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1.
The purpose of this study was to make a prognosis of the effects of extended purification of terrestrial waste water, reaching the Wadden Sea by the River Rhine and Lake IJssel, on the phosphate concentration in the western Wadden Sea.The quantities of different phosphorus fractions in intertidal and subtidal sediments of the Marsdiep tidal basin (western Dutch Wadden Sea) were measured. Different methods are applied to determine the amount of phosphorus that can be released from these sediments. The direct bioavailability is determined by inoculating sediment suspensions with a natural mixture of precultured micro-organisms from the sampling area. A second approach is the measurement of the phosphate release under different redox conditions. Sequential extraction of sediment samples with different solvents is also applied. Under the present conditions and compared to the nutrient loads from fresh water (Lake IJssel) and from the North Sea, the phosphorus stored in the sediments of the western Dutch Wadden Sea plays a minor role in the total supply to micro-algae and bacteria. The bulk of the biologically available phosphorus in the sediments originates from the metal-associated fraction. Releasable phosphate may contribute to the local annual primary production to an extent of ca 45 to ca 150 g C m–2 a–1. The total amount of phosphorus in the sediment (mainly calcite associated) is twice to 6 times the biologically available amount. 相似文献
2.
Presence of Plant Viruses in some Rivers of Southern Italy 总被引:1,自引:0,他引:1
Water samples were collected from some rivers of Southern Italy whose water is normally used for irrigation and checked for the presence of plant viruses. The assayes were carried out by centrifuging at 5000x g one liter of water, resuspending the sediments in phosphate buffer and testing their infectivities on Chenopodium quinoa Willd. It was possible to isolate tobacco mosaic virus, cucumber mosaic virus and two more viruses not identified yet. 相似文献
3.
F. Andrieux-Loyer X. Philippon G. Bally R. Kérouel A. Youenou J. Le Grand 《Biogeochemistry》2008,88(3):213-231
The macrotidal estuary of Penzé (Brittany, Western part of the Channel, France) has been subjected to recurrent annual toxic
blooms of Alexandrium minutum since 1988. This study aims to specify the phosphorus dynamics and bioavailability in sediments in order to improve our understanding
of Alexandrium occurrences. Sediment-P pools and diffusive phosphate fluxes were studied under similar hydrodynamic conditions, in the intermediate
estuary in May, June and July 2003 and along the salinity gradient from August 2004 to June 2005. The results highlight a
decrease in bioavailable phosphorus (iron and organic bound) from the inner part of the estuary seaward. The ratio of iron-bound
phosphorus to iron-oxyhydroxides is lower in the inner and intermediate estuaries (5–8) than in the outer site (15), suggesting
a saturation of sorption sites and greater phosphorus bioavailability in this area. Pools of bioavailable phosphorus in surficial
sediments are about eight times higher than the annual net-export of P (7 ton year−1). Phosphate releases from sediments are always lower than 5 μmol m−2 d−1 in March. The highest supplies occur in June and August in the intermediate area (up to 400 μmol m−2 d−1) where they represent up to 50% of river loadings. These results further suggest that phosphate pulses coincide with occurrences
of Alexandrium reported in June. 相似文献
4.
Benthic phosphorus regeneration in the Potomac River Estuary 总被引:2,自引:2,他引:0
The flux of dissolved reactive phosphate from Potomac riverine and estuarine sediments is controlled by processes occurring
at the water-sediment interface and within surficial sediment.In situ benthic fluxes (0.1 to 2.0 mmoles m−2 day−1) are generally five to ten times higher than calculated diffusive fluxes (0.020 to 0.30 mmoles m−2 day−1). The discrepancy between the two flux estimates is greatest in the transition zone (river mile 50 to 70) and is attributd
to macrofaunal irrigation.
Bothin situ and diffusive fluxes of dissolved reactive phosphate from Potomac tidal river sediments are low while those from anoxic lower
estuarine sediments are high. The net accumulation rate of phosphorus in benthic sediment exhibits an inverse pattern. Thus
a large fraction of phosphorus is retained by Potomac tidal river sediments, which contain a surficial oxidized layer and
oligochaete worms tolerant of low oxygen conditions, and a large fraction of phosphorus is released from anoxic lower estuary
sediments. Tidal river sediment pore waters are in equilibrium with amorphous Fe (OH)3 while lower estuary pore waters are significantly undersaturated with respect to this phase. Benthic regeneration of dissolved
reactive phosphorus is sufficient to supply all the phosphorus requirements for net primary production in the lower tidal
river and transition-zone waters of the Potomac River Estuary. Benthic regeneration supplies approximately 25% as much phosphorus
as inputs from sewage treatment plants and 10% of all phosphorus inputs to the tidal Potomac River.
When all available point source phosphorus data are put into a steady-state conservation of mass model and reasonable coefficients
for uptake of dissolved phosphorus, remineralization of particulate phosphorus, and sedimentation of particulate phosphorus
are used in the model, a reasonably accurate simulation of dissolved and particulate phosphorus in the water column is obtained
for the summer of 1980. 相似文献
5.
Mangrove [Kandelia obovata (S. L.)] seedlings were cultivated in rhizoboxes under different rates of phosphorus (P) and cadmium (Cd) level. The speciation distributions of P both in the rhizosphere and non-rhizosphere sediments were examined using sequential extraction procedures. P contents in different K. obovata (S.L.) tissues were also determined. Results showed that considerable differences existed in P speciation distribution between rhizosphere and bulk sediments. A higher proportion of iron-bound phosphate (Fe-P) was found in the rhizosphere sediments, while a relatively higher concentration of exchangeable phosphate (Ex-P) and Aluminum-bound phosphate was found in the bulk sediments. P accumulation in plant tissues was significantly positively correlated to Ex-P and Fe-P. Results indicated that root activities play an important role in the P cycling. And the coexistence of P and Cd induced higher P accumulation in mangrove plants. It is suggested that the root-induced chemical and biological changes in the rhizosphere environment play an important role in enhancing the bioavailability of soil P. 相似文献
6.
《Chemical Speciation and Bioavailability》2013,25(3):143-154
AbstractThe speciation and bioavailability of zinc (Zn) in smelter-contaminated sediments were investigated as a function of phosphate (apatite) and organic amendment loading rate. Zinc species identified in preamendment sediment were zinc hydroxide-like phases, sphalerite, and zinc sorbed to an iron oxide via X-ray adsorption near edge structure (XANES) spectroscopy. Four months after adding the amendments to the contaminated sediment, hopeite, a Zn phosphate mineral, was identified indicating phosphate was binding and sequestering available Zn and Zn pore water concentrations were decreased at levels of 90% or more. Laboratory experiments indicate organic amendments exhibit a limited effect and may hinder sequestration of pore water Zn when mixed with apatite. The acute toxicity of the sediment Zn was evaluated with Hyalella azteca, and bioaccumulation of Zn with Lumbriculus variegates. The survivability of H. azteca increased as a function of phosphate (apatite) loading rate. In contaminated sediment without apatite, no specimens of H. azteca survived. The bioaccumulation of Zn in L. variegates also followed a trend of decreased bioaccumulation with increased phosphate loading in the contaminated sediment. The research supports an association between Zn speciation and bioavailability. 相似文献
7.
R. Gothwal 《Soil & Sediment Contamination》2017,26(5):501-509
Improper disposal of domestic sewage and effluents from drug manufacturing units for several years has resulted in the accumulation of pollutants in Musi river sediments. There were no studies carried out before to quantify the antibiotic resistance in this river, despite the fact that its sediments are loaded with antibiotics. The present study investigated the relationship between the proliferation of ciprofloxacin resistant culture with the occurrence of fluoroquinolone and heavy metals in sediments of Musi River. The fluoroquinolones concentration in river sediments were observed in high concentration (13336.4 ng/g) and were found to be positively correlated with the occurrence of ciprofloxacin resistant bacteria (r = 0.386 to 0.675, p < 0.05). The occurrence of heavy metals was also in positive correlation with the distribution of antibiotic resistant bacteria in the river (r = 0.454 to 0.881, p < 0.05). This study indicated the spread of antibiotic resistance in polluted river sediments that might pose a serious threat to public health as the river water is used for irrigation, drinking, and recreational purposes; and needs an immediate risk assessment and mitigation strategies. 相似文献
8.
Atta Rasool 《Geomicrobiology journal》2013,30(10):854-868
AbstractThe study of microbial communities in river sediments contaminated by thallium (Tl) is necessary to achieve the information for in-situ microbially mediated bioremediation. However, little is known about the microbial community in Tl-contaminated river sediments. In the present study, we characterized the microbial community and their responses to Tl pollution in river sediments from the Tl-mineralized Lanmuchang area, Southwest Guizhou, China. Illumina sequencing of 16S rRNA amplicons revealed that over 40 phyla belong to the domain bacteria. In all samples, Proteobacteria, Cyanobacteria, and Actinobacteria were the most dominant phyla. Based on the UPGMA (Unweighted Pair Group Method with Arithmetic Mean) tree and PCoA (Principal Coordinates Analysis) analysis, microbial composition of each segment was distinct, indicating in-situ geochemical parameters (including Tl, sulfate, TOC, Eh, and pH) had influenced on the microbial communities. Moreover, canonical correspondence analysis (CCA) was employed to further elucidate the impact of geochemical parameters on the distribution of microbial communities in local river sediments. The results indicated that a number of microbial communities including Cyanobacteria, Spirochaete, Hydrogenophaga, and Acinetobacter were positively correlated with total Tl, suggesting potential roles of these microbes to Tl tolerance or to biogeochemical cycling of Tl. Our results suggested a reliable location for the microbial community’s diversity in the presence of high concentrations of Tl and might have a potential association for in-situ bioremediation strategies of Tl-contaminated river. Overall, in situ microbial community could provide a useful tool for monitoring and assessing geo-environmental stressors in Tl-polluted river sediments. 相似文献
9.
In the Jequetepeque basin (Peru), gold extraction activity has been performed in the last decades, leading to a release of metals and metalloids into the environment. Sediment samples were taken in the vicinity of two mines and analyzed. Extraction of metals and metalloids from sediments was carried out using single extraction procedures, acidic (HNO3), and complexation (EDTA) leaching, in order to determine the mobility of trace elements. Results indicated that acidic extraction at low pH values increased the leachability of trace elements. EDTA showed a higher bioavailability of metals in sediments than acidic extraction under similar pH conditions because of its greater leaching capacity. This is an important issue in view of risk assessment analysis. The highest extractability was observed for Cd in all sediments with up to 90% of extraction after 1 h. The mobility index analysis indicated that faster kinetic leachability of some trace elements leads to a higher mobility in sediments, especially those near the active gold extraction mine. The ecological risk assessment suggested that the four river sediments were at high and very high risk levels, indicating that sediment contamination is an issue of environmental concern in the Jequetepeque basin of northern Peru. 相似文献
10.
《Chemical Speciation and Bioavailability》2013,25(4):291-302
AbstractThe relationships are evaluated between the heavy metal species in sediments and the accumulation by the soft tissues of Saccostrea cucullata collected from the northern and southern coasts of Qeshm Island, Persian Gulf. The sequential extraction technique was employed to fractionate the sediment into non resistant and resistant fractions. Data from sequential extractions indicated that the metals were mainly associated with the residual fraction at the north coast and with non residual fractions at the south coast. The results showed that the best correlations were observed between heavy metals concentrations in soft tissues and the fractions in the southern sediment. Note that the bioavailability of trace metals is influenced by the chemical characteristics and properties of the sediment. Therefore, the present results generally supported the use of soft tissues of S. cucullata as a more accurate biomonitoring organism for Cu, Pb and Cd in sediments from the southern coast of Qeshm Island, Persian Gulf. 相似文献
11.
Assessment of the eutrophication of Al Massira reservoir (Morocco) by means of a survey of the biogeochemical balance of phosphate 总被引:3,自引:1,他引:2
The biogeochemical balance of phosphate was studied in Al Massira reservoir (Morocco) from February 1991 to end January 1992. The study concerned P-supplies and losses by the Oum errbia river, sedimentation rate and water-sediment exchange.Supply and loss of phosphate were calculated from samples collected every 48 hours. Phosphate sedimentation rate was measured with sediment traps. The assessment of phosphate release at the water-sediment interface during either low oxic or anoxic conditions was made in situ with a benthic chamber.The results showed that phosphate input was higher than phosphate output resulting in a progressive increase of the internal phosphorus stock. The sedimentation flux ranged between 9 and 19 mg m–2 d–1 of P. Release of phosphate depended on the oxygen concentrations in the water.We suggest that a drastic control of phosphate input into the water must be achieved through a programme of dephosphorylation of the tributaries to avoid accumulation of calcium-bound phosphate which may become a source of upward release of bioavailable phosphate.Further investigations of this flux should be carried out to check the quantitative influence on phytoplankton community dynamics. 相似文献
12.
Vertical distribution and release characteristics of phosphorus forms in the sediments from the river inflow area of Dianchi Lake,China 总被引:1,自引:0,他引:1
Columnar sediment samples were collected from five representative river inflow areas of Dianchi Lake, China. The vertical distribution of each form of P were tested. Results showed that the concentration of TP in the sediments from areas A, B, C, D and E in the order of D > B > A > C > E, and the average concentration of D, B, A, C and E were 2991, 2064, 1308, 879, and 759 mg?kg?1, respectively. The concentration of Ex-P, Fe/Al-P, Ca-P and Org-P all decreased with increasing depth. The release of Ex-P was significantly related to TP whereas the Fe/Al-P was not significantly related to TP in the samples from areas polluted by domestic sewage. However, the release of Ex-P and Fe/Al-P were both significantly related to TP in the samples from areas polluted by phosphate mining and phosphate fertilizer application. The results of equilibrium P concentration (EPC0) analysis showed that P in the sediments of areas A, D and E were the source of P in Dianchi Lake, and the P in the sediments of areas B and C were in relative equilibrium with the overlying water. 相似文献
13.
Syouhei Nishihama Akira Haraguchi Tomonori Kawano Keisuke Michiki Kohji Nakazawa Takuya Suzuki Kazuya Uezu Kazuharu Yoshizuka 《Limnology》2008,9(1):35-45
The total viable count, population density of Escherichia coli and coliform bacteria, and nitrogen in the microbiomass (microbiomass-N) in sediments were monitored monthly at 12 points
in the Ongagawa River basin from June 2002 to May 2006. The measurement of the sediment microbiomass-N was used for evaluation
of the sediment’s microbial population in the river ecosystem. An extraordinarily high population of E. coli was observed during the season when there was stagnant water in the basin, with a high population and an insufficient drain
diffusion system, and, thus hydrological water control is indispensable to prevent rapid E. coli growth. Microbiomass-N in sediments showed a negative correlation or independent fluctuation in relation to the bacterial
population in the water column of the river. Seasonal changes in extracted nitrogen (N) in river sediments did not show correspondence
with microbiomass-N in sediments. The microbiomass-N in sediments changed independently of the bacterial population in the
river water, indicating that the high population of bacteria in the water does not lead to a high microbial population in
river sediments. Ordination of the microbial parameters by canonical correspondence analysis (CCA) showed that microbiomass-N
in sediments was quite different from other parameters. Relatively higher H+ (lower pH), PO4
3− concentration and dissolved oxygen (DO) were the determinant parameters of higher microbiomass-N in sediments. A relative
microbial abundance between the water column and sediments as well as each of the microbial populations in the water column
and sediments could be a quantitative parameter for evaluating the biochemical processes of stream water. 相似文献
14.
Geochemical partitioning and bioavailability of copper to aquatic plants in an artificial oxide-organic sediment 总被引:2,自引:0,他引:2
This study investigated the effects of competition between binding substrates (organic matter and iron oxide) and between
metals (cadmium and copper), on the partitioning of sedimentary copper and its subsequent bioavailability to an aquatic plant.
Organic matter and a synthesized iron oxide, ferrihydrite, were added singly and in combination to a series of sand sediments,
which were then dosed with environmentally realistic concentrations of cadmium and copper and planted with rice,Oryza sativa.
Organic matter controlled copper partitioning and bioavailability, whereas the synthetic ferrihydrite bound negligible amounts
of either metal, even in the absence of organic matter. As organic matter concentrations increased, operationally-defined
leachable copper decreased, organic-associated copper increased and the survival of rice plants improved in an approximately
linear fashion. At a nominal starting copper concentration of 5.8 μg g dry wt−1, plant survival after four weeks averaged 0–8% in sediments without organic matter, 25% in a sediment containing 0.18% organic
matter and 58% in a sediment containing 0.36% organic matter. These results suggest that organic-associated forms of copper
are unavailable to plants, and that the operational definition of ‘leachable’ copper (extracted with dilute ammonium acetate)
adequately represents the species of copper that is (are) available to plants. Our study using a well-characterized artificial
sediment supports the copper fractionation patterns and correlations between copper partitioning and bioavailability reported
from the heterogeneous, poorly characterized sediments of natural lake and river sediments. 相似文献
15.
Comparison of the relative sensitivity of three benthic invertebrates to copper-contaminated sediments from the Keweenaw Waterway 总被引:2,自引:2,他引:0
Corlis W. West Vincent R. Mattson Edward N. Leonard Gary L. Phipps Gerald T. Ankley 《Hydrobiologia》1993,262(1):57-63
The Keweenaw Peninsula in northern Michigan was once a major copper mining area and these mining activities were responsible
for depositing tons of tailings in and around the Keweenaw Waterway. In recent years there has been concern about possible
toxic effects of the contaminated sediments on aquatic communities in the system. In the fall of 1990, sediments were collected
from various locations along the Waterway. Ten-day tests were conducted with the samples using three species of benthic invertebrates
that have been proposed as suitable for evaluating the toxicity of freshwater sediments: Hyalella azteca (amphipods), Chironomus tentans (chironomids) and Lumbriculus variegatus(oligochaetes). A number of sediments were toxic to one or more of the three species and, in general, there was good agreement
among the tests with regard to identifying toxic samples. Unexpectedly, the relative sensitivity of the three species to the
test sediments was not accurately predicted from water-only copper exposures. This indicates that factors modifying exposure,
such as different lifestyles and/or varying sensitivity to physico-chemical characteristics of sediments can influence results
of sediment toxicity tests. 相似文献
16.
Long-term survival of marine planktonic diatoms and dinoflagellates in stored sediment samples 总被引:7,自引:0,他引:7
Sediment samples from Scottish coastal sites, taken over the last 9 years,
were stored in closed containers at 5C.
Slurry cultures were used to determine the survival of phytoplankton in
these sediments. A range of diatom and dinoflagellate species survived for
at least 27 months in these stored samples. A number of species grew for
which no resting stage has yet been described: Thalassiosira
angulata, T.pacifica, T.punctigera, T.eccentrica, T.minima and
T.anguste-lineata. Notable results were survival times
of 73 months for Skeletonema costatum, 96 months for
Chaetoceros socialis, C.didymus and
C.diadema, 109 months for
Scrippsiella sp. and 112 months for
Lingulodinium polyedrum. A single sample was stored
and repeatedly cultured for diatoms over a period of 16 months. The number
of species cultured from the sediment declined over this time.
Lingulodinium polyedrum cysts isolated from sediments
collected at least 18 months previously gave a hatching success of 97%, and
cysts isolated from a 9-year-old sample gave a hatching success of 3%. The
study indicated the potential importance of coastal sediments as a source
of phytoplankton to their overlying waters. The validity of using marine
planktonic diatoms and dinoflagellates for modelling geological events is
discussed.
相似文献
17.
Parvaresh H Abedi Z Farshchi P Karami M Khorasani N Karbassi A 《Biological trace element research》2011,143(2):1121-1130
The concentration and bioavailability of Ni, Cu, Cd, Zn, and Pb in the sediments and leaves of grey mangrove, Avicennia marina, were studied throughout Sirik Azini creek (Iran) with a view to determine heavy metals bioavailability, and two methods
were used. Results show that Zn and Ni had the highest concentrations in the sediments, while Cd and Cu were found to have
the lowest concentrations in the sediments. Compared to the mean concentrations of heavy metals in sedimentary rock (shales),
Zn and Cu showed lower concentration, possibly indicating that the origin of these heavy metals is natural. A geo-accumulation
index (I
geo) was used to determine the degree of contamination in the sediments. I
geo values for Zn, Cu, Pb, and Ni showed that there is no pollution from these metals in the study area. As heavy metal concentrations
in leaves were higher than the bioavailable fraction of metals in sediments, it follows that bioconcentration factors (leaf/bioavailable
sediment) for some metals were higher than 1. 相似文献
18.
The distribution of macroinvertebrate assemblages in a reach of the River Allier (France), in relation to riverbed characteristics 总被引:1,自引:0,他引:1
Investigations on large canalised rivers, for example the Danube, have shown that transported particulate matter, which is
typically inorganic, is predominantly deposited in waters near the river’s main channel. This investigation deals with the
lower section of the River Havel (NE Germany), a canalised lowland river with a very flat floodplain. This river is highly
polluted by nutrients from urban areas (Berlin) and a long chain of river lakes produces high concentrations of phytoplankton.
Due to the high proportion of planktogenic detritus, it was hypothesised that greater quantities of nutrient-rich fine particulate
organic matter (FPOM) would be deposited in floodplain waters located further from the main channel than has been reported
for large rivers. The total nutrient, P-binding metal (Fe, Al, and Mn), organic and inorganic carbon (TOC, TIC) contents of
the upper organic sediment layer (0–4 cm) were analysed in samples collected from 48 floodplain water and river sites. The
sediment bulk density, calculated on the basis of dry mass content and loss on ignition, was used to characterise the waters
according to the impact of the river current. The results showed that the variability of total phosphorus (TP) was best explained
by the variability of total iron (TFe, R2 = 0.52). The floodplain water sediments could clearly be separated into two groups on the basis of the sediment particle
size composition, and of the element ratios TOC:TP, TN:TP, primarily TFe:TP. The sediments from impounded river sections and
from mouth sections of backwaters (approx. 100–200 m) were characterised by a high proportion particles from the 0.1 to 0.5 mm
size fraction and by homogeneous, low TFe:TP, TOC:TP and TN:TP ratios. Sediments from distal sections of backwaters and of
oxbow lakes tended to exhibit high element ratios with much higher variability. These results were interpreted as a spatially
limited impact of the river on the floodplain water sediments. Contrary to expectation, the phosphorus bound in river seston
was predominantly and very homogeneously deposited in the impounded river and mouth sections of backwaters. This implies that
the inundation of the floodplain waters during spring floods seems to have no important material impact on the sediments in
waters of low hydrological connectivity with the River Havel. 相似文献
19.
20.
O. N. Lukyanova S. A. Ireykina A. P. Chernyaev A. S. Vazhova M. D. Boyarova 《Russian Journal of Marine Biology》2010,36(7):489-496
A complex ecotoxicological assessment of several estuarine zones of the Razdol’naya, Barabashevka, Ryazanovka, and Gladkaya
rivers in Amur Bay, and the Artyomovka and Sukhodol rivers in Ussyry Bay was carried out in 2007 and 2008. Bottom sediments
in the estuary of the Kievka river were collected in 2009. The content of petroleum hydrocarbons was determined in the water
and bottom sediments of riverine and marine sectors of estuaries and the total toxicity of bottom sediments was tested with
the use of mysids. Bottom sediments from a small river on Reineke Island, in which the concentrations of primary pollutants
corresponded to the background values for the entire Peter the Great Bay, were used as a control. The content of organochlorine
pesticides in the muscles and liver of the Redeye Eastern Redfin (Tribolodon brandtii) was determined and molecular biomarkers of oxidative stress in organs of the Redlip Mullet (Liza haematocheila) analyzed. The amount of wastewater and pollutants flowing into Amur Bay and Ussyry Bay with some of the rivers was estimated.
The correlation coefficient between the toxicity of bottom sediments and the petroleum hydrocarbons content in them was found.
The higher sediment toxicity in the riverine zone, as compared to the marine zone, proves the concept of the “river-sea” biogeochemical
barrier. 相似文献