs alone in some samples or concentrations of total PAHs alone in other samples were likely high enough to have caused the reduced survival or length of amphipods (i.e., concentrations of PAHs or PCBs exceeded mechanistically based and empirically based sediment quality guidelines). While elevated concentrations of ammonia in pore water may have contributed to the reduced length of amphipods, it is unlikely that the reduced length was caused solely by elevated ammonia (i.e., concentrations of ammonia were not significantly correlated with the concentrations of PCBs or PAHs and concentrations of ammonia were elevated both in the reference sediments and in the test sediments). Results of this study show that PAHs, PCBs, and ammonia are the primary COPCs that are likely causing or substantially contributing to the toxicity to sediment-dwelling organisms. ?? 2009 US Government.

Targeting sediment management strategies using sediment quantification and fingerprinting methods

NASA Astrophysics Data System (ADS)

Sherriff, Sophie; Rowan, John; Fenton, Owen; Jordan, Phil; hUallacháin, Daire Ó.

2016-04-01

Cost-effective sediment management is required to reduce excessive delivery of fine sediment due to intensive land uses such as agriculture, resulting in the degradation of aquatic ecosystems. Prioritising measures to mitigate dominant sediment sources is, however, challenging, as sediment loss risk is spatially and temporally variable between and within catchments. Fluctuations in sediment supply from potential sources result from variations in land uses resulting in increased erodibility where ground cover is low (e.g., cultivated, poached and compacted soils), and physical catchment characteristics controlling hydrological connectivity and transport pathways (surface and/or sub-surface). Sediment fingerprinting is an evidence-based management tool to identify sources of in-stream sediments at the catchment scale. Potential sediment sources are related to a river sediment sample, comprising a mixture of source sediments, using natural physico-chemical characteristics (or 'tracers'), and contributions are statistically un-mixed. Suspended sediment data were collected over two years at the outlet of three intensive agricultural catchments (approximately 10 km2) in Ireland. Dominant catchment characteristics were grassland on poorly-drained soils, arable on well-drained soils and arable on moderately-drained soils. High-resolution (10-min) calibrated turbidity-based suspended sediment and discharge data were combined to quantify yield. In-stream sediment samples (for fingerprinting analysis) were collected at six to twelve week intervals, using time-integrated sediment samplers. Potential sources, including stream channel banks, ditches, arable and grassland field topsoils, damaged road verges and tracks were sampled, oven-dried (<40oC) and sieved (125 microns). Soil and sediment samples were analysed for mineral magnetics, geochemistry and radionuclide tracers, particle size distribution and soil organic carbon. Tracer data were corrected to account for particle size and organic matter selectivity processes. Contributions from potential sources type groups (channel - ditches and stream banks, roads - road verges and tracks, fields - grassland and arable topsoils) were statistically un-mixed using FR2000, an uncertainty-inclusive algorithm, and combined with sediment yield data. Results showed sediment contributions from channel, field and road groups were 70%, 25% and 5% in the poorly-drained catchment, 59%, 22% and 19% in the well-drained catchment, and 17%, 74% and 9% in the moderately-drained catchment. Higher channel contributions in the poorly-drained catchment were attributed to bank erosion accelerated by the rapid diversion of surface runoff into channels, facilitated by surface and sub-surface artificial drainage networks, and bank seepage from lateral pressure gradients due to confined groundwater. Despite the greatest proportion of arable soils in the well-drained catchment, this source was frequently hydrologically disconnected as well-drained soils largely infiltrated rainfall and prevented surface soil erosion. Periods of high and intense rainfall were associated with greater proportions of field losses in the well-drained catchment likely due to infiltration exceeding the saturated hydraulic conductivity of soils and establishment of surface hydrological connectivity. Losses from field topsoils dominated in the moderately-drained catchment as antecedent soil wetness maintained surface flow pathways and coincided with low groundcover on arable soils. For cost-effective management of sediment pressures to aquatic ecosystems, catchment specific variations in sediment sources must be considered.

Influence of Wastewater Discharge on the Metabolic Potential of the Microbial Community in River Sediments.

PubMed

Li, Dong; Sharp, Jonathan O; Drewes, Jörg E

2016-01-01

To reveal the variation of microbial community functions during water filtration process in river sediments, which has been utilized widely in natural water treatment systems, this study investigates the influence of municipal wastewater discharge to streams on the phylotype and metabolic potential of the microbiome in upstream and particularly various depths of downstream river sediments. Cluster analyses based on both microbial phylogenetic and functional data collectively revealed that shallow upstream sediments grouped with those from deeper subsurface downstream regions. These sediment samples were distinct from those found in shallow downstream sediments. Functional genes associated with carbohydrate, xenobiotic, and certain amino acid metabolisms were overrepresented in upstream and deep downstream samples. In contrast, the more immediate contact with wastewater discharge in shallow downstream samples resulted in an increase in the relative abundance of genes associated with nitrogen, sulfur, purine and pyrimidine metabolisms, as well as restriction-modification systems. More diverse bacterial phyla were associated with upstream and deep downstream sediments, mainly including Actinobacteria, Planctomycetes, and Firmicutes. In contrast, in shallow downstream sediments, genera affiliated with Betaproteobacteria and Gammaproteobacteria were enriched with putative functions that included ammonia and sulfur oxidation, polyphosphate accumulation, and methylotrophic bacteria. Collectively, these results highlight the enhanced capabilities of microbial communities residing in deeper stream sediments for the transformation of water contaminants and thus provide a foundation for better design of natural water treatment systems to further improve the removal of contaminants.

Characterization of endocrine disruption potentials of coastal sediments of Taean, Korea employing H295R and MVLN assays-Reconnaissance at 5years after Hebei Spirit oil spill.

PubMed

Liu, Xiaoshan; Jung, Dawoon; Zhou, Kairu; Lee, Sangwoo; Noh, Kiwan; Khim, Jong Seong; Giesy, John P; Yim, Un Hyuk; Shim, Won Joon; Choi, Kyungho

2018-02-01

Endocrine disrupting potentials were assessed for sediment samples collected near Hebei Spirit oil spill (HSOS) site, between December 2007 and January 2012. For comparison, major crude oil (CO) of HSOS, or its weathered form were assessed. Both raw extracts (REs) and their fractionated samples were tested using H295R and MVLNluc bioassays. In H295R cells, REs of crude and weathered oil (WO), and nine of 14 sediments significantly increased E2 levels, which were correlated with the concentrations of PAHs. Steroidogenic disruption potentials of the sediments generally decreased over time. Among silica fractions of all REs, aromatic hydrocarbons (F2) and polar compounds (F3) caused greater E2 levels. While, in MVLN cell bioassay, only three of 14 sediment REs showed estrogen receptor binding potencies, and no temporal trend was observed. In conclusion, oil spill can cause endocrine disruption in the affected ecosystem through steroidogenic alteration for years, and such potencies attenuate over time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genotoxic and teratogenic effect of freshwater sediment samples from the Rhine and Elbe River (Germany) in zebrafish embryo using a multi-endpoint testing strategy.

PubMed

Garcia-Käufer, M; Gartiser, S; Hafner, C; Schiwy, S; Keiter, S; Gründemann, C; Hollert, H

2015-11-01

The embryotoxic potential of three model sediment samples with a distinct and well-characterized pollutant burden from the main German river basins Rhine and Elbe was investigated. The Fish Embryo Contact Test (FECT) in zebrafish (Danio rerio) was applied and submitted to further development to allow for a comprehensive risk assessment of such complex environmental samples. As particulate pollutants are constructive constituents of sediments, they underlay episodic source-sink dynamics, becoming available to benthic organisms. As bioavailability of xenobiotics is a crucial factor for ecotoxicological hazard, we focused on the direct particle-exposure pathway, evaluating throughput-capable endpoints and considering toxicokinetics. Fish embryo and larvae were exposed toward reconstituted (freeze-dried) sediment samples on a microcosm-scale experimental approach. A range of different developmental embryonic stages were considered to gain knowledge of potential correlations with metabolic competence during the early embryogenesis. Morphological, physiological, and molecular endpoints were investigated to elucidate induced adverse effects, placing particular emphasis on genomic instability, assessed by the in vivo comet assay. Flow cytometry was used to investigate the extent of induced cell death, since cytotoxicity can lead to confounding effects. The implementation of relative toxicity indices further provides inter-comparability between samples and related studies. All of the investigated sediments represent a significant ecotoxicological hazard by disrupting embryogenesis in zebrafish. Beside the induction of acute toxicity, morphological and physiological embryotoxic effects could be identified in a concentration-response manner. Increased DNA strand break frequency was detected after sediment contact in characteristic non-monotonic dose-response behavior due to overlapping cytotoxic effects. The embryonic zebrafish toxicity model along with the in vivo comet assay and molecular biomarker analysis should prospectively be considered to assess the ecotoxicological potential of sediments allowing for a comprehensive hazard ranking. In order to elucidate mode of action, novel techniques such as flow cytometry have been adopted and proved to be valuable tools for advanced risk assessment and management.

Seasonal flux and assemblage composition of planktic foraminifers from a sediment-trap study in the northern Gulf of Mexico

USGS Publications Warehouse

Poore, Richard Z.; Spear, Jessica W.; Tedesco, Kathy A.

2013-01-01

Sediment-trap samples from the northern Gulf of Mexico reveal that Globorotalia truncatulinoides, Neogloboquadrina dutertrei, Pulleniatina spp. (includes P. obliquiloculata and P. finalis), and the Globorotalia menardii group (includes Gt. menardii, Gt. tumida, and Gt. ungulata) generally occur in cold months. Globigerinoides ruber (white and pink varieties) and Globigennoides sacculifer occur throughout the year. The seasonal occurrence of individual taxa of planktic foraminifers in the Gulf of Mexico have important differences with the seasonal occurrence of the same taxa observed in a 6-year sediment-trap dataset from the western Sargasso Sea. Thus information on the ecologic preferences of individual taxa determined in one region cannot necessarily be applied directly to another area. In the northern Gulf of Mexico 90% of the total flux of Globorotalia truncatulinoides tests to sediments occurs in January and February. Mg/Ca and d18Ο measurements indicate that nonencrusted forms of Gt. truncatulinoides calcify in the upper-surface-mixed zone. Thus, analyses of nonencrusted Gt. truncatulinoides in sediments of the northern Gulf of Mexico have potential for monitoring past conditions in the winter-surface-mixed layer. The relatively low overall abundance of Globigerinoides ruber (white) in sediment-trap samples is anomalous because Gs. ruber (white) is one of the most abundant foraminifers in>150 µm census data from northern Gulf of Mexico Holocene sediment core samples. Globigerinoides ruber (pink) is a relatively persistent and common component of the sediment-trap samples. Thus Gs. ruber (pink) has potential as a proxy for mean annual sea-surface temperature in the Gulf of Mexico

Chemical fractionation of Cu and Zn in stormwater, roadway dust and stormwater pond sediments

USGS Publications Warehouse

Camponelli, Kimberly M.; Lev, Steven M.; Snodgrass, Joel W.; Landa, Edward R.; Casey, Ryan E.

2010-01-01

This study evaluated the chemical fractionation of Cu and Zn from source to deposition in a stormwater system. Cu and Zn concentrations and chemical fractionation were determined for roadway dust, roadway runoff and pond sediments. Stormwater Cu and Zn concentrations were used to generate cumulative frequency distributions to characterize potential exposure to pond-dwelling organisms. Dissolved stormwater Zn exceeded USEPA acute and chronic water quality criteria in approximately 20% of storm samples and 20% of the storm duration sampled. Dissolved Cu exceeded the previously published chronic criterion in 75% of storm samples and duration and exceeded the acute criterion in 45% of samples and duration. The majority of sediment Cu (92–98%) occurred in the most recalcitrant phase, suggesting low bioavailability; Zn was substantially more available (39–62% recalcitrant). Most sediment concentrations for Cu and Zn exceeded published threshold effect concentrations and Zn often exceeded probable effect concentrations in surface sediments.

The Halekulani Sand Channel and Makua Shelf sediment deposits: Are they a sand resource for replenishing Waikiki's beaches?

USGS Publications Warehouse

Hampton, M.A.; Fletcher, C. H.; Barry, J.H.; Lemmo, S.J.; ,

2000-01-01

The Halekulani Sand Channel and the Makua Shelf off the south shore of Oahu contain at least 1.3 million m3 of sediment that is a possible resource for nourishing degraded sections of Waikiki Beach. A sidescan sonar survey indicates continuous sediment cover within the channel and on the shelf, and samples from the top and bottom of vibracores from the channel and shelf contain from 29% to 77% of grains between 0 to 2.5 phi (1 to 0.177 mm), the size range of four samples from Waikiki Beach. Compositional analyses indicate high variability, but the vibracore samples normally have relatively high Halimeda content compared to beach sand samples. Laboratory tests show a positive correlation of abrasion with Halimeda content, suggesting that the offshore sediment would abrade more than beach sediment under nearshore wave action. The common gray color of the offshore sediment can be aesthetically undesirable for sand on popular tourist beaches such as Waikiki; however, visual observation of native beach sand indicates that a significant component of gray color is endemic to many Hawaiian beaches. The gray color was removed in the laboratory by soaking in heated hydrogen peroxide. The geological properties of the offshore sediment indicate potential as a resource for beach nourishment, but industrial treatment might be necessary to remove excess fine and coarse grains, and possibly the gray color. Further, the abrasion potential might have to be considered in calculating beach sand losses over time.

Quantifying ratios of suspended sediment sources in forested headwater streams following timber-harvesting operations

NASA Astrophysics Data System (ADS)

Rachels, A. A.; Bladon, K. D.; Bywater-Reyes, S.

2017-12-01

Historically, timber-harvesting has increased fine sediment inputs to streams due to increased hillslope and streambank erosion and mass wasting along roads. However, under modern best management practices, the relative importance and variability of these sources is poorly understood. We present preliminary results from an ongoing study investigating the primary sources of suspended sediment in Oregon Coast Range streams influenced by timber harvesting. We instrumented two catchments, Enos Creek (harvested 2016) and Scheele Creek (reference) in fall 2016. Phillips samplers (5-6 per catchment) have been deployed longitudinally down the streams to enable robust characterization of suspended sediments—the collected samples integrate the chemical signatures of upstream sediment exports. We will collect samples monthly over 2 wet seasons and return to the laboratory to analyze the sediment using source fingerprinting approaches. The fingerprinting technique compares the chemical properties of stream sediment samples with the chemical properties of potential source areas, including 1) roads, 2) stream banks, and 3) hillslopes. To design a robust model for sediment-source identification, different types of chemical data are required—we will analyze sediment samples using a combination of: a) stable isotopes and C/N ratios (i.e., δ15N, δ13C, and C/N), b) geochemistry (Fe, K, and Ca), and c) radiogenic isotopes (137Cs and 210Pb). At the harvested site, the C/N ratios of the streambanks (17.9 ± 3.8) and the hillslopes (26.4 ± 4.8) are significantly different from one another (p = .016). C/N ratios of the suspended sediment (20.5 ± 2.0) are intermediate values between potential endmembers and behave conservatively with transport. The C/N ratios of the suspended sediment appear unaffected by roads (18.9 ± 8.7) along specific sections of the stream, suggesting that roads are not a primary sediment contributor. Under this assumption, the suspended sediment is, on average, comprised of 69.5% streambank sediments and 30.5% hillslope sediments. Additional analyses are required (and in progress) to support these implications and to further interpret the importance and variability of suspended sediment sources through both space (from head to outlet) and time.

Phosphorus in sediment in the Kent Park Lake watershed, Johnson County, Iowa, 2014–15

USGS Publications Warehouse

Kalkhoff, Stephen J.

2016-07-12

Phosphorus data were collected from the Kent Park Lake watershed in Johnson County, Iowa, in 2014 and 2015 to obtain information to assist in the management of the water quality in the lake. Phosphorus concentrations were measured for sediment from several ponds in the watershed and sediment deposited in the lake. The first set of samples was collected in 2014 to understand phosphorus in several potential sources to the lake and the spatial variability in lake sediments. Phosphorus concentrations ranged from 68 to 380 milligrams per kilogram in lake sediment and from 57 to 220 milligrams per kilogram in sedimentation and dredge spoil ponds. Additional samples were collected in 2015 to determine how phosphorus concentrations vary with depth in the lake sediment. Phosphorus concentrations generally decreased with increasing depth within the lake sediment. In 2015, total phosphorus concentrations in lake sediment ranged from 50 to 340 milligrams per kilogram.

Overview of the U.S. EPA/SERDP/ESTCP: Laboratory, Field, and Analytical Procedures for Using Passive Sampling in the Evaluation of Contaminated Sediments: User’s Manual

EPA Science Inventory

Passive sampling can be used for applications at contaminated sediment sites including performing assessments of contaminant bioavailability (i.e., freely dissolved concentration (Cfree)), conducting remedial investigations and feasibility studies, and assessing the potential for...

Overview of the U.S. EPA/SERDP/ESTCP: Laboratory, Field, and Analytical Procedures for Using Passive Sampling in the Evaluation of Contaminated Sediments: User’s Manual.

EPA Science Inventory

Passive sampling is used for applications at contaminated sediment sites including performing assessments of contaminant bioavailability (i.e., freely dissolved concentration (Cfree)), conducting remedial investigations and feasibility studies, and assessing the potential for con...

UTILIZATION OF THE CARBON AND HYDROGEN ISOTOPIC COMPOSITION OF INDIVIDUAL COMPOUNDS IN REFINED HYDROCARBON PRODUCTS TO MONITOR THEIR FATE IN THE ENVIRONMENT

EPA Science Inventory

Isotope effects resulting from biodegradation of MTBE
To conduct the microcosm biodegradation study, sediment samples were collected from sites offering high potential of MTBE biodegradation. Sites where sediment samples were collected for the MTBE microcosm c...

Quantifying Differences in the Impact of Variable Chemistry on Equilibrium Uranium(VI) Adsorption Properties of Aquifer Sediments

PubMed Central

2011-01-01

Uranium adsorption–desorption on sediment samples collected from the Hanford 300-Area, Richland, WA varied extensively over a range of field-relevant chemical conditions, complicating assessment of possible differences in equilibrium adsorption properties. Adsorption equilibrium was achieved in 500–1000 h although dissolved uranium concentrations increased over thousands of hours owing to changes in aqueous chemical composition driven by sediment-water reactions. A nonelectrostatic surface complexation reaction, >SOH + UO22+ + 2CO32- = >SOUO2(CO3HCO3)2–, provided the best fit to experimental data for each sediment sample resulting in a range of conditional equilibrium constants (logKc) from 21.49 to 21.76. Potential differences in uranium adsorption properties could be assessed in plots based on the generalized mass-action expressions yielding linear trends displaced vertically by differences in logKc values. Using this approach, logKc values for seven sediment samples were not significantly different. However, a significant difference in adsorption properties between one sediment sample and the fines (<0.063 mm) of another could be demonstrated despite the fines requiring a different reaction stoichiometry. Estimates of logKc uncertainty were improved by capturing all data points within experimental errors. The mass-action expression plots demonstrate that applying models outside the range of conditions used in model calibration greatly increases potential errors. PMID:21923109

Quantifying differences in the impact of variable chemistry on equilibrium Uranium(VI) adsorption properties of aquifer sediments.

PubMed

Stoliker, Deborah L; Kent, Douglas B; Zachara, John M

2011-10-15

Uranium adsorption-desorption on sediment samples collected from the Hanford 300-Area, Richland, WA varied extensively over a range of field-relevant chemical conditions, complicating assessment of possible differences in equilibrium adsorption properties. Adsorption equilibrium was achieved in 500-1000 h although dissolved uranium concentrations increased over thousands of hours owing to changes in aqueous chemical composition driven by sediment-water reactions. A nonelectrostatic surface complexation reaction, >SOH + UO₂²⁺ + 2CO₃²⁻ = >SOUO₂(CO₃HCO₃)²⁻, provided the best fit to experimental data for each sediment sample resulting in a range of conditional equilibrium constants (logK(c)) from 21.49 to 21.76. Potential differences in uranium adsorption properties could be assessed in plots based on the generalized mass-action expressions yielding linear trends displaced vertically by differences in logK(c) values. Using this approach, logK(c) values for seven sediment samples were not significantly different. However, a significant difference in adsorption properties between one sediment sample and the fines (< 0.063 mm) of another could be demonstrated despite the fines requiring a different reaction stoichiometry. Estimates of logK(c) uncertainty were improved by capturing all data points within experimental errors. The mass-action expression plots demonstrate that applying models outside the range of conditions used in model calibration greatly increases potential errors.

Novel MixSIAR fingerprint model implementation in a Mediterranean mountain catchment

NASA Astrophysics Data System (ADS)

Lizaga, Ivan; Gaspar, Leticia; Blake, William; Palazón, Leticia; Quijano, Laura; Navas, Ana

2017-04-01

Increased sediment erosion levels can lead to degraded water and food quality, reduced aquatic biodiversity, decrease reservoir capacity and restrict recreational usage but determining soil redistribution and sediment budgets in watersheds is often challenging. One of the methods for making such determinations applies sediment fingerprinting methods by using sediment properties. The fingerprinting procedure tests a range of source material tracer properties to select a subset that can discriminate between the different potential sediment sources. The present study aims to test the feasibility of geochemical and radioisotopic fingerprint properties to apportion sediment sources within the Barués catchment. For this purpose, the new MixSIAR unmixing model was implemented as statistical tool. A total of 98 soil samples from different land cover sources (Mediterranean forest, pine forest scrubland, agricultural and subsoil) were collected in the Barués catchment (23 km2). This new approach divides the catchment into six different sub-catchments to evaluate how the sediment provenance varies along the river and the percentage of its sources and not only the contribution at the end. For this purpose, target sediments were collected at the end of each sub-catchment to introduce the variation along the entire catchment. Geochemistry and radioisotopic activity were analyzed for each sample and introduced as input parameters in the model. Percentage values from the five sources were different along the different subcatchments and the variations of all of them are summarized at the final target sample located at the end of the catchment. This work represents a good approximation to the fine sediment provenance in Mediterranean agricultural catchments and has the potential to be used for water resource control and future soil management. Identifying sediment contribution from different land uses offers considerable potential to prevent environmental degradation and the decrease in food production and quality.

Geochemistry of Mercury and other trace elements in fluvial tailings upstream of Daguerre Point Dam, Yuba River, California, August 2001

USGS Publications Warehouse

Hunerlach, Michael P.; Alpers, Charles N.; Marvin-DiPasquale, Mark; Taylor, Howard E.; DeWild, John F.

2004-01-01

This study was designed to characterize the particle-size distribution and the concentrations of total mercury (HgT), methylmercury (MeHg), and other constituents in sediments trapped behind Daguerre Point Dam, a 28-foot-high structure on the lower Yuba River in California. The results of the study will assist other agencies in evaluating potential environmental impacts from mobilization of sediments if Daguerre Point Dam is modified or removed to improve the passage of anadromous fish. Methylmercury is of particular concern owing to its toxicity and propensity to bioaccumulate. A limited amount of recent work on hydraulic and dredge tailings in other watersheds has indicated that mercury and MeHg concentrations may be elevated in the fine-grained fractions of placer mining debris, particularly clay and silt. Mercury associated with tailings from placer gold mines is a source of continued contamination in Sierra Nevada watersheds and downstream water bodies, including the Sacramento?San Joaquin Delta and the San Francisco Bay of northern California. Churn drilling was used to recover sediments and heavy minerals at 5-foot intervals from six locations upstream of Daguerre Point Dam. Maximum depth of penetration ranged from 17.5 to 35 feet below land surface, resulting in 31 discreet drilled intervals. Drilling in permeable, unconsolidated sediments below the streambed of the Yuba River released a significant volume of water along with the sediment, which complicated the sampling and characterization effort. Overflow of a silty fraction sampled at the drill site contained suspended sediment consisting predominantly of silt and clay, with HgT concentration ranging from 33 to 1,100 ng/g (nanogram per gram) dry weight. A sandy fraction, collected after sieving sediment through a 2-millimeter vibratory screen, contained from 14 to 82 percent sand and 1 to 29 percent silt plus clay, and had HgT concentrations ranging from 6.8 to 81 ng/g dry weight. A clay-silt fraction, sampled from material remaining in suspension after the sandy fraction settled for 15-20 minutes, contained mercury concentrations from 23 to 370 ng/g dry weight. Concentrations of MeHg were less than the detection limit (<0.001 ng/g dry weight) in 30 of 31 samples of the sandy fraction. In the suspended clay-silt fraction, MeHg was detected in 16 of 31 samples, in which it ranged in concentration from 0.04 (estimated) to 0.61 ng/g wet weight. Potential rates of mercury methylation and demethylation were evaluated in seven samples using radiotracer methods. Mercury methylation (MeHg production) potentials were generally low, ranging from less than 0.15 to about 1.6 ng/g/d (nanogram per gram of dry sediment per day). Mercury demethylation (MeHg degradation) potentials were moderately high, ranging from 1.0 to 2.2 ng/g/d. The ratio of methylation potential (MP) to demethylation potential (DP) ranged from less than 0.14 to about 1.4 (median = 0.24, mean = 0.44, number of samples = 7), suggesting that the potential for net production of MeHg in deep sediments is generally low. The MeHg production rates and MP/DP ratios were higher in the shallower interval in two of the three holes where two depth intervals were assessed, whereas the MeHg concentrations were higher in the shallower interval for all three holes. A similar spatial distribution was found for concentrations of solid-phase sulfide (measured as total reduced sulfur and likely representing iron-sulfide and iron-disulfide compounds), which were much higher in shallower samples (about 700 to about 2,100 nanomoles per gram, dry sediment) than in deeper samples (32 to 55 nanomoles per gram, dry sediment) in these three holes. If reduced sulfur compounds are oxidized to sulfate as a consequence of sediment disturbance, the activity of sulfate-reducing bacteria might be stimulated, causing a short-term increase in methylation of inorganic Hg(II) (divalent mercury). The extent of increased Hg(II)-methylation w

The use of sequential extraction to evaluate the remediation potential of heavy metals from contaminated harbour sediment

NASA Astrophysics Data System (ADS)

Nystrøm, G. M.; Ottosen, L. M.; Villumsen, A.

2003-05-01

In this work sequential extraction is performed with harbour sediment in order to evaluate the electrodialytic remediation potential for harbour sediments. Sequential extraction was performed on a sample of Norwegian harbour sediment; with the original sediment and after the sediment was treated with acid. The results from the sequential extraction show that 75% Zn and Pb and about 50% Cu are found in the most mobile phases in the original sediment and more than 90% Zn and Pb and 75% Cu are found in the most mobile phase in the sediment treated with acid. Electrodialytic remediation experiments were made. The method uses a low direct current as cleaning agent, removing the heavy metals towards the anode and cathode according to the charge of the heavy metals in the electric field. The electrodialytic experiments show that up to 50% Cu, 85% Zn and 60% Pb can be removed after 20 days. Thus, there is still a potential for a higher removal, with some changes in the experimental set-up and longer remediation time. The experiments show that thc use of sequential extraction can be used to predict the electrodialytic remediation potential for harbour sediments.

Detection of multiple potentially pathogenic bacteria in Matang mangrove estuaries, Malaysia.

PubMed

Ghaderpour, Aziz; Mohd Nasori, Khairul Nazrin; Chew, Li Lee; Chong, Ving Ching; Thong, Kwai Lin; Chai, Lay Ching

2014-06-15

The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public. Copyright © 2014 Elsevier Ltd. All rights reserved.

Trace metals and persistent organic pollutants in sediments from river-reservoir systems in Democratic Republic of Congo (DRC): Spatial distribution and potential ecotoxicological effects.

PubMed

Mwanamoki, Paola M; Devarajan, Naresh; Thevenon, Florian; Birane, Niane; de Alencastro, Luiz Felippe; Grandjean, Dominique; Mpiana, Pius T; Prabakar, Kandasamy; Mubedi, Josué I; Kabele, Christophe G; Wildi, Walter; Poté, John

2014-09-01

This paper discusses the occurrence and spatial distribution of metals and persistent organic pollutants (POPs: including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), Polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) in sediments from a river-reservoir system. Surface sediments were sampled from thirteen sites of the Congo River Basin and Lake Ma Vallée, both situated in the vicinity of the capital city Kinshasa (Congo Democratic Republic). Sediment qualities were evaluated using toxicity test based on exposing Ostracods to the sediment samples. The highest metal concentrations were observed in sediments subjected to anthropogenic influences, urban runoff and domestic and industrial wastewaters, discharge into the Congo River basin. Ostracods exposed to the sediments resulted in 100% mortality rates after 6d of incubation, indicating the ultimate toxicity of these sediments as well as potential environmental risks. The POPs and PAHs levels in all sediment samples were low, with maximum concentration found in the sediments (area of pool Malebo): OCP value ranged from 0.02 to 2.50 with ∑OCPs: 3.3μgkg(-1); PCB ranged from 0.07 to 0.99 with Total PCBs (∑7×4.3): 15.31μgkg(-1); PAH value ranged from 0.12 to 9.39 with ∑PAHs: 63.89μgkg(-1). Our results indicate that the deterioration of urban river-reservoir water quality result mainly from urban stormwater runoff, untreated industrial effluents which discharge into the river-reservoirs, human activities and uncontrolled urbanization. This study represents useful tools incorporated to evaluate sediment quality in river-reservoir systems which can be applied to similar aquatic environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Verifying Sediment Fingerprinting Results with Known Mixtures

NASA Astrophysics Data System (ADS)

Gellis, A.; Gorman-Sanisaca, L.; Cashman, M. J.

2017-12-01

Sediment fingerprinting is a widely used approach to determine the specific sources of fluvial sediment within a watershed. It relies on the principle that potential sediment sources can be identified using a set of chemical tracers (or fingerprints), and comparison of these source fingerprints with fluvial (target) sediment allows for source apportionment of the fluvial sediment. There are numerous source classifications, fingerprints, and statistical approaches used in the literature to apportion sources of sediment. However, few of these studies have sought to test the method by creating controls on the ratio of sources in the target sediment. Without a controlled environment for inputs and outputs, such verification of results is ambiguous. Here, we generated artificial mixtures of source sediment from an agricultural/forested watershed in Virginia, USA (Smith Creek, 246 km2) to verify the apportionment results. Target samples were established from known mixtures of the four major sediment sources in the watershed (forest, pasture, cropland, and streambanks). The target samples were sieved to less than 63 microns and analyzed for elemental and isotopic chemistry. The target samples and source samples were run through the Sediment Source Assessment Tool (Sed_SAT) to verify if the statistical operations provided the correct apportionment. Sed_SAT uses a multivariate parametric approach to identify the minimum suite of fingerprints that discriminate the source areas and applies these fingerprints through an unmixng model to apportion sediment. The results of this sediment fingerprinting verification experiment will be presented in this session.

Assessment of sediment toxicity and chemical concentrations in the San Diego Bay region, California, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fairey, R.; Roberts, C.; Jacobi, M.

1998-08-01

Sediment quality within San Diego Bay, Mission Bay, and the Tijuana River Estuary of California was investigated as part of an ongoing statewide monitoring effort (Bay Protection and Toxic Cleanup Program). Study objectives were to determine the incidence, spatial patterns, and spatial extent of toxicity in sediments and porewater; the concentration and distribution of potentially toxic anthropogenic chemicals; and the relationships between toxicity and chemical concentrations. Rhepoxynius abronius survival bioassays, grain size, and total organic carbon analyses were performed on 350 sediment samples. Strongylocentrotus purpuratus development bioassays were performed on 164 pore-water samples. Toxicity was demonstrated throughout the San Diegomore » Bay region, with increased incidence and concordance occurring in areas of industrial and shipping activity. Trace metal and trace synthetic organic analyses were performed on 229 samples. Copper, zinc, mercury, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and chlordane were found to exceed ERM (effects range median) or PEL (probable effects level) sediment quality guidelines and were considered the six major chemicals or chemical groups of concern. Statistical analysis of the relationships between amphipod toxicity, bulk phase sediment chemistry, and physical parameters demonstrated few significant linear relationships. Significant differences in chemical levels were found between toxic and nontoxic responses using multivariate and univariate statistics. Potential sources of anthropogenic chemicals were discussed.« less

Heavy metals and metalloids in the surface sediments of the Xiangjiang River, Hunan, China: distribution, contamination, and ecological risk assessment.

PubMed

Chai, Liyuan; Li, Huan; Yang, Zhihui; Min, Xiaobo; Liao, Qi; Liu, Yi; Men, Shuhui; Yan, Yanan; Xu, Jixin

2017-01-01

Here, we aim to determine the distribution, ecological risk and sources of heavy metals and metalloids in the surface sediments of the Xiangjiang River, Hunan Province, China. Sixty-four surface sediment samples were collected in 16 sites of the Xiangjiang River, and the concentrations of ten heavy metals and metalloids (Mn, Zn, Cr, V, Pb, Cu, As, Ni, Co, and Cd) in the sediment samples were investigated using an inductively coupled plasma mass spectrometer (ICP-MS) and an atomic fluorescence spectrophotometer (AFS), respectively. The results showed that the mean concentrations of the ten heavy metals and metalloids in the sediment samples followed the order Mn > Zn > Cr > V > Pb > Cu > As ≈ Ni >Co > Cd. The geoaccumulation index (I geo ), enrichment factor (EF), modified degree of contamination (mC d ), and potential ecological risk index (RI) revealed that Cd, followed by Pb, Zn, and Cu, caused severely contaminated and posed very highly potential ecological risk in the Xiangjiang River, especially in Shuikoushan of Hengyang, Xiawan of Zhuzhou, and Yijiawan of Xiangtan. The Pearson's correlation coefficient (PCC) analysis, principal component analysis (PCA), and hierarchical cluster analysis (HCA) indicated that the ten heavy metals and metalloids in the sampling sediments of the Xiangjiang River were classified into three groups: (1) Cd, Pb, Zn, and Cu which possibly originated from Shuikoushan, Xiawan, and Yijiawan clustering Pb-Zn mining and smelting industries; (2) Co, V, Ni, Cr, and Al from natural resources; and (3) Mn and As. Therefore, our results suggest that anthropogenic activities, especially mining and smelting, have caused severe contamination of Cd, Pb, Zn, and Cu and posed very high potential ecological risk in the Xiangjiang River.

Use of stable isotopes of carbon and nitrogen to identify sources of organic matter to bed sediments of the Tualatin River, Oregon

USGS Publications Warehouse

Bonn, Bernadine A.; Rounds, Stewart A.

2010-01-01

The potential sources of organic matter to bed sediment of the Tualatin River in northwestern Oregon were investigated by comparing the isotopic fractionation of carbon and nitrogen and the carbon/nitrogen ratios of potential sources and bed sediments. Samples of bed sediment, suspended sediment, and seston, as well as potential source materials, such as soil, plant litter, duckweed, and wastewater treatment facility effluent particulate were collected in 1998-2000. Based on the isotopic data, terrestrial plants and soils were determined to be the most likely sources of organic material to Tualatin River bed sediments. The delta 13C fractionation matched well, and although the delta 15N and carbon/nitrogen ratio of fresh plant litter did not match those of bed sediments, the changes expected with decomposition would result in a good match. The fact that the isotopic composition of decomposed terrestrial plant material closely resembled that of soils and bed sediments supports this conclusion. Phytoplankton probably was not a major source of organic matter to bed sediments. Compared to the values for bed sediments, the delta 13C values and carbon/nitrogen ratios of phytoplankton were too low and the delta 15N values were too high. Decomposition would only exacerbate these differences. Although phytoplankton cannot be considered a major source of organic material to bed sediment, a few bed sediment samples in the lower reach of the river showed a small influence from phytoplankton as evidenced by lower delta 13C values than in other bed sediment samples. Isotopic data and carbon/nitrogen ratios for bed sediments generally were similar throughout the basin, supporting the idea of a widespread source such as terrestrial material. The delta 15N was slightly lower in tributaries and in the upper reaches of the river. Higher rates of sediment oxygen demand have been measured in the tributaries in previous studies and coupled with the isotopic data may indicate the presence of more labile organic matter in these areas. Results from this study indicate that strategies to improve oxygen conditions in the Tualatin River are likely to be more successful if they target sources of soil, leaf litter, and other terrestrially derived organic materials to the river rather than the instream growth of algae.

The legacy of lead (Pb) in fluvial bed sediments of an urban drainage basin, Oahu, Hawaii.

PubMed

Hotton, Veronica K; Sutherland, Ross A

2016-03-01

The study of fluvial bed sediments is essential for deciphering the impact of anthropogenic activities on water quality and drainage basin integrity. In this study, a systematic sampling design was employed to characterize the spatial variation of lead (Pb) concentrations in bed sediment of urban streams in the Palolo drainage basin, southeastern Oahu, Hawaii. Potentially bioavailable Pb was assessed with a dilute 0.5 N HCl extraction of the <63 μm grain-size fraction from the upper bed sediment layer of 169 samples from Palolo, Pukele, and Waiomao streams. Contamination of bed sediments was associated with the direct transport of legacy Pb from the leaded gasoline era to stream channels via a dense network of storm drains linked to road surfaces throughout the basin. The Palolo Stream had the highest median Pb concentration (134 mg/kg), and the greatest road and storm drain densities, the greatest population, and the most vehicle numbers. Lower median Pb concentrations were associated with the less impacted Pukele Stream (24 mg/kg), and Waiomao Stream (7 mg/kg). The median Pb enrichment ratio values followed the sequence of Palolo (68) > Pukele (19) > Waiomao (8). Comparisons to sediment quality guidelines and potential toxicity estimates using a logistic regression model (LRM) indicated a significant potential risk of Palolo Stream bed sediments to bottom-dwelling organisms.

Selenium in irrigated agricultural areas of the western United States

USGS Publications Warehouse

Nolan, B.T.; Clark, M.L.

1997-01-01

A logistic regression model was developed to predict the likelihood that Se exceeds the USEPA chronic criterion for aquatic life (5 ??g/L) in irrigated agricultural areas of the western USA. Preliminary analysis of explanatory variables used in the model indicated that surface-water Se concentration increased with increasing dissolved solids (DS) concentration and with the presence of Upper Cretaceous, mainly marine sediment. The presence or absence of Cretaceous sediment was the major variable affecting Se concentration in surface-water samples from the National Irrigation Water Quality Program. Median Se concentration was 14 ??g/L in samples from areas underlain by Cretaceous sediments and < 1 ??g/L in samples from areas underlain by non-Cretaceous sediments. Wilcoxon rank sum tests indicated that elevated Se concentrations in samples from areas with Cretaceous sediments, irrigated areas, and from closed lakes and ponds were statistically significant. Spearman correlations indicated that Se was positively correlated with a binary geology variable (0.64) and DS (0.45). Logistic regression models indicated that the concentration of Se in surface water was almost certain to exceed the Environmental Protection Agency aquatic-life chronic criterion of 5 ??g/L when DS was greater than 3000 mg/L in areas with Cretaceous sediments. The 'best' logistic regression model correctly predicted Se exceedances and nonexceedances 84.4% of the time, and model sensitivity was 80.7%. A regional map of Cretaceous sediment showed the location of potential problem areas. The map and logistic regression model are tools that can be used to determine the potential for Se contamination of irrigated agricultural areas in the western USA.

Relationships of sedimentation and benthic macroinvertebrate assemblages in headwater streams using systematic longitudinal sampling at the reach scale.

PubMed

Longing, S D; Voshell, J R; Dolloff, C A; Roghair, C N

2010-02-01

Investigating relationships of benthic invertebrates and sedimentation is challenging because fine sediments act as both natural habitat and potential pollutant at excessive levels. Determining benthic invertebrate sensitivity to sedimentation in forested headwater streams comprised of extreme spatial heterogeneity is even more challenging, especially when associated with a background of historical and intense watershed disturbances that contributed unknown amounts of fine sediments to stream channels. This scenario exists in the Chattahoochee National Forest where such historical timber harvests and contemporary land-uses associated with recreation have potentially affected the biological integrity of headwater streams. In this study, we investigated relationships of sedimentation and the macroinvertebrate assemblages among 14 headwater streams in the forest by assigning 30, 100-m reaches to low, medium, or high sedimentation categories. Only one of 17 assemblage metrics (percent clingers) varied significantly across these categories. This finding has important implications for biological assessments by showing streams impaired physically by sedimentation may not be impaired biologically, at least using traditional approaches. A subsequent multivariate cluster analysis and indicator species analysis were used to further investigate biological patterns independent of sedimentation categories. Evaluating the distribution of sedimentation categories among biological reach clusters showed both within-stream variability in reach-scale sedimentation and sedimentation categories generally variable within clusters, reflecting the overall physical heterogeneity of these headwater environments. Furthermore, relationships of individual sedimentation variables and metrics across the biological cluster groups were weak, suggesting these measures of sedimentation are poor predictors of macroinvertebrate assemblage structure when using a systematic longitudinal sampling design. Further investigations of invertebrate sensitivity to sedimentation may benefit from assessments of sedimentation impacts at different spatial scales, determining compromised physical habitat integrity of specific taxa and developing alternative streambed measures for quantifying sedimentation.

Organic compounds and trace elements in fish tissue and bed sediment from streams in the Yellowstone River basin, Montana and Wyoming, 1998

USGS Publications Warehouse

Peterson, David A.; Boughton, Gregory K.

2000-01-01

A comprehensive water-quality investigation of the Yellowstone River Basin began in 1997, under the National Water-Quality Assessment (NAWQA) Program. Twenty-four sampling sites were selected for sampling of fish tissue and bed sediment during 1998. Organic compounds analyzed included organochlorine insecticides and their metabolites and total polychlorinated biphenyls (PCBs) from fish-tissue and bed-sediment samples, and semivolatile organic compounds from bed-sediment samples. A broad suite of trace elements was analyzed from both fish-tissue and bed-sediment samples, and a special study related to mercury also was conducted. Of the 12 organochlorine insecticides and metabolites detected in the fish-tissue samples, the most compounds per site were detected in samples from integrator sites which represent a mixture of land uses. The presence of DDT, and its metabolites DDD and DDE, in fish collected in the Yellowstone Park area likely reflects long-term residual effects from historical DDT-spraying programs for spruce budworm. Dieldrin, chlordane, and other organic compounds also were detected in the fish-tissue samples. The compound p, p'-DDE was detected at 71 percent of the sampling sites, more than any other compound. The concentrations of total DDT in fish samples were low, however, compared to concentrations from historical data from the study area, other NAWQA studies in the Rocky Mountains, and national baseline concentrations. Only 2 of the 27 organochlorine insecticides and metabolites and total PCBs analyzed in bed sediment were detected. Given that 12 of the compounds were detected in fish-tissue samples, fish appeared to be more sensitive indicators of contamination than bed sediment.Concentrations of some trace elements in fish and bed sediment were higher at sites in mineralized areas than at other sites. Concentrations of selenium in fish tissue from some sites were above background levels. Concentrations of arsenic, chromium, copper, and lead in some of the bed-sediment samples potentially exceeded criteria for the protection of aquatic life.

Electron donor concentrations in sediments and sediment properties at the agricultural chemicals team research site near New Providence, Iowa, 2006-07

USGS Publications Warehouse

Maharjan, Bijesh; Korom, Scott F.; Smith, Erik A.

2013-01-01

The concentrations of electron donors in aquifer sediments are important to the understanding of the fate and transport of redox-sensitive constituents in groundwater, such as nitrate. For a study by the U.S. Geological Survey National Water-Quality Assessment Program, 50 sediment samples were collected from below the water table from 11 boreholes at the U.S. Geological Survey Agricultural Chemicals Team research site near New Providence, Iowa, during 2006-07. All samples were analyzed for gravel, sand (coarse, medium, and fine), silt, clay, Munsell soil color, inorganic carbon content, and for the following electron donors: organic carbon, ferrous iron, and inorganic sulfide. A subset of 14 sediment samples also was analyzed for organic sulfur, but all of these samples had concentrations less than the method detection limit; therefore, the presence of this potential electron donor was not considered further. X-ray diffraction analyses provided important semi-quantitative information of well-crystallized dominant minerals within the sediments that might be contributing electron donors.

Hourly and daily variation of sediment redox potential in tidal wetland sediments

USGS Publications Warehouse

Catallo, W. James

1999-01-01

Variation of electrochemical oxidation-reduction (redox) potential was examined in surface salt march sediments under conditions of flooding and tidal simulation in mesocosms and field sites. Time series were generated of redox potential measured in sediment profiles at 2-10 cm depth using combination Pt-Ag/AgCl (ORP) electrodes. Redox potential data were acquired at rapid rates (1-55 samples/h) over extended periods (3-104 days) along with similar times series of temperature (water, air, soil) and pH. It was found that redox potential vaired as a result of water level changes and was unrelated to diurnal changes in temperature or pH, the latter of which changed by 370 mV redox potential decrease in under 48 hours). Attenuatoin of microbial activity by [gamma] y-radiation and toxic chemicals elimintated this response. In tidal salt marsh mesocosms where the sediment-plant assemblages were exposed to a simulated diurnal tide, redox potenial oscillations of 40-300 mV amplitude were recoded that has the same periodicity as the flood-drain cycle. Periodic redoc potential time series were observed repeatedly in sediments receiving tidal pulsing but not in those sediments exposed to static hydrological conditions. Data collected over 12 days from a coastal marsh site experiencing diurnal tides showed similar fluctuations in redox potential. Data from the experimentents indicated that (a) redox potential can be a dynamic, nonlinear variable in coastal and estuarine wetland sediments over hourly and daily scales, and the designs of biogeochemical experiments should reflect this, (b) redox potential can change rapidly and signigicantly in coastal wetland sediments in response of flooding and draining, (c) microbial community processes are primarily determinants of the time course of redox potential in wetland sediments, and elimination of inhibition of microbial activity (e.g. by pollutants) can significantly alter that behavior, and (d) fast redox potential dynamics appear to be characteristic of sediments that experience changes in hydrology. The rapid redox potential changes observed in these systems indicated dynamic metabolic and biogeochemical conditions in the field, and confirmed that hourly and daily redox potential variations should be resolved in studies of sediment functioning.

Effect of Oxalic Acid Treatment on Sediment Arsenic Concentrations and Lability under Reducing Conditions

PubMed Central

Sun, Jing; Bostick, Benjamin C.; Mailloux, Brian J.; Ross, James M.; Chillrud, Steven N.

2016-01-01

Oxalic acid enhances arsenic (As) mobilization by dissolving As host minerals and competing for sorption sites. Oxalic acid amendments thus could potentially improve the efficiency of widely used pump-and-treat (P&T) remediation. This study investigates the effectiveness of oxalic acid on As mobilization from contaminated sediments with different As input sources and redox conditions, and examines whether residual sediment As after oxalic acid treatment can still be reductively mobilized. Batch extraction, column, and microcosm experiments were performed in the laboratory using sediments from the Dover Municipal Landfill and the Vineland Chemical Company Superfund sites. Oxalic acid mobilized As from both Dover and Vineland sediments, although the efficiency rates were different. The residual As in both Dover and Vineland sediments after oxalic acid treatment was less vulnerable to microbial reduction than before the treatment. Oxalic acid could thus improve the efficiency of P&T. X-ray absorption spectroscopy analysis indicated that the Vineland sediment samples still contained reactive Fe(III) minerals after oxalic acid treatment, and thus released more As into solution under reducing conditions than the Dover samples. Therefore, the efficacy of P&T must consider sediment Fe mineralogy when evaluating its overall potential for remediating groundwater As. PMID:26970042

Concentrations of selected metals in Quaternary-age fluvial deposits along the lower Cheyenne and middle Belle Fourche Rivers, western South Dakota, 2009-10

USGS Publications Warehouse

Stamm, John F.; Hoogestraat, Galen K.

2012-01-01

The headwaters of the Cheyenne and Belle Fourche Rivers drain the Black Hills of South Dakota and Wyoming, an area that has been affected by mining and ore-milling operations since the discovery of gold in 1875. A tributary to the Belle Fourche River is Whitewood Creek, which drains the area of the Homestake Mine, a gold mine that operated from 1876 to 2001. Tailings discharged into Whitewood Creek contained arsenopyrite, an arsenic-rich variety of pyrite associated with gold ore, and mercury used as an amalgam during the gold-extraction process. Approximately 18 percent of the tailings that were discharged remain in fluvial deposits on the flood plain along Whitewood Creek, and approximately 25 percent remain in fluvial deposits on the flood plain along the Belle Fourche River, downstream from Whitewood Creek. In 1983, a 29-kilometer (18-mile) reach of Whitewood Creek and the adjacent flood plain was included in the U.S. Environmental Protection Agency's National Priority List of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, commonly referred to as a "Superfund site." Listing of this reach of Whitewood Creek was primarily in response to arsenic toxicity of fluvial deposits on the flood plain. Lands along the lower Cheyenne River were transferred to adjoining States and Tribes in response to the Water Resources Development Act (WRDA) of 1999. An amendment in 2000 to WRDA required a study of sediment contamination of the Cheyenne River. In response to the WRDA amendment, the U.S. Geological Survey completed field sampling of reference sites (not affected by mine-tailing disposal) along the lower Belle Fourche and lower Cheyenne Rivers. Reference sites were located on stream terraces that were elevated well above historical stream stages to ensure no contamination from historical mining activity. Sampling of potentially contaminated sites was performed on transects of the active flood plain and adjacent terraces that could potentially be inundated during high-flow events. Sampling began in 2009 and was completed in 2010. A total of 74 geochemical samples were collected from fluvial deposits at reference sites, and 473 samples were collected from potentially contaminated sites. Sediment samples collected were analyzed for 23 metals, including arsenic and mercury. Sequential replicate, split duplicate, and field quality-control samples were analyzed for quality assurance of data-collection methods. The metal concentrations in sediment samples and location information are presented in this report in electronic format (Microsoft Excel), along with non-parametric summary statistics of those data. Cross-sectional topography is graphed with arsenic and mercury concentrations on transects at the potentially contaminated sites. The mean arsenic concentration in reference sediment samples was 8 milligrams per kilogram (mg/kg), compared to 250, 650, and 76 mg/kg for potentially contaminated sediment samples at the surface of the middle Belle Fourche River site, the subsurface of the middle Belle Fourche River site, and the surface of the lower Cheyenne River site, respectively. The mean mercury concentration in reference sediment samples was 16 micrograms per kilogram (μg/kg), compared to 130, 370, and 71 μg/kg for potentially contaminated sediment samples at the surface of the middle Belle Fourche River site, the subsurface of the middle Belle Fourche River site, and the surface of the lower Cheyenne River site, respectively.

Occurrence, Ecological and Human Health Risks, and Seasonal Variations of Phenolic Compounds in Surface Water and Sediment of a Potential Polluted River Basin in China.

PubMed

Zhou, Mo; Zhang, Jiquan; Sun, Caiyun

2017-09-27

Five phenolic compounds in water and sediment of Yinma River Basin were investigated. The average concentration of phenol was the highest in water samples as well as in sediment samples during the wet season, 101.68 ng/L and 127.76 ng/g, respectively. 2,4,6-Trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP) was not detected in some sampling sites. Shitou Koumen Reservoir and the neighboring area were the severest areas of phenolic pollution. The lower reach was more polluted in three water seasons than the middle reach and upper reach. Phenol had ecological risks in sediment during three water seasons. 2-Nitrophenol (2-NP) and 2,4-dichlorophenol (2,4-DCP) had ecological risks in sediment in both the normal and wet season. The concentrations of five phenolic compounds from high to low were in the wet season, normal season, and dry season in water and sediment, respectively. There were middle risks in water of total concentrations for five phenolic compounds in several sampling sites. Total concentrations for five phenolic compounds in sediment had high ecological risks in all sampling sites. However, there was no human health risk in the Yinma River Basin.

Occurrence, Ecological and Human Health Risks, and Seasonal Variations of Phenolic Compounds in Surface Water and Sediment of a Potential Polluted River Basin in China

PubMed Central

Zhou, Mo; Sun, Caiyun

2017-01-01

Five phenolic compounds in water and sediment of Yinma River Basin were investigated. The average concentration of phenol was the highest in water samples as well as in sediment samples during the wet season, 101.68 ng/L and 127.76 ng/g, respectively. 2,4,6-Trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP) was not detected in some sampling sites. Shitou Koumen Reservoir and the neighboring area were the severest areas of phenolic pollution. The lower reach was more polluted in three water seasons than the middle reach and upper reach. Phenol had ecological risks in sediment during three water seasons. 2-Nitrophenol (2-NP) and 2,4-dichlorophenol (2,4-DCP) had ecological risks in sediment in both the normal and wet season. The concentrations of five phenolic compounds from high to low were in the wet season, normal season, and dry season in water and sediment, respectively. There were middle risks in water of total concentrations for five phenolic compounds in several sampling sites. Total concentrations for five phenolic compounds in sediment had high ecological risks in all sampling sites. However, there was no human health risk in the Yinma River Basin. PMID:28953252

Comparison of methods for the concentration of suspended sediment in river water for subsequent chemical analysis

USGS Publications Warehouse

Horowltz, A.J.

1986-01-01

Centrifugation, settling/centrifugation, and backflush-filtration procedures have been tested for the concentration of suspended sediment from water for subsequent trace-metal analysis. Either of the first two procedures is comparable with in-line filtration and can be carried out precisely, accurately, and with a facility that makes the procedures amenable to large-scale sampling and analysis programs. There is less potential for post-sampling alteration of suspended sediment-associated metal concentrations with the centrifugation procedure because sample stabilization is accomplished more rapidly than with settling/centrifugation. Sample preservation can be achieved by chilling. Suspended sediment associated metal levels can best be determined by direct analysis but can also be estimated from the difference between a set of unfiltered-digested and filtered subsamples. However, when suspended sediment concentrations (<150 mg/L) or trace-metal levels are low, the direct analysis approach makes quantitation more accurate and precise and can be accomplished with simpler analytical procedures.

Passive sampling methods for contaminated sediments: State of the science for metals

PubMed Central

Peijnenburg, Willie JGM; Teasdale, Peter R; Reible, Danny; Mondon, Julie; Bennett, William W; Campbell, Peter GC

2014-01-01

“Dissolved” concentrations of contaminants in sediment porewater (Cfree) provide a more relevant exposure metric for risk assessment than do total concentrations. Passive sampling methods (PSMs) for estimating Cfree offer the potential for cost-efficient and accurate in situ characterization of Cfree for inorganic sediment contaminants. In contrast to the PSMs validated and applied for organic contaminants, the various passive sampling devices developed for metals, metalloids, and some nonmetals (collectively termed “metals”) have been exploited to a limited extent, despite recognized advantages that include low detection limits, detection of time-averaged trends, high spatial resolution, information about dissolved metal speciation, and the ability to capture episodic events and cyclic changes that may be missed by occasional grab sampling. We summarize the PSM approaches for assessing metal toxicity to, and bioaccumulation by, sediment-dwelling biota, including the recognized advantages and limitations of each approach, the need for standardization, and further work needed to facilitate broader acceptance and application of PSM-derived information by decision makers. Integr Environ Assess Manag 2014;10:179–196. © 2014 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC. Key Points Passive sampling methods (PSMs) offer the potential for cost-efficient and accurate in situ characterization of the dissolved concentrations for inorganic sediment contaminants. PSMs are useful for evaluating the geochemical behavior of metals in surficial sediments, including determination of fluxes across the sediment-water interface, and post-depositional changes in metal speciation. Few studies have tried to link PSM responses in sediments to metal uptake and toxicity responses in benthic organisms. There is a clear need for further studies. Future PSMs could be designed to mimic saturable kinetics, which would fill the gap between the kinetic and the equilibrium regime samplers currently used, and may improve prediction of metals accumulation by benthic organisms. PMID:24470168

Integrating Uncertainty Analysis in the Risk Characterization of In-Place Remedial Strategies for Contaminated Sediments

DTIC Science & Technology

2009-03-01

sediment. The plastic limit for the samples tested averaged to 43.4 percent while the liquid limit was 77.7 percent. As discussed above, the sediment...sediment from the drums, clean it of debris such as plastic , clam shells, sticks, etc., mix to a density to be maintained consistently among all... pollutant loading to aquatic ecosystems has decreased in the past decades, contaminated sediments have shifted from a sink to a potential source of

Toxicity of sediments potentially contaminated by coal mining and natural gas extraction to unionid mussels and commonly tested benthic invertebrates

USGS Publications Warehouse

Wang, Ning; Ingersoll, Christopher G.; Kunz, James L.; Brumbaugh, William G.; Kane, Cindy M.; Evans, R. Brian; Alexander, Steven; Walker, Craig; Bakaletz, Steve

2013-01-01

Sediment toxicity tests were conducted to assess potential effects of contaminants associated with coal mining or natural gas extraction activities in the upper Tennessee River basin and eastern Cumberland River basin in the United States. Test species included two unionid mussels (rainbow mussel, Villosa iris, and wavy-rayed lampmussel, Lampsilis fasciola, 28-d exposures), and the commonly tested amphipod, Hyalella azteca (28-d exposure) and midge, Chironomus dilutus (10-d exposure). Sediments were collected from seven test sites with mussel communities classified as impacted and in proximity to coal mining or gas extraction activities, and from five reference sites with mussel communities classified as not impacted and no or limited coal mining or gas extraction activities. Additional samples were collected from six test sites potentially with high concentrations of polycyclic aromatic hydrocarbons (PAHs) and from a test site contaminated by a coal ash spill. Mean survival, length, or biomass of one or more test species was reduced in 10 of 14 test samples (71%) from impacted areas relative to the response of organisms in the five reference samples. A higher proportion of samples was classified as toxic to mussels (63% for rainbow mussels, 50% for wavy-rayed lampmussels) compared with amphipods (38%) or midge (38%). Concentrations of total recoverable metals and total PAHs in sediments did not exceed effects-based probable effect concentrations (PECs). However, the survival, length, or biomasses of the mussels were reduced significantly with increasing PEC quotients for metals and for total PAHs, or with increasing sum equilibrium-partitioning sediment benchmark toxic units for PAHs. The growth of the rainbow mussel also significantly decreased with increasing concentrations of a major anion (chloride) and major cations (calcium and magnesium) in sediment pore water. Results of the present study indicated that (1) the findings from laboratory tests were generally consistent with the field observations of impacts on mussel populations; (2) total recoverable metals, PAHs, or major ions, or all three in sediments might have contributed to the sediment toxicity; (3) the mussels were more sensitive to the contaminants in sediments than the commonly tested amphipod and midge; and (4) a sediment toxicity benchmark of 1.0 based on PECs may not be protective of mussels.

[Sources, pollution statue and potential ecological risk of heavy metals in surface sediments of Aibi Lake, Northwest China].

PubMed

Zhang, Zhao-Yong; Abuduwaili, Jilili; Jiang, Feng-Qing

2015-02-01

In this paper, the surface sediment samples were harvested from Aibi Lake, and total contents of 8 heavy metals ( Cu, Pb, Zn, As, Hg, Cr, Ni and Cd) were determined. Then the sources, pollution statue, and potential ecological risk were analyzed by using multiple analysis methods. The results show that: (1) The order of the skewness for these 8 heavy metals is: Hg > Cd > Pb > Zn > As > Cu > Cr > Ni. (2) Multivariate statistical analysis shows that 8 heavy metals can be classified to 2 principle components, among which PC1 ( Cd, Pb, Hg and Zn) is man-made source factor and mainly came from all kinds of waste of agriculture; PC2 ( Cu, Ni, Cr and As) is natural source and was mainly controlled by the background of the natural geography of this area. (3) Accumulation of index evaluation results show that the order of pollution degree values of 8 heavy metals in surface sediments of Aibi Lake is: Cd > Hg > Pb > Zn > As > Cu > Ni > Cr. In all samples, heavy metals Hg, Cd and Pb all belong to low and partial moderate pollution statue, while Zn, As, Cr, Ni and Cu belong to no pollution statue in majority samples. (4) Potential ecological risk assessment results show that the potential ecological risk of heavy metals in surface sediments of Aibi Lake mainly caused by Cd, Hg and Pb, and they accounting for 42.6%, 28.6% and 24.0% of the total amount, respectively, among which Cd is the main ecological risk factor, followed by Hg and Pb. In all samples, the potential ecological risk index values (RI) of 8 heavy metals are all lower than 150, and they are all at low ecological risk levels. However, this research also shows that there have high content of Cd and Pb in the sediment. Therefore, we should make long-term monitoring of the lake environment.

300 Area process trench sediment analysis report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zimmerman, M.G.; Kossik, C.D.

1987-12-01

This report describes the results of a sampling program for the sediments underlying the Process Trenches serving the 300 Area on the Hanford reservation. These Process Trenches were the subject of a Closure Plan submitted to the Washington State Department of Ecology and to the US Environmental Protection Agency in lieu of a Part B permit application on November 8, 1985. The closure plan described a proposed sampling plan for the underlying sediments and potential remedial actions to be determined by the sample analyses results. The results and proposed remedial action plan are presented and discussed in this report. 50more » refs., 6 figs., 8 tabs.« less

Assessing the Potential for Sediment Gravity-Driven Underflows at the Currently Active Mouth of the Huanghe Delta

NASA Astrophysics Data System (ADS)

Mullane, M.; Kumpf, L. L.; Kineke, G. C.

2017-12-01

The Huanghe (Yellow River), once known for extremely high suspended-sediment concentrations (SSCs) that could produce hyperpycnal plumes (10s of g/l), has experienced a dramatic reduction in sediment load following the construction of several reservoirs, namely the Xiaolangdi reservoir completed in 1999. Except for managed flushing events, SSC in the lower river is now on the order of 1 g/l or less. Adaptations of the Chezy equation for gravity-driven transport show that dominant parameters driving hyperpycnal underflows include concentration (and therefore density), thickness of a sediment-laden layer and bed slope. The objectives of this research were to assess the potential for gravity-driven underflows given modern conditions at the active river mouth. Multiple shore-normal transects were conducted during research cruises in mid-July of 2016 and 2017 using a Knudsen dual-frequency echosounder to collect bathymetric data and to document the potential presence of fluid mud layers. An instrumented profiling tripod equipped with a CTD, optical backscatterance sensor and in-situ pump system were used to sample water column parameters. SSCs were determined from near-bottom and surface water samples. Echosounder data were analyzed for bed slopes at the delta-front and differences in depth of return for the two frequencies (50 and 200 kHz), which could indicate fluid muds. Bathymetric data analysis yielded bed slope measurements near or above threshold values to produce gravity-driven underflows (0.46°). The maximum observed thickness of a potential fluid mud layer was 0.7 m, and the highest sampled near-bed SSCs were nearly 14 g/l for both field campaigns. These results indicate that the modern delta maintains potential for sediment gravity-driven underflows, even during ambient conditions prior to maximum summer discharge. These results will inform future work quantitatively comparing the contributions of all sediment dispersal mechanisms near the active Huanghe delta environment, including advection of the buoyant river plume and wave resuspension and transport by tidal currents.

Organic Carbon Release from Groundwater Sediments under Changing Geochemical Conditions

NASA Astrophysics Data System (ADS)

Tinnacher, R. M.; Bhattacharyya, A.; Fox, P. M.; Nico, P. S.

2016-12-01

Due to climate change, local weather patterns are expected to change, especially with respect to precipitation, the frequency of extreme storm water events, and `drought-like' conditions. This in turn, may affect groundwater recharge, the geochemical conditions in natural groundwater systems, and the chemical and microbiological processes involved in organic matter degradation. Besides the complexity of organic matter structures and local limitations in nutrients, the association of organic carbon with sediment minerals can strongly limit organic matter bioaccessability and degradability. In this study, we investigate how variations in groundwater chemistry, e.g. with respect to dissolved CO2 concentrations, may potentially affect the release of natural organic carbon from groundwater sediments, and render organic matter more bioaccessible. In lab-scale experiments under anaerobic conditions, aquifer sediments from the floodplain of the Colorado River (Rifle, USA) were brought into contact with fresh, organic-carbon free groundwater solutions, at natural or reduced CO2 concentration levels. During the repeated exchange of solutions at two temperature settings (room-temperature and 4 °C), supernatant solutions were characterized in terms of pH, dissolved metal and organic carbon (OC) concentrations, and potential changes in released OC characteristics. Sediment samples were evaluated for possible differences in Fe-speciation before and after the experiment based on EXAFS (bulk Fe K-edge). Preliminary results for 20 exchanges of groundwater solutions show a repeated release of low OC concentrations ( 0.5-2 mg OC/g sediment; 0.05-0.2% of sediment-associated OC) without any apparent depletion in the overall source term over 50 days. After 14 days, room-temperature samples released slightly higher OC concentrations than samples kept at 4 °C. An increase in solution pH, after switching to a `CO2-free' groundwater solution, did not trigger a higher OC release. Last, specific UV absorbance measurements for room-temperature samples suggest changes in released OC characteristics due to repeated solution exchanges. Additional sample characterization is ongoing, with the goal to elucidate potential changes in released OC characteristics over the course of the experiment.

Evaluation of toxicity to the amphipod, Hyalella azteca, and to the midge, Chironomus dilutus; and bioaccumulation by the oligochaete, Lumbriculus variegatus, with exposure to PCB-contaminated sediments from Anniston, Alabama

USGS Publications Warehouse

Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.; Brumbaugh, William G.; Coady, Matthew R.; Farrar, J. Daniel; Lotufo, Guilherme R.; Kemble, Nile E.; Kunz, James L.; Stanley, Jacob K.; Sinclair, Jesse A.; Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.

2014-01-01

The U.S. Environmental Protection Agency (USEPA) requested that as part of the remedial investigation for the Anniston, Alabama Polychlorinated Biphenyl (PCB) Site (Anniston PCB Site), that Pharmacia Corporation and Solutia Inc. (P/S) perform long-term reproduction toxicity tests with the amphipod, Hyalella azteca, and the midge, Chironomus dilutus, and bioaccumulation tests with the oligochaete, Lumbriculus variegatus, using sediment samples collected from reference locations and from Operable Unit 4 of the Anniston PCB Site. The sediment toxicity testing and sediment bioaccumulation results will be used by ARCADIS U.S., Inc. (ARCADIS) as part of a weight-of-evidence assessment to evaluate risks and establish sediment remediation goals for contaminants to sediment-dwelling organisms inhabiting the Anniston PCB Site. The goal of this study was to characterize relations between sediment chemistry and sediment toxicity and relations between sediment chemistry and sediment bioaccumulation in samples of sediments collected from the Anniston PCB Site. A total of 32 samples were evaluated from six test sites and one reference site to provide a wide range in concentrations of chemicals of potential concern (COPCs) including PCBs in samples of whole sediment. The goal of this study was not to determine the extent of sediment contamination across the Anniston PCB Site. Hence, the test sites or samples collected from within a test site were not selected to represent the spatial extent of sediment contamination across the Anniston PCB Site. Sediment chemistry, pore-water chemistry, and sediment toxicity data were generated for 26 sediment samples from the Anniston PCB Site. All of the samples were evaluated to determine if they qualified as reference sediment samples. Those samples that met the chemical selection criteria and biological selection criteria were identified as reference samples and used to develop the reference envelope for each toxicity test endpoint. Physical characterization of samples of whole sediment included analyses of grain size, TOC, and nutrients. Organic chemical characterization of samples of whole sediment included PCB homologs and select (13) PCB congeners, parent and alkylated polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, and polychlorinated dibenzo-p-dioxins; and dibenzofurans. The PCB aroclors analyzed included 1016, 1221, 1232, 1242, 1248, 1254, 1260, 1262 and 1268. Analyses of whole sediment also included total metals, simultaneously extracted metals, and acid volatile sulfide. Chemical characterization of samples of pore water isolated from samples of whole sediment at the start of the sediment toxicity exposures or at the start of the sediment bioaccumulation exposures included metals, major cations, major anions, dissolved organic carbon, and additional water-quality characteristics. Concentrations of metals or PCBs in pore water during the sediment toxicity exposures or during sediment bioaccumulation exposures also were determined using peeper samples (for metals) or solid-phase microextraction (SPME) samplers (for PCBs). The bioavailability and bioaccumulation of PCBs in 14 sediment samples were investigated using SPME passive samplers and the 28-d L. variegatus whole-sediment bioaccumulation exposures In general the accumulation of PCBs consistently was predicted through the use of organic carbon normalization and equilibrium partitioning. In these sediments, PCB homologs were accumulated differently based on bioavailability and potential to accumulate in oligochaetes. As part of this assessment homolog specific biota sediment accumulation factor values were developed that could be applied across the larger site to predict tissue levels of PCBs. The whole-sediment toxicity tests done with H. azteca and C. dilutus met the established ASTM and USEPA test acceptability criteria. The most responsive H. azteca endpoints were day 42 survival normalized young per female and day 28 biomass and that the most responsive C. dilutus endpoints were adult biomass and percent adult emergence. Overall, between the two species, the most responsive endpoint assessed for these two species was H. azteca survival-normalized young per female (67 percent of the samples classified as toxic). Concentration-response models (CRMs) and site-specific sediment toxicity thresholds (TTs) were generated with matching sediment chemistry and sediment toxicity data. Sediment chemistry, pore-water chemistry, and sediment toxicity data were evaluated for as many as 26 sediment samples from the Anniston PCB Site. The reference-envelope approach was used to identify the sediment samples that were toxic to benthic invertebrates. This procedure involved identification of reference sediment samples, normalizing the toxicity data to reflect control responses, developing a reference envelope for each toxicity test endpoint, and designating each sediment sample as toxic or not toxic for each toxicity test endpoint, for each species, and for all species combined. These results demonstrated percent emergence of adult C. dilutus, biomass of adult C. dilutus, and reproduction of H. azteca normalized to percent survival were among the most responsive endpoints that were evaluated. Therefore, these endpoints were selected for CRM development. The site-specific TTs for whole sediment provide a reliable basis for identifying toxic and not toxic sediment samples in the Anniston PCB Site (that is, for correctly classifying the sediment samples used to derive the TTs as toxic or not toxic, for the endpoint used to derive the TTs). Among the 69 TTs for sediment, the TTLRs for total PCB homologs [499 to 1,870 micrograms per kilogram dry weight (μg/kg DW)] and for lead [(9.48 to 10.3 milligrams per kilogram (mg/kg) DW] based on reproduction of H. azteca or based on emergence or biomass of adult C. dilutus, were the most reliable. Such TTs had low rates of false negative errors (that is, only 0 to 11 percent of the samples below the TT were toxic to benthic invertebrates), low rates of false positive errors (only 0 to 6 percent of the samples greater than the TT were not toxic to benthic invertebrates), and high rates of correct classification (that is, 92 to 96 percent). The site-specific TTs for PCBs and other COPCs derived in this study also were compared to empirically based sediment quality guidelines (SQGs), to equilibrium-partitioning based SQGs, and to the results of spiked-sediment toxicity tests. The results of this evaluation indicated that the site-specific sediment TTs for PCBs were comparable to the consensus-based SQGs that were derived for PCBs. In addition, the site-specific sediment TTs for PCBs are well within the range of SQGs derived using the equilibrium partitioning approach. The site-specific sediment TTs for PCBs also are consistent with the results of chronic TTs that have been estimated for benthic invertebrates using the results of spiked-sediment toxicity tests. As the site-specific sediment TTs for PCBs are consistent with empirically based SQGs, equilibrium-partitioning based SQGs, and results of sediment-spiking studies, these site- specific sediment TTs likely represent the concentrations of PCBs that are sufficient to cause toxicity to benthic invertebrates (as opposed to simply being correlated with adverse effects on the survival, weight, or reproduction of benthic invertebrates). Importantly, such site-specific sediment TTs have been demonstrated to accurately classify sediment samples as toxic or not toxic to benthic invertebrates at the Anniston PCB Site. In contrast, the TTs for metals, PAHs, and organochlorine pesticides were generally lower than consensus-based SQGs (that is, probable effect concentrations), and LC50s (median lethal effect concentrations) generated in spiked-sediment toxicity tests, indicating that these COPCs are likely not the main contributors to the observed toxicity of the site sediments evaluated in this study. The reproduction endpoint for H. azteca provided lower TTs compared to the day 28 biomass endpoint for H. azteca and the emergence or biomass endpoints for adult C. dilutus provided lower TTs compared to the day 13 biomass endpoint for C. dilutus.

Passive sampling methods for contaminated sediments: Scientific rationale supporting use of freely dissolved concentrations

PubMed Central

Mayer, Philipp; Parkerton, Thomas F; Adams, Rachel G; Cargill, John G; Gan, Jay; Gouin, Todd; Gschwend, Philip M; Hawthorne, Steven B; Helm, Paul; Witt, Gesine; You, Jing; Escher, Beate I

2014-01-01

Passive sampling methods (PSMs) allow the quantification of the freely dissolved concentration (Cfree) of an organic contaminant even in complex matrices such as sediments. Cfree is directly related to a contaminant's chemical activity, which drives spontaneous processes including diffusive uptake into benthic organisms and exchange with the overlying water column. Consequently, Cfree provides a more relevant dose metric than total sediment concentration. Recent developments in PSMs have significantly improved our ability to reliably measure even very low levels of Cfree. Application of PSMs in sediments is preferably conducted in the equilibrium regime, where freely dissolved concentrations in the sediment are well-linked to the measured concentration in the sampler via analyte-specific partition ratios. The equilibrium condition can then be assured by measuring a time series or a single time point using passive samplers with different surface to volume ratios. Sampling in the kinetic regime is also possible and generally involves the application of performance reference compounds for the calibration. Based on previous research on hydrophobic organic contaminants, it is concluded that Cfree allows a direct assessment of 1) contaminant exchange and equilibrium status between sediment and overlying water, 2) benthic bioaccumulation, and 3) potential toxicity to benthic organisms. Thus, the use of PSMs to measure Cfree provides an improved basis for the mechanistic understanding of fate and transport processes in sediments and has the potential to significantly improve risk assessment and management of contaminated sediments. Integr Environ Assess Manag 2014;10:197–209. © 2014 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC. PMID:24288295

Using sediment particle size distribution to evaluate sediment sources in the Tobacco Creek Watershed

NASA Astrophysics Data System (ADS)

Liu, Cenwei; Lobb, David; Li, Sheng; Owens, Philip; Kuzyk, ZouZou

2014-05-01

Lake Winnipeg has recently brought attention to the deteriorated water quality due to in part to nutrient and sediment input from agricultural land. Improving water quality in Lake Winnipeg requires the knowledge of the sediment sources within this ecosystem. There are a variety of environmental fingerprinting techniques have been successfully used in the assessment of sediment sources. In this study, we used particle size distribution to evaluate spatial and temporal variations of suspended sediment and potential sediment sources collected in the Tobacco Creek Watershed in Manitoba, Canada. The particle size distribution of suspended sediment can reflect the origin of sediment and processes during sediment transport, deposition and remobilization within the watershed. The objectives of this study were to quantify visually observed spatial and temporal changes in sediment particles, and to assess the sediment source using a rapid and cost-effective fingerprinting technique based on particle size distribution. The suspended sediment was collected by sediment traps twice a year during rainfall and snowmelt periods from 2009 to 2012. The potential sediment sources included the top soil of cultivated field, riparian area and entire profile from stream banks. Suspended sediment and soil samples were pre-wet with RO water and sieved through 600 μm sieve before analyzing. Particle size distribution of all samples was determined using a Malvern Mastersizer 2000S laser diffraction with the measurement range up to 600μm. Comparison of the results for different fractions of sediment showed significant difference in particle size distribution of suspended sediment between snowmelt and rainfall events. An important difference of particle size distribution also found between the cultivated soil and forest soil. This difference can be explained by different land uses which provided a distinct fingerprint of sediment. An overall improvement in water quality can be achieved by managing sediment according to the identified sediment sources in the watershed.

Heavy metals pollution status in surface sediments (rivers and artifical lakes, Serbia)

NASA Astrophysics Data System (ADS)

Sakan, Sanja; Đorđević, Dragana

2017-04-01

Potentially hazardous trace elements, often in literature referred as "heavy metals", are deemed serious pollutants due to their toxicity, persistence and non-degradability in the environment. These elements play an important role in extent of water pollution and threaten the health of populations and ecosystems. As the sink of heavy metals, sediment beds adsorb metals in quantities that are many times higher than those found in the water column in the long-term polluted water environment. It is believed that most of the metal content, as much as 90% in aquatic sediments is bound to sediments. Metal contamination in these sediments could be directly affect the river water quality, resulting in potential consequences to the sensitive lowest levels of the food chain and ultimately to human health. The objective of this research was the evaluation of heavy metal contamination level in sediments of the most important rivers and artificial lakes in Serbia. The heavy metal enrichment in studied sediments was conducted by using: determination of total metal content, sequential extraction procedure for the fractionation of studied elements, quantification of the metal enrichment degree in the sediments by calculating geo-accumulation indices, determination of actual and potential element availability and application of BRAI index for the assessment of heavy metal bioavailability. The sediments were found to be contaminated by heavy metals to various extents, mostly with Cd, Cu, and Zn. The significant variation in heavy metal distribution among samples collected in this large region, encompassing all Serbian watersheds, suggests the selective contamination of sediments by heavy metals. Elevated concentrations of elements in most cases were detected in samples of river sediments, since artificial lake reservoirs are usually built in rural areas, where the less anthropogenic pollution. Rivers often flow through the towns and these water basins less or more loaded micronutrients, toxic substances, organic or inorganic, waste materials, depending on the species and type of industrial processes that are often without the necessary technological and mandatory treatment directly discharged into them. Due to the potential risk of heavy metal pollution in studied sediments, pollution prevention and control measurements seems necessary, especially in areas where we found increased levels of these elements.

Integrating Passive Sampling Methods into Management of Contaminated Sediment Sites: A Guide for Department of Defense Remedial Project Managers

DTIC Science & Technology

2016-04-01

concentration and toxicity to invertebrates (Kreitinger et al. 2007). Bulk contaminant sediment measurements do not reveal the differences across...feed on fish and invertebrates , while others can affect wildlife through direct contact or ingestion; regardless, both effects are influenced by and...sediment management. PAHs are risk drivers primarily because of the potential for adverse effects on benthic invertebrates and sediment-associated fish

Assessing potential removal of low-head dams in urban settings: an example from the Ottawa River, NW Ohio.

PubMed

Roberts, Sheila J; Gottgens, Johan F; Spongberg, Alison L; Evans, James E; Levine, Norman S

2007-01-01

This is a study of the scientific component of an effort to restore an urban river by removing a low-head dam. The Secor Dam is owned by a local government entity near Toledo, Ohio. The proposed removal of the last structure impeding flow on the Ottawa River has broad appeal, but the owner is concerned about liability issues, particularly potential changes to the flood regime, the presence of contaminated sediments behind the dam, and possible downstream transport of reservoir sediments. Assessing sediment contamination involved sediment sampling and analysis of trace metals and organic contaminants. Forecasting sediment transport involved field methods to determine the volume and textural properties of reservoir and upstream sediment and calculations to determine the fate of reservoir sediments. Forecasting changes in the flood regime involved HEC-RAS hydrological models to determine before and after dam removal flood scenarios using LiDAR data imported into an ArcGIS database. The resulting assessment found potential sediment contamination to be minor, and modeling showed that the removal of the dam would have minimal impacts on sediment transport and flood hazards. Based on the assessment, the removal of the dam has been approved by its owners.

High resolution microprofiling, fractionation and speciation at sediment water interfaces

NASA Astrophysics Data System (ADS)

Fabricius, Anne-Lena; Duester, Lars; Ecker, Dennis; Ternes, Thomas A.

2016-04-01

Within aquatic environments, the exchange between the sediment and the overlaying water is often driven by steep gradients of, e.g., the oxygen concentration, the redox potential or the pH value at the sediment water interface (SWI). Important transport processes at the SWI are sedimentation and resuspension of particulate matter and diffusional fluxes of dissolved substances. To gain a better understanding of the key factors and processes determining the fate of substances at the SWI, methods with a spatial high resolution are required that enable the investigation of several sediment parameters in parallel to different analytes of interest in the sediment pore water. Moreover, beside the total content, questions concerning the speciation and fractionation are of concern in studying the different (transport) processes. Due to the availability of numerous micro-sensors and -electrodes (e.g., O2, redox potential, pH value, H2S, N2O) and the development of methods for pore water sampling [1], the toolbox to study the heterogeneous and often dynamic conditions at the SWI at a sub-millimetre scale were considerably improved. Nevertheless, the methods available for pore water sampling often require the installation of the sampling devices at the sampling site and/or intensive preparation procedures that may influence the conditions at the area studied and/or the characteristics of the samples taken. By combination of a micro profiling system with a new micro filtration probe head connected to a pump and a fraction collector, a micro profiling and micro sampling system ("missy") was developed that enables for the first time a direct, automate and low invasive sampling of small volumes (<500 μL) at a spatial high resolution of a few millimetres to sub-millimetres [2]. Via the application of different sample preparation procedures followed by inductively plasma-mass spectrometry analyses, it was possible to address not only the total content of metal(loid)s, but also their fractionation (size dependent and micelle mediated) or speciation related distributions along sediment depth profiles in parallel to different sediment parameters (O2, redox and pH). Together with the results of missy-experiments, the results of different experimental approaches will be given and discussed, especially with regard to their potentials and limitations. Based on application examples it will be demonstrated how a variety of parameters can be studied in parallel with the aim to get a more holistic understanding of natural and anthropogenic caused processes that govern the fate of substances at the SWI. 1. Stockdale, A., W. Davison, and H. Zhang, Micro-scale biogeochemical heterogeneity in sediments: A review of available technology and observed evidence. Earth-Science Reviews, 2009. 92(1-2): p. 81-97. 2. Fabricius, A.-L., et al., New Microprofiling and Micro Sampling System for Water Saturated Environmental Boundary Layers. Environmental Science & Technology, 2014.

Community genomic analyses constrain the distribution of metabolic traits across the Chloroflexi phylum and indicate roles in sediment carbon cycling

PubMed Central

2013-01-01

Background Sediments are massive reservoirs of carbon compounds and host a large fraction of microbial life. Microorganisms within terrestrial aquifer sediments control buried organic carbon turnover, degrade organic contaminants, and impact drinking water quality. Recent 16S rRNA gene profiling indicates that members of the bacterial phylum Chloroflexi are common in sediment. Only the role of the class Dehalococcoidia, which degrade halogenated solvents, is well understood. Genomic sampling is available for only six of the approximate 30 Chloroflexi classes, so little is known about the phylogenetic distribution of reductive dehalogenation or about the broader metabolic characteristics of Chloroflexi in sediment. Results We used metagenomics to directly evaluate the metabolic potential and diversity of Chloroflexi in aquifer sediments. We sampled genomic sequence from 86 Chloroflexi representing 15 distinct lineages, including members of eight classes previously characterized only by 16S rRNA sequences. Unlike in the Dehalococcoidia, genes for organohalide respiration are rare within the Chloroflexi genomes sampled here. Near-complete genomes were reconstructed for three Chloroflexi. One, a member of an unsequenced lineage in the Anaerolinea, is an aerobe with the potential for respiring diverse carbon compounds. The others represent two genomically unsampled classes sibling to the Dehalococcoidia, and are anaerobes likely involved in sugar and plant-derived-compound degradation to acetate. Both fix CO2 via the Wood-Ljungdahl pathway, a pathway not previously documented in Chloroflexi. The genomes each encode unique traits apparently acquired from Archaea, including mechanisms of motility and ATP synthesis. Conclusions Chloroflexi in the aquifer sediments are abundant and highly diverse. Genomic analyses provide new evolutionary boundaries for obligate organohalide respiration. We expand the potential roles of Chloroflexi in sediment carbon cycling beyond organohalide respiration to include respiration of sugars, fermentation, CO2 fixation, and acetogenesis with ATP formation by substrate-level phosphorylation. PMID:24450983

Sediment and water chemistry of the San Juan River and Escalante River deltas of Lake Powell, Utah, 2010-2011

USGS Publications Warehouse

Hornewer, Nancy J.

2014-01-01

Recent studies have documented the presence of trace elements, organic compounds including polycyclic aromatic hydrocarbons, and radionuclides in sediment from the Colorado River delta and from sediment in some side canyons in Lake Powell, Utah and Arizona. The fate of many of these contaminants is of significant concern to the resource managers of the National Park Service Glen Canyon National Recreation Area because of potential health impacts to humans and aquatic and terrestrial species. In 2010, the U.S. Geological Survey began a sediment-core sampling and analysis program in the San Juan River and Escalante River deltas in Lake Powell, Utah, to help the National Park Service further document the presence or absence of contaminants in deltaic sediment. Three sediment cores were collected from the San Juan River delta in August 2010 and three sediment cores and an additional replicate core were collected from the Escalante River delta in September 2011. Sediment from the cores was subsampled and composited for analysis of major and trace elements. Fifty-five major and trace elements were analyzed in 116 subsamples and 7 composited samples for the San Juan River delta cores, and in 75 subsamples and 9 composited samples for the Escalante River delta cores. Six composited sediment samples from the San Juan River delta cores and eight from the Escalante River delta cores also were analyzed for 55 low-level organochlorine pesticides and polychlorinated biphenyls, 61 polycyclic aromatic hydrocarbon compounds, gross alpha and gross beta radionuclides, and sediment-particle size. Additionally, water samples were collected from the sediment-water interface overlying each of the three cores collected from the San Juan River and Escalante River deltas. Each water sample was analyzed for 57 major and trace elements. Most of the major and trace elements analyzed were detected at concentrations greater than reporting levels for the sediment-core subsamples and composited samples. Low-level organochlorine pesticides and polychlorinated biphenyls were not detected in any of the samples. Only one polycyclic aromatic hydrocarbon compound was detected at a concentration greater than the reporting level for one San Juan composited sample. Gross alpha and gross beta radionuclides were detected at concentrations greater than reporting levels for all samples. Most of the major and trace elements analyzed were detected at concentrations greater than reporting levels for water samples.

A continuously weighing, high frequency sand trap: Wind tunnel and field evaluations

NASA Astrophysics Data System (ADS)

Yang, Fan; Yang, XingHua; Huo, Wen; Ali, Mamtimin; Zheng, XinQian; Zhou, ChengLong; He, Qing

2017-09-01

A new continuously weighing, high frequency sand trap (CWHF) has been designed. Its sampling efficiency is evaluated in a wind tunnel and the potential of the new trap has been demonstrated in field trials. The newly designed sand trap allows fully automated and high frequency measurement of sediment fluxes over extensive periods. We show that it can capture the variations and structures of wind-driven sand transport processes and horizontal sediment flux, and reveal the relationships between sand transport and meteorological parameters. Its maximum sampling frequency can reach 10 Hz. Wind tunnel tests indicated that the sampling efficiency of the CWHF sand trap varies between 39.2 to 64.3%, with an average of 52.5%. It achieved a maximum sampling efficiency of 64.3% at a wind speed of 10 m s- 1. This is largely achieved by the inclusion of a vent hole which leads to a higher sampling efficiency than that of a step-like sand trap at high wind speeds. In field experiments, we show a good agreement between the mass of sediment from the CWHF sand trap, the wind speed at 2 m and the number of saltating particles at 5 cm above the ground surface. According to analysis of the horizontal sediment flux at four heights from the CWHF sand trap (25, 35, 50, and 100 cm), the vertical distribution of the horizontal sediment flux up to a height of 100 cm above the sand surface follows an exponential function. Our field experiments show that the new instrument can capture more detailed information on sediment transport with much reduced labor requirement. Therefore, it has great potential for application in wind-blown sand monitoring and process studies.

Importance of background values in assessing the impact of heavy metals in river ecosystems: case study of Tisza River, Serbia.

PubMed

Štrbac, Snežana; Kašanin Grubin, Milica; Vasić, Nebojša

2017-11-30

The main objective of this paper is to evaluate how a choice of different background values may affect assessing the anthropogenic heavy metal pollution in sediments from Tisza River (Serbia). The second objective of this paper is to underline significance of using geochemical background values when establishing quality criteria for sediment. Enrichment factor (EF), geoaccumulation index (I geo ), pollution load index (PLI), and potential ecological risk index (PERI) were calculated using different background values. Three geochemical (average metal concentrations in continental crust, average metal concentrations in shale, and average metal concentrations in non-contaminated core sediment samples) and two statistical methods (delineation method and principal component analyses) were used for calculating background values. It can be concluded that obtained information of pollution status can be more dependent on the use of background values than the index/factor chosen. The best option to assess the potential river sediment contamination is to compare obtained concentrations of analyzed elements with concentrations of mineralogically and texturally comparable, uncontaminated core sediment samples. Geochemical background values should be taken into account when establishing quality criteria for soils, sediments, and waters. Due to complexity of the local lithology, it is recommended that environmental monitoring and assessment include selection of an appropriate background values to gain understanding of the geochemistry and potential source of pollution in a given environment.

Widespread occurrence and potential for biodegradation of bioactive contaminants in Congaree National Park, USA

USGS Publications Warehouse

Bradley, Paul M.; Battaglin, William A.; Clark, Jimmy M.; Henning, Frank; Hladik, Michelle L.; Iwanowicz, Luke R.; Journey, Celeste A.; Riley, Jeffrey W.; Romanok, Kristin

2017-01-01

Organic contaminants with designed molecular bioactivity, such as pesticides and pharmaceuticals, originate from human and agricultural sources, occur frequently in surface waters, and threaten the structure and function of aquatic and terrestrial ecosystems. Congaree National Park in South Carolina (USA) is a vulnerable park unit due to its location downstream of multiple urban and agricultural contaminant sources and its hydrologic setting, being composed almost entirely of floodplain and aquatic environments. Seventy-two water and sediment samples were collected from 16 sites in Congaree National Park during 2013 to 2015, and analyzed for 199 and 81 targeted organic contaminants, respectively. More than half of these water and sediment analytes were not detected or potentially had natural sources. Pharmaceutical contaminants were detected (49 total) frequently in water throughout Congaree National Park, with higher detection frequencies and concentrations at Congaree and Wateree River sites, downstream from major urban areas. Forty-seven organic wastewater indicator chemicals were detected in water, and 36 were detected in sediment, of which approximately half are distinctly anthropogenic. Endogenous sterols and hormones, which may originate from humans or wildlife, were detected in water and sediment samples throughout Congaree National Park, but synthetic hormones were detected only once, suggesting a comparatively low risk of adverse impacts. Assessment of the biodegradation potentials of 8 14C-radiolabeled model contaminants indicated poor potentials for some contaminants, particularly under anaerobic sediments conditions.

Analyzing legacy U.S. Geological Survey geochemical databases using GIS: applications for a national mineral resource assessment

USGS Publications Warehouse

Yager, Douglas B.; Hofstra, Albert H.; Granitto, Matthew

2012-01-01

This report emphasizes geographic information system analysis and the display of data stored in the legacy U.S. Geological Survey National Geochemical Database for use in mineral resource investigations. Geochemical analyses of soils, stream sediments, and rocks that are archived in the National Geochemical Database provide an extensive data source for investigating geochemical anomalies. A study area in the Egan Range of east-central Nevada was used to develop a geographic information system analysis methodology for two different geochemical datasets involving detailed (Bureau of Land Management Wilderness) and reconnaissance-scale (National Uranium Resource Evaluation) investigations. ArcGIS was used to analyze and thematically map geochemical information at point locations. Watershed-boundary datasets served as a geographic reference to relate potentially anomalous sample sites with hydrologic unit codes at varying scales. The National Hydrography Dataset was analyzed with Hydrography Event Management and ArcGIS Utility Network Analyst tools to delineate potential sediment-sample provenance along a stream network. These tools can be used to track potential upstream-sediment-contributing areas to a sample site. This methodology identifies geochemically anomalous sample sites, watersheds, and streams that could help focus mineral resource investigations in the field.

Sediment sources in a small agricultural catchment: A composite fingerprinting approach based on the selection of potential sources

NASA Astrophysics Data System (ADS)

Zhou, Huiping; Chang, Weina; Zhang, Longjiang

2016-08-01

Fingerprinting techniques have been widely used as a reasonable and reliable means for investigating sediment sources, especially in relatively large catchments in which there are significant differences in surface materials. However, the discrimination power of fingerprint properties for small catchments, in which the surface materials are relatively homogeneous and human interference is marked, may be affected by fragmentary or confused source information. Using fingerprinting techniques can be difficult, and there is still a need for further studies to verify the effectiveness of such techniques in these small catchments. A composite fingerprinting approach was used in this study to investigate the main sources of sediment output, as well as their relative contributions, from a small catchment (30 km2) with high levels of farming and mining activities. The impact of the selection of different potential sediment sources on the derivation of composite fingerprints and its discrimination power were also investigated by comparing the results from different combinations of potential source types. The initial source types and several samples that could cause confusion were adjusted. These adjustments improved the discrimination power of the composite fingerprints. The results showed that the composite fingerprinting approach used in this study had a discriminatory efficiency of 89.2% for different sediment sources and that the model had a mean goodness of fit of 0.90. Cultivated lands were the main sediment source. The sediment contribution of the studied cultivated lands ranged from 39.9% to 87.8%, with a mean of 76.6%, for multiple deposited sediment samples. The mean contribution of woodlands was 21.7%. Overall, the sediment contribution from mining and road areas was relatively low. The selection of potential sources is an important factor in the application of fingerprinting techniques and warrants more attention in future studies, as is the case with other uncertainty factors.

Biodegradation of 17β-estradiol, estrone, and testosterone in stream sediments

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.; Barber, L.B.; McMahon, P.B.; Gray, J.L.; Kolpin, D.W.

2009-01-01

The release of endocrine-disrupting chemicals (EDCs) in wastewater treatment plant (WWTP) effluent poses a significant threat to the ecology of surface water receptors, due to impacts on the hormonal control, sexual development, reproductive success and community structure of the indigenous aquatic organisms and associated wildlife. Among the EDCs commonly observed in WWTP effluent, the natural [e.g., 17??-estradiol (E2) and estrone (E1)] and synthetic [e.g., ethynylestradiol (EE2)] estrogens are particular concerns owing to their high endocrine reactivity in both in vitro and in vivo laboratory models. These reproductive hormones have been identified as the primary cause of estrogenic effects in wastewater effluent, with greater than 95% of the estrogen receptor agonist activity in effluent attributed to this contaminant group. The potentials for in situ biodegradation of 17??-estradiol (E2), estrone (E1), and testosterone (T) were investigated in three, hydrologically-distinct, WWTP-impacted streams in the United States. Relative differences in the mineralization of [4-14C] substrates were assessed in oxic microcosms containing sediment or water-only from locations upstream and downstream of the WWTP outfall in each system. Upstream samples provided insight into the biodegradative potential of sediment microbial communities that were not under the immediate impact of WWTP effluent. Upstream sediment from all three systems demonstrated significant mineralization of the "A" ring of E2, E1 and T, with the potential of T biodegradation consistently greater than of E2 and no systematic difference in the potentials of E2 and E1. Downstream samples provided insight into the impacts of effluent on reproductive hormone biodegradation. Significant "A" ring mineralization was also observed in downstream sediment, with the potentials for E1 and T mineralization being substantially depressed relative to upstream samples. In marked contrast, the potentials for E2 mineralization immediately downstream of the WWTP outfalls were more than double that of upstream samples. E2 mineralization was also observed in water, albeit at insufficient rate to prevent substantial downstream transport in the water column. The results of this study indicate that, in combination with sediment sorption processes which effectively scavenge hydrophobic contaminants from the water column and immobilize them in the vicinity of the WWTP outfall, aerobic biodegradation of reproductive hormones can be an environmentally important mechanism for nonconservative (destructive) attenuation of hormonal endocrine disruptors in effluent-impacted streams.

Linking hysteresis patterns and variations in suspended sediment sources in a highly urbanized river: a case of the River Aire, UK

NASA Astrophysics Data System (ADS)

Vercruysse, Kim; Grabowski, Robert

2017-04-01

The natural sediment balance of rivers is often disturbed as a result of increased fine sediment influx from soil erosion and/or modifications to the river channel and floodplains, causing numerous problems related to ecology, water quality, flood risk and infrastructure. It is of great importance to understand fine sediment dynamics in rivers in order to manage the problems appropriately. However, despite decades of research, our understanding of fine sediment transport is not yet sufficient to fully explain the spatial and temporal variability in sediment concentrations in rivers. To this end, the study aims to investigate the importance of sediment source variations to explain hysteresis patterns in suspended sediment transport. A sediment fingerprinting technique based on infrared spectrometry was applied in the highly urbanized River Aire catchment in northern England to identify the dominant sources of suspended sediment. Three types of potential sediment source samples were collected: soil samples from pasture in three lithological areas (limestone, millstone grit and coal measures), eroding riverbanks and urban street dust. All source samples were analyzed with Diffuse Reflectance Infrared Fourier Transform spectrometry (DRIFTS). Discriminant analysis demonstrated that the source materials could be discriminated based on their respective infrared spectra. Infrared spectra of experimental mixtures were then used to develop statistical models to estimate relative source contributions from suspended sediment samples. Suspended sediment samples were collected during a set of high flow events between 2015 and 2016, showing different hysteresis patterns between suspended sediment concentration and discharge. The fingerprinting results suggest that pasture from the limestone area is the dominant source of fine sediment. However, significant variations in source contributions during and between events are present. Small events, in terms of discharge, are marked by relatively high contributions of urban street dust, while high stream flows correspond with higher sediment contributions from riverbanks and pasture. Seasonal variations in the dominant sources are also present. The results emphasize the importance of capturing sediment source variations to gain better insights into the drivers of fine sediment transport over various timescales.

Final report for 105-N Basin sediment disposition task, phase 2 -- samples BOMPC8 and BOMPC9

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esch, R.A.

1998-02-05

This document is the final report deliverable for Phase 2 analytical work for the 105-N Basin Sediment Disposition Task. On December 23, 1997, ten samples were received at the 222-S Laboratory as follows: two (2) bottles of potable water, six (6) samples for process control testing and two (2) samples for characterization. Analyses were performed in accordance with the Letter of Instruction for Phase 2 Analytical Work for the 105-N Basin Sediment Disposition Task (Logan and Kessner, 1997) (Attachment 7) and 105-N Basin Sediment Disposition Phase-Two Sampling and Analysis Plan (SAP) (Smith, 1997). The analytical results are included in Tablemore » 1. This document provides the values of X/Qs for the onsite and offsite receptors, taking into account the building wake and the atmospheric stability effects. X/Qs values for the potential fire accident were also calculated. In addition, the unit dose were calculated for the mixtures of isotopes.« less

Hydrogeochemical assessment of mine-impacted water and sediment of iron ore mining

NASA Astrophysics Data System (ADS)

Nur Atirah Affandi, Fatin; Kusin, Faradiella Mohd; Aqilah Sulong, Nur; Madzin, Zafira

2018-04-01

This study was carried out to evaluate the hydrogeochemical behaviour of mine-impacted water and sediment of a former iron ore mining area. Sampling of mine water and sediment were carried out at selected locations within the mine including the former mining ponds, mine tailings and the nearby stream. The water samples were analysed for their hydrochemical facies, major and trace elements including heavy metals. The water in the mining ponds and the mine tailings was characterised as highly acidic (pH 2.54-3.07), but has near-neutral pH in the nearby stream. Results indicated that Fe and Mn in water have exceeded the recommended guidelines values and was also supported by the results of geochemical modelling. The results also indicated that sediments in the mining area were contaminated with Cd and As as shown by the potential ecological risk index values. The total risk index of heavy metals in the sediment were ranked in the order of Cd>As>Pb>Cu>Zn>Cr. Overall, the extent of potential ecological risks of the mining area were categorised as having low to moderate ecological risk.

Crushing of Subglacial Lake Sediment as a Source of Bio-utilisable Gases.

NASA Astrophysics Data System (ADS)

Gill Olivas, B.; Telling, J.; Michaud, A. B.; Skidmore, M. L.; Priscu, J. C.; Tranter, M.

2017-12-01

Recent research has shown microbial ecosystems exist under glaciers and ice sheets. The sources of energy to support these ecosystems are still not fully understood, particularly beneath the Antarctic Ice Sheet, where direct access to the atmosphere and in-washed organic matter and oxidising agents does not occur. Hence, sub-ice sheet energy sources are restricted to those in subglacial environments, except for ice-margin environments. This study focuses on sediments from Subglacial Lake Whillans (SLW), the first subglacial lake to be directly and cleanly sampled. Sediment from three depths in a shallow core extracted from SLW were used to assess the possible energy contributions from mechanochemical reactions to this subglacial ecosystem. To do this, the samples were crushed under an anoxic atmosphere using a ball mill. The sediments were then transferred into serum bottles under anoxic conditions. They were wetted and the headspace gas was subsequently sampled and analysed during a 40 day incubation. Results show the release of substantial amounts of hydrogen, which could potentially serve as an abiotic source of energy to microbes, in particular, methanogenic archaea. Significant amounts of short chain hydrocarbons (including methane and ethylene), possibly from the reactivation of ancient organic carbon, were also observed. Crushed samples showed a significant concentration of hydrogen peroxide produced on contact with water, as well as significant amounts of Si radicals, showing comminution of these sediments unlocks the potential for a wide range of redox conditions and reactions to develop within glacially eroded sediment under ice. This in turn provides a previously overlooked source of nutrients and energy for microbes to utilise.

MAHLI at the Rocknest sand shadow: Science and science-enabling activities

NASA Astrophysics Data System (ADS)

Minitti, M. E.; Kah, L. C.; Yingst, R. A.; Edgett, K. S.; Anderson, R. C.; Beegle, L. W.; Carsten, J. L.; Deen, R. G.; Goetz, W.; Hardgrove, C.; Harker, D. E.; Herkenhoff, K. E.; Hurowitz, J. A.; Jandura, L.; Kennedy, M. R.; Kocurek, G.; Krezoski, G. M.; Kuhn, S. R.; Limonadi, D.; Lipkaman, L.; Madsen, M. B.; Olson, T. S.; Robinson, M. L.; Rowland, S. K.; Rubin, D. M.; Seybold, C.; Schieber, J.; Schmidt, M.; Sumner, D. Y.; Tompkins, V. V.; Van Beek, J. K.; Van Beek, T.

2013-11-01

Martian solar days 57-100, the Mars Science Laboratory Curiosity rover acquired and processed a solid (sediment) sample and analyzed its mineralogy and geochemistry with the Chemistry and Mineralogy and Sample Analysis at Mars instruments. An aeolian deposit—herein referred to as the Rocknest sand shadow—was inferred to represent a global average soil composition and selected for study to facilitate integration of analytical results with observations from earlier missions. During first-time activities, the Mars Hand Lens Imager (MAHLI) was used to support both science and engineering activities related to sample assessment, collection, and delivery. Here we report on MAHLI activities that directly supported sample analysis and provide MAHLI observations regarding the grain-scale characteristics of the Rocknest sand shadow. MAHLI imaging confirms that the Rocknest sand shadow is one of a family of bimodal aeolian accumulations on Mars—similar to the coarse-grained ripples interrogated by the Mars Exploration Rovers Spirit and Opportunity—in which a surface veneer of coarse-grained sediment stabilizes predominantly fine-grained sediment of the deposit interior. The similarity in grain size distribution of these geographically disparate deposits support the widespread occurrence of bimodal aeolian transport on Mars. We suggest that preservation of bimodal aeolian deposits may be characteristic of regions of active deflation, where winnowing of the fine-sediment fraction results in a relatively low sediment load and a preferential increase in the coarse-grained fraction of the sediment load. The compositional similarity of Martian aeolian deposits supports the potential for global redistribution of fine-grained components, combined with potential local contributions.

Total and settling velocity-fractionated pollution potential of sewer sediments in Jiaxing, China.

PubMed

Zhou, Yongchao; Zhang, Ping; Zhang, Yiping; Li, Jin; Zhang, Tuqiao; Yu, Tingchao

2017-10-01

Sewer sediments and their associated contaminant released along with wet-weather discharges pose potential pollution risks to environment. This paper presents total characteristics of sediments collected from Jiaxing, China. Size distribution and concentrations of volatile solids (VS) and four metals (Pb, Cu, Zn, Cr) of sediment samples from seven land use categories were analyzed. Then, the sediment samples were graded five fractions according to its settling velocity through the custom-built settling velocity-grading device. Sediment mass and pollution load distribution based on settling velocity were also assessed. The results show that there are relatively high level of heavy metal load in the sediment of separated storm drainage systems in Jiaxing, especially for the catchment of residential area (RA), road of developed area (RDA), and industrial area (IA). Although grain size follows a trend of increasing along with settling velocity, the methods of settling velocity grading are meaningful for stormwater treatment facilities with precipitation. For all land use categories, the pollution concentrations of the three lower settling velocity-fractionated sediment are relatively consistent and higher than others. Combined with mass distribution, the pollution percentage of fraction with different velocities for seven land use categories were also evaluated. Based on it, the statistical conclusion of design target settling velocity to different pollution load removal rates are drawn, which is helpful to guide design of on-site precipitation separation facilities.

Equilibrium sampling to determine the thermodynamic potential for bioaccumulation of persistent organic pollutants from sediment.

PubMed

Jahnke, Annika; MacLeod, Matthew; Wickström, Håkan; Mayer, Philipp

2014-10-07

Equilibrium partitioning (EqP) theory is currently the most widely used approach for linking sediment pollution by persistent hydrophobic organic chemicals to bioaccumulation. Most applications of the EqP approach assume (I) a generic relationship between organic carbon-normalized chemical concentrations in sediments and lipid-normalized concentrations in biota and (II) that bioaccumulation does not induce levels exceeding those expected from equilibrium partitioning. Here, we demonstrate that assumption I can be obviated by equilibrating a silicone sampler with chemicals in sediment, measuring chemical concentrations in the silicone, and applying lipid/silicone partition ratios to yield concentrations in lipid at thermodynamic equilibrium with the sediment (CLip⇌Sed). Furthermore, we evaluated the validity of assumption II by comparing CLip⇌Sed of selected persistent, bioaccumulative and toxic pollutants (polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB)) to lipid-normalized concentrations for a range of biota from a Swedish background lake. PCBs in duck mussels, roach, eel, pikeperch, perch and pike were mostly below the equilibrium partitioning level relative to the sediment, i.e., lipid-normalized concentrations were ≤CLip⇌Sed, whereas HCB was near equilibrium between biota and sediment. Equilibrium sampling allows straightforward, sensitive and precise measurement of CLip⇌Sed. We propose CLip⇌Sed as a metric of the thermodynamic potential for bioaccumulation of persistent organic chemicals from sediment useful to prioritize management actions to remediate contaminated sites.

Comparing geological and statistical approaches for element selection in sediment tracing research

NASA Astrophysics Data System (ADS)

Laceby, J. Patrick; McMahon, Joe; Evrard, Olivier; Olley, Jon

2015-04-01

Elevated suspended sediment loads reduce reservoir capacity and significantly increase the cost of operating water treatment infrastructure, making the management of sediment supply to reservoirs of increasingly importance. Sediment fingerprinting techniques can be used to determine the relative contributions of different sources of sediment accumulating in reservoirs. The objective of this research is to compare geological and statistical approaches to element selection for sediment fingerprinting modelling. Time-integrated samplers (n=45) were used to obtain source samples from four major subcatchments flowing into the Baroon Pocket Dam in South East Queensland, Australia. The geochemistry of potential sources were compared to the geochemistry of sediment cores (n=12) sampled in the reservoir. The geochemical approach selected elements for modelling that provided expected, observed and statistical discrimination between sediment sources. Two statistical approaches selected elements for modelling with the Kruskal-Wallis H-test and Discriminatory Function Analysis (DFA). In particular, two different significance levels (0.05 & 0.35) for the DFA were included to investigate the importance of element selection on modelling results. A distribution model determined the relative contributions of different sources to sediment sampled in the Baroon Pocket Dam. Elemental discrimination was expected between one subcatchment (Obi Obi Creek) and the remaining subcatchments (Lexys, Falls and Bridge Creek). Six major elements were expected to provide discrimination. Of these six, only Fe2O3 and SiO2 provided expected, observed and statistical discrimination. Modelling results with this geological approach indicated 36% (+/- 9%) of sediment sampled in the reservoir cores were from mafic-derived sources and 64% (+/- 9%) were from felsic-derived sources. The geological and the first statistical approach (DFA0.05) differed by only 1% (σ 5%) for 5 out of 6 model groupings with only the Lexys Creek modelling results differing significantly (35%). The statistical model with expanded elemental selection (DFA0.35) differed from the geological model by an average of 30% for all 6 models. Elemental selection for sediment fingerprinting therefore has the potential to impact modeling results. Accordingly is important to incorporate both robust geological and statistical approaches when selecting elements for sediment fingerprinting. For the Baroon Pocket Dam, management should focus on reducing the supply of sediments derived from felsic sources in each of the subcatchments.

Assessment of sediments in the riverine impoundments of national wildlife refuges in the Souris River Basin, North Dakota

USGS Publications Warehouse

Tangen, Brian A.; Laubhan, Murray K.; Gleason, Robert A.

2014-01-01

Accelerated sedimentation of reservoirs and riverine impoundments is a major concern throughout the United States. Sediments not only fill impoundments and reduce their effective life span, but they can reduce water quality by increasing turbidity and introducing harmful chemical constituents such as heavy metals, toxic elements, and nutrients. U.S. Fish and Wildlife Service national wildlife refuges in the north-central part of the United States have documented high amounts of sediment accretion in some wetlands that could negatively affect important aquatic habitats for migratory birds and other wetland-dependent wildlife. Therefore, information pertaining to sediment accumulation in refuge impoundments potentially is important to guide conservation planning, including future management actions of individual impoundments. Lands comprising Des Lacs, Upper Souris, and J. Clark Salyer National Wildlife Refuges, collectively known as the Souris River Basin refuges, encompass reaches of the Des Lacs and Souris Rivers of northwestern North Dakota. The riverine impoundments of the Souris River Basin refuges are vulnerable to sedimentation because of the construction of in-stream dams that interrupt and slow river flows and because of post-European settlement land-use changes that have increased the potential for soil erosion and transport to rivers. Information regarding sediments does not exist for these refuges, and U.S. Fish and Wildlife Service personnel have expressed interest in assessing refuge impoundments to support refuge management decisions. Sediment cores and surface sediment samples were collected from impoundments within Des Lacs, Upper Souris, and J. Clark Salyer National Wildlife Refuges during 2004–05. Cores were used to estimate sediment accretion rates using radioisotope (cesium-137 [137Cs], lead-210 [210Pb]) dating techniques. Sediment cores and surface samples were analyzed for a suite of elements and agrichemicals, respectively. Examination of core characteristics along the depth profile suggests that there has been regular sediment mixing and removal, as well as non-uniform sediment deposition with time. Estimated mean accretion rates based on the three methods of determination (two time markers for 137Cs, 210Pb) ranged from 0.22–0.35 centimeters per year, and approximately 70 percent of cores had less 137Cs than expected. Concentrations of sediment-associated elements generally were within reported reference ranges, and all agrichemicals analyzed were below detection limits. Results suggest that there does not appear to be widespread sediment accumulation in impoundments of the Souris River Basin refuges. In addition, there were no identifiable patterns among sedimentation rates from the upstream (Des Lacs, Upper Souris) to the downstream (J. Clark Salyer) refuges. There were, however, apparent upstream to downstream patterns of increased concentrations of some elements (for example, aluminum, boron, and vanadium) that may warrant further exploration. Future related monitoring and research efforts should focus on areas with high potential for sediment accumulation, such as upstream areas adjacent to dams, to identify potential sediment problems before they become too severe. Further, assessments of suspended sediments transported in the Des Lacs and Souris Rivers would augment interpretation of sedimentation data by identifying potential sediment sources and areas with the greatest potential for accumulation.

Laboratory, Field, and Analytical Procedures for Using ...

EPA Pesticide Factsheets

Regardless of the remedial technology invoked to address contaminated sediments in the environment, there is a critical need to have tools for assessing the effectiveness of the remedy. In the past, these tools have included chemical and biomonitoring of the water column and sediments, toxicity testing and bioaccumulation studies performed on site sediments, and application of partitioning, transport and fate modeling. All of these tools served as lines of evidence for making informed environmental management decisions at contaminated sediment sites. In the last ten years, a new tool for assessing remedial effectiveness has gained a great deal of attention. Passive sampling offers a tool capable of measuring the freely dissolved concentration (Cfree) of legacy contaminants in water and sediments. In addition to assessing the effectiveness of the remedy, passive sampling can be applied for a variety of other contaminated sediments site purposes involved with performing the preliminary assessment and site inspection, conducting the remedial investigation and feasibility study, preparing the remedial design, and assessing the potential for contaminant bioaccumulation. While there is a distinct need for using passive sampling at contaminated sediments sites and several previous documents and research articles have discussed various aspects of passive sampling, there has not been definitive guidance on the laboratory, field and analytical procedures for using pas

Mercury methylation in sediments of a Brazilian mangrove under different vegetation covers and salinities.

PubMed

de Oliveira, Diana Ciannella Martins; Correia, Raquel Rose Silva; Marinho, Claudio Cardoso; Guimarães, Jean Remy Davée

2015-05-01

The presence and formation of methylmercury (MMHg), a highly toxic form of Hg, in mangrove ecosystems is poorly studied. Therefore the aim of this study was to evaluate mercury methylation potentials in sediment, litter and root samples (Avicennia shaueriana and Spartina alterniflora) from different regions of a mangrove ecosystem, as well as the influence of salinity on methylation. Sediment was sampled under different depths and in mangrove regions with different plant covers and salinities. All samples were incubated with (203)Hg and MM(203)Hg was extracted and measured by liquid scintillation. MMHg was formed in all samples and sites tested including plant roots and litter. Higher Hg methylation was found in the superficial fraction of sediments (0.47-7.82%). Infralittoral sandy sediment had low MMHg formation (0.44-1.61%). Sediment under Rhizophora mangle had lower MMHg formation (0.018-2.23%) than under A. shaueriana (0.2-4.63%) and Laguncularia racemosa (0.08-7.82). MMHg formation in sediment tended to increase with salinity but the differences were not significant. Therefore, MMHg formation occurs in different sites of mangrove ecosystems and may be an important threat that requires further study. Copyright © 2015 Elsevier Ltd. All rights reserved.

Trace element, semivolatile organic, and chlorinated organic compound concentrations in bed sediments of selected streams at Fort Gordon, Georgia, February-April 2010

USGS Publications Warehouse

Thomas, Lashun K.; Journey, Celeste A.; Stringfield, Whitney J.; Clark, Jimmy M.; Bradley, Paul M.; Wellborn, John B.; Ratliff, Hagan; Abrahamsen, Thomas A.

2011-01-01

A spatial survey of streams was conducted from February to April 2010 to assess the concentrations of major ions, selected trace elements, semivolatile organic compounds, organochlorine pesticides, and polychlorinated biphenyls associated with the bed sediments of surface waters at Fort Gordon military installation near Augusta, Georgia. This investigation expanded a previous study conducted in May 1998 by the U.S. Geological Survey, in cooperation with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, that evaluated the streambed sediment quality of selected surface waters at Fort Gordon. The data presented in this report are intended to help evaluate bed sediment quality in relation to guidelines for the protection of aquatic life, and identify temporal trends in trace elements and semivolatile organic compound concentrations at streambed sites previously sampled. Concentrations of 34 major ions and trace elements and 102 semivolatile organic, organochlorine pesticide, and polychlorinated biphenyl compounds were determined in the fine-grained fraction of bed sediment samples collected from 13 of the original 29 sites in the previous study, and 22 additional sites at Fort Gordon. Three of the sites were considered reference sites as they were presumed to be located away from potential sources of contaminants and were selected to represent surface waters flowing onto the fort, and the remaining 32 nonreference sites were presumed to be located within the contamination area at the fort. Temporal trends in trace elements and semivolatile organic compound concentrations also were evaluated at 13 of the 32 nonreference sites to provide an assessment of the variability in the number of detections and concentrations of constituents in bed sediment associated with potential sources, accumulation, and attenuation processes. Major ion and trace element concentrations in fine-grained bed sediment samples from most nonreference sites exceeded concentrations in samples from reference sites at Fort Gordon. Bed sediments from one of the nonreference sites sampled contained the highest concentrations of copper and lead with elevated levels of zinc and chromium relative to reference sites. The percentage change of major ions, trace elements, and total organic carbon that had been detected at sites previously sampled in May 1998 and current bed sediment sites ranged from -4 to 8 percent with an average percentage change of less than 1 percent. Concentrations of major ions and trace elements in bed sediments exceeded probable effect levels for aquatic life (based on the amphipod Hyalella azteca) established by the U.S. Environmental Protection Agency at 46 and 69 percent of the current and previously sampled locations, respectively. The greatest frequency of exceedances for major ions and trace elements in bed sediments was observed for lead. Concentrations of semivolatile organic compounds, organochlorine pesticides, and polychlorinated biphenyls were detected in bed sediment samples at 94 percent of the sites currently sampled. Detections of these organic compounds were reported with greater frequency in bed sediments at upstream sampling locations, when compared to downstream locations. The greatest number of detections of these compounds was reported for bed sediment samples collected from two creeks above a lake. The percentage change of semivolatile organic compounds detected at previously sampled and current bed sediment sites ranged from -68 to 100 percent with the greatest percentage increase reported for one of the creeks above the lake. Concentrations of semivolatile organic compounds and polychlorinated biphenyls in bed sediments exceeded aquatic life criteria established by the U.S. Environmental Protection Agency at three sites. Contaminant compounds exceeding aquatic life criteria included fluoranthene, phenanthrene, anthracene, benzo(a)anthracene

[Residues and potential ecological risk assessment of metal in sediments from lower reaches and estuary of Pearl River].

PubMed

Xie, Wen-Ping; Wang, Shao-Bing; Zhu, Xin-Ping; Chen, Kun-Ci; Pan, De-Bo; Hong, Xiao-You; Yin, Yi

2012-06-01

In order to investigate the heavy metal concentrations and their potential ecological risks in surface sediments of lower reaches and estuary of Pearl River, 21 bottom sediment samples were collected from lower reaches and estuary of Pearl River. Total contents of Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Sb, Pb and Hg in these samples were measured by the inductively coupled plasma mass spectrometry (ICP-MS) and the atomic fluorescence spectrometry (AFS) and using the index of geoaccumulation and the potential ecological risk index to evaluate the pollution degree of heavy metals in the sediments. Results indicated that the concentration of total Fe and total Mn were 41658.73 and 1104.73 mg x kg(-1) respectively and toxic trace metals, such as Cr, Co, Ni, Cu, Zn, As, Se, Cd, Sb, Pb and Hg were 86.62, 18.18, 54.10, 80.20, 543.60, 119.55, 4.28, 10.60, 20.26, 104.58 and 0.520 mg x kg(-1). The descending order of pollution degree of various metals is: Cd > As approximately Zn > Hg > Pb approximately Cu approximately Cr, while the single potential ecological risk followed the order: Cd > Hg > As > Cu > Pb > Zn > Cr. The pollution extent and potential ecological risk of Cd were the most serious among all heavy metals. The distribution pattern of Cd individual potential ecological risk indices is exactly the same as that of general potential ecological risk indices for all heavy metals. Clustering analysis indicates that the sampling stations may be classified into five groups which basically reflected the characteristics of the heavy metal contamination and sedimentation environments along the different river reaches in lower reaches and estuary of Pearl Rive. In general, the serious heavy metal pollution and the high potential ecological risk existed in three river reaches: Chengcun-Shawan, Chengcun-Shundegang and Waihai-Hutiaomen. The pollution degree and potential ecological risk are higher in related river reaches of Beijiang than that in other lower reaches and estuary of Pearl River.

Identifying the cause of sediment toxicity in agricultural sediments: the role of pyrethroids and nine seldom-measured hydrophobic pesticides.

PubMed

Weston, Donald P; Ding, Yuping; Zhang, Minghua; Lydy, Michael J

2013-01-01

Few currently used agricultural pesticides are routinely monitored for in the environment. Even if concentrations are known, sediment LC(50) values are often lacking for common sediment toxicity testing species. To help fill this data gap, sediments in California's Central Valley were tested for nine hydrophobic pesticides seldom analyzed: abamectin, diazinon, dicofol, fenpropathrin, indoxacarb, methyl parathion, oxyfluorfen, propargite, and pyraclostrobin. Most were detected, but rarely at concentrations acutely toxic to Hyalella azteca or Chironomus dilutus. Only abamectin, fenpropathrin, and methyl parathion were found at concentrations of potential concern, and only in one or two samples. One-quarter of over 100 samples from agriculture-affected waterways exhibited toxicity, and in three-fourths of the toxic samples, pyrethroids exceeded concentrations expected to cause toxicity. The pyrethroid Bi-fen-thrin in particular, as well as lambda-cyhalothrin, cypermethrin, esfenvalerate, permethrin, and the organophosphate chlorpyrifos, were primarily responsible for the observed toxicity, rather than the more novel analytes, despite the fact that much of the sampling targeted areas of greatest use of the novel pesticides. Copyright © 2012 Elsevier Ltd. All rights reserved.

Survival of Salmonella enterica in Freshwater and Sediments and Transmission by the Aquatic Midge Chironomus tentans (Chironomidae: Diptera)

PubMed Central

Moore, Barry C.; Martinez, Edward; Gay, John M.; Rice, Daniel H.

2003-01-01

Survival of a nalidixic acid-resistant strain of Salmonella enterica serovar Typhimurium mr-DT-104 in water and sediments was tested using artificially contaminated aquaria. Water samples remained culture positive for salmonella for up to 54 days. Sediment samples were culture positive up to 119 days. In addition, potential mechanisms for spreading salmonella in the environments by chironomid larvae and adults were tested. We evaluated the acquisition of mr-DT-104 by chironomids from contaminated aquatic sediments and subsequent spread to uncontaminated sediments. Larval chironomids raised in contaminated sediments became culture positive, and the bacteria were carried over to adults after emergence. Contamination of clean sediments by chironomid larvae was not demonstrated. These findings clearly suggest that mr-DT-104 serovar organisms can survive in aquatic sediments for at least several months. Uptake of salmonellae by chironomid larvae and adults suggests that they are possible vectors of mr-DT-104 in both aquatic and terrestrial environments, although the role of larval defecation in movement of bacteria to new sediments was not demonstrated. PMID:12902242

Detection by denaturing gradient gel electrophoresis of ammonia-oxidizing bacteria in microcosms of crude oil-contaminated mangrove sediments.

PubMed

dos Santos, A C F; Marques, E L S; Gross, E; Souza, S S; Dias, J C T; Brendel, M; Rezende, R P

2012-01-27

Currently, the effect of crude oil on ammonia-oxidizing bacterium communities from mangrove sediments is little understood. We studied the diversity of ammonia-oxidizing bacteria in mangrove microcosm experiments using mangrove sediments contaminated with 0.1, 0.5, 1, 2, and 5% crude oil as well as non-contaminated control and landfarm soil from near an oil refinery in Camamu Bay in Bahia, Brazil. The evolution of CO(2) production in all crude oil-contaminated microcosms showed potential for mineralization. Cluster analysis of denaturing gradient gel electrophoresis-derived samples generated with primers for gene amoA, which encodes the functional enzyme ammonia monooxygenase, showed differences in the sample contaminated with 5% compared to the other samples. Principal component analysis showed divergence of the non-contaminated samples from the 5% crude oil-contaminated sediment. A Venn diagram generated from the banding pattern of PCR-denaturing gradient gel electrophoresis was used to look for operational taxonomic units (OTUs) in common. Eight OTUs were found in non-contaminated sediments and in samples contaminated with 0.5, 1, or 2% crude oil. A Jaccard similarity index of 50% was found for samples contaminated with 0.1, 0.5, 1, and 2% crude oil. This is the first study that focuses on the impact of crude oil on the ammonia-oxidizing bacterium community in mangrove sediments from Camamu Bay.

Reducing uncertainty in dust monitoring to detect aeolian sediment transport responses to land cover change

NASA Astrophysics Data System (ADS)

Webb, N.; Chappell, A.; Van Zee, J.; Toledo, D.; Duniway, M.; Billings, B.; Tedela, N.

2017-12-01

Anthropogenic land use and land cover change (LULCC) influence global rates of wind erosion and dust emission, yet our understanding of the magnitude of the responses remains poor. Field measurements and monitoring provide essential data to resolve aeolian sediment transport patterns and assess the impacts of human land use and management intensity. Data collected in the field are also required for dust model calibration and testing, as models have become the primary tool for assessing LULCC-dust cycle interactions. However, there is considerable uncertainty in estimates of dust emission due to the spatial variability of sediment transport. Field sampling designs are currently rudimentary and considerable opportunities are available to reduce the uncertainty. Establishing the minimum detectable change is critical for measuring spatial and temporal patterns of sediment transport, detecting potential impacts of LULCC and land management, and for quantifying the uncertainty of dust model estimates. Here, we evaluate the effectiveness of common sampling designs (e.g., simple random sampling, systematic sampling) used to measure and monitor aeolian sediment transport rates. Using data from the US National Wind Erosion Research Network across diverse rangeland and cropland cover types, we demonstrate how only large changes in sediment mass flux (of the order 200% to 800%) can be detected when small sample sizes are used, crude sampling designs are implemented, or when the spatial variation is large. We then show how statistical rigour and the straightforward application of a sampling design can reduce the uncertainty and detect change in sediment transport over time and between land use and land cover types.

Effects of Storage on Sediment Toxicity, Bioaccumulation Potential, and Chemistry

DTIC Science & Technology

1991-01-01

and tested with organisms used by the US Army Engineer District, New York. Test sedi- ments were collected from Westchester Creek (WC), Gowanus Bay ...Ms. Carole Brown, ERSD, obtained the sediment samples. Dr. Eric Crecelius, Battelle Pacific Northwest Laboratories, Sequim , WA, coordinated chemical...other sites, suspected of containing contam- inated sediment, were Westchester Creek (WC), Gowanus Bay (GB), and Arthur Kill (AK), all located in

Presence of selected chemicals of emerging concern in water and bottom sediment from the St. Louis River, St. Louis Bay, and Superior Bay, Minnesota and Wisconsin, 2010

USGS Publications Warehouse

Christensen, Victoria G.; Lee, Kathy E.; Kieta, Kristen A.; Elliott, Sarah M.

2012-01-01

The St. Louis Bay of Lake Superior receives substantial urban runoff, wastewater treatment plant effluent, and industrial effluent. In 1987, the International Joint Commission designated the St. Louis Bay portion of the lower St. Louis River as one of the Great Lakes Areas of Concern. Concerns exist about the potential effects of chemicals of emerging concern on aquatic biota because many of these chemicals, including endocrine active chemicals, have been shown to affect the endocrine systems of fish. To determine the occurrence of chemicals of emerging concern in the St. Louis River, the St. Louis Bay, and Superior Bay, the U.S. Geological Survey in cooperation with the Minnesota Pollution Control Agency and the Wisconsin Department of Natural Resources collected water and bottom-sediment samples from 40 sites from August through October 2010. The objectives of this study were to (1) identify the extent to which chemicals of emerging concern, including pharmaceuticals, hormones, and other organic chemicals, occur in the St. Louis River, St. Louis Bay, and Superior Bay, and (2) identify the extent to which the chemicals may have accumulated in bottom sediment of the study area. Samples were analyzed for selected wastewater indicators, hormones, sterols, bisphenol A, and human-health pharmaceuticals. During this study, 33 of 89 chemicals of emerging concern were detected among all water samples collected and 56 of 104 chemicals of emerging concern were detected in bottom-sediment samples. The chemical N,N-diethyl-meta-toluamide (DEET) was the most commonly detected chemical in water samples and 2,6-dimethylnaphthalene was the most commonly detected chemical in bottom-sediment samples. In general, chemicals of emerging concern were detected at a higher frequency in bottom-sediment samples than in water samples. Estrone (a steroid hormone) and hexahydrohexamethyl cyclopentabensopyran (a synthetic fragrance) were the most commonly detected endocrine active chemicals in water samples; beta-sitosterol (a plant sterol), estrone, and 4-tert-octylphenol (an alkylphenol) were the most commonly detected endocrine active chemicals in bottom-sediment samples. The greater detection frequency of chemicals in bottom-sediment samples compared to the detection frequency in water samples indicates that bottom sediment is an important sink for chemicals of emerging concern. At least one polycyclic aromatic hydrocarbon was detected in every sample; and in most samples, all nine polycyclic aromatic hydrocarbons included in analyses were detected. Bottom sediment collected from Superior Bay had the most polycyclic aromatic hydrocarbon detections of the sediment sampling locations.

Spider-mediated flux of PCBs from contaminated sediments to terrestrial ecosystems and potential risks to arachnivorous birds

EPA Science Inventory

We investigated aquatic insect utilization and PCB exposure in riparian spiders at the Lake Hartwell superfund site (Clemson, SC , USA). We sampled sediments, adult chironomids, terrestrial insects, riparian spiders (Tetragnathidae, Araneidae, and Mecynogea lemniscata), and upla...

Total Reducing Capacity in Aquifer Minerals and Sediments: Quantifying the Potential to Attenuate Cr(VI) in Groundwater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sisman, S. Lara

2015-07-20

Hexavalent chromium, Cr(VI), is present in the environment as a byproduct of industrial processes. Due to its mobility and toxicity, it is crucial to attenuate or remove Cr(VI) from the environment. The objective of this investigation was to quantify potential natural attenuation, or reduction capacity, of reactive minerals and aquifer sediments. Samples of reduced-iron containing minerals such as ilmenite, as well as Puye Formation sediments representing a contaminated aquifer in New Mexico, were reacted with chromate. The change in Cr(VI) during the reaction was used to calculate reduction capacity. This study found that minerals that contain reduced iron, such asmore » ilmenite, have high reducing capacities. The data indicated that sample history may impact reduction capacity tests due to surface passivation. Further, this investigation identified areas for future research including: a) refining the relationships between iron content, magnetic susceptibility and reduction capacity, and b) long term kinetic testing using fresh aquifer sediments.« less

Sediment quality in Burlington Harbor, Lake Champlain, U.S.A.

USGS Publications Warehouse

Lacey, E.M.; King, J.W.; Quinn, J.G.; Mecray, E.L.; Appleby, P.G.; Hunt, A.S.

2001-01-01

Surface samples and cores were collected in 1993 from the Burlington Harbor region of Lake Champlain. Sediment samples were analyzed for trace metals (cadmium, copper, lead, nickel, silver and zinc), simultaneously extracted metal/acid volatile sulfide (SEM-AVS), grain size, nutrients (carbon and nitrogen) and organic contaminants (polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)). The concentrations of cadmium, copper, silver and zinc from the partial sediment digestion of the surface samples correlated well with each other (r2 > 0.60) indicating that either a common process, or group of processes determined the sediment concentrations of these metals. In an analysis of the spatial distribution of the trace metals and PAHs, high surficial concentrations were present in the southern portion of the Harbor. The trace metal trend was strengthened when the concentrations were normalized by grain size. A sewage treatment plant outfall discharge was present in the southeastern portion of the Harbor at the time of this study and is the major source of trace metal and PAH contamination. Evaluation of sediment cores provides a proxy record of historical trace metal and organic inputs. The peak accumulation rate for copper, cadmium, lead, and zinc was in the late 1960s and the peak silver accumulation rate was later. The greatest accumulation of trace metals occurred in the late 1960s after discharges from the STP began. Subsequent declines in trace metal concentrations may be attributed to increased water and air regulations. The potential toxicity of trace metals and organic contaminants was predicted by comparing contaminant concentrations to benchmark concentrations and potential trace metal bioavailability was predicted with SEM-AVS results. Surface sample results indicate lead, silver, ???PAHs and ???PCBs are potentially toxic and/or bioavailable. These predictions were supported by studies of biota in the Burlington Harbor watershed. There is a clear trend of decreasing PAH and trace metal contaminant concentrations with distance from the STP outfall.Surface samples and cores were collected in 1993 from the Burlington Harbor region of Lake Champlain. Sediment samples were analyzed for trace metals (cadmium, copper, lead, nickel, silver and zinc), simultaneously extracted metal/acid volatile sulfide (SEM-AVS), grain size, nutrients (carbon and nitrogen) and organic contaminants (polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)). The concentrations of cadmium, copper, silver and zinc from the partial sediment digestion of the surface samples correlated well with each other (r2>0.60) indicating that either a common process, or group of processes determined the sediment concentrations of these metals. In an analysis of the spatial distribution of the trace metals and PAHs, high surficial concentrations were present in the southern portion of the Harbor. The trace metal trend was strengthened when the concentrations were normalized by grain size. A sewage treatment plant outfall discharge was present in the southeastern portion of the Harbor at the time of this study and is the major source of trace metal and PAH contamination. Evaluation of sediment cores provides a proxy record of historical trace metal and organic inputs. The peak accumulation rate for copper, cadmium, lead, and zinc was in the late 1960s and the peak silver accumulation rate was later. The greatest accumulation of trace metals occurred in the late 1960s after discharges from the STP began. Subsequent declines in trace metal concentrations may be attributed to increased water and air regulations. The potential toxicity of trace metals and organic contaminants was predicted by comparing contaminant concentrations to benchmark concentrations and potential trace metal bioavailability was predicted with SEM-AVS results. Surface sample results indicate lead, silver, ??PAHs and ??PCBs are potentially toxic and/or bi

Biomonitoring for deposited sediment using benthic invertebrates: A test on 4 Missouri streams

USGS Publications Warehouse

Zweig, L.D.; Rabeni, Charles F.

2001-01-01

The response of stream benthic invertebrates to surficially deposited fine sediment was investigated in 4 Missouri streams. Twenty to 24 sampling sites in each stream were selected based on similarities of substrate particle-size distributions, depths, and current velocities but for differences in amounts of deposited sediment, which ranged from 0 to 100% surface cover. Deposited sediment was quantified 2 ways: a visual estimate of % surface cover, and a measurement of substrate embeddedness, which were highly correlated with each other and with the amount of sand. Invertebrates were collected using a kicknet for a specified time in a 1-m2 area. Five commonly used biomonitoring metrics (taxa richness, density, Ephemeroptera, Plecoptera, and Trichoptera [EPT] richness, EPT density, and EPT/Chironomidae richness) were consistently significantly correlated across streams to deposited sediment. Shannon diversity index, Chironomidae richness, Chironomidae density, a biotic index, and % dominant taxon did not relate to increasing levels of deposited sediment. Tolerance values representing taxa responses to deposited sediment were developed for 30 taxa. Deposited-sediment tolerance values were not correlated with biotic index tolerance values, indicating a different response by taxa to deposited sediment than to organic enrichment. Deposited-sediment tolerance values were used to develop the Deposited Sediment Biotic Index (DSBI). The DSBI was calculated for all samples (n = 85) to characterize sediment impairment of the sampled streams. DSBI values for each site were highly correlated with measures of deposited sediment. Model validation by a resampling procedure confirmed that the DSBI is a potentially useful tool for assessing ecological effects of deposited sediment.

Fine Increment Soil Collector (FISC): A new device to support high resolution soil and sediment sampling for agri-environmental assessments

NASA Astrophysics Data System (ADS)

Mabit, Lionel; Meusburger, Katrin; Iurian, Andra-Rada; Owens, Philip N.; Toloza, Arsenio; Alewell, Christine

2014-05-01

Soil and sediment related research for terrestrial agri-environmental assessments requires accurate depth incremental sampling of soil and exposed sediment profiles. Existing coring equipment does not allow collecting soil/sediment increments at millimetre resolution. Therefore, the authors have designed an economic, portable, hand-operated surface soil/sediment sampler - the Fine Increment Soil Collector (FISC) - which allows extensive control of soil/sediment sampling process and easy recovery of the material collected by using a simple screw-thread extraction system. In comparison with existing sampling tools, the FISC has the following advantages and benefits: (i) it permits sampling of soil/sediment samples at the top of the profile; (ii) it is easy to adjust so as to collect soil/sediment at mm resolution; (iii) it is simple to operate by one single person; (iv) incremental samples can be performed in the field or at the laboratory; (v) it permits precise evaluation of bulk density at millimetre vertical resolution; and (vi) sample size can be tailored to analytical requirements. To illustrate the usefulness of the FISC in sampling soil and sediments for 7Be - a well-known cosmogenic soil tracer and fingerprinting tool - measurements, the sampler was tested in a forested soil located 45 km southeast of Vienna in Austria. The fine resolution increments of 7Be (i.e. 2.5 mm) affects directly the measurement of the 7Be total inventory but above all impacts the shape of the 7Be exponential profile which is needed to assess soil movement rates. The FISC can improve the determination of the depth distributions of other Fallout Radionuclides (FRN) - such as 137Cs, 210Pbexand239+240Pu - which are frequently used for soil erosion and sediment transport studies and/or sediment fingerprinting. Such a device also offers great potential to investigate FRN depth distributions associated with fallout events such as that associated with nuclear emergencies. Furthermore, prior to remediation activities - such as topsoil removal - in contaminated soils and sediments (e.g. by heavy metals, pesticides or nuclear power plant accident releases), basic environmental assessment often requires the determination of the extent and the depth penetration of the different contaminants, precision that can be provided by using the FISC.

Freezing and hungry? Hydrocarbon degrading microbial communities in Barents Sea sediments around Svalbard

NASA Astrophysics Data System (ADS)

Krueger, Martin; Straaten, Nontje

2017-04-01

The Polar Regions are characterised by varying temperatures and changing ice coverage, so most of the primary production take place in the warmer season. Consequently, sedimentation rates and nutrient input are low. The diversity and metabolic potentials of the microbial communities inhabiting these sediments in the Northern Barents Sea are largely unknown. Recent reports on natural methane seeps as well as the increase in hydrocarbon exploration activities in the Arctic initiated our studies on the potential of indigenous microbial communities to degrade methane and higher hydrocarbons under in situ pressure and temperature conditions. Furthermore, the subseafloor geochemistry in these areas was studied, together with important microbial groups, like methanotrophs, methanogens, metal and sulfate reducers, which may drive seafloor ecosystems in the Northern Barents Sea. Sediment samples were collected in several areas around Svalbard in the years 2013-2016 ranging from shallow (200m) areas on the Svalbard shelf to deep sea areas on the eastern Yermak Plateau (3200m water depths). Shelf sediments showed the highest organic carbon content which decreased with increasing depths. Iron and manganese as potential electron acceptors were found in the porewater especially in the top 50 cm of the cores, while sulfate was always present in substantial amounts in porewater samples down to the end of the up to two metre long cores. Concentrations of dissolved methane and carbon dioxide were low. The potential of the indigenous microorganisms to degrade methane and higher hydrocarbons as well as different oils under in situ temperatures and pressures was widespread in surface sediments. Degradation rates were higher under aerobic than under anaerobic conditions, and decreased with increasing sediment as well as water depths. Similar pattern were found for other metabolic processes, including sulfate, Fe and Mn reduction as well as carbon dioxide and methane production rates. Ongoing molecular biological analyses of original sediments and enrichment cultures indicate the presence of diverse and varying microbial communities.

Pressurized liquid extraction using water/isopropanol coupled with solid-phase extraction cleanup for industrial and anthropogenic waste-indicator compounds in sediment

USGS Publications Warehouse

Burkhardt, M.R.; ReVello, R.C.; Smith, S.G.; Zaugg, S.D.

2005-01-01

A broad range of organic compounds is recognized as environmentally relevant for their potential adverse effects on human and ecosystem health. This method was developed to better determine the distribution of 61 compounds that are typically associated with industrial and household waste as well as some that are toxic and known (or suspected) for endocrine-disrupting potential extracted from environmental sediment samples. Pressurized liquid extraction (PLE) coupled with solid-phase extraction (SPE) was used to reduce sample preparation time, reduce solvent consumption to one-fifth of that required using dichloromethane-based Soxhlet extraction, and to minimize background interferences for full scan GC/MS analysis. Recoveries from spiked Ottawa sand, commercially available topsoil, and environmental stream sediment, fortified at 4-720 ??g per compound, averaged 76 ?? 13%. Initial method detection limits for single-component compounds ranged from 12.5 to 520 ??g/kg, based on 25 g samples. Results from 103 environmental sediment samples show that 36 out of 61 compounds (59%) were detected in at least one sample with concentrations ranging from 20 to 100,000 ??g/kg. The most frequently detected compound, beta-sitosterol, a plant sterol, was detected in 87 of the 103 (84.5%) environmental samples with a concentration range 360-100,000 ??g/kg. Results for a standard reference material using dichloromethane Soxhlet-based extraction are also compared. ?? 2004 Published by Elsevier B.V.

Effects of Hurricanes Katrina and Rita on the chemistry of bottom sediments in Lake Pontchartrain, La.: Chapter 7F in Science and the storms-the USGS response to the hurricanes of 2005

USGS Publications Warehouse

Van Metre, Peter C.; Horowitz, Arthur J.; Mahler, Barbara J.; Foreman, William T.; Fuller, Christopher C.; Burkhardt, Mark R.; Elrick, Kent A.; Furlong, Edward T.; Skrobialowski, Stanley C.; Smith, James J.; Wilson, Jennifer T.; Zaugg, Stephen D.

2007-01-01

Concerns about the effect of pumping contaminated flood waters into Lake Pontchartrain following the hurricanes of 2005 prompted the U.S. Geological Survey (USGS) to sample street mud, canal-suspended sediment, and bottom sediment in Lake Pontchartain. The samples were analyzed for a wide variety of potential inorganic and organic contaminants. Results indicate that contamination of lake sediment relative to other urban lakes and to accepted sedimentquality guidelines was limited to a relatively small area offshore from the Metairie Outfall Canal (popularly known as the 17th Street Canal) and that this contamination is probably transient.

Metagenomic analyses of the late Pleistocene permafrost - additional tools for reconstruction of environmental conditions

NASA Astrophysics Data System (ADS)

Rivkina, Elizaveta; Petrovskaya, Lada; Vishnivetskaya, Tatiana; Krivushin, Kirill; Shmakova, Lyubov; Tutukina, Maria; Meyers, Arthur; Kondrashov, Fyodor

2016-04-01

A comparative analysis of the metagenomes from two 30 000-year-old permafrost samples, one of lake-alluvial origin and the other from late Pleistocene Ice Complex sediments, revealed significant differences within microbial communities. The late Pleistocene Ice Complex sediments (which have been characterized by the absence of methane with lower values of redox potential and Fe2+ content) showed a low abundance of methanogenic archaea and enzymes from both the carbon and nitrogen cycles, but a higher abundance of enzymes associated with the sulfur cycle. The metagenomic and geochemical analyses described in the paper provide evidence that the formation of the sampled late Pleistocene Ice Complex sediments likely took place under much more aerobic conditions than lake-alluvial sediments.

What food and feeding rates are optimum for the Chironomus dilutus sediment toxicity test method?

EPA Science Inventory

Laboratory tests with benthic macroinvertebrates conducted using standard toxicity test procedures are used to assess the potential toxicity of contaminated sediments. Results are compared across sites or for batches of samples, and the performance of organisms in control treatme...

Sediment studies in the Assabet River, central Massachusetts, 2003

USGS Publications Warehouse

Zimmerman, Marc J.; Sorenson, Jason R.

2005-01-01

From its headwaters in Westborough, Massachusetts, to its confluence with the Sudbury River, the 53-kilometer-long Assabet River passes through a series of small towns and mixed land-use areas. Along the way, wastewater-treatment plants release nutrient-rich effluents that contribute to the eutrophic state of this waterway. This condition is most obvious where the river is impounded by a series of dams that have sequestered large amounts of sediment and support rooted and floating macrophytes and epiphytic algae. The water in parts of these impoundments may also have low concentrations of dissolved oxygen, another symptom of eutrophication. All of the impoundments had relatively shallow maximum water depths, which ranged from approximately 2.4 to 3.4 meters, and all had extensive shallow areas. Sediment volumes estimated for the six impoundments ranged from approximately 380 cubic meters in the Aluminum City impoundment to 580,000 cubic meters in the Ben Smith impoundment. The other impoundments had sediment volumes of 120,000 cubic meters (Powdermill), 67,000 cubic meters (Gleasondale), 55,000 cubic meters (Hudson), and 42,000 cubic meters (Allen Street). The principal objective of this study was the determination of sediment volume, extent, and chemistry, in particular, the characterization of toxic inorganic and organic chemicals in the sediments. To determine the bulk-sediment chemical-constituent concentrations, more than one hundred sediment cores were collected in pairs from the six impoundments. One core from each pair was sampled for inorganic constituents and the other for organic constituents. Most of the cores analyzed for inorganics were sectioned to provide information on the vertical distribution of analytes; a subset of the cores analyzed for organics was also sectioned. Approximately 200 samples were analyzed for inorganic constituents and 100 for organics; more than 10 percent were quality-control replicate or blank samples. Maximum bulk-sediment phosphorus concentrations in surface samples from the impoundments increased along a downstream gradient, with the exception of samples from the last impoundment, where the concentrations decreased. In addition, the highest phosphorus concentrations were generally in the surface samples; this finding may prove helpful if surface dredging is selected as a means to control phosphorus release from sediments. There is no known relation, however, between bulk-sediment concentration of phosphorus and the concentrations of phosphorus available to biota. Potentially toxic metals, including arsenic, cadmium, chromium, copper, nickel, lead, and zinc were frequently measured at concentrations that exceeded U.S. Environmental Protection Agency sediment-quality guidelines for the protection of aquatic life and that occasionally exceeded Massachusetts Department of Environmental Protection guidelines governing landfill disposal (reuse). Due to the effects of matrix interference and sample dilution on laboratory analyses, neither pesticides nor volatile organic compounds were detected at any sites. However, samples collected in other studies from nearby streams indicated the possibility that pesticides might have been detected in the impoundments if not for these analytical problems. Although polychlorinated biphenyl concentrations, as individual Aroclors, generally exceeded published U.S. Environmental Protection Agency guideline concentrations for potential effects on aquatic life, the U.S. Environmental Protection Agency guideline concentrations for human contact or the Massachusetts guidelines for landfill reuse were rarely exceeded. Concentrations of polycyclic aromatic hydrocarbons, both individually and total, frequently were greater than guideline concentrations. Concentrations of total extractable petroleum hydrocarbons did not exceed Massachusetts guideline concentrations in any samples. When the sediment analytes from surface samples are considered togethe

Next-Generation Sequencing of Microbial Communities in the Athabasca River and Its Tributaries in Relation to Oil Sands Mining Activities

PubMed Central

Yergeau, Etienne; Lawrence, John R.; Sanschagrin, Sylvie; Waiser, Marley J.; Korber, Darren R.

2012-01-01

The Athabasca oil sands deposit is the largest reservoir of crude bitumen in the world. Recently, the soaring demand for oil and the availability of modern bitumen extraction technology have heightened exploitation of this reservoir and the potential unintended consequences of pollution in the Athabasca River. The main objective of the present study was to evaluate the potential impacts of oil sands mining on neighboring aquatic microbial community structure. Microbial communities were sampled from sediments in the Athabasca River and its tributaries as well as in oil sands tailings ponds. Bacterial and archaeal 16S rRNA genes were amplified and sequenced using next-generation sequencing technology (454 and Ion Torrent). Sediments were also analyzed for a variety of chemical and physical characteristics. Microbial communities in the fine tailings of the tailings ponds were strikingly distinct from those in the Athabasca River and tributary sediments. Microbial communities in sediments taken close to tailings ponds were more similar to those in the fine tailings of the tailings ponds than to the ones from sediments further away. Additionally, bacterial diversity was significantly lower in tailings pond sediments. Several taxonomic groups of Bacteria and Archaea showed significant correlations with the concentrations of different contaminants, highlighting their potential as bioindicators. We also extensively validated Ion Torrent sequencing in the context of environmental studies by comparing Ion Torrent and 454 data sets and by analyzing control samples. PMID:22923391

Performance of a novel multiple-signal luminescence sediment tracing method

NASA Astrophysics Data System (ADS)

Reimann, Tony

2014-05-01

Optically Stimulated Luminescence (OSL) is commonly used for dating sediments. Luminescence signals build up due to exposure of mineral grains to natural ionizing radiation, and are reset when these grains are exposed to (sun)light during sediment transport and deposition. Generally, luminescence signals can be read in two ways, potentially providing information on the burial history (dating) or the transport history (sediment tracing) of mineral grains. In this study we use a novel luminescence measurement procedure (Reimann et al., submitted) that simultaneously monitors six different luminescence signals from the same sub-sample (aliquot) to infer the transport history of sand grains. Daylight exposure experiments reveal that each of these six signals resets (bleaches) at a different rate, thus allowing to trace the bleaching history of the sediment in six different observation windows. To test the feasibility of luminescence sediment tracing in shallow-marine coastal settings we took eight sediment samples from the pilot mega-nourishment Zandmotor in Kijkduin (South-Holland). This site provides relatively controlled conditions as the morphological evolution of this nourishment is densely monitored (Stive et al., 2013). After sampling the original nourishment source we took samples along the seaward facing contour of the spit that was formed from August 2011 (start of nourishment) to June 2012 (sampling). It is presumed that these samples originate from the source and were transported and deposited within the first year after construction. The measured luminescence of a sediment sample was interpolated onto the daylight bleaching curve of each signal to assign the Equivalent Exposure Time (EET) to a sample. The EET is a quantitative measure of the full daylight equivalent a sample was exposed to during sediment transport, i.e. the higher the EET the longer the sample has been transported or the more efficient it has been exposed to day-light during sediment transport. The EET increases with increasing distance from the nourishment source, indicating that our method is capable to quantify sediment transport distances. We furthermore observed that the EET of an aeolian analogue is orders of magnitudes higher than those of the water-lain transported Zandmotor samples, suggesting that our approach is also able to differentiate between different modes of coastal sediment transport. This new luminescence approach offers new possibilities to decipher the sedimentation history of palaeo-environmental archives e.g. in coastal, fluvial or aeolian settings. References: Reimann, T.et al. Quantifying the degreeof bleaching during sediment transport using a polymineral multiple-signalluminescence approach. Submitted. Stive, M.J.F. et al. 2013. A New Alternative to Saving Our Beaches from Sea-Level Rise: The SandEngine. Journal of Coastal research 29, 1001-1008.

Calculation and evaluation of sediment effect concentrations for the amphipod Hyalella azteca and the midge Chironomus riparius

USGS Publications Warehouse

Ingersoll, Christopher G.; Haverland, Pamela S.; Brunson, Eric L.; Canfield, Timothy J.; Dwyer, F. James; Henke, Chris; Kemble, Nile E.; Mount, David R.; Fox, Richard G.

1996-01-01

Procedures are described for calculating and evaluating sediment effect concentrations (SECs) using laboratory data on the toxicity of contaminants associated with field-collected sediment to the amphipod Hyalella azteca and the midge Chironomus riparius. SECs are defined as the concentrations of individual contaminants in sediment below which toxicity is rarely observed and above which toxicity is frequently observed. The objective of the present study was to develop SECs to classify toxicity data for Great Lake sediment samples tested with Hyalella azteca and Chironomus riparius. This SEC database included samples from additional sites across the United States in order to make the database as robust as possible. Three types of SECs were calculated from these data: (1) Effect Range Low (ERL) and Effect Range Median (ERM), (2) Threshold Effect Level (TEL) and Probable Effect Level (PEL), and (3) No Effect Concentration (NEC). We were able to calculate SECs primarily for total metals, simultaneously extracted metals, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The ranges of concentrations in sediment were too narrow in our database to adequately evaluate SECs for butyltins, methyl mercury, polychlorinated dioxins and furans, or chlorinated pesticides. About 60 to 80% of the sediment samples in the database are correctly classified as toxic or not toxic depending on type of SEC evaluated. ERMs and ERLs are generally as reliable as paired PELs and TELs at classifying both toxic and non-toxic samples in our database. Reliability of the SECs in terms of correctly classifying sediment samples is similar between ERMs and NECs; however, ERMs minimize Type I error (false positives) relative to ERLs and minimize Type II error (false negatives) relative to NECs. Correct classification of samples can be improved by using only the most reliable individual SECs for chemicals (i.e., those with a higher percentage of correct classification). SECs calculated using sediment concentrations normalized to total organic carbon (TOC) concentrations did not improve the reliability compared to SECs calculated using dry-weight concentrations. The range of TOC concentrations in our database was relatively narrow compared to the ranges of contaminant concentrations. Therefore, normalizing dry-weight concentrations to a relatively narrow range of TOC concentrations had little influence on relative concentra of contaminants among samples. When SECs are used to conduct a preliminary screening to predict the potential for toxicity in the absence of actual toxicity testing, a low number of SEC exceedances should be used to minimize the potential for false negatives; however, the risk of accepting higher false positives is increased.

Heterotrophic potential of Atribacteria from deep marine Antarctic sediment

NASA Astrophysics Data System (ADS)

Carr, S. A.; Orcutt, B.; Mandernack, K. W.; Spear, J. R.

2015-12-01

Bacteria belonging to the newly classified candidate phylum "Atribacteria" (formerly referred to as "OP9" and "JS1") are common in anoxic methane-rich sediments. However, the metabolic functions and biogeochemical role of these microorganisms in the subsurface remains unrealized due to the lack of pure culture representatives. This study observed a steady increase of Atribacteria-related sequences with increasing sediment depth throughout the methane-rich zone of the Adélie Basin, Antarctica (according to a 16S rRNA gene survey). To explore the functional potential of Atribacteria in this basin, samples from various depths (14, 25 and 97 meters below seafloor), were subjected to metagenomic sequencing. Additionally, individual cells were separated from frozen, unpreserved sediment for whole genome amplification. The successful isolation and sequencing of a single-amplified Atribacteria genome from these unpreserved sediments demonstrates a future use of single cell techniques with previously collected and frozen sediments. Our resulting single-cell amplified genome, combined with metagenomic interpretations, provides our first insights to the functional potential of Atribacteria in deep subsurface settings. As observed for non-marine Atribacteria, genomic analyses suggest a heterotrophic metabolism, with Atribacteria potentially producing fermentation products such as acetate, ethanol and CO2. These products may in turn support methanogens within the sediment microbial community and explain the frequent occurrence of Atribacteria in anoxic methane-rich sediments.

Invasion by a Japanese marine microorganism in western North America

USGS Publications Warehouse

McGann, M.; Sloan, D.; Cohen, A.N.

2000-01-01

The earliest record in western North America of Trochammina hadai Uchio, a benthic foraminifer common in Japanese estuaries, is from sediment collected in Puget Sound in 1971. It was first found in San Francisco Bay in sediment samples taken in 1983, and since 1986 has been collected at 91% of the sampled sites in the Bay, constituting up to 93% of the foraminiferal assemblage at individual sites. The species is also present in recent sediment samples from 12 other sites along the west coast of North America. The evidence indicates that T. hadai is a recent introduction to San Francisco Bay, and is probably also not native to the other North American sites. Trochammina hadai was probably transported from Japan in ships' ballast tanks, in mud associated with anchors, or in sediments associated with oysters imported for mariculture. Its remarkable invasion of San Francisco Bay suggests the potential for massive, rapid invasions by other marine microorganisms.

Occurrence and concentrations of selected trace elements and halogenated organic compounds in stream sediments and potential sources of polychlorinated biphenyls, Leon Creek, San Antonio, Texas, 2012–14

USGS Publications Warehouse

Wilson, Jennifer T.

2016-06-23

Sediment samples collected from Leon Creek by the USGS during 2007–9 and 2012–14 at a total of eight sites following identical field and laboratory methods were evaluated to determine if potential PCB sources could be identified. Total PCB concentrations in the sediment samples collected upstream from the Joint Base site were low or nondetections; while concentrations in the samples collected on and downstream from the Joint Base site were greater. Congeners 180 and 138 constituted the greatest proportion of the PCB mixture in samples collected upstream from, on, and downstream from the Joint Base site. Upstream from the Joint Base site, congeners 180 and 138 constituted 50 percent and 35 percent respectively of the PCBs congeners found in the samples. On and downstream from the Joint Base site, congeners 180 and 138 constituted 80 percent and 13 percent respectively of the PCBs congeners found in the samples. Chi-square (C2) tests also indicate that samples collected from the Loop 410 site were statistically different from samples collected from the Joint Base site and sites downstream. The PCB congener pattern in the Leon Creek samples is most like the congener mixture in Aroclor 1260, which is chemically similar to the PCBs detected in the fish samples that resulted in the 2003 fish consumption advisory.

Sediment erosion and transport at the Rio Grande mouth : report for the National Border Technology Program and International Boundary and Water Commission.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chapin, D. Michael, Jr.; Langford, Richard; Neu, Roene

2003-11-01

The mouth of the Rio Grande has become silted up, obstructing its flow into the Gulf of Mexico. This is problematic in that it has created extensive flooding. The purpose of this study was to determine the erosion and transport potential of the sediments obstructing the flow of the Rio Grande by employing a unique Mobile High Shear Stress flume developed by Sandia's Carlsbad Programs Group for the US Army Corps of Engineers. The flume measures in-situ sediment erosion properties at shear stresses ranging from normal flow to flood conditions for a variable depth sediment core. The flume is inmore » a self-contained trailer that can be placed on site in the field. Erosion rates and sediment grain size distributions were determined from sediment samples collected in and around the obstruction and were subsequently used to characterize the erosion potential of the sediments under investigation.« less

Phosphorus fractionation and distribution in sediments from wetlands and canals of a water conservation area in the Florida Everglades

Treesearch

Qingren Wang; Yuncong Li; Ying Ouyang

2011-01-01

Phosphorus (P) fractionation and distribution in sediments are of great concern in the Florida Everglades ecosystem because potential eutrophication of surface waters usually results from P external loading and stability. Intact core sediment samples were collected to a depth of 35 cm from wetlands and canals across Water Conservation Area 3 (WCA‐3) of the Florida...

Correlations of turbidity to suspended-sediment concentration in the Toutle River Basin, near Mount St. Helens, Washington, 2010-11

USGS Publications Warehouse

Uhrich, Mark A.; Kolasinac, Jasna; Booth, Pamela L.; Fountain, Robert L.; Spicer, Kurt R.; Mosbrucker, Adam R.

2014-01-01

Researchers at the U.S. Geological Survey, Cascades Volcano Observatory, investigated alternative methods for the traditional sample-based sediment record procedure in determining suspended-sediment concentration (SSC) and discharge. One such sediment-surrogate technique was developed using turbidity and discharge to estimate SSC for two gaging stations in the Toutle River Basin near Mount St. Helens, Washington. To provide context for the study, methods for collecting sediment data and monitoring turbidity are discussed. Statistical methods used include the development of ordinary least squares regression models for each gaging station. Issues of time-related autocorrelation also are evaluated. Addition of lagged explanatory variables was used to account for autocorrelation in the turbidity, discharge, and SSC data. Final regression model equations and plots are presented for the two gaging stations. The regression models support near-real-time estimates of SSC and improved suspended-sediment discharge records by incorporating continuous instream turbidity. Future use of such models may potentially lower the costs of sediment monitoring by reducing time it takes to collect and process samples and to derive a sediment-discharge record.

[Pollution Characteristics and Potential Ecological Risk of Heavy Metals in Urban Surface Water Sediments from Yongkang].

PubMed

Qi, Peng; Yu, Shu-quan; Zhang, Chao; Liang, Li-cheng; Che, Ji-lu

2015-12-01

In order to understand the pollution characteristics of heavy metals in surface water sediments of Yongkang, we analyzed the concentrations of 10 heavy metals including Ti, Cr, Mn, Co, Ni, Cu, Zn, As, Pb and Fe in 122 sediment samples, explored the underlying source of heavy metals and then assessed the potential ecological risks of those metals by methods of the index of geo-accumulation and the potential ecological risk. The study results showed that: 10 heavy metal contents followed the order: Fe > Ti > Mn > Zn > Cr > Cu > Ph > Ni > As > Co, all heavy metals except for Ti were 1. 17 to 3.78 times higher than those of Zhejiang Jinhua- Quzhou basin natural soils background values; The concentrations of all heavy metals had a significantly correlation between each other, indicating that those heavy metals had similar sources of pollution, and it mainly came from industrial and vehicle pollutions; The pollution extent of heavy metals in sediments by geo-accumulation index (Igeo) followed the order: Cr > Zn > Ni > Cu > Fe > As > Pb >Mn > Ti, thereinto, Cr, Zn, Cu and Ni were moderately polluted or heavily polluted at some sampling sites; The potential ecological risk of 9 heavy metals in sediments were in the following order: Cu > As > Ni > Cr > Pb > Co > Zn > Mn > Ti, Cu and As contributed the most to the total potential ecological risk, accounting for 22.84% and 21. 62% , others had a total of 55.54% , through the ecological risk assessment, 89. 34% of the potential ecological risk indexes ( RI) were low and 10. 66% were higher. The contamination level of heavy metals in Yongkang was slight in total, but was heavy in local areas.

Hydrologic and Water-Quality Responses in Shallow Ground Water Receiving Stormwater Runoff and Potential Transport of Contaminants to Lake Tahoe, California and Nevada, 2005-07

USGS Publications Warehouse

Green, Jena M.; Thodal, Carl E.; Welborn, Toby L.

2008-01-01

Clarity of Lake Tahoe, California and Nevada has been decreasing due to inflows of sediment and nutrients associated with stormwater runoff. Detention basins are considered effective best management practices for mitigation of suspended sediment and nutrients associated with runoff, but effects of infiltrated stormwater on shallow ground water are not known. This report documents 2005-07 hydrogeologic conditions in a shallow aquifer and associated interactions between a stormwater-control system with nearby Lake Tahoe. Selected chemical qualities of stormwater, bottom sediment from a stormwater detention basin, ground water, and nearshore lake and interstitial water are characterized and coupled with results of a three-dimensional, finite-difference, mathematical model to evaluate responses of ground-water flow to stormwater-runoff accumulation in the stormwater-control system. The results of the ground-water flow model indicate mean ground-water discharge of 256 acre feet per year, contributing 27 pounds of phosphorus and 765 pounds of nitrogen to Lake Tahoe within the modeled area. Only 0.24 percent of this volume and nutrient load is attributed to stormwater infiltration from the detention basin. Settling of suspended nutrients and sediment, biological assimilation of dissolved nutrients, and sorption and detention of chemicals of potential concern in bottom sediment are the primary stormwater treatments achieved by the detention basins. Mean concentrations of unfiltered nitrogen and phosphorus in inflow stormwater samples compared to outflow samples show that 55 percent of nitrogen and 47 percent of phosphorus are trapped by the detention basin. Organic carbon, cadmium, copper, lead, mercury, nickel, phosphorus, and zinc in the uppermost 0.2 foot of bottom sediment from the detention basin were all at least twice as concentrated compared to sediment collected from 1.5 feet deeper. Similarly, concentrations of 28 polycyclic aromatic hydrocarbon compounds were all less than laboratory reporting limits in the deeper sediment sample, but 15 compounds were detected in the uppermost 0.2 foot of sediment. Published concentrations determined to affect benthic aquatic life also were exceeded for copper, zinc, benz[a]anthracene, phenanthrene, and pyrene in the shallow sediment sample. Isotopic composition of water (oxygen 18/16 and hydrogen 2/1 ratios) for samples of shallow ground water, lakewater, and interstitial water from Lake Tahoe indicate the lake was well mixed with a slight ground-water signature in samples collected near the lakebed. One interstitial sample from 0.8 foot beneath the lakebed was nearly all ground water and concentrations of nitrogen and phosphorus were comparable to concentrations in shallow ground-water samples. However, ammonium represented 65 percent of filtered nitrogen in this interstitial sample, but only 10 percent of the average nitrogen in ground-water samples. Nitrate was less than reporting limits in interstitial water, compared with mean nitrate concentration of 750 micrograms per liter in ground-water samples, indicating either active dissimilative nitrate reduction to ammonium by micro-organisms or hydrolysis of organic nitrogen to ammonium with concomitant nitrate reduction. The other interstitial sample falls along a mixing line between ground water and lake water and most of the nitrogen was organic nitrogen.

Vertical variation of potential mobility of heavy metal in sediment to groundwater of the Kanto plain, Japan

NASA Astrophysics Data System (ADS)

Hossain, S.; Hachinohe, S.; Ishiyama, T.; Hamamoto, H.; Oguchi, C. T.

2014-12-01

Heavy metals release from sediment may occur due to sediment water interaction under different changing environmental conditions. This has substantial influence on groundwater quality. However, identification of potentially mobile fractions of metals like Cu, Cr, Ni, Pb, Zn, Fe, Mn and Ti requires for the sustainable land and groundwater development and pollution management. 44 sediment and pore water samples at 1 m interval were analyzed from a vertical profile beneath the Naka river at the bottom of Central Kanto plain, Japan. Sequential extraction method was applied to determine potentially mobile forms of metals such as water soluble, ion exchangeable, acid soluble and Fe-Mn oxide bound. Metals were determined using X-Ray Fluorescence, Inductively coupled plasma atomic emission and mass spectrometer. Analyses show that potential mobility is high in river bed, volcanic ash mix, marine and transitional clayey silt. Metal mobility was higher in lower gravelly aquifer than upper sandy aquifer. Potential mobility and bioavailability of Zn, Cu, Ni, Pb and Mn are very high in river bed sediment which may pose threat to river bottom aquatic system. Zn, Cu and Ni concentration in pore water is high in river bed and peat bearing sediment. In pore water of marine and transitional sediment ion concentration such as Ca2+ and SO42- is very high indicating high mobility of Calcium and Sulfur from sediment as no significant variation observed in total content. In vertical profile, potential mobility tendency of metal in sediment trends to be Zn > Cu > Ni > Cr > Pb > Mn > Fe > Ti. Current study indicates low potential mobility and pollution risk to groundwater due to overall low metal concentration in pore water and high portion of metals attached with sediment as Fe-Mn oxide bound. More over under strong reducing condition considerable amount of metals will release and pollute groundwater.

Increasing precision of turbidity-based suspended sediment concentration and load estimates.

PubMed

Jastram, John D; Zipper, Carl E; Zelazny, Lucian W; Hyer, Kenneth E

2010-01-01

Turbidity is an effective tool for estimating and monitoring suspended sediments in aquatic systems. Turbidity can be measured in situ remotely and at fine temporal scales as a surrogate for suspended sediment concentration (SSC), providing opportunity for a more complete record of SSC than is possible with physical sampling approaches. However, there is variability in turbidity-based SSC estimates and in sediment loadings calculated from those estimates. This study investigated the potential to improve turbidity-based SSC, and by extension the resulting sediment loading estimates, by incorporating hydrologic variables that can be monitored remotely and continuously (typically 15-min intervals) into the SSC estimation procedure. On the Roanoke River in southwestern Virginia, hydrologic stage, turbidity, and other water-quality parameters were monitored with in situ instrumentation; suspended sediments were sampled manually during elevated turbidity events; samples were analyzed for SSC and physical properties including particle-size distribution and organic C content; and rainfall was quantified by geologic source area. The study identified physical properties of the suspended-sediment samples that contribute to SSC estimation variance and hydrologic variables that explained variability of those physical properties. Results indicated that the inclusion of any of the measured physical properties in turbidity-based SSC estimation models reduces unexplained variance. Further, the use of hydrologic variables to represent these physical properties, along with turbidity, resulted in a model, relying solely on data collected remotely and continuously, that estimated SSC with less variance than a conventional turbidity-based univariate model, allowing a more precise estimate of sediment loading, Modeling results are consistent with known mechanisms governing sediment transport in hydrologic systems.

Selective separation of iron from uranium in quantitative determination of traces of uranium by alpha spectrometry in soil/sediment sample.

PubMed

Singhal, R K; Narayanan, Usha; Karpe, Rupali; Kumar, Ajay; Ranade, A; Ramachandran, V

2009-04-01

During this work, controlled redox potential methodology was adopted for the complete separation of traces of uranium from the host matrix of mixed hydroxide of Iron. Precipitates of Fe(+2) and Fe(+3) along with other transuranic elements were obtained from acid leached solution of soil by raising the pH to 9 with 14N ammonia solution. The concentration of the uranium observed in the soil samples was 200-600 ppb, whereas in sediment samples, the concentration range was 61-400 ppb.

Occurrence and concentrations of selected trace elements, halogenated organic compounds, and polycyclic aromatic hydrocarbons in streambed sediments and results of water-toxicity testing in Westside Creeks and the San Antonio River, San Antonio, Texas, 2014

USGS Publications Warehouse

Crow, Cassi L.; Wilson, Jennifer T.; Kunz, James L.

2016-12-01

Sediment samples and samples for water-toxicity testing were collected during 2014 from several streams in San Antonio, Texas, known locally as the Westside Creeks (Alazán, Apache, Martínez, and San Pedro Creeks) and from the San Antonio River. Samples were collected during base flow and after periods of stormwater runoff (poststorm conditions) to determine baseline sediment- and water-quality conditions. Streambed-sediment samples were analyzed for selected constituents, including trace elements and organic contaminants such as pesticides, polychlorinated biphenyls (PCBs), brominated flame retardants, and polycyclic aromatic hydrocarbons (PAHs). Potential risks of contaminants in sediment were evaluated by comparing concentrations of contaminants in sediment to two effects-based sediment-quality guidelines: (1) a lower level, called the threshold effect concentration, below which, harmful effects to benthic biota are not expected, and (2) a higher level, the probable effect concentration (PEC), above which harmful effects are expected to occur frequently. Samples for water-toxicity testing were collected from each stream to provide information about fish toxicity in the study area. The trace metal lead was detected at potentially toxic concentrations greater than the PEC in both the base-flow and poststorm samples collected at two sites sampled on San Pedro Creek. The PECs for the pesticides dichlorodiphenyldichloroethane, dichlorodiphenyldichloroethylene, dichlorodiphenyltrichloroethane, and chlordane were exceeded in some of the samples at the same two sites on San Pedro Creek. Brominated flame retardants and polybrominated diphenyl ether (PBDE) 85, 153, and 154 were found in all streambed-sediment samples. Federal Environmental Quality Guidelines established by Environment Canada for PBDE 99 and PBDE 100 were exceeded in all samples in which PBDE 99 was detected and in a majority of the samples in which PBDE 100 was detected; the greatest concentrations occurred in samples collected at the same two sites on San Pedro Creek where the samples containing elevated lead and pesticide concentrations were collected. All concentrations of total PCBs (computed as the sum of the 18 reported PCB congeners) in the individual streambed-sediment samples were less than the threshold effect concentration, but the concentrations were elevated in the two sites on San Pedro Creek compared to concentrations at other sites. At one site on Apache Creek, 6 of the individual PAHs measured in the sample collected during base-flow conditions exceeded the PECs and 8 of the 9 PECs were exceeded in the sample collected during poststorm conditions. The total PAH concentration in the sample collected at the site during poststorm conditions was 3.3 times greater than the PEC developed for total PAHs. Average PAH profiles computed for base-flow samples and poststorm samples most closely resemble the parking lot coal-tar sealcoat dust PAH source profile, defined as the average PAH concentrations in dust swept from parking lots in six cities in the United States that were sealed with a black, viscous liquid containing coal-tar pitch. Six of ten water samples collected during base-flow conditions caused reductions in Pimephales promelas (fathead minnow) survival and were considered to be toxic.

Loosely bound oxytetracycline in riverine sediments from two tributaries of the Chesapeake Bay

USGS Publications Warehouse

Simon, N.S.

2005-01-01

The fate of antibiotics that bind to riverine sediment is not well understood. A solution used in geochemical extraction schemes to determine loosely bound species in sediments, 1 M MgCl2 (pH 8), was chosen to determine loosely bound, and potentially bioavailable, tetracycline antibiotics (TCs), including oxytetracycline (5-OH tetracycline) (OTC) in sediment samples from two rivers on the eastern shore of the Chesapeake Bay. Bottom sediments were collected at sites upstream from, at, and downstream from municipal sewage-treatment plants (STPs) situated on two natural waterways, Yellow Bank Stream, MD, and the Pocomoke River, MD. Concentrations of easily desorbed OTC ranged from 0.6 to approximately 1.2 ??g g-1 dry wt sediment in Yellow Bank Stream and from 0.7 to approximately 3.3 ??g g-1 dry wt sediment in the Pocomoke River. Concentrations of easily desorbable OTC were generally smaller in sediment upstream than in sediment downstream from the STP in the Pocomoke River. STPs and poultry manure are both potential sources of OTC to these streams. OTC that is loosely bound to sediment is subject to desorption. Other researchers have found desorbed TCs to be biologically active compounds.

Geomorphic field experiment to quantify grain size and biotic influence on riverbed sedimentation dynamics in a dry-season reservoir, Russian River, CA

NASA Astrophysics Data System (ADS)

Florsheim, J. L.; Ulrich, C.; Hubbard, S. S.; Borglin, S. E.; Rosenberry, D. O.

2013-12-01

An important problem in geomorphology is to differentiate between abiotic and biotic fine sediment deposition on coarse gravel river beds because of the potential for fine sediment to infiltrate and clog the pore space between gravel clasts. Infiltration of fines into gravel substrate is significant because it may reduce permeability; therefore, differentiation of abiotic vs. biotic sediment helps in understanding the causes of such changes. We conducted a geomorphic field experiment during May to November 2012 in the Russian River near Wohler, CA, to quantify biotic influence on riverbed sedimentation in a small temporary reservoir. The reservoir is formed upstream of a small dam inflated during the dry season to enhance water supply pumping from the aquifer below the channel; however, some flow is maintained in the reservoir to facilitate fish outmigration. In the Russian River field area, sediment transport dynamics during storm flows prior to dam inflation created an alternate bar-riffle complex with a coarser gravel surface layer over the relatively finer gravel subsurface. The objective of our work was to link grain size distribution and topographic variation to biotic and abiotic sediment deposition dynamics in this field setting where the summertime dam annually increases flow depth and inundates the bar surfaces. The field experiment investigated fine sediment deposition over the coarser surface sediment on two impounded bars upstream of the reservoir during an approximately five month period when the temporary dam was inflated. The approach included high resolution field surveys of topography, grain size sampling and sediment traps on channel bars, and laboratory analyses of grain size distributions and loss on ignition (LOI) to determine biotic content. Sediment traps were installed at six sites on bars to measure sediment deposited during the period of impoundment. Preliminary results show that fine sediment deposition occurred at all of the sample sites, and is spatially variable--likely influenced by topographic differences that moderate flow over the bars. Traps initially filled with coarse gravel from the bar's surface trapped more fine sediment than traps initially filled with material from the bar's subsurface sediment, suggesting that a gravel bar's armor layer may enhance the source of material available to infiltrate into the channel substrate. LOI analysis indicates that both surface and subsurface samples have organic content ranging between 2 and 4%, following winter storm flows prior to impoundment. In contrast, samples collected after the 5-month impoundment have higher organic content ranging between 5 and 11%. This work aids in differentiating between abiotic and biotic fine sediment deposition in order to understand their relative potential for clogging gravel substrate.

Phase I Source Investigation, Heckathorn Superfund Site, Richmond, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohn, Nancy P; Evans, Nathan R

This report represents Phase I of a multi-phase approach to a source investigation of DDT at the Heckathorn Superfund Site, Richmond, California, the former site of a pesticide packaging plant, and the adjacent waterway, the Lauritzen Channel. Potential identified sources of contamination were from sloughed material from undredged areas (such as side banks) and from outfall pipes. Objectives of Phase I included the (1) evaluation of pesticide concentrations associated with discharge from outfalls, (2) identification of additional outfalls in the area, (3) identification of type, quantity, and distribution of sediment under the Levin pier, (4) quantification of pesticide concentrations inmore » sediment under the pier, and (5) evaluation of sediment structure and slope stability under the pier. Field operations included the collection of sediment directly from inside the mouths of outfall pipes, when possible, or the deployment of specially designed particle traps where direct sampling was problematic. Passive water samplers were placed at the end of known outfall pipes and analyzed for DDT and other pesticides of concern. Underwater dive surveys were conducted beneath the Levin pier to document type, slope, and thickness of sediment. Samples were collected at locations of interest and analyzed for contaminants. Also sampled was soil from bank areas, which were suspected of potentially contributing to continued DDT contamination of the Lauritzen Channel through erosion and groundwater leaching. The Phase I Source Investigation was successful in identifying significant sources of DDT contamination to Lauritzen Channel sediment. Undredged sediment beneath the Levin pier that has been redistributed to the channel is a likely source. Two outfalls tested bear further investigation. Not as well-defined are the contributions of bank erosional material and groundwater leaching. Subsequent investigations will be based on the results of this first phase.« less

Water-quality monitoring for a pilot piling removal field evaluation, Coal Creek Slough, Washington, 2008-09

USGS Publications Warehouse

Nilsen, Elena B.; Alvarez, David A.

2011-01-01

Significant Findings Water and sediment quality monitoring was conducted before and after the removal of a piling field located in Coal Creek Slough near Longview, Washington. Passive chemical samplers and continuous water-quality monitoring instruments were deployed at the piling removal site, Coal Creek Slough Site 1 (CCS1), and at a comparison site, Coal Creek Slough Site 2 (CCS2), before (2008) and after (2009) piling removal. Surface and subsurface (core) sediment samples were collected before and after piling removal and were analyzed for grain size, organic carbon content, and chemicals of concern. Significant findings from this study include: * Phenanthrene was the only compound detected in wood piling samples analyzed for a large suite of semivolatile organic compounds and polycyclic aromatic hydrocarbons (PAHs). Metals potentially associated with wood treatment were detected in the wood piling samples at low concentrations. * Organic carbon was slightly lower in core samples from CCS1 in pre-removal (2008) and post-removal (2009) samples than in surface samples from both sites in both years. * Grain-size class distributions were relatively uniform between sites and years. * Thirty-four out of 110 chemicals of concern were detected in sediments. Eight of those detected were anthropogenic waste indicator (AWI) compounds, 18 were PAHs, 4 were sterols, and 4 were metals potentially associated with wood treatment. * Nearly all reported concentrations of chemicals of concern in sediments are qualified as estimates, primarily due to interferences in extracts resulting from complex sample matrices. Indole, perylene, and fluoranthene are reported without qualification for some of the samples, and the metals are reported without qualification for all samples. * The highest frequency of detection of chemicals of concern was seen in the pre-removal surface samples at both sites. * AWI compounds were detected less frequently and at lower concentrations during the post-removal sampling compared to the pre-removal sampling. * Several PAHs were detected at relatively high concentrations in core samples, likely indicating historical sources. * Most commonly detected PAHs in sediments were 2,6-dimethylnaphthalene, fluoranthene, perylene, and pyrene. * Most commonly detected AWIs in sediments were 3-methyl-1h-indole (skatol), acetophenone, indole, phenol, and paracresol. * Sedimentary concentrations of perylene exceeded available sediment quality guidelines. Perylene is widespread in the environment and has large potential natural sources in addition to its anthropogenic sources. * Concentrations of metals did not exceed sediment quality guidelines. * Multiple organochlorine pesticides, both banned and currently used, were detected at each site using passive samplers. * Commonly detected pesticides included hexachlorobenzene, pentachloroanisole (a degradation product of pentachlorophenol), diazinon, cis-chlordane, endosulfan, DDD, and endosulfan sulfate. * PBDE concentrations detected in passive sampler extracts were less than the method detection limit at all sites with the exception of PBDE-99, detected at a concentration less than the reporting limit. * The fragrance galaxolide was detected at a concentration greater than the method detection limit. * Common PAHs, such as phenanthrene, fluoranthene, and pyrene, were detected in every passive sampler. * Dissolved oxygen concentration was slightly higher at site CCS1 compared to site CCS2 in both years. * Overall, there was no systematic increase in chemicals of concern at the restoration site during post-removal monitoring compared to conditions during pre-removal monitoring. Any immediate, short-duration effects of piling removal on water quality could not be determined because monitoring was not conducted during the removal.

Dissolution Rates of Biogenic Carbonate Sediments from the Bermuda Platform

NASA Astrophysics Data System (ADS)

Finlay, A. J.; Andersson, A. J.

2016-02-01

The contribution of biogenic carbonate sediment dissolution rates to overall net reef accretion/erosion (under both present and future oceanic pCO2 levels) has been strikingly neglected, despite experimental results indicating that sediment dissolution might be more sensitive to ocean acidification (OA) than calcification. Dissolution of carbonate sediments could impact net reef accretion rates as well as the formation and preservation of valuable marine and terrestrial ecosystems. Bulk sediment dissolution rates of samples from the Bermuda carbonate platform were measured in natural seawater at pCO2 values ranging from approximately 3500 μatm to 9000 μatm. This range of pCO2 levels incorporates values currently observed in porewaters on the Bermuda carbonate platform as well as a potential future increase in porewater pCO2 levels due to OA. Sediment samples from two different stations on the reef platform were analyzed for grain size and mineralogy. Dissolution rates of sediments in the dominant grain size fraction of the platform (500-1000 μm) from both stations ranged between 16.25 and 47.19 (± 0.27 to 0.79) μmoles g-1 hr-1 and are comparable to rates previously obtained from laboratory experiments on other natural carbonate sediments. At a pCO2 of 3500 μatm, rates from both samples were similar, despite their differing mineralogy. However, at pCO2 levels above 3500 μatm, the sediment sample with a greater weight percent of Mg-calcite had slightly higher dissolution rates. Despite many laboratory studies on biogenic carbonate dissolution, a significant disparity still exists between laboratory measurements and field observations. Performing additional controlled, laboratory experiments on natural sediment may help to elucidate the reasons for this disparity.

Linking microbial heterotrophic activity and sediment lithology in oxic, oligotrophic sub-seafloor sediments of the north atlantic ocean.

PubMed

Picard, Aude; Ferdelman, Timothy G

2011-01-01

Microbial heterotrophic activity was investigated in oxic sub-seafloor sediments at North Pond, a sediment pond situated at 23°N on the western flank of the Mid-Atlantic Ridge. The North Pond sediments underlie the oligotrophic North Atlantic Gyre at 4580-m water depth and cover a 7-8 million-year-old basaltic crust aquifer through which seawater flows. Discrete samples for experimentation were obtained from up to ~9 m-long gravity cores taken at 14 stations in the North Pond area. Potential respiration rates were determined in sediment slurries incubated under aerobic conditions with (14)C-acetate. Microbial heterotrophic activity, as defined by oxidation of acetate to CO(2) (with O(2) as electron acceptor), was detected in all 14 stations and all depths sampled. Potential respiration rates were generally low (<0.2 nmol of respired acetate cm(-3) d(-1)) in the sediment, but indicate that microbial heterotrophic activity occurs in deep-sea, oxic, sub-seafloor sediments. Furthermore, discernable differences in activity existed between sites and within given depth profiles. At seven stations, activity was increased by several orders of magnitude at depth (up to ~12 nmol of acetate respired cm(-3) d(-1)). We attempted to correlate the measures of activity with high-resolution color and element stratigraphy. Increased activities at certain depths may be correlated to variations in the sediment geology, i.e., to the presence of dark clay-rich layers, of sandy layers, or within clay-rich horizons presumably overlying basalts. This would suggest that the distribution of microbial heterotrophic activity in deeply buried sediments may be linked to specific lithologies. Nevertheless, high-resolution microbial examination at the level currently enjoyed by sedimentologists will be required to fully explore this link.

Linking Microbial Heterotrophic Activity and Sediment Lithology in Oxic, Oligotrophic Sub-Seafloor Sediments of the North Atlantic Ocean

PubMed Central

Picard, Aude; Ferdelman, Timothy G.

2011-01-01

Microbial heterotrophic activity was investigated in oxic sub-seafloor sediments at North Pond, a sediment pond situated at 23°N on the western flank of the Mid-Atlantic Ridge. The North Pond sediments underlie the oligotrophic North Atlantic Gyre at 4580-m water depth and cover a 7–8 million-year-old basaltic crust aquifer through which seawater flows. Discrete samples for experimentation were obtained from up to ~9 m-long gravity cores taken at 14 stations in the North Pond area. Potential respiration rates were determined in sediment slurries incubated under aerobic conditions with 14C-acetate. Microbial heterotrophic activity, as defined by oxidation of acetate to CO2 (with O2 as electron acceptor), was detected in all 14 stations and all depths sampled. Potential respiration rates were generally low (<0.2 nmol of respired acetate cm−3 d−1) in the sediment, but indicate that microbial heterotrophic activity occurs in deep-sea, oxic, sub-seafloor sediments. Furthermore, discernable differences in activity existed between sites and within given depth profiles. At seven stations, activity was increased by several orders of magnitude at depth (up to ~12 nmol of acetate respired cm−3 d−1). We attempted to correlate the measures of activity with high-resolution color and element stratigraphy. Increased activities at certain depths may be correlated to variations in the sediment geology, i.e., to the presence of dark clay-rich layers, of sandy layers, or within clay-rich horizons presumably overlying basalts. This would suggest that the distribution of microbial heterotrophic activity in deeply buried sediments may be linked to specific lithologies. Nevertheless, high-resolution microbial examination at the level currently enjoyed by sedimentologists will be required to fully explore this link. PMID:22207869

Bioaccumulation Potential of Contaminants from Bedded and Suspended Oakland Harbor Deepening Project Sediments to San Francisco Bay Flatfish and Bivalve Mollusks

DTIC Science & Technology

1994-08-01

Descriptive Statistics of Sediment Conventional Parameters and Statistical Comparisons of Oil and Grease and Total Petroleum Hydrocarbon Concentrations in...7000 Series, USEPA 1986, Bloom and Crecelius 1987). Oil and grease, total petroleum hydrocarbons . BPNL. Oil and grease were determined accord- ing to...infrared spectrometer. Total petroleum hydrocarbons were determined according to Method 418.1 (USEPA 1983). Sediment samples were extracted with freon

Examining offshore sediment-hosted contaminant transport from Hurricane Katrina: Chapter 7A in Science and the storms-the USGS response to the hurricanes of 2005

USGS Publications Warehouse

Swarzenski, Peter W.; Campbell, Pamela L.; Poore, Richard Z.; Osterman, Lisa E.; Rosenbauer, Robert J.

2007-01-01

A rapid-response expedition was organized after the passage of Hurricane Katrina to investigate potential offshore environmental impacts and storm-induced sediment-transport processes. Both water-column and sediment samples were collected on the Louisiana shelf for a full complement of organic, inorganic, and geochronological tracers. Based on excess lead-210 (210Pb) inventories in cores collected before and after Katrina, the surface sediments and their associated geochemical signatures were considerably affected by the passage of this storm.

Ubiquity of microplastics in coastal seafloor sediments.

PubMed

Ling, S D; Sinclair, M; Levi, C J; Reeves, S E; Edgar, G J

2017-08-15

Microplastic pollutants occur in marine environments globally, however estimates of seafloor concentrations are rare. Here we apply a novel method to quantify size-graded (0.038-4.0mm diam.) concentrations of plastics in marine sediments from 42 coastal and estuarine sites spanning pollution gradients across south-eastern Australia. Acid digestion/density separation revealed 9552 individual microplastics from 2.84l of sediment across all samples; equating to a regional average of 3.4 microplastics·ml -1 sediment. Microplastics occurred as filaments (84% of total) and particle forms (16% of total). Positive correlations between microplastic filaments and wave exposure, and microplastic particles with finer sediments, indicate hydrological/sediment-matrix properties are important for deposition/retention. Contrary to expectations, positive relationships were not evident between microplastics and other pollutants (heavy metals/sewage), nor were negative relationships with neighbouring reef biota detected. Rather, microplastics were ubiquitous across sampling sites. Positive associations with some faunal-elements (i.e. invertebrate species richness) nevertheless suggest high potential for microplastic ingestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heavy metals and polycyclic aromatic hydrocarbons in surface sediments of Karoon River, Khuzestan Province, Iran.

PubMed

Keshavarzi, Behnam; Mokhtarzadeh, Zeinab; Moore, Farid; Rastegari Mehr, Meisam; Lahijanzadeh, Ahmadreza; Rostami, Soqra; Kaabi, Helena

2015-12-01

Karoon is the longest river in Iran and provides water for industries located along its banks, such as metal, petrochemical, and oil industries. It is also the source of drinking water for cities such as Ahwas, Abadan, and Khorramshahr. In this study, 34 and 18 surface sediment samples were collected and analyzed for heavy metals (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and polycyclic aromatic hydrocarbons (PAHs). The measured concentrations of heavy metals were compared with US EPA sediment quality guidelines, and the results showed that Cu concentration was above the threshold effect level (TEL) in 65.67% of the samples and Hg concentration was above the effect range median (ERM) in some samples. The results revealed that Hg was severely enriched (5 < enrichment factor < 20) and classified in very high ecological risk index category. It is the major metallic contaminant in the study area. The total PAH concentrations ranged from 11.54-117,730 μg/kg, with the mean value of 7034.55 μg/kg dominated by lower molecular weight (LMW) PAHs. The total potentially carcinogenic PAHs (∑cPAHs) in sediment samples ranged from 2.09 to 31,930 μg/kg, indicating high carcinogenic potential of sediments in the study area. The total toxic equivalent (TEQ) values ranged from 1.06 to 7228.7 μg/kg. Maximum TEQ occurred in Abadan oil refinery station followed by Khorramshahr soap factory and Abadan petrochemical complex. Principal component analysis and cluster analysis also revealed the relationships between the studied parameters and identified their probable sources.

Semi-automatic surface sediment sampling system - A prototype to be implemented in bivalve fishing surveys

NASA Astrophysics Data System (ADS)

Rufino, Marta M.; Baptista, Paulo; Pereira, Fábio; Gaspar, Miguel B.

2018-01-01

In the current work we propose a new method to sample surface sediment during bivalve fishing surveys. Fishing institutes all around the word carry out regular surveys with the aim of monitoring the stocks of commercial species. These surveys comprise often more than one hundred of sampling stations and cover large geographical areas. Although superficial sediment grain sizes are among the main drivers of benthic communities and provide crucial information for studies on coastal dynamics, overall there is a strong lack of this type of data, possibly, because traditional surface sediment sampling methods use grabs, that require considerable time and effort to be carried out on regular basis or on large areas. In face of these aspects, we developed an easy and un-expensive method to sample superficial sediments, during bivalve fisheries monitoring surveys, without increasing survey time or human resources. The method was successfully evaluated and validated during a typical bivalve survey carried out on the Northwest coast of Portugal, confirming that it had any interference with the survey objectives. Furthermore, the method was validated by collecting samples using a traditional Van Veen grabs (traditional method), which showed a similar grain size composition to the ones collected by the new method, on the same localities. We recommend that the procedure is implemented on regular bivalve fishing surveys, together with an image analysis system to analyse the collected samples. The new method will provide substantial quantity of data on surface sediment in coastal areas, using a non-expensive and efficient manner, with a high potential application in different fields of research.

Source Apportionment of Suspended Sediment Sources using 137Cs and 210Pbxs

NASA Astrophysics Data System (ADS)

Lamba, J.; Karthikeyan, K.; Thompson, A.

2017-12-01

A study was conducted in the Pleasant Valley Watershed (50 km 2) in South Central Wisconsin to better understand sediment transport processes using sediment fingerprinting technique. Previous studies conducted in this watershed showed that resuspension of fine sediment deposited on the stream bed is an important source of suspended sediment. To better understand the role of fine sediment deposited on the stream bed, fallout radionuclides,137Cs and 210Pbxs were used to determine relative contribution to suspended sediment from in-stream (stream bank and stream bed) and upland sediment sources. Suspended sediment samples were collected during the crop growing season. Potential sources of suspended sediment considered in this study included cropland, pasture and in-stream (stream bed and stream bank). Suspended sediment sources were determined at a subwatershed level. Results of this study showed that in-stream sediment sources are important sources of suspended sediment. Future research should be conducted to better understand the role of legacy sediment in watershed-level sediment transport processes.

Estuarine bed-sediment-quality data collected in New Jersey and New York after Hurricane Sandy, 2013

USGS Publications Warehouse

Fischer, Jeffrey M.; Phillips, Patrick J.; Reilly, Timothy J.; Focazio, Michael J.; Loftin, Keith A.; Benzel, William M.; Jones, Daniel K.; Smalling, Kelly L.; Fisher, Shawn C.; Fisher, Irene J.; Iwanowicz, Luke R.; Romanok, Kristin M.; Jenkins, Darkus E.; Bowers, Luke; Boehlke, Adam; Foreman, William T.; Deetz, Anna C.; Carper, Lisa G.; Imbrigiotta, Thomas E.; Birdwell, Justin E.

2015-01-01

Bed-sediment samples were collected from June to October 2013 from 167 estuarine sites extending from Cape May, New Jersey, to the New York Harbor and the eastern end of Long Island. Each sampling location and study region was characterized by using geographic information to identify potential contaminant sources. Characterizations included land cover, locations and types of businesses (industrial, financial, and others), spills (sewage, chemical, and others), bulk storage facilities, effluent discharges within 2 kilometers of the sampling point, and discharges within inundated and non-inundated regions near the sampling location. Samples were analyzed for particle size, total organic carbon, metals and trace elements, semivolatile organic compounds, wastewater compounds, hormones, and sediment toxicity. Samples were also screened using x-ray fluorescence, Fourier transform infrared spectroscopy, and x-ray diffraction. In addition, bioassays for endocrine disruptors and protein phosphatase 2A inhibition were conducted. The study was designed to provide the data needed to understand the extent and sources of contamination resulting from Hurricane Sandy, to compare the chemistry and toxicity of estuarine bed sediments before and after the storm, and to evaluate the usefulness of rapid screening and bioassay approaches in disaster settings.

Hydrologic and sediment data collected from selected basins at the Fort Leonard Wood Military Reservation, Missouri--2010-11

USGS Publications Warehouse

Richards, Joseph M.; Rydlund, Jr., Paul H.; Barr, Miya N.

2012-01-01

Commercial and residential development within a basin often increases the amount of impervious area, which changes the natural hydrologic response to storm events by increasing runoff. Land development and disturbance combined with increased runoff from impervious areas potentially can increase sediment transport. At the Fort Leonard Wood Military Reservation in Missouri, there has been an increase in population and construction activities in the recent past, which has initiated an assessment of the hydrology in selected basins. From April 2010 to December 2011, the U.S. Geological Survey, in cooperation with the U.S. Army Maneuver Support Center at the Fort Leonard Wood Military Reservation, collected hydrologic and suspended-sediment concentration data in six basins at Fort Leonard Wood. Storm-sediment concentration, load, and yield varied from basin to basin and from storm to storm. In general, storm-sediment yield, in pounds per square mile per minute, was greatest from Ballard Hollow tributary (06928410) and Dry Creek (06930250), and monthly storm-sediment yield, in tons per square mile, estimates were largest in Ballard Hollow tributary (06928410), East Gate Hollow tributary (06930058), and Dry Creek (06930250). Sediment samples, collected at nine sites, primarily were collected using automatic samplers and augmented with equal-width-increment cross-sectional samples and manually collected samples when necessary. Storm-sediment load and yield were computed from discharge and suspended-sediment concentration data. Monthly storm-sediment yields also were estimated from the total storm discharge and the mean suspended-sediment concentration at each given site.

Evaluating suitability of MODIS-Terra images for reproducing historic sediment concentrations in water bodies: Lake Tana, Ethiopia

NASA Astrophysics Data System (ADS)

Kaba, Essayas; Philpot, William; Steenhuis, Tammo

2014-02-01

Government and NGO funded conservation programs are being implemented in developing countries with the potential benefit of reduced sediment inflow into fresh water lakes. However, these claims are difficult to verify due to limited historical sediment concentration data in lakes and rivers. Remote sensing can potentially aid in monitoring sediment concentration. With almost daily availability over the past ten years and consistent atmospheric correction applied to the images, Moderate Resolution Imaging Spectroradiometer (MODIS) 250 meter images are potential resources capable of monitoring future concentrations and reconstructing historical sediment concentration records. In this paper, site-specific relationships are developed between reflectance in near-infrared (NIR) images and three factors: total suspended solids (TSS), turbidity and Secchi depth for Lake Tana near the mouth of the Gumara River. The first two sampling campaigns on November 27, 2010 and May 13, 2011 are used in calibration. Reflectance in the NIR varies linearly with turbidity (R2 = 0.89) and TSS (R2 = 0.95). Secchi depth fit best to an exponential relation with R2 of 0.74. The relationships are validated using a third sample set collected on November 7, 2011 with RMSE of 11 Nephelometric Turbidity Units (NTU) for Turbidity, 16.5 mg l-1 for TSS and 0.12 meters for Secchi depth. The MAE was 10% for TSS, 14% for turbidity and 0.1% for Secchi depth. Using the relationship for TSS, a 10-year time series of sediment concentration in Lake Tana near the Gumara River was plotted. It was found that after the severe drought of 2002 and 2003 the concentration in the lake increased significantly. The results showed that MODIS images are potential cost effective tools to monitor suspended sediment concentration and obtain a past history of concentration for evaluating the effect of best management practices.

Physical and chemical properties of water and sediments, Grand Portage and Wauswaugoning Bays, Lake Superior, Grand Portage Indian Reservation, northeastern Minnesota, 1993-96

USGS Publications Warehouse

Ruhl, J.F.

1997-01-01

This report is a compilation of data on the physical and chemical properties of water and sediments in Grand Portage and Wauswaugoning Bays of Lake Superior along the shoreline of the Grand Portage Indian Reservation. The data were collected during 1993-96 by the U.S. Geological Survey in cooperation with the Grand Portage Indian Reservation. The data include: (1) temperature, pH, and specific conductance measurements and dissolved oxygen concentrations; (2) Secchi disk transparency, alkalinity, and turbidity measurements; (3) fecal Coliform and fecal Streptococcal bacteria colony counts (per 100 milliliters of sample water); (4) major and minor ion, nutrient, and trace-metal concentrations; (5) dissolved and suspended residue concentrations; (6) pesticide, phenol, and asbestos concentrations; (7) suspended sediment trace-metal concentrations; and (8) bottom sediment trace-metal concentrations. Water samples were collected from nine sites; suspended and bottom sediment samples were collected from five sites. The data in this report can be used to evaluate present water-quality conditions and as a reference to monitor potential long-term changes in these conditions.

Butyltin compounds in sediments from the commercial harbor of Alexandria City, Egypt.

PubMed

Barakat, A O; Kim, M; Qian, Y; Wade, T L

2001-12-01

Tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) compounds were quantitatively determined in surface-sediment samples collected from 23 sites in the commercial harbor of Alexandria City, Egypt. Butyltin concentrations in sediments varied widely depending on the sample location, ranging from less than 0.1 to 186 ng g(-1) of Sn for MBT, less than 0.1 to 379 ng g(-1) of Sn for DBT, and 1 to 2,067 ng g(-1) of Sn for TBT Elevated TBT concentrations, ranging from 727 to 2,067 ng g(-1) of Sn were observed in harbors, marinas, and near ship-repair facilities, indicating that the butyltin-containing, antifouling paints of boats and vessels are the major source of butyltin contamination. The TBT concentration decreased rapidly away from potential source areas of boat docking and repair facilities. The high relative concentrations of TBT in the sediments indicated that degradation processes in the sediments are minor, probably due to the anoxic sedimentary conditions at the sampling sites and/or relatively fresh input of TBT to these sites.

Assessment of the ecotoxicity of urban estuarine sediment using benthic and pelagic copepod bioassays.

PubMed

Charry, Maria P; Keesing, Vaughan; Costello, Mark; Tremblay, Louis A

2018-01-01

Urban estuarine sediments are sinks to a range of contaminants of anthropogenic origin, and a key challenge is to characterize the risk of these compounds to receiving environments. In this study, the toxicity of urban estuarine sediments was tested using acute and chronic bioassays in the benthic harpacticoid Quinquelaophonte sp., and in the planktonic calanoid Gladioferens pectinatus , two New Zealand copepod species. The sediment samples from the estuary tributary sites significantly impacted reproduction in Quinquelaophonte sp. However, results from one of the estuary sites were not significantly different to those from the tributaries sites, suggesting that chemicals other than trace metals, polycyclic aromatic hydrocarbons and ammonia may be the causative stressors. Sediment elutriate samples had significant effects on reproductive endpoints in G. pectinatus , and on the induction of DNA damage in cells, as shown by the comet assay. The results indicate that sediment contamination at the Ahuriri Estuary has the potential to impact biological processes of benthic and pelagic organisms. The approach used provides a standardized methodology to assess the toxicity of estuarine sediments.

Metal release from contaminated coastal sediments under changing pH conditions: Implications for metal mobilization in acidified oceans.

PubMed

Wang, Zaosheng; Wang, Yushao; Zhao, Peihong; Chen, Liuqin; Yan, Changzhou; Yan, Yijun; Chi, Qiaoqiao

2015-12-30

To investigate the impacts and processes of CO2-induced acidification on metal mobilization, laboratory-scale experiments were performed, simulating the scenarios where carbon dioxide was injected into sediment-seawater layers inside non-pressurized chambers. Coastal sediments were sampled from two sites with different contamination levels and subjected to pre-determined pH conditions. Sediment samples and overlying water were collected for metal analysis after 10-days. The results indicated that CO2-induced ocean acidification would provoke increased metal mobilization causing adverse side-effects on water quality. The mobility of metals from sediment to the overlying seawater was correlated with the reduction in pH. Results of sequential extractions of sediments illustrated that exchangeable metal forms were the dominant source of mobile metals. Collectively, our data revealed that high metal concentrations in overlying seawater released from contaminated sediments under acidic conditions may strengthen the existing contamination gradients in Maluan Bay and represent a potential risk to ecosystem health in coastal environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Geochemical Fractionations and Mobility of Arsenic, Lead and Cadmium in Sediments of the Kanto Plain, Japan.

NASA Astrophysics Data System (ADS)

Hossain, Sushmita; Oguchi, Chiaki T.; Hachinohe, Shoichi; Ishiyama, Takashi; Hamamoto, Hideki

2014-05-01

Lowland alluvial and floodplain sediment play a major role in transferring heavy metals and other elements to groundwater through sediment water interaction in changing environmental conditions. However identification of geochemical forms of toxic elements such as arsenic (As), lead (Pb) and cadmium (Cd) requires risk assessment of sediment and subsequent groundwater pollution. A four steps sequential extraction procedure was applied to characterize the geochemical fractionations of As, Pb and Cd for 44 sediment samples including one peat sample from middle basin area of the Nakagawa river in the central Kanto plain. The studied sediment profile extended from the bottom of the river to 44 m depth; sediment samples were collected at 1m intervals from a bored core. The existing sedimentary facies in vertical profile are continental, transitional and marine. There are two aquifers in vertical profile; the upper aquifer (15-20m) contains fine to medium sand whereas medium to coarse sand and gravelly sand contain in lower aquifer (37-44m). The total As and Pb contents were measured by the X-Ray Fluorescence analysis which ranged from 4 to 23 mg/kg of As and 10 to 27 mg/kg of Pb in sediment profile. The three trace elements and major heavy metals were determined by ICP/MS and ICP/AES, and major ions were measured by an ion chromatograph. The marine sediment is mainly Ca-SO4 type. The Geochemical analysis showed the order of mobility trends to be As > Pb > Cd for all the steps. The geochemical fractionations order was determined to be Fe-Mn oxide bound > carbonate bound > ion exchangeable > water soluble for As and Pb whereas the order for Cd is carbonate bound > Fe-Mn oxide bound > ion exchangeable > water soluble. The mobility tendency of Pb and Cd showed high in fine silty sediment of marine environment than for those from continental and transitional environments. In the case of As, the potential mobility is very high (>60%) in the riverbed sediments and clayey silt sediment at 13m depth which is just above the upper aquifer. This potential mobility may pose a threat to upper aquifer and riverbed aquatic system. The overall geochemical analysis revealed that the dissolution of Fe-Mn oxide is the most effective mechanism for As, Pb in groundwater however the mobility of Cd is mainly carbonate bound. In the present study, the pollution level is much below from leaching environmental standards (0.01 mg/L) for all three elements and the total content is within the natural abundance of As, Pb and Cd in sediment. The potential mobility of these elements in oxidized fine silty sediment and the possible further effect to the aquifer suggest that shallow groundwater abstraction should be restricted to protect seasonal groundwater fluctuation. Moreover marine sediment containing high total toxic element contents and mobility tendency at changing oxidation and reduction environments requires proper management when sediments are excavated for construction purpose.

Ecological-Evaluation of Organotin-Contaminated Sediment.

DTIC Science & Technology

1985-07-01

the potential for bioaccumulation of cadmium, chromium, copper, mercury , silver, pesticides, PCBs, petroleum hydrocarbons, and organotins RESULTS The...tissues were frozen for subsequent bioaccumulation estimates. Tissues and sediment samples were analyzed for cadmium, chromium, copper, mercury , silver...spectroscopy; mercury was analyzed by cold vapor atomic absorption spectroscopy. Pesticides, PCBs, and petroleum hydrocarbons were measured by gas

Assessment of Heavy Metal Pollution in Sediments of Inflow Rivers to Lake Taihu, China.

PubMed

Niu, Yong; Niu, Yuan; Pang, Yong; Yu, Hui

2015-11-01

Lake Taihu, the third-largest freshwater body in China, has many functions, including drinking water supply, flood control, cultivation, navigation, and tourism. In this study, sediment samples were collected at 31 sites from 11 inflow rivers in 2012, to investigate the distribution and concentration of heavy metals copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), and chromium (Cr), and to assess their potential ecological risk. The highest mean concentration was found for Zn, followed by Cu, Cr, Pb, and Ni. Generally, heavy metal pollution was more serious in Wu Jingang River and Caoqiao River, probably because they receive large amounts of wastewater from various local industrial enterprises. The potential ecological risk values of the heavy metals were larger than 120 in more than 25.8% of the sediment samples, indicating a very high risk. The largest ecological risk was due to copper. Furthermore, the results of a principal component analysis and subsequent analysis of variance showed that heavy metal concentrations in the sediment of inflow rivers were higher than those of the lake, which created a large hazard for the aquatic ecosystems of Lake Taihu.

Polycyclic aromatic hydrocarbons in oysters and sediments from the Yatsushiro Sea, Japan: comparison of potential risks among PAHs, dioxins and dioxin-like compounds in benthic organisms.

PubMed

Nakata, Haruhiko; Uehara, Kiriko; Goto, Yuta; Fukumura, Miki; Shimasaki, Hideyuki; Takikawa, Kiyoshi; Miyawaki, Takashi

2014-01-01

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in oysters collected from 18 stations in the Yatsushiro Sea, western Japan. PAHs were detected in all samples analyzed, and the highest concentration (mean 230 ng/g wet weight) was found in oysters from Tanoura Bay. The high molecular weight PAHs to low molecular weight PAHs ratios in oysters from Tanoura Bay were higher than at other stations. Sediment samples collected from 42 stations in Tanoura Bay were analyzed for PAHs to understand their concentrations and distribution. Higher concentrations were found in sediment samples at two stations in the southern inner bay (mean 30,200 ng/g dry weight), which were approximately two orders of magnitude higher than at a reference site. These observations strongly suggest severe contamination and significant sources of PAHs in Tanoura Bay. Dioxins and dioxin-like compounds (PCDFs, and non- and mono-ortho coplanar PCBs) were analyzed in sediments from eight stations in Tanoura Bay. The concentrations were comparable to, or lower than, at the reference sites, suggesting that there are no specific sources of these compounds in this bay. PAH, dioxins and dioxin-like compounds DR-CALUX relative potencies (REP) were applied to the sediment concentrations to evaluate the potential for toxicological effects on benthic organisms. PAHs made the highest contribution to the total REP concentration, supplying 99% of the total REP, followed by PCDDs (0.18%), PCDFs (0.04%), and PCBs (<0.001%). In this area, PAHs appear to be the most important Ah receptor binding chemicals for potential toxicity to benthic species. © 2013 Published by Elsevier Inc.

Organic waste compounds in streams: Occurrence and aquatic toxicity in different stream compartments, flow regimes, and land uses in southeast Wisconsin, 2006–9

USGS Publications Warehouse

Baldwin, Austin K.; Corsi, Steven R.; Richards, Kevin D.; Geis, Steven W.; Magruder, Christopher

2013-01-01

An assessment of organic chemicals and aquatic toxicity in streams located near Milwaukee, Wisconsin, indicated high potential for adverse impacts on aquatic organisms that could be related to organic waste compounds (OWCs). OWCs used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewage overflows, among other sources. Many of these compounds are toxic at elevated concentrations and (or) known to have endocrine-disrupting potential, and often they occur as complex mixtures. There is still much to be learned about the chronic exposure effects of these compounds on aquatic populations. During 2006–9, the U.S. Geological Survey, in cooperation with the Milwaukee Metropolitan Sewerage District (MMSD), conducted a study to determine the occurrence and potential toxicity of OWCs in different stream compartments and flow regimes for streams in the Milwaukee area. Samples were collected at 17 sites and analyzed for a suite of 69 OWCs. Three types of stream compartments were represented: water column, streambed pore water, and streambed sediment. Water-column samples were subdivided by flow regime into stormflow and base-flow samples. One or more compounds were detected in all 196 samples collected, and 64 of the 69 compounds were detected at least once. Base-flow samples had the lowest detection rates, with a median of 12 compounds detected per sample. Median detection rates for stormflow, pore-water, and sediment samples were more than double that of base-flow samples. Compounds with the highest detection rates include polycyclic aromatic hydrocarbons (PAHs), insecticides, herbicides, and dyes/pigments. Elevated occurrence and concentrations of some compounds were detected in samples from urban sites, as compared with more rural sites, especially during stormflow conditions. These include the PAHs and the domestic waste-water-indicator compounds, among others. Urban runoff and storm-related leaks of sanitary sewers and (or) septic systems may be important sources of these and other compounds to the streams. The Kinnickinnic River, a highly urbanized site, had the highest detection rates and concentrations of compounds of all the sampled sites. The Milwaukee River near Cedarburg—one of the least urban sites—and the Outer Milwaukee Harbor site had the lowest detection rates and concentrations. Aquatic-toxicity benchmarks were exceeded for 12 of the 25 compounds with known benchmarks. The compounds with the greatest benchmark exceedances were the PAHs, both in terms of exceedance frequency (up to 93 percent for some compounds in sediment samples) and magnitude (concentrations up to 1,024 times greater than the benchmark value). Other compounds with toxicity-benchmark exceedances include Bis(2-ethylhexyl) phthalate (a plasticizer), 2-Methylnapthalene (a component of fuel and oil), phenol (an antimicrobial disinfectant with diverse uses), and 4-Nonylphenol (sum of all isomers; a detergent metabolite, among other uses). Analyzed as a mixture, the suite of PAH compounds were found to be potentially toxic for most non-base-flow samples. Bioassay tests were conducted on samples from 14 streams: Ceriodaphnia dubia in base-flow samples, Ceriodaphnia dubia and Hyallela azteca in pore-water samples, and Hyallela azteca and Chironomus tentans in sediment samples. The greatest adverse effect was observed in tests with Chironomus tentans from sediment samples. The weight of Chironomus tentans after exposure to sediments decreased with increased OWC concentrations. This was most evident in the relation between PAH results and Chironomus tentans bioassay results for the majority of samples; however, solvents and flame retardants appeared to be important for one site each. These results for PAHs were consistent with assessment of PAH potency factors for sediment, indicating that PAHs were likely to have adverse effects on aquatic organisms in many of the streams studied.

Trace elements and organic chemicals in stream-bottom sediments and fish tissues, Red River of the North basin, Minnesota, North Dakota, and South Dakota, 1992-95

USGS Publications Warehouse

Brigham, M.E.; Goldstein, R.M.; Tornes, L.H.

1998-01-01

Stream-bottom sediment and fish-tissue samples from the Red River of the North Basin, were analyzed for a large suite of chemical elements and organic chemicals. Cadmium, lead, and mercury were widespread in sediments, at concentrations not indicative of acute contamination. Mercury, the element of greatest health concern in the region, was detected at low concentrations in 38 of 43 sediment samples (<0.02-0.13 micrograms per gram) and all of eleven fish-liver samples (0.03-0.6 micrograms per gram dry weight, or 0.0066-0.13 micrograms per gram wet weight). Concentrations of many elements appeared to be controlled by mineral rather than anthropogenic sources. DDT and its metabolites were the most frequently detected synthetic organochlorines: p,p'-DDE was detected in 9 of 38 sediment samples (concentration range: <1-16 nanograms per gram) and also frequently in whole-fish samples. Total DDT (the sum of DDT and its metabolites) concentrations ranged from <5 to 217 nanograms per gram, and at least one component of total DDT was detected in 19 of 23 fish samples. Concentrations of DDT and its metabolites in stream sediments were significantly higher in the intensively cropped Red River Valley Lake Plain, compared to upland areas, probably because of greater historical DDT usage in the lake plain. Several polycyclic aromatic hydrocarbons were detected in stream-bottom sediments. Although the potentially toxic chemicals measured in this study were at low levels, relative to more contaminated areas of the Nation, maximum concentrations of some chemicals are of concern because of their possible effects on aquatic biota and human health.

Characterization and physical properties of hydrate bearing sediments

NASA Astrophysics Data System (ADS)

Terzariol, M.; Santamarina, C.

2016-12-01

The amount of carbon trapped in hydrates is estimated to be larger than in conventional oil and gas reservoirs, thus methane hydrate is a promising energy resource. The high water pressure and the relatively low temperature needed for hydrate stability restrict the distribution of methane hydrates to continental shelves and permafrost regions. Stability conditions add inherent complexity to coring, sampling, handling, testing and data interpretation, have profound implications on potential production strategies. Thus a novel technology is developed for handling, transferring, and testing of natural hydrate bearing sediments without depressurization in order to preserve the sediment structure. Results from the first deployment of these tools on natural samples from Nankai Trough, Japan will also be summarized. Finally, to avoid consequences of poor sampling, a new multi-sensor in-situ characterization tool will be introduced.

Geochemical data for mercury, methylmercury, and other constituents in sediments from Englebright Lake, California, 2002

USGS Publications Warehouse

Alpers, Charles N.; Hunerlach, Michael P.; Marvin-DePasquale, Mark C.; Antweiler, Ronald C.; Lasorsa, Brenda K.; De Wild, John F.; Snyder, Noah P.

2006-01-01

Deep coring penetrated the full thickness of material deposited after 1940 at six locations in the reservoir; the cores reached a maximum depth of 32.8 meters below the reservoir floor. At the three deep coring sites closest to Englebright Dam, concentrations of HgT (dry basis) were consistently in the range of 100 to 500 ng/g (nanogram per gram), in sediment dominantly of silt size (median grain size of 0.004 to 0.063 mm [millimeter]). At the deep coring sites located farther upstream, the upper parts of the profile had lower concentrations of HgT, generally ranging from 2 to 100 ng/g, in sediment dominantly of sand size (median grain size from 0.063 to 2 mm). The lower part of the vertical profiles at three upstream coring sites had higher concentrations of HgT than the upper and middle parts of these profiles, and had finer median grain size. The highest median concentration of MeHg (1.1 ng/g) was in the top 2 cm (centimeter) of the shallow box cores. This vertical interval also had the highest value of the ratio of MeHg to HgT, 0.41 percent. Median concentrations of MeHg and median values of MeHg/HgT decreased systematically with depth from 0-4 to 4-8 to 8-12 cm in the shallow cores. However, similar systematic decreases were not observed at the meter scale in the deep cores of the MEM (MEthylMercury) series. The overall median of the ratio MeHg/HgT in the deep cores was 0.25 percent, not much less than the overall median value for the shallow cores (0.33 percent). Mercury-203 radiotracer divalent inorganic mercury (203Hg(II)) was used to determine microbial mercury-methylation potential rates for 11 samples collected from three reservoir locations and various depths in the sediment profile. For the five shallow mercury-methylation subsamples, ancillary geochemical parameters were assayed, including microbial sulfate reduction rates, sulfur speciation (sediment acid volatile sulfide, total reduced sulfur, and pore-water sulfate), iron speciation (sediment acid extractable iron(II), amorphous iron(III), crystalline iron(III) and pore-water iron(II)), pore-water chloride and dissolved organic carbon, and pH, oxidation-reduction potential (Eh) and whole-sediment organic content. The highest potential rates of microbial mercury methylation were measured in shallow (0 to 8 cm depth) sediments (5 to 30 nanograms of mercury per gram dry sediment per day), whereas potential rates for subsamples collected from depths greater than 500 cm were consistently below the detection limit of the radiotracer method (< 0.02 nanogram of mercury per gram dry sediment per day). Chemical analyses of trace and major elements in bed sediment are presented for 202 samples from deep cores from five locations in Englebright Lake. The mean values and standard deviations for selected trace elements were as follows (in micrograms per gram): antimony, 2.4 ? 1.6; arsenic, 69 ? 48; chromium, 134 ? 23; lead, 33 ? 25; and nickel, 87 ? 24. Concentrated samples of heavy-mineral grains, prepared using nine large-volume composite samples from

Identification of functionally active aerobic methanotrophs in sediments from an arctic lake using stable isotope probing

USGS Publications Warehouse

He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Catranis, Catharine; Quensen, John; Tiedje, James M.; Leigh, Mary Beth

2012-01-01

Arctic lakes are a significant source of the greenhouse gas methane (CH4), but the role that methane oxidizing bacteria (methanotrophs) play in limiting the overall CH4 flux is poorly understood. Here, we used stable isotope probing (SIP) techniques to identify the metabolically active aerobic methanotrophs in upper sediments (0–1 cm) from an arctic lake in northern Alaska sampled during ice-free summer conditions. The highest CH4 oxidation potential was observed in the upper sediment (0–1 cm depth) with 1.59 μmol g wet weight-1 day-1 compared with the deeper sediment samples (1–3 cm, 3–5 cm and 5–10 cm), which exhibited CH4 oxidation potentials below 0.4 μmol g wet weight-1 day-1. Both type I and type II methanotrophs were directly detected in the upper sediment total communities using targeted primer sets based on 16S rRNA genes. Sequencing of 16S rRNA genes and functional genes (pmoA and mxaF) in the 13C-DNA from the upper sediment indicated that type I methanotrophs, mainly Methylobacter, Methylosoma, Methylomonas and Methylovulum miyakonense, dominated the assimilation of CH4. Methylotrophs, including the genera Methylophilus and/or Methylotenera, were also abundant in the 13CDNA. Our results show that a diverse microbial consortium acquired carbon from CH4 in the sediments of this arctic lake.

Exploring the differences of antibiotic resistance genes profiles between river surface water and sediments using metagenomic approach.

PubMed

Jiang, Haoyu; Zhou, Renjun; Zhang, Mengdi; Cheng, Zhineng; Li, Jun; Zhang, Gan; Chen, Baowei; Zou, Shichun; Yang, Ying

2018-05-30

To better understand the potential genic communication and dissemination of antibiotic resistance genes (ARGs) in different environmental matrices, the differences of ARG profiles between river surface water and sediments were explored. Metagenomic analysis was applied to investigate the comprehensive ARG profiles in water and sediment samples collected from the highly human-impacted catchment of the Beijiang River and its river source. A total of 135 ARG subtypes belonging to 18 ARG types were identified. Generally, ARGs in surface water were more diverse and abundant than those in sediments. ARG profiles in the surface water and sediment samples were distinct from each other, but some ARGs were shared by the surface water and sediments. Results revealed that multidrug and bacitracin resistance genes were the predominant ARGs types in both surface water (0.30, 0.17 copies/cell) and sediments (0.19, 0.15 copies/cell). 73 ARG subtypes were shared by the water and sediment samples and had taken over 90% of the total detected ARG abundance. Most of the shared ARGs are resistant to the clinically relevant antibiotics. Furthermore, significant correlations between the ARGs and 21 shared genera or mobile genetic elements (MGEs) (plasmids and integrons) were found in surface water and sediments, suggesting the important role of genera or MGEs in shaping ARGs profiles, propagation and distribution. These findings provide deeper insight into mitigating the propagation of ARGs and the associated risks to public health. Copyright © 2018 Elsevier Inc. All rights reserved.

Runoff of genotoxic compounds in river basin sediment under the influence of contaminated soils.

PubMed

da Costa, Thatiana Cappi; de Brito, Kelly Cristina Tagliari; Rocha, Jocelita Aparecida Vaz; Leal, Karen Alam; Rodrigues, Maria Lucia Kolowski; Minella, Jean Paolo Gomes; Matsumoto, Silvia Tamie; Vargas, Vera Maria Ferrão

2012-01-01

Contaminated sites must be analyzed as a source of hazardous compounds in the ecosystem. Contaminant mobility in the environment may affect sources of surface and groundwater, elevating potential risks. This study looked at the genotoxic potential of samples from a contaminated site on the banks of the Taquari River, RS, Brazil, where potential environmental problems had been identified (pentachlorophenol, creosote and hydrosalt CCA). Samplers were installed at the site to investigate the drainage material (water and particulate soil matter) collected after significant rainfall events. Organic extracts of this drained material, sediment river samples of the Taquari River (interstitial water and sediment organic extracts) were evaluated by the Salmonella/microsome assay to detect mutagenicity and by Allium cepa bioassays (interstitial water and whole sediment samples) to detect chromosomal alterations. Positive mutagenicity results in the Salmonella/microsome assay of the material exported from the area indicate that contaminant mixtures may have drained into the Taquari River. This was confirmed by the similarity of mutagenic responses (frameshift indirect mutagens) of organic extracts from soil and river sediment exported from the main area under the influence of the contaminated site. The Allium cepa test showed significant results of cytotoxicity, mutagenic index and chromosome aberration in the area under the same influence. However, it also showed the same similarity in positive results at an upstream site, which probably meant different contaminants. Chemical compounds such as PAHs, PCF and chromium, copper and arsenic were present in the runoff of pollutants characteristically found in the area. The strategy employed using the Salmonella/microsome assay to evaluate effects of complex contaminant mixtures, together with information about the main groups of compounds present, allowed the detection of pollutant dispersion routes from the contaminated site to the Taquari River sediment. Copyright © 2011 Elsevier Inc. All rights reserved.

Organochlorine compounds and trace elements in fish tissue and streambed sediment in the Mobile River Basin, Alabama, Mississippi, and Georgia, 1998

USGS Publications Warehouse

Zappia, Humbert

2002-01-01

During the summer of 1998, as part of the National Water-Quality Assessment Program, a survey was conducted to determine which organochlorine compounds and trace elements occur in fish tissues and streambed sediments in the Mobile River Basin, which includes parts of Alabama, Mississippi, Georgia, and Tennessee. The data collected were compared to guidelines related to wildlife, land use, and to 1991 and 1994 National Water-Quality Assessment Program Study-Unit data.Twenty-one sites were sampled in subbasins of the Mobile River Basin. The subbasins ranged in size from about 9 to 22,000 square miles and were dominated by either a single land use or a combination of land uses. The major land-use categories were urban, agriculture, and forest.Organochlorine compounds were widespread spatially in the Mobile River Basin. At least one organochlorine compound was reported at the majority of sampling sites (84 percent) and in a majority of whole-fish (80 percent) and streambed-sediment (52 percent) samples. Multiple organochlorine compounds were reported at 75 percent of the sites where fish tissues were collected and were reported at many of the streambed-sediment sampling sites (45 percent). The majority of concentrations reported, however, were less than 5 micrograms per kilogram in fish-tissue samples and less than 1 microgram per kilogram in streambed-sediment samples.The majority of trace elements analyzed in fish-liver tissue (86 percent) and streambed-sediment (98 percent) samples were reported during this study. Multiple trace elements were reported in all samples and at all sites.Based on comparisons of concentrations of organochlorine compounds and trace elements in fish-tissue and streambed-sediment samples in relation to National Academy of Science and National Academy of Engineering and Canadian tissue guidelines, probable-effects concentrations, and mean probable-effects concentration quotients for streambed sediment, the potential exists for adverse effects to wildlife at 15 (72 percent) of the sites sampled. The potential for adverse effects at these sites is because of the presence of residues or breakdown products related to polychlorinated biphenyls (PCB?s), chlordane, dichlorodiphenyltrichloroethane (DDT), chromium, lead, and zinc.The majority of compounds reported (65 percent) were chlordane, DDT, and PCB?s, or their breakdown products. Concentrations of chlordane and heptachlor epoxide in whole-fish tissue were positively correlated to the amount of urban land use in a basin. Total DDT concentrations in whole-fish tissues were positively correlated to agriculture.The relation of trace elements to land use is not as clear as the relation of organochlorine compounds to land use. This lack of clarity may be due to the possibility of geologic sources of trace elements in the Mobile River Basin and to the ubiquitous nature of many of these trace elements. However, there may be a correlation between the amount of urban land use and concentrations of antimony, cadmium, lead, and zinc in streambed-sediment samples from the Mobile River Basin.Fewer organochlorine compounds and trace elements were reported in samples from the Mobile River Basin than in samples collected during the 1991 and 1994 National Water-Quality Assessment Program studies. Of the organochlorine compounds analyzed nationally, 57 percent were reported in whole-fish tissue samples collected locally and 41 percent were reported in streambed-sediment samples collected locally, whereas 96 percent and 86 percent, respectively, were reported nationally. Of trace elements analyzed nationally, 86 percent were reported in fish-liver tissue locally and 95 percent were reported in streambed-sediment samples locally, whereas 95 percent and 98 percent, respectively, were reported nationally.In general, concentrations of organochlorine compounds and trace elements and the frequency with which they were reported in the Mobile River Basin are similar to or less than t

A preliminary assessment of the spatial sources of contemporary suspended sediment in the Ohio River basin, United States, using water quality data from the NASQAN programme in a source tracing procedure

USGS Publications Warehouse

Zhang, Y.-S.; Collins, A.L.; Horowitz, A.J.

2012-01-01

Reliable information on catchment scale suspended sediment sources is required to inform the design of management strategies for helping abate the numerous environmental issues associated with enhanced sediment mobilization and off-site loadings. Since sediment fingerprinting techniques avoid many of the logistical constraints associated with using more traditional indirect measurement methods at catchment scale, such approaches have been increasingly reported in the international literature and typically use data sets collected specifically for sediment source apportionment purposes. There remains scope for investigating the potential for using geochemical data sets assembled by routine monitoring programmes to fingerprint sediment provenance. In the United States, routine water quality samples are collected as part of the US Geological Survey's revised National Stream Quality Accounting Network programme. Accordingly, the geochemistry data generated from these samples over a 10-year period (1996-2006) were used as the basis for a fingerprinting exercise to assess the key tributary sub-catchment spatial sources of contemporary suspended sediment transported by the Ohio River. Uncertainty associated with the spatial source estimates was quantified using a Monte Carlo approach in conjunction with mass balance modelling. Relative frequency weighted means were used as an alternative way of summarizing the spatial source contributions, thereby avoiding the need to use confidence limits. The results should be interpreted in the context of the routine, but infrequent nature, of the suspended sediment samples used to assemble geochemistry as a basis for the sourcing exercise. Nonetheless, the study demonstrates how routine monitoring samples can be used to provide some preliminary information on sediment provenance in large drainage basins. ?? 2011 John Wiley & Sons, Ltd.

Characterization and Modeling of Settling, Consolidation, and Suspension to Optimize Sediment Retention of Sediment Diversions for Coastal Restoration

NASA Astrophysics Data System (ADS)

Sha, X.; Xu, K.; Bentley, S. J.; Robichaux, P.

2016-02-01

Although many studies of sediment diversions have been conducted on the Mississippi Delta, relatively less attention has been paid to understanding sediment retention and basic cohesive sedimentation processes in receiving basins. Our research evaluates long-term (up to six months) sedimentation processes through various laboratory experiments, especially cohesive sediment settling, consolidation and resuspension and their impacts on sediment retention. Bulk sediment samples were collected from West Bay, near Head of Passes of the Mississippi Delta, and the Big Mar basin that receive water and sediment from the Caernarvon Diversion in the upper Breton Sound region of Louisiana, USA. A-230-cm tall settling column with nine sampling ports at 15 cm intervals was used to measure the consolidation for four initial sediment concentrations (10-120 kg m-3) with two salinities (1 ppt & 5 ppt). Samples of sediment slurry were taken from every port at different time intervals up to 15 days or longer (higher concentration needs longer time to consolidate) to record concentrations gravimetrically. A 200 cm long tube was connected to a 50 cm long core chamber to accumulate at least a 10 cm thick sediment column for erosion tests. A dual-core Gust Erosion Microcosm System was employed to measure time-series (0.5, 1, 2, 3, 4, 5, 6 months) erodibility at seven shear stress regimes (0.01-0.60 Pa). Our preliminary results show a significant decrease of erodibility with time and high concentration (120g/L). Salinity impacted on sediment behavior in consolidation experiments. Our study reveals that more enclosed receiving basins, intermittent openings of diversions, or reduced shear stress due to man-made structure all can potentially reduce cohesive sediment erosion in coastal Louisiana. Further results will be analyzed to determine the model constants. Consolidating rates and corresponding erosional changes will be determined to optimize sediment retention in coastal protection.

A Synopsis of Technical Issues for Monitoring Sediment in Highway and Urban Runoff

USGS Publications Warehouse

Bent, Gardner C.; Gray, John R.; Smith, Kirk P.; Glysson, G. Douglas

2000-01-01

Accurate and representative sediment data are critical for assessing the potential effects of highway and urban runoff on receiving waters. The U.S. Environmental Protection Agency identified sediment as the most widespread pollutant in the Nation's rivers and streams, affecting aquatic habitat, drinking water treatment processes, and recreational uses of rivers, lakes, and estuaries. Representative sediment data are also necessary for quantifying and interpreting concentrations, loads, and effects of trace elements and organic constituents associated with highway and urban runoff. Many technical issues associated with the collecting, processing, and analyzing of samples must be addressed to produce valid (useful for intended purposes), current, complete, and technically defensible data for local, regional, and national information needs. All aspects of sediment data-collection programs need to be evaluated, and adequate quality-control data must be collected and documented so that the comparability and representativeness of data obtained for highway- and urban-runoff studies may be assessed. Collection of representative samples for the measurement of sediment in highway and urban runoff involves a number of interrelated issues. Temporal and spatial variability in runoff result from a combination of factors, including volume and intensity of precipitation, rate of snowmelt, and features of the drainage basin such as area, slope, infiltration capacity, channel roughness, and storage characteristics. In small drainage basins such as those found in many highway and urban settings, automatic samplers are often the most suitable method for collecting samples of runoff for a variety of reasons. Indirect sediment-measurement methods are also useful as supplementary and(or) surrogate means for monitoring sediment in runoff. All of these methods have limitations in addition to benefits, which must be identified and quantified to produce representative data. Methods for processing raw sediment samples (including homogenization and subsampling) for subsequent analysis for total suspended solids or suspended-sediment concentration often increase variance and may introduce bias. Processing artifacts can be substantial if the methods used are not appropriate for the concentrations and particle-size distributions present in the samples collected. Analytical methods for determining sediment concentrations include the suspended-sediment concentration and the total suspended solids methods. Although the terms suspended-sediment concentration and total suspended solids are often used interchangeably to describe the total concentration of suspended solid-phase material, the analytical methods differ and can produce substantially different results. The total suspended solids method, which commonly is used to produce highway- and urban-runoff sediment data, may not be valid for studies of runoff water quality. Studies of fluvial and highway-runoff sediment data indicate that analyses of samples by the total suspended solids method tends to under represent the true sediment concentration, and that relations between total suspended solids and suspended-sediment concentration are not transferable from site to site even when grain-size distribution information is available. Total suspended solids data used to calculate suspended-sediment loads in highways and urban runoff may be fundamentally unreliable. Consequently, use of total suspended solids data may have adverse consequences for the assessment, design, and maintenance of sediment-removal best management practices. Therefore, it may be necessary to analyze water samples using the suspended-sediment concentration method. Data quality, comparability, and utility are important considerations in collection, processing, and analysis of sediment samples and interpretation of sediment data for highway- and urban-runoff studies. Results from sediment studies must be comparable and readily transf

Aerobic biodegradation potential of endocrine disrupting chemicals in surface-water sediment at Rocky Mountains National Park, USA

USGS Publications Warehouse

Bradley, Paul M.; Battaglin, William A.; Iwanowicz, Luke R.; Clark, Jimmy M.; Journey, Celeste A.

2016-01-01

Endocrine disrupting chemicals (EDC) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDC, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountains National Park (ROMO). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 14C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. ROMO bed sediment microbial communities also effectively degraded the xenoestrogens, bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The current results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged.

Sediment loads and transport at constructed chutes along the Missouri River - Upper Hamburg Chute near Nebraska City, Nebraska, and Kansas Chute near Peru, Nebraska

USGS Publications Warehouse

Densmore, Brenda K.; Rus, David L.; Moser, Matthew T.; Hall, Brent M.; Andersen, Michael J.

2016-02-04

Comparisons of concentrations and loads from EWI samples collected from different transects within a study site resulted in few significant differences, but comparisons are limited by small sample sizes and large within-transect variability. When comparing the Missouri River upstream transect to the chute inlet transect, similar results were determined in 2012 as were determined in 2008—the chute inlet affected the amount of sediment entering the chute from the main channel. In addition, the Kansas chute is potentially affecting the sediment concentration within the Missouri River main channel, but small sample size and construction activities within the chute limit the ability to fully understand either the effect of the chute in 2012 or the effect of the chute on the main channel during a year without construction. Finally, some differences in SSC were detected between the Missouri River upstream transects and the chute downstream transects; however, the effect of the chutes on the Missouri River main-channel sediment transport was difficult to isolate because of construction activities and sampling variability.

First post-fire flush in a Mediterranean temporary stream: source ascription in bed sediments

NASA Astrophysics Data System (ADS)

Estrany Bertos, Joan; García-Comendador, Julián; Fortesa, Josep; Calsamiglia, Aleix; Garcias, Francesca

2017-04-01

First flushes can be of great importance for suspended-sediment transport in fluvial systems of drylands, being temporary streams a characteristic feature of Mediterranean basins. After a wildfire, storm flows may enhance runoff delivery to channels and then increasing the first-flush effect. 137Cs and 210Pbex were used as tracers for recognizing the first post-fire flush effect in the source ascription of bed sediments temporarily stored in a Mediterranean temporary stream severely affected by a wildfire. Thirty potential sediment source samples were collected along the main stem of a catchment located in Mallorca (Spain) during a field campaign developed some weeks after the wildfire. The sample collection was designed considering the wildfire affection, and also distinguishing between soil surface and channel bank. To quantify the relative source contribution to the bed sediment temporarily stored, five sediment samples -deposited during the first storm occurred three months after the wildfire- were collected into the bed stream of the main channel. The 137Cs and 210Pbex concentrations were measured by gamma spectrometry. Then, a linear mixing model was used to establish the relative contribution of each source type to the bed sediments discerning between the most upstream and the downstream parts of the catchment. Post-fire first-flush effect was generated by a torrential event with a suspended-sediment concentration peak ca. 33,618 mg L-1, although transmission losses under a very low runoff coefficient (1%) promoted sediment deposition. Significant differences were observed in fallout radionuclide concentrations between burned surface soil and channel bank samples (p < 0.05), as well as between burned and unburned sources at the downstream part of the catchment (p < 0.01). The radioactivity concentrations in bed sediments samples were statistically similar (p > 0.05). Source ascription in bed sediments in the middle stream shows that 67% was generated in burned hillslopes, reaching 75% in the downstream part because downstream propagation of the sediment derived from the burned area. Bed sediments were mostly generated in burned hillslopes because of the fire effects on soils and sediment availability, high intensity rainfall and limited contribution of channel banks that are fixed by dry-stone walls. This hydro-sedimentary response indicates an association between driven sediment transport factors and sediment availability, generating an effective slope-to-channel sediment connectivity. Long-term sediment sources monitoring will elucidate if the most effective period of the window of disturbance at catchment scale is further extended (i.e., ≈5 years).

A procedure for estimating Bacillus cereus spores in soil and stream-sediment samples - A potential exploration technique

USGS Publications Warehouse

Watterson, J.R.

1985-01-01

The presence of bacterial spores of the Bacillus cereus group in soils and stream sediments appears to be a sensitive indicator of several types of concealed mineral deposits, including vein-type gold deposits. The B. cereus assay is rapid, inexpensive, and inherently reproducible. The test, currently under investigation for its potential in mineral exploration, is recommended for use on a research basis. Among the aerobic spore-forming bacilli, only B. cereus and closely related strains produce an opaque zone in egg-yolk emulsion agar. This characteristic, also known as the Nagler of lecitho-vitellin reaction, has long been used to rapidly indentify and estimate presumptive B. cereus. The test is here adapted to permit rapid estimation of B. cereus spores in soil and stream-sediment samples. Relative standard deviation was 10.3% on counts obtained from two 40-replicate pour-plate determinations. As many as 40 samples per day can be processed. Enough procedural detail is included to permit investigation of the test in conventional geochemical laboratories using standard microbiological safety precautions. ?? 1985.

The microbiome of Brazilian mangrove sediments as revealed by metagenomics.

PubMed

Andreote, Fernando Dini; Jiménez, Diego Javier; Chaves, Diego; Dias, Armando Cavalcante Franco; Luvizotto, Danice Mazzer; Dini-Andreote, Francisco; Fasanella, Cristiane Cipola; Lopez, Maryeimy Varon; Baena, Sandra; Taketani, Rodrigo Gouvêa; de Melo, Itamar Soares

2012-01-01

Here we embark in a deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology. The extraction of DNA from sediment samples and the direct application of pyrosequencing resulted in approximately 215 Mb of data from four distinct mangrove areas (BrMgv01 to 04) in Brazil. The taxonomic approaches applied revealed the dominance of Deltaproteobacteria and Gammaproteobacteria in the samples. Paired statistical analysis showed higher proportions of specific taxonomic groups in each dataset. The metabolic reconstruction indicated the possible occurrence of processes modulated by the prevailing conditions found in mangrove sediments. In terms of carbon cycling, the sequences indicated the prevalence of genes involved in the metabolism of methane, formaldehyde, and carbon dioxide. With respect to the nitrogen cycle, evidence for sequences associated with dissimilatory reduction of nitrate, nitrogen immobilization, and denitrification was detected. Sequences related to the production of adenylsulfate, sulfite, and H(2)S were relevant to the sulphur cycle. These data indicate that the microbial core involved in methane, nitrogen, and sulphur metabolism consists mainly of Burkholderiaceae, Planctomycetaceae, Rhodobacteraceae, and Desulfobacteraceae. Comparison of our data to datasets from soil and sea samples resulted in the allotment of the mangrove sediments between those samples. The results of this study add valuable data about the composition of microbial communities in mangroves and also shed light on possible transformations promoted by microbial organisms in mangrove sediments.

The Microbiome of Brazilian Mangrove Sediments as Revealed by Metagenomics

PubMed Central

Andreote, Fernando Dini; Jiménez, Diego Javier; Chaves, Diego; Dias, Armando Cavalcante Franco; Luvizotto, Danice Mazzer; Dini-Andreote, Francisco; Fasanella, Cristiane Cipola; Lopez, Maryeimy Varon; Baena, Sandra; Taketani, Rodrigo Gouvêa; de Melo, Itamar Soares

2012-01-01

Here we embark in a deep metagenomic survey that revealed the taxonomic and potential metabolic pathways aspects of mangrove sediment microbiology. The extraction of DNA from sediment samples and the direct application of pyrosequencing resulted in approximately 215 Mb of data from four distinct mangrove areas (BrMgv01 to 04) in Brazil. The taxonomic approaches applied revealed the dominance of Deltaproteobacteria and Gammaproteobacteria in the samples. Paired statistical analysis showed higher proportions of specific taxonomic groups in each dataset. The metabolic reconstruction indicated the possible occurrence of processes modulated by the prevailing conditions found in mangrove sediments. In terms of carbon cycling, the sequences indicated the prevalence of genes involved in the metabolism of methane, formaldehyde, and carbon dioxide. With respect to the nitrogen cycle, evidence for sequences associated with dissimilatory reduction of nitrate, nitrogen immobilization, and denitrification was detected. Sequences related to the production of adenylsulfate, sulfite, and H2S were relevant to the sulphur cycle. These data indicate that the microbial core involved in methane, nitrogen, and sulphur metabolism consists mainly of Burkholderiaceae, Planctomycetaceae, Rhodobacteraceae, and Desulfobacteraceae. Comparison of our data to datasets from soil and sea samples resulted in the allotment of the mangrove sediments between those samples. The results of this study add valuable data about the composition of microbial communities in mangroves and also shed light on possible transformations promoted by microbial organisms in mangrove sediments. PMID:22737213

Maps showing water geochemistry of the Buffalo Peaks Wilderness Study Area, Lake, Park, and Chaffee Counties, Colorado

USGS Publications Warehouse

Nowlan, G.A.; Ficklin, Walter H.; Dover, Robert A.

1985-01-01

This report presents results of geochemical studies carried out in June and July of 1982 in the Buffalo Peaks Wilderness Study Area, Colo. (see index map). Samples of water were collected from 84 streams and 18 springs draining the study area. Tabulations of the analyses and a sample locality map are in Ficklin and others (1984). The geochemistry of stream sediments and panned concentrates of the study area is in Nowlan and Gerstel (1985). The geology of the study area and vicinity is in Hedlund (1985). The mineral resource potential of the study area is described in Hedlund and others (1983). This report (1) assists in the assessment of the mineral resource potential of the Buffalo Peaks Wilderness Study Area; and (2) compares analyses of water samples with analyses of stream-sediment and panned-concentrate samples (Nowlan and Gerstel, 1985).

Accumulation, Release, and Solubility of Arsenic, Molybdenum, and Vanadium in Wetland Sediments

USGS Publications Warehouse

Fox, P.M.; Doner, H.E.

2003-01-01

This study was undertaken to determine the fate of As, Mo, and V (trace elements, TEs) in the sediments of a constructed wetland in use for the remediation of potentially toxic trace element-contaminated agricultural drainwater. After three years of wetland operation, sediment cores were collected to determine changes in TE concentrations as a function of depth and the effects of varying water column depth. All TE concentrations were highest in the top 2 to 4 cm and decreased with depth. Molybdenum accumulated in the wetland sediments, up to levels of 32.5 ?? 4.6, 30.2 ?? 8.9, and 59.3 ?? 26.1 mg kg-1 in the top 1 cm of sediment at water depths of 15, 30, and 60 cm, respectively. In the top 2 cm of sediment, As accumulated (28.2 ?? 3.0 mg kg-1) only at the 60-cm water depth. Below 2 cm, as much as 10 mg kg-1 of As was lost from the sediment at all water depths. In most cases, V concentrations decreased in the sediment. In this wetland system, the lowest redox potentials were found near the sediment surface and increased with depth. Thus, in general As, Mo, and V concentrations in the sediment were highest under more reducing conditions and lowest under more oxidizing conditions. Most of the accumulated Mo (73%) became water soluble on drying of samples. This has important implications for systems undergoing changes in redox status; for instance, if these wetland sediments are dried, potentially large amounts of Mo may be solubilized.

Assessing anthropogenic levels, speciation, and potential mobility of rare earth elements (REEs) in ex-tin mining area.

PubMed

Khan, Aysha Masood; Yusoff, Ismail; Bakar, Nor Kartini Abu; Bakar, Ahmad Farid Abu; Alias, Yatimah

2016-12-01

A study was carried out to determine the level of rare earth elements (REEs) in water and sediment samples from ex-mining lakes and River in Kinta Valley, Perak, Malaysia. Surface water and sediments from an ex-mining lake and Kinta River water samples were analyzed for REEs by inductively coupled plasma mass spectrometry. The total concentration of REEs in the ex-mining lake water samples and sediments were found to be 3685 mg/l and 14159 mg/kg, respectively, while the total concentration of REEs in Kinta River water sample was found to be 1224 mg/l. REEs in mining lake water were found to be within 2.42 mg/l (Tb) to 46.50 mg/l (Ce), while for the Kinta River, it was 1.33 mg/l (Ho) to 29.95 mg/l (Ce). Sediment samples were also found with REEs from 9.81 mg/kg (Ho) to 765.84 mg/kg (Ce). Ce showed the highest average concentrations for mining lake (3.88 to 49.08 mg/l) and Kinta River (4.44 to 33.15 mg/l) water samples, while the concentration of La was the highest (11.59 to 771.61 mg/kg) in the mining lake sediment. Lu was shown to have the highest enrichment of REEs in ex-mining lake sediments (107.3). Multivariate statistical analyses such as factor analysis and principal component analysis indicated that REEs were associated and controlled by mixed origin, with similar contributions from anthropogenic and geogenic sources. The speciation study of REEs in ex-tin mining sediments using a modified five-stage sequential extraction procedure indicated that yttrium (Y), gadolinium (Gd), and lanthanum (La) were obtained at higher percentages from the adsorbed/exchanged/carbonate fraction. The average potential mobility of the REEs was arranged in a descending order: Yb > Gd > Y = Dy > Pr > Er > Tm > Eu > Nd > Tb > Sc > Lu > Ce > La, implying that under favorable conditions, these REEs could be released and subsequently pollute the environment.

Selected streambed sediment compounds and water toxicity results for Westside Creeks, San Antonio, Texas, 2014

USGS Publications Warehouse

Crow, Cassi L.; Wilson, Jennifer T.; Kunz, James L.

2016-12-01

IntroductionThe Alazán, Apache, Martínez, and San Pedro Creeks in San Antonio, Texas, are part of a network of urban tributaries to the San Antonio River, known locally as the Westside Creeks. The Westside Creeks flow through some of the oldest neighborhoods in San Antonio. The disruption of streambed sediment is anticipated during a planned restoration to improve and restore the environmental condition of 14 miles of channelized sections of the Westside Creeks in San Antonio. These construction activities can create the potential to reintroduce chemicals found in the sediments into the ecosystem where, depending on hydrologic and environmental conditions, they could become bioavailable and toxic to aquatic life. Elevated concentrations of sediment-associated contaminants often are measured in urban areas such as San Antonio, Tex. Contaminants found in sediment can affect the health of aquatic organisms that ingest sediment. The gradual accumulation of trace elements and organic compounds in aquatic organisms can cause various physiological issues and can ultimately result in death of the aquatic organisms; in addition, subsequent ingestion of aquatic organisms can transfer the accumulated contaminants upward through the food chain (a process called biomagnification).The U.S. Geological Survey, in cooperation with the San Antonio River Authority, collected sediment samples and water samples for toxicity testing from sites on the Westside Creeks as part of an initial characterization of selected contaminants in the study area. Samples were collected in January 2014 during base-flow conditions and again in May 2104 after a period of stormwater runoff (poststorm conditions). Sediment samples were analyzed for selected constituents, including trace elements and organic contaminants such as pesticides, brominated flame retardants, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). In addition, as an indicator of ecological health (and possibly bioavailability of contaminants in disturbed streambed sediments), the toxicity of water samples to the indicator species Pimephales promelas (fathead minnow) was evaluated by using standard 7-day water-toxicity testing.

Hospital and urban effluent waters as a source of accumulation of toxic metals in the sediment receiving system of the Cauvery River, Tiruchirappalli, Tamil Nadu, India.

PubMed

Devarajan, Naresh; Laffite, Amandine; Ngelikoto, Patience; Elongo, Vicky; Prabakar, Kandasamy; Mubedi, Josué I; Piana, Pius T M; Wildi, Walter; Poté, John

2015-09-01

Hospital and urban effluents contain a variety of toxic and/or persistent substances in a wide range of concentrations, and most of these compounds belong to the group of emerging contaminants. The release of these substances into the aquatic ecosystem can lead to the pollution of water resources and may place aquatic organisms and human health at risk. Sediments receiving untreated and urban effluent waters from the city of Tiruchirappalli in the state of Tamil Nadu, India, are analyzed for potential environmental and human health risks. The sediment samples were collected from five hospital outlet pipes (HOP) and from the Cauvery River Basin (CRB) both of which receive untreated municipal effluent waters (Tiruchirappalli, Tamil Nadu, India). The samples were characterized for grain size, organic matter, toxic metals, and ecotoxicity. The results highlight the high concentration of toxic metals in HOP, reaching values (mg kg(-1)) of 1851 (Cr), 210 (Cu), 986 (Zn), 82 (Pb), and 17 (Hg). In contrast, the metal concentrations in sediments from CRB were lower than the values found in the HOP (except for Cu, Pb), with maximum values (mg kg(-1)) of 75 (Cr), 906 (Cu), 649 (Zn), 111 (Pb), and 0.99 (Hg). The metal concentrations in all sampling sites largely exceed the Sediment Quality Guidelines (SQGs) and the Probable Effect Concentration (PEC) for the Protection of Aquatic Life recommendation. The ecotoxicity test with ostracods exposed to the sediment samples presents a mortality rate ranging from 22 to 100 % (in sediments from HOP) and 18-87 % (in sediments from CRB). The results of this study show the variation of toxic metal levels as well as toxicity in sediment composition related to both the type of hospital and the sampling period. The method of elimination of hospital and urban effluents leads to the pollution of water resources and may place aquatic organisms and human health at risk.

Trace Metal Content of Sediments Close to Mine Sites in the Andean Region

PubMed Central

Yacoub, Cristina; Pérez-Foguet, Agustí; Miralles, Nuria

2012-01-01

This study is a preliminary examination of heavy metal pollution in sediments close to two mine sites in the upper part of the Jequetepeque River Basin, Peru. Sediment concentrations of Al, As, Cd, Cu, Cr, Fe, Hg, Ni, Pb, Sb, Sn, and Zn were analyzed. A comparative study of the trace metal content of sediments shows that the highest concentrations are found at the closest points to the mine sites in both cases. The sediment quality analysis was performed using the threshold effect level of the Canadian guidelines (TEL). The sediment samples analyzed show that potential ecological risk is caused frequently at both sites by As, Cd, Cu, Hg, Pb, and Zn. The long-term influence of sediment metals in the environment is also assessed by sequential extraction scheme analysis (SES). The availability of metals in sediments is assessed, and it is considered a significant threat to the environment for As, Cd, and Sb close to one mine site and Cr and Hg close to the other mine site. Statistical analysis of sediment samples provides a characterization of both subbasins, showing low concentrations of a specific set of metals and identifies the main characteristics of the different pollution sources. A tentative relationship between pollution sources and possible ecological risk is established. PMID:22606058

Underestimated effects of sediments on enhanced startup performance of biofilm systems for polluted source water pretreatment.

PubMed

Lv, Zheng-Hui; Wang, Jing; Yang, Guang-Feng; Feng, Li-Juan; Mu, Jun; Zhu, Liang; Xu, Xiang-Yang

2018-02-01

In order to evaluate the enhancement mechanisms of enhanced startup performance in biofilm systems for polluted source water pretreatment, three lab-scale reactors with elastic stereo media (ESM) were operated under different enhanced sediment and hydraulic agitation conditions. It is interesting to found the previously underestimated or overlooked effects of sediment on the enhancement of pollutants removal performance and enrichment of functional bacteria in biofilm systems. The maximum NH 4 + -N removal rate of 0.35 mg L -1 h -1 in sediment enhanced condition was 2.19 times of that in control reactor. Sediment contributed to 42.0-56.5% of NH 4 + -N removal and 15.4-41.2% of total nitrogen removal in different reactors under different operation conditions. The enhanced hydraulic agitation with sediment further improved the operation performance and accumulation of functional bacteria. Generally, Proteobacteria (48.9-52.1%), Bacteroidetes (18.9-20.8%) and Actinobacteria (15.7-18.5%) were dominant in both sediment and ESM bioiflm at  phylum level. The potentially functional bacteria found in sediment and ESM biofilm samples with some functional bacteria mainly presented in sediment samples only (e.g., Genera Bacillus and Lactococcus of Firmicutes phylum) may commonly contribute to the removal of nitrogen and organics.

The potential of Lake Karakul in the eastern Pamirs as a long-term climate archive

NASA Astrophysics Data System (ADS)

Mischke, S.; Rajabov, I.; Mustaeva, N.; Zhang, C.; Boomer, I.; Sherlock, S. C.; Myrbo, A.; Noren, A.; Brady, K.; Herzschuh, U.; Schudack, M. E.; Ito, E.

2008-12-01

Lake Karakul is a large closed-basin lake in the eastern Pamirs (NE Tajikistan) at an altitude of 3930 m. The lake fills a large basin about 45 km in diameter which may originate from a meteorite impact in the late Neogene. Exposed lake sediments at the northwestern shore 20 m above the lake display a bizarre Yardang relief indicating higher water levels in the past. Eroded remnants of lake, playa and fluvial sediments can be found on the northeastern slopes of the basin 200 m above the lake but their depositional age remains unknown. A field survey of the Lake Karakul region was conducted in July 2008 as a first attempt to evaluate the potential of the lake as a long-term climate archive in Central Asia. Sediment samples from the lake's bottom, water samples from the lake and inflowing streams, aquatic and terrestrial plant samples, and rock samples were collected to enable an interdisciplinary investigation of the lake and its catchment. A 1.04 m sediment core was obtained near the centre of the more shallow and flat eastern sub-basin of the lake at 19 m water depth. Corresponding to the lack of outlet and the resulting high pH (9.1) and electrical conductivity of the lake (10.3 mS/cm), fine aragonite needles constitute most of the sediments. Additionally, ostracod shells, aquatic plant fragments, detrital grains and Radix (Gastropoda) shells were recorded. First results of AMS 14C dating and ostracod analysis will be used to infer the environmental and climatic evolution of Lake Karakul in the Late Holocene.

Beryllium-7 in vegetation, soil, sediment and runoff on the northern Loess Plateau.

PubMed

Zhang, Fengbao; Yang, Mingyi; Zhang, Jiaqiong

2018-06-01

Beryllium-7 ( 7 Be), as a potentially powerful tracer, was widely used to document soil redistribution and identify sediment sources in recent decades, but the quantity and distribution of 7 Be in vegetation, soil, sediment and runoff on the Loess Plateau have not been fully described. In this study, we measured 7 Be in vegetation, soil, sediment and runoff on the northern Loess Plateau of China and analyzed its variations during the rainy season to assess the potential of the 7 Be method for documenting soil redistribution and identifying sediment sources in a wide range of environments. The results indicated that vegetation, soil, and sediment samples showed higher levels and larger variations of 7 Be activities during the rainy season. The drying plants showed 7 Be mass activity that was more than three times higher than that of living and semi-decomposed plants. 7 Be mass activity in plants and sediment was much higher than in the soil. 7 Be activity in runoff water with a few submicron suspended particles varied slightly and was far lower than in plant, soil and sediment samples. The cumulative precipitation generally determined 7 Be inventory held by plants and soil. An inverse relationship was found between the 7 Be mass activity in sediment and the sediment amount. Globally, approximate 30% of the total 7 Be was held by plants in both the herbaceous and subshrub plots. Approximate 10% of the total 7 Be was lost with sediment from the bare plot. A very small proportion of 7 Be (1.18%-3.20%) was lost with runoff, and the vast majority of 7 Be was retained in the slope soil at the end of rainy season. Vegetation cover and soil erosion significantly affected the spatial distribution and variations of the 7 Be inventory in soil, providing a necessary condition for the development of a 7 Be method to document soil erosion on slopes with vegetation. Copyright © 2018 Elsevier B.V. All rights reserved.

Occurrences, composition profiles and source identifications of polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ship ballast sediments.

PubMed

Su, Peng-Hao; Lv, Bao-Yi; Tomy, Gregg T; Xu, Jin-Xiang; Tian, Wen; Hou, Chun-Yan; Yin, Fang; Li, Yi-Fan; Feng, Dao-Lun

2017-02-01

The aim of this study was to investigate the levels of persistent organic pollutants (POPs) including polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ship ballast sediments. The ballast sediment samples were collected from six merchant ships docked in 2015 in Jiangyin City, China. Ballast sediments represent a potential vector for the transport of POPs and invasive species between marine environments. An attempt was also made to determine the sources of these compounds in the ballast sediment. The results indicated ballast sediments generally contain greater amounts of BDE-209 and comparable amounts of PAHs, PBDEs (exclusive of BDE-209) and PCBs compared to those in marine surface sediments. Based on the sediment quality guidelines, PAHs and PCBs in ballast sediments were estimated to have median or high potential of posing ecological risks, respectively, to marine life if ballast sediments were disposed without specific treatment. POPs in ballast sediments were derived from multiple sources with atmospheric deposition being an important origin. Ship activities including diesel exhaust and illegal oil sewage discharge were considerable contributors of certain individual POPs to ballast sediments. Our study is important because it represents the first report on levels, health risk assessment and source apportionments of POPs in ballast sediments and is a first step in the implementation of specific ballast sediment management measures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Denitrification rates in estuarine sediments of Ashtamudi, Kerala, India.

PubMed

Salahudeen, Junaid Hassan; Reshmi, R R; Anoop Krishnan, K; Ragi, M S; Vincent, Salom Gnana Thanga

2018-05-03

Estuarine sediments are important sites for denitrification, which is microbially mediated reduction of nitrate to dinitrogen that also influences global climate change by co-production of nitrous oxide, a potent greenhouse gas. Physicochemical properties and nutrients of sediment samples that influence denitrification rate were studied in Ashtamudi estuarine sediments. They were pH, electrical conductivity (EC), salinity, nitrate-nitrogen (NO 3 - -N), exchangeable ammonia (NH 3 - -N), total kjeldahl nitrogen (TKN) and organic carbon (Corg). Sediment samples were collected from six stations during summer, monsoon of 2013 and 13 stations from monsoon 2014 and summer 2015. The sedimentary denitrification potential ranged from 0.49 ± 0.05 to 4.85 ± 0.782 mmol N 2 O m -2 h -1 . Maximum denitrification was observed in S4, which is attributed to a local anthropogenic source coupled with intense rainfall episode preceding the sampling season of monsoon 2013. However, this trend was not repeated in the subsequent monsoon samples. This shows that in Ashtamudi, monsoonal effects do not influence sedimentary denitrification. Among the various environmental variables, NO 3 - -N, Corg and NH 3 -N were the key factors that influence denitrification in the Ashtamudi estuarine sediments. Among these key factors, NO 3 - -N was the limiting factor for denitrification, and hence, it is of prime importance to understand the source of NO 3 - -N that fuel denitrification in the sediments. In Ashtamudi, the concentration of NO 3 - -N in overlying water was very less, which suggests reduced nitrogen yield in the estuary from the fluvial input of Kallada River and agricultural runoff. Sedimentary NO 3 - -N correlated with denitrification which reveals that denitrification is coupled with nitrification in the sediments. This is further explained by the fact that NH 3 -N positively correlated with denitrification. The anoxic sediments were the source of ammonia for nitrous oxide production by nitrogen mineralisation. Also, the Corg in sediment samples were sufficient to support denitrification and Corg was an important factor favouring but not limiting denitrification. The results of sediment denitrification in Ashtamudi can be a model for tropical estuaries experiencing unpredictable rainfall as well as high temperature than temperate systems.

Occurrence, ecological risk assessment, and spatio-temporal variation of polychlorinated biphenyls (PCBs) in water and sediments along River Ravi and its northern tributaries, Pakistan.

PubMed

Baqar, Mujtaba; Sadef, Yumna; Ahmad, Sajid Rashid; Mahmood, Adeel; Qadir, Abdul; Aslam, Iqra; Li, Jun; Zhang, Gan

2017-12-01

Ecological risk assessment, spatio-temporal variation, and source apportionment of polychlorinated biphenyls (PCBs) were studied in surface sediments and water from River Ravi and its three northern tributaries (Nullah Deg, Nullah Basantar, and Nullah Bein) in Pakistan. In total, 35 PCB congeners were analyzed along 27 sampling stations in pre-monsoon and post-monsoon seasons. The ∑ 35 PCB concentration ranged from 1.06 to 95.76 ng/g (dw) in sediments and 1.94 to 11.66 ng/L in water samples, with hexa-CBs and tetra-CBs as most dominant homologs in sediments and water matrixes, respectively. The ∑ 8 DL-PCB levels were 0.33-22.13 ng/g (dw) and 0.16-1.95 ng/L in sediments and water samples, respectively. The WHO-toxic equivalent values were ranged from 1.18 × 10 -6 to 0.012 ng/L and 1.8 × 10 -6 to 0.031 ng/g in water and sediments matrixes, respectively. The ecological risk assessment indicates considerable potential ecological risk during pre-monsoon season ([Formula: see text] = 95.17) and moderate potential ecological risk during post-monsoon season ([Formula: see text] = 49.11). The industrial and urban releases were recognized as key ongoing sources for high PCB levels in environment. Therefore, we recommend more freshwater ecological studies to be conducted in the study area and firm regulatory initiatives are required to be taken in debt to the Stockholm Convention, 2001 to cop up with PCB contamination on emergency basis.

Transport and Sources of Suspended Sediment in the Mill Creek Watershed, Johnson County, Northeast Kansas, 2006-07

USGS Publications Warehouse

Lee, Casey J.; Rasmussen, Patrick P.; Ziegler, Andrew C.; Fuller, Christopher C.

2009-01-01

The U.S. Geological Survey, in cooperation with the Johnson County Stormwater Management Program, evaluated suspended-sediment transport and sources in the urbanizing, 57.4 mi2 Mill Creek watershed from February 2006 through June 2007. Sediment transport and sources were assessed spatially by continuous monitoring of streamflow and turbidity as well as sampling of suspended sediment at nine sites in the watershed. Within Mill Creek subwatersheds (2.8-16.9 mi2), sediment loads at sites downstream from increased construction activity were substantially larger (per unit area) than those at sites downstream from mature urban areas or less-developed watersheds. Sediment transport downstream from construction sites primarily was limited by transport capacity (streamflow), whereas availability of sediment supplies primarily influenced transport downstream from mature urban areas. Downstream sampling sites typically had smaller sediment loads (per unit area) than headwater sites, likely because of sediment deposition in larger, less sloping stream channels. Among similarly sized storms, those with increased precipitation intensity transported more sediment at eight of the nine monitoring sites. Storms following periods of increased sediment loading transported less sediment at two of the nine monitoring sites. In addition to monitoring performed in the Mill Creek watershed, sediment loads were computed for the four other largest watersheds (48.6-65.7 mi2) in Johnson County (Blue River, Cedar, Indian, and Kill Creeks) during the study period. In contrast with results from smaller watersheds in Mill Creek, sediment load (per unit area) from the most urbanized watershed in Johnson County (Indian Creek) was more than double that of other large watersheds. Potential sources of this sediment include legacy sediment from earlier urban construction, accelerated stream-channel erosion, or erosion from specific construction sites, such as stream-channel disturbance during bridge renovation. The implication of this finding is that sediment yields from larger watersheds may remain elevated after the majority of urban development is complete. Surface soil, channel-bank, suspended-sediment, and streambed-sediment samples were analyzed for grain size, nutrients, trace elements, and radionuclides in the Mill Creek watershed to characterize suspended sediment between surface or channel-bank sources. Although concentrations and activities of cobalt, nitrogen, selenium, total organic carbon, cesium-137, and excess lead-210 had significant differences between surface and channel-bank samples, biases resulting from urban construction, additional sorption of constituents during sediment transport, and inability to accurately represent erosion from rills and gullies precluded accurate characterization of suspended-sediment source.

Annual radiological environmental operating report: Browns Ferry Nuclear Plant, 1992. Operations Services/Technical Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-04-01

This report describes the environmental radiological monitoring program conducted by TVA in the vicinity of Browns Ferry Nuclear Plant (BFN) in 1992. The program includes the collection of samples from the environment and the determination of the concentrations of radioactive materials in the samples. Samples are taken from stations in the general area of the plant and from areas not influenced by plant operations. Station locations are selected after careful consideration of the weather patterns and projected radiation doses to the various areas around the plant. Material sampled includes air, water, milk, foods, vegetation, soil, fish, sediment, and direct radiationmore » levels. Results from stations near the plant are compared with concentrations from control stations and with preoperational measurements to determine potential impacts of plant operations. Small amounts of Co-60 and Cs-134 were found in sediment samples downstream from the plant. This activity in stream sediment would result in no measurable increase over background in the dose to the general public.« less

Distribution of brominated flame retardants and dechloranes between sediments and benthic fish--A comparison of a freshwater and marine habitat.

PubMed

Sühring, Roxana; Busch, Friederike; Fricke, Nicolai; Kötke, Danijela; Wolschke, Hendrik; Ebinghaus, Ralf

2016-01-15

A total of 53 halogenated flame retardants (HFRs) were analysed in sediments, European eels and dabs from both freshwater and marine sampling stations in the German Bight and the river Elbe. Classic HFRs, such as polybrominated diphenylethers (PBDEs), were the highest concentrated HFRs in eels as well as in most dabs (apart from 1,2,5,6-tetrabromocyclooctane (TBCO)). In sediments, on the other hand, alternate BFRs and especially dechloranes dominated the contamination pattern. Dabs were still found to be statistically representative for the contamination patterns and relative magnitude in sediments from their respective habitats. Contamination patterns in eels seemed to be more driven by the contamination situation in the food chain or historical contamination of their habitat. Unsuspectedly the alternate flame retardant TBCO was found in comparably high concentrations (up to 12 ng g(-1) ww) in dabs from two sampling stations as well as in sediments from these stations (up to 1.2 ng g(-1) dw). It could not be detected in any other analysed fish or sediment samples, indicating a localised contamination source in the area. This study provides information on HFR contamination patterns and behaviour in both marine and freshwater sediments and their potential role as contamination source for benthic fish. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessment of the Mutagenicity of Sediments from Yangtze River Estuary Using Salmonella Typhimurium/Microsome Assay

PubMed Central

Liu, Li; Chen, Ling; Floehr, Tilman; Xiao, Hongxia; Bluhm, Kerstin; Hollert, Henner; Wu, Lingling

2015-01-01

Sediments in estuaries are of important environmental concern because they may act as pollution sinks and sources to the overlying water body. These sediments can be accumulated by benthic organisms. This study assessed the mutagenic potential of sediment extracts from the Yangtze River estuary by using the Ames fluctuation assay with the Salmonella typhimurium his (−) strain TA98 (frameshift mutagen indicator) and TA100 (baseshift mutagen indicator). Most of the sediment samples were mutagenic to the strain TA98, regardless of the presence or absence of exogenous metabolic activation (S9 induction by β-naphthoflavone/phenobarbital). However, none of the samples were mutagenic to the strain TA100. Thus, the mutagenicity pattern was mainly frameshift mutation, and the responsible toxicants were both direct (without S9 mix) and indirect (with S9 mix) mutagens. The mutagenicity of the sediment extracts increased when S9 was added. Chemical analysis showed a poor correlation between the content of priority polycyclic aromatic hydrocarbons and the detected mutagenicity in each sample. The concept of effect-directed analysis was used to analyze possible compounds responsible for the detected mutagenic effects. With regard to the mutagenicity of sediment fractions, non-polar compounds as well as weakly and moderately polar compounds played a main role. Further investigations should be conducted to identify the responsible components. PMID:26606056

Mobility and chemical fate of arsenic and antimony in water and sediments of Sarouq River catchment, Takab geothermal field, northwest Iran.

PubMed

Sharifi, Reza; Moore, Farid; Keshavarzi, Behnam

2016-04-01

Arsenic (As) and antimony (Sb) concentrations in water and sediments were determined along flow paths in the Sarouq River, Zarshuran and Agh Darreh streams. The results indicate high As and Sb concentrations in water and sediment samples. Raman spectroscopy shows hematite (α-Fe2O3), goethite [α-FeO(OH)] and lepidocrocite [γ-FeO(OH)] in sediment samples. Calculated saturation indices (SI) indicate oversaturation with respect to amorphous Fe(OH)3 for all samples, but undersaturation with respect to Al and Mn mineral and amorphous phases. Therefore, ferric oxides and hydroxides are assumed to be principal mineral phases for arsenic and antimony attenuation by adsorption/co-precipitation processes. The considerable difference between As and Sb concentration in sediment is due to strong adsorption of As(V) into the solid phase. Also, lower affinity of Sb(V) for mineral surfaces suggests a greater potential for aqueous transport. The adsorption of arsenic and antimony was examined using the Freundlich adsorption isotherm to determine their distribution model in water-sediment system and its compatibility with the existing theoretical model. The results showed that the adsorption behavior of both elements complies with the Freundlich adsorption isotherm. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnesium-rich minerals in sediment and suspended particulates of South Florida water bodies: implications for turbidity.

PubMed

Harris, W G; Fisher, M M; Cao, X; Osborne, T; Ellis, L

2007-01-01

Fine sediments in shallow water bodies such as Lake Okeechobee are prone to resuspension. Predominantly inorganic "mud" sediment that covers approximately 670 km2 of the lake has been recognized as a persistent source of turbidity. The objective of this study was to determine if mineral components of sediments in Lake Okeechobee and water conveyances of the northern Everglades also occur as suspended sediment and hence constitute a potential abiotic contributor to turbidity. Sediment samples were collected from nine stations within the lake and eight locations north of Water Conservation Area 2A in the Everglades. Water samples were also collected at selected locations. The silt and clay mineralogy of sediment and suspended particles was determined using X-ray diffraction, thermogravimetry, scanning-electron microscopy, energy-dispersive X-ray elemental microanalysis, and high-resolution transmission-electron microscopy. Clay fractions of the lake sediment contained the Mg silicate minerals sepiolite and palygorskite, along with smectite, dolomite, calcite, and kaolinite. Sediment silt fractions were dominated by carbonates and/or quartz, with smaller amounts of Ca phosphates and sepiolite. Mineralogy of the mud sediment was similar to that reported for geologic phosphate deposits. This suggests that the mud sediment might have accumulated by stream transport of minerals from these deposits. Suspended solids and mud-sediment mineralogy were similar, except that smectite was more abundant in suspended solids. Everglade samples also contained Mg-rich minerals. The small size, low density, and fibrous or platy nature of the prevalent mud sediment minerals make them an abiotic, hydrodynamically sensitive source of persistent turbidity in a shallow lake. Mitigation efforts focused exclusively on P-induced biogeochemical processes do not address the origin or effects of these minerals. Ecological management issues such as turbidity control, P retention, geologic P input, and suitability of dredging are related to mud-sediment properties and provenance.

Influence of porewater sulfide on methylmercury production and partitioning in sulfate-impacted lake sediments.

PubMed

Bailey, Logan T; Mitchell, Carl P J; Engstrom, Daniel R; Berndt, Michael E; Coleman Wasik, Jill K; Johnson, Nathan W

2017-02-15

In low-sulfate and sulfate-limited freshwater sediments, sulfate loading increases the production of methylmercury (MeHg), a potent and bioaccumulative neurotoxin. Sulfate loading to anoxic sediments leads to sulfide production that can inhibit mercury methylation, but this has not been commonly observed in freshwater lakes and wetlands. In this study, sediments were collected from sulfate-impacted, neutral pH, surface water bodies located downstream from ongoing and historic mining activities to examine how chronic sulfate loading produces porewater sulfide, and influences MeHg production and transport. Sediments were collected over two years, during several seasons from lakes with a wide range of overlying water sulfate concentration. Samples were characterized for in-situ solid phase and porewater MeHg, Hg methylation potentials via incubations with enriched stable Hg isotopes, and sulfur, carbon, and iron content and speciation. Porewater sulfide reflected historic sulfur loading and was strongly related to the extractable iron content of sediment. Overall, methylation potentials were consistent with the accumulation of MeHg on the solid phase, but both methylation potentials and MeHg were significantly lower at chronically sulfate-impacted sites with a low solid-phase Fe:S ratio. At these heavily sulfate-impacted sites that also contained elevated porewater sulfide, both MeHg production and partitioning are influenced: Hg methylation potentials and sediment MeHg concentrations are lower, but occasionally porewater MeHg concentrations in sediment are elevated, particularly in the spring. The dual role of sulfide as a ligand for inorganic mercury (decreasing bioavailability) and methylmercury (increasing partitioning into porewater) means that elucidating the role of iron and sulfur loads as they define porewater sulfide is key to understanding sulfate's influence on MeHg production and partitioning in sulfate-impacted freshwater sediment. Copyright © 2016 Elsevier B.V. All rights reserved.

A summary of chemical and biological testing of proposed disposal of sediment from Richmond Harbor relative to the Deep Off-Shelf Reference Area, the Bay Farm Borrow Area, and the Alcatraz Environs Reference Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayhew, H.L.; Karle, L.M.; Gruendell, B.D.

The US Army Corps of Engineers was authorized to dredge Richmond Harbor to accomodate large, deep-draft vessels. An ecological evaluation of the Harbor sediments was performed describing the physical characteristics, toxic substances, effects on aquatic organisms,and potential for bioaccumulation of chemical contaminants. The objective of this report is to compare the sediment chemistry, acute toxicity, and bioaccumulation results of the Richmond Harbor sediments to each of the reference areas; i.e., the Deep Off-Shelf Reference Area, the Bay Farm Borrow Area, and the Alcatraz Environs Reference Area. This report will enable the US Army Corps of Engineers to determine whether disposalmore » at a reference area is appropriate for all or part of the dredged material from Richmond Harbor. Chemical analyses were performed on 30 sediment samples; 28 of those samples were then combined to form 7 composites. The seven composites plus sediment from two additional stations received both chemical and biological evaluations.« less

Spatial distribution and ecological risk assessment of heavy metals in coastal surface sediments in the Hebei Province offshore area, Bohai Sea, China

USGS Publications Warehouse

Ding, Xigui; Ye, Siyuan; Yuan, Hongming; Krauss, Ken W.

2018-01-01

Seven hundred and nine surface sediment samples, along with deeper sediment samples, were collected from Hebei Province along the coastal section of the Bohai Sea, China, and analyzed for grain size, concentrations of organic carbon (Corg) and heavy metals (Cu, Pb, Zn, Cr, Cd, As, and Hg). Results indicated that the average concentrations in the sediments were 16.1 mg/kg (Cu), 19.4 mg/kg (Pb), 50 mg/kg (Zn), 48.8 mg/kg (Cr), 0.1 mg/kg (Cd), 8.4 mg/kg (As), and 20.3 μg/kg (Hg). These concentrations generally met the China Marine Sediment Quality criteria. However, both pollution assessments indicated moderate to strong Cd and Hg contamination in the study area. The potential ecological risk index suggested that the combined ecological risk of the seven studied metals may be low, but that 24.5% of the sites, where sediments were more finer and higher in Corg concentration, had high ecological risk in Hg and Cd pollution.

Presence, concentrations and risk assessment of selected antibiotic residues in sediments and near-bottom waters collected from the Polish coastal zone in the southern Baltic Sea - Summary of 3years of studies.

PubMed

Siedlewicz, Grzegorz; Białk-Bielińska, Anna; Borecka, Marta; Winogradow, Aleksandra; Stepnowski, Piotr; Pazdro, Ksenia

2018-04-01

Concentrations of selected antibiotic compounds from different groups were measured in sediment samples (14 analytes) and in near-bottom water samples (12 analytes) collected in 2011-2013 from the southern Baltic Sea (Polish coastal zone). Antibiotics were determined at concentration levels of a few to hundreds of ng g -1 d.w. in sediments and ng L -1 in near-bottom waters. The most frequently detected compounds were sulfamethoxazole, trimethoprim, oxytetracycline in sediments and sulfamethoxazole and trimethoprim in near-bottom waters. The occurrence of the identified antibiotics was characterized by spatial and temporal variability. A statistically important correlation was observed between sediment organic matter content and the concentrations of sulfachloropyridazine and oxytetracycline. Risk assessment analyses revealed a potential high risk of sulfamethoxazole contamination in near-bottom waters and of contamination by sulfamethoxazole, trimethoprim and tetracyclines in sediments. Both chemical and risk assessment analyses show that the coastal area of the southern Baltic Sea is highly exposed to antibiotic residues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Erosion properties of cohesive sediments in the Colorado River in Grand Canyon

USGS Publications Warehouse

Akahori, R.; Schmeeckle, M.W.; Topping, D.J.; Melis, T.S.

2008-01-01

Cohesive sediment deposits characterized by a high fraction of mud (silt plus clay) significantly affect the morphology and ecosystem of rivers. Potentially cohesive sediment samples were collected from deposits in the Colorado River in Marble and Grand Canyons. The erosion velocities of these samples were measured in a laboratory flume under varying boundary shear stresses. The non-dimensional boundary shear stress at which erosion commenced showed a systematic deviation from that of non-cohesive sediments at mud fractions greater than 0.2. An empirical relation for the boundary shear stress threshold of erosion as a function of mud fraction was proposed. The mass erosion rate was modelled using the Ariathurai-Partheniades equation. The erosion rate parameter of this equation was found to be a strong function of mud fraction. Under similar boundary shear stress and sediment supply conditions in the Colorado River, cohesive lateral eddy deposits formed of mud fractions in excess of 0.2 will erode less rapidly than non-cohesive deposits. Copyright ?? 2008 John Wiley & Sons, Ltd.

Anaerobic Oxidation of Methane in Sediments of Two Boreal Lakes

NASA Astrophysics Data System (ADS)

Tiirola, M. A.; Rissanen, A. J.; Karvinen, A.; Nykänen, H.; Mpamah, P.; Peura, S.; Kankaala, P.

2014-12-01

In this study, potential for Anaerobic oxidation of methane (AOM) coupled with metal reduction was studied in boreal lake sediments. Slurries of sediment samples collected from two sites in southeastern Finland, i.e. from Lake Orivesi, Heposelkä, an vegetated littoral site, dominated by Phragmites australis (Sample Sa, sediment layer 0 - 25 cm) and from the profundal zone of a mesotrophic Lake Ätäskö (Aa, 0 - 10 cm; Ab, 10 - 30 cm; Ac, 90 - 130 cm), were incubated in laboratory in anaerobic conditions at in situ temperatures for up to 5 months. The samples were amended either 1) with 13CH4, 2) 13CH4 + manganese(IV) oxide (MnO2) or 3) 13CH4 + iron(III) hydroxide (Fe(OH)3), and the processes were measured by following the 13C transfer to the carbon dioxide (CO2) pool and by concentration measurements of CH4 and CO2. Changes in microbial communities were studied from DNA extracted from sediment samples before and after incubation period by next-generation sequencing (Ion Torrent) of polymerase chain reaction (PCR) - amplified bacterial and archaeal 16S rRNA and methyl coenzyme-M reductase gene (mcrA) amplicons. AOM took place in every sample except in deepest sample (Ac) with potential rates up to 2.1 nmol CH4 d-1 g-1wetsedim (~2 nmol d-1 cm-3) which are considerably lower than previously reported metal-driven AOM in marine sediments (10-40 nmol d-1 cm-3) but within a range of NO3- -driven AOM in an oligotrophic lake (0.6-3.6 nmol d-1 cm-3). AOM took place without metal additions but addition of Mn4+ increased the potential rates and this increase was especially high in 10-30 cm layer (Ab) of the profundal site (5-fold increase). The structure of the bacterial and archaeal communities changed considerably during incubation. Communities incubated with Mn4+ were especially different from those incubated with Fe3+ or without metals which were more similar with each other. Surprisingly, anaerobic methanotrophic archaea detected, ANME-2D and AOM-associated archaea (AAA), were almost absent in the littoral site and constituted only up to 3.5% and 5% of archaeal 16S rRNA and mcrA gene sequences, respectively, in the profundal site. Mn4+ induced an increase in the abundance of ANME-2D and AAA in the profundal site which indicates that they are involved in Mn4+ - dependent AOM.

Application of quantitative composite fingerprinting technique to identify the main sediment sources in two small catchments of Iran

NASA Astrophysics Data System (ADS)

Kouhpeima, A.; Feiznia, S.; Ahmadi, H.; Hashemi, S. A.; Zareiee, A. R.

2010-09-01

The targeting of sediment management strategies is a key requirement in developing countries including Iran because of the limited resources available. These targeting is, however hampered by the lack of reliable information on catchment sediment sources. This paper reports the results of using a quantitative composite fingerprinting technique to estimate the relative importance of the primary potential sources within the Amrovan and Royan catchments in Semnan Province, Iran. Fifteen tracers were first selected for tracing and samples were analyzed in the laboratory for these parameters. Statistical methods were applied to the data including nonparametric Kruskal-Wallis test and Differentiation Function Analysis (DFA). For Amrovan catchment three parameters (N, Cr and Co) were found to be not significant in making the discrimination. The optimum fingerprint, comprising Oc, PH, Kaolinite and K was able to distinguish correctly 100% of the source material samples. For the Royan catchment, all of the 15 properties were able to distinguish between the six source types and the optimum fingerprint provided by stepwise DFA (Cholorite, XFD, N and C) correctly classifies 92.9% of the source material samples. The mean contributions from each sediment source obtained by multivariate mixing model varied at two catchments. For Amrovan catchment Upper Red formation is the main sediment sources as this sediment source approximately supplies 36% of the reservoir sediment whereas the dominant sediment source for the Royan catchment is from Karaj formation that supplies 33% of the reservoir sediments. Results indicate that the source fingerprinting approach appears to work well in the study catchments and to generate reliable results.

High-resolution chronology of sediment below CCD based on Holocene paleomagnetic secular variations in the Tohoku-oki earthquake rupture zone

NASA Astrophysics Data System (ADS)

Kanamatsu, Toshiya; Usami, Kazuko; McHugh, Cecilia M. G.; Ikehara, Ken

2017-08-01

Using high-resolution paleomagnetic data, we examined the potential for obtaining precise ages from sediment core samples recovered from deep-sea basins close to rupture zones of the 2011 and earlier earthquakes off Tohoku, Japan. Obtaining detailed stratigraphic ages from deep-sea sediments below the calcium compensation depth (CCD) is difficult, but we found that the samples contain excellent paleomagnetic secular variation records to constrain age models. Variations in paleomagnetic directions obtained from the sediments reveal systematic changes in the cores. A stacked paleomagnetic profile closely matches the Lake Biwa data sets in southwest Japan for the past 7000 years, one can establish age models based on secular variations of the geomagnetic field on sediments recovered uniquely below the CCD. Comparison of paleomagnetic directions near a tephra and a paleomagnetic direction of contemporaneous pyroclastic flow deposits acquired by different magnetization processes shows precise depositional ages reflecting the magnetization delay of the marine sediment record.