Fates of Metal Radiotracers Added to a Whole Lake: Sediment–Water Interactions

1980 ◽  
Vol 37 (3) ◽  
pp. 378-386 ◽  
Author(s):  
R. H. Hesslein ◽  
W. S. Broecker ◽  
D. W. Schindler
Keyword(s):  
Water Column ◽  
Environmental Fate ◽  
Particulate Material ◽  
Experimental Lakes Area ◽  
Suspended Particulates ◽  
Northwestern Ontario ◽  
Suspended Particulate ◽  
Suspended Particulate Material ◽  
Deep Sediments ◽  
Dissolved Form

A whole-lake radiotracer experiment with the isotopes Se-75, Hg-203, Cs-134, Fe-59, Co-60 was carried out in Lake 224 of the Experimental Lakes Area, northwestern Ontario. The results of the analyses of isotopes in the water column show an exponential decrease in concentration with time. The rate of loss from the water column does not show dependence on the affinity of the isotope for suspended particulate material. This affinity ranged from 98% for Fe-59 to < 1% for Cs-134 over the first 65 d. The major sink for isotopes lost from the water column is the sediments. Ratios of isotopes in the sediments show that those isotopes associated with suspended particulates more easily reach deep sediments than those in dissolved form which are restricted by the thermocline to adsorption to epilimnion sediments.Key words: Experimental Lakes Area, metal and radioisotope budgets, environmental fate of radionuclides

Environmental Fate of Polychlorinated Dibenzo-p-dioxins in Lake Enclosures

1992 ◽  
Vol 49 (4) ◽  
pp. 722-734 ◽  
Author(s):  
Mark R. Servos ◽  
Derek C. G. Muir ◽  
G. R. Barrie Webster
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Particulate Organic Matter ◽  
Environmental Fate ◽  
Aquatic Environments ◽  
Surficial Sediments ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Chlorine Substitution ◽  
Sediment Slurry

The environmental fate of 1,3,6,8-tetra- (T4CDD) and octachlorodibenzo-p-dioxin (O8CDD), two major dioxin congeners emitted into the environment, was studied in large (40 m3) lake enclosures at the Experimental Lakes Area in northwestern Ontario. The polychlorinated dioxins (PCDDs) were added to replicate enclosures as a sediment slurry at a nominal concentration of 58–59 ng∙L−1. Both congeners partitioned/settled rapidly to the surficial sediments where they persisted over the 2 yr of the study. Initially the concentrations of the T4CDD in water were higher than those of O8CDD, but the concentrations of the T4CDD in the water column declined more rapidly than those of O8CDD, with t1/2 of 2.6 ± 0.2 and 4.0 ± 0.3 d, respectively. Approximately 10–15% of the T4CDD and < 1% of the O8CDD detected in the water column during the first 48 h were determined to be truly dissolved. The rapid partitioning of O8CDD and to a lesser extent T4CDD to dissolved and particulate organic matter in the water column and sediments limited their bioavailability. Increased retentive capacity of the higher chlorinated PCDDs may explain the pattern of increasing concentration of PCDDs in sediments with increasing chlorine substitution observed in the Great Lakes and other aquatic environments.

Phosphorus Budgets and Stoichiometry during the Open-Water Season in Two Unmanipulated Lakes in the Experimental Lakes Area, Northwestern Ontario

1994 ◽  
Vol 51 (12) ◽  
pp. 2739-2755 ◽  
Author(s):  
P. Campbell
Keyword(s):  
Water Column ◽  
Bottom Sediments ◽  
Open Water ◽  
Short Term ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Phosphorus Budgets ◽  
Mass Balance Approach ◽  
Primary And Secondary Producers ◽  
Column Total

A comparative mass-balance approach is used to describe and quantify phosphorus (P) cycles during the open-water season in two unmanipulated Experimental Lakes Area (ELA) lakes. A bimodal cycle generally prevailed, in which water-column total phosphorus (TP = total dissolved P plus sestonic particulate P) peaked just after ice-out and again late in the summer. Changes in mass of water-column TP were often much larger than corresponding net external inputs. Shifts of P to and from either zooplankton or fish in the water column do not explain the P residuals. Rather, the bottom sediments must have been adding P to the water column. Short-term regeneration of P from the bottom sediments also probably occurs in artificially eutrophied ELA lakes. The mechanism of regeneration is probably biological. Other aspects of P cycling and P stoichiometry are discussed, particularly in relation to nutrient control of population structure and the function of primary and secondary producers.

scholarly journals Análise Espaço-Temporal da Pluma de Dispersão dos Sedimentos Dragados do Porto de Maceió, Alagoas

2021 ◽  
pp. 2087-2113
Author(s):  
Anderson Marques Araújo do Nascimento ◽  
Paulo Ricardo Petter Medeiros ◽  
Geovânia Ricardo dos Santos ◽  
Geórgenes Hilário Cavalcante Segundo
Keyword(s):  
Gravimetric Method ◽  
Linear Interpolation ◽  
Particulate Material ◽  
Physical Parameters ◽  
Plot Analysis ◽  
Suspended Particulate ◽  
Suspended Particulate Material ◽  
Sedimentary Dynamics ◽  
Box Plot

The understanding of the sedimentary dynamics is important in the characterization of impacts caused by dredging and this knowledge becomes decisive for their discernment. The aim of this article was to analyze the plume of dispersion of the sediments of the Port of Maceió. The analyzes were carried out in three sampling campaigns, before, during and after the port works, in which the collection points in the dredging and discard areas were plotted. The suspended particulate material (SPM) was analyzed using the gravimetric method and in situ sampling of the parameters turbidity, dissolved oxygen and percentage of saturation, salinity and electrical conductivity with a multiparameter probe and water transparency with Secchi disk. The parameters SPM, turbidity and transparency were analyzed by linear interpolation, while the other variables were subjected to analysis on a polynomial calibration curve. The multiparameters worked were submitted to box plot analysis in order to assess the variance between campaigns. The variation of SPM in the sample campaigns showed dynamic spatial and temporal behavior; The interpolation promoted a better visualization of the physical parameters that directly express the plume of dispersion; The supplementary variables showed trend patterns in relation to the sediment charge; Box plot analysis proved to be pertinently useful for evaluating and interpreting the results in an integrated manner, mainly due to the large number of parameters analyzed; The dredging works had a balanced management between the amount of dredged sediments and their spatial disposition at the discard site when compared to the dredging area.

Distribution and geochemical composition of suspended particulate material in the shallow embayment of northern Thermaikos Gulf, Greece

2017 ◽  
Vol 143 ◽  
pp. 295-310 ◽  
Author(s):  
K. Tsompanoglou ◽  
Ch. Anagnostou ◽  
E. Krasakopoulou ◽  
K. Pagou ◽  
A.P. Karageorgis ◽  
...  
Keyword(s):  
Particulate Material ◽  
Geochemical Composition ◽  
Suspended Particulate ◽  
Suspended Particulate Material
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