scholarly journals Survival and development of copepod larvae Tisbe battagliai in surface microlayer, water and sediment elutriates from the German Bight

1992 ◽  
Vol 91 ◽  
pp. 221-228 ◽  
Author(s):  
TD Williams
Keyword(s):  
German Bight ◽  
Surface Microlayer ◽  
Water And Sediment ◽  
Sediment Elutriates ◽  
Survival And Development

scholarly journals Allium cepa Bio Assay to Assess the Water and Sediment Cytogenotoxicity in a Tropical Stream Subjected to Multiple Point and Nonpoint Source Pollutants

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
W. M. Dimuthu Nilmini Wijeyaratne ◽  
L. G. Y. J. G. Wadasinghe
Keyword(s):  
Root Growth ◽  
Allium Cepa ◽  
Water Samples ◽  
Root Tip ◽  
Sediment Samples ◽  
Water And Sediment ◽  
Sediment Elutriates ◽  
Tip Cells ◽  
Root Tip Cells ◽  
Water And Sediment Samples

The present study was conducted to assess the cytotoxicity of water and sediments of an industrial effluent receiving water body in the western province of Sri Lanka using Allium cepa bioassay. Six sampling sites (Site A: Urban; B: Industrial; C: Water intake for public water supply; D: Industrial; E: Agricultural; F: Reference) were selected from the study area. Ten replicate water and sediment samples were collected from each site, and physical and chemical parameters were measured using standard analytical methods. Cytotoxicity of water and sediment elutriates were measured using Allium cepa bioassay. Despite the significant spatial variations, the overall water and sediment quality parameters of the study sites were in accordance with the standard ambient environment parameters to sustain a healthy aquatic life. In the A. cepa bulbs exposed to water samples, significant root growth variations were not observed within 48 hours of exposure. However, significant root length variations were observed in A. cepa bulbs exposed to sediment elutriates within the 48-hour exposure and the percentage root growth inhibition increased with increase of exposure time. Similar trend was observed in mitotic activity indicating significantly lower mitotic indices (compared to that of the reference site) in A. cepa root tip cells exposed to sediment elutriates than those exposed to water samples. Further, the highest number of nuclear abnormalities was recorded from root tip cells of A. cepa exposed to water and sediment samples from sites B, C, and D. Therefore, it is of extreme importance to identify the composition and speciation of these cytogenotoxic compounds in the tropical climatic conditions and to propose possible clean-up or treatment solutions to overcome this environmental and public health risk associated problem.

A whole sample toxicity assessment to evaluate the sub-lethal toxicity of water and sediment elutriates from a lake exposed to diffuse pollution

2009 ◽  
Vol 24 (3) ◽  
pp. 259-270 ◽  
Author(s):  
N. Abrantes ◽  
R. Pereira ◽  
D. R. de Figueiredo ◽  
C. R. Marques ◽  
M. J. Pereira ◽  
...  
Keyword(s):  
Toxicity Assessment ◽  
Diffuse Pollution ◽  
Water And Sediment ◽  
Lethal Toxicity ◽  
Sediment Elutriates

Modelling Air-Water Exchange Process of Pentachlorophenol in the Aquatic Environment

2002 ◽  
Vol 37 (2) ◽  
pp. 445-458 ◽  
Author(s):  
Jie Chi ◽  
Guo-Lan Huang
Keyword(s):  
Model Calculation ◽  
Aquatic Environment ◽  
Water Exchange ◽  
Exchange Process ◽  
Compartment Model ◽  
Water Phase ◽  
Surface Microlayer ◽  
Fugacity Model ◽  
Water And Sediment ◽  
Photodegradation Rate

Abstract To study the effects of the surface microlayer (SM) on the air-water exchange process of pentachlorophenol (PCP), simulated experiments were carried out in a microcosm containing air, water and sediment. A four-compartment (i.e., air, SM, water and sediment) fugacity model was successfully applied to the simulated experiments in the microcosm. Data obtained from the four-compartment model calculation yielded a more satisfactory fit with experimental results than the use of a model that does not address the effects of the SM compartment. Results of model calculation show that 97.8% of PCP is distributed to the water phase in the aquatic environment, and 82.2% PCP is removed by the advective outflow and biodegradation in the water phase. The results obtained demonstrate that the higher photodegradation rate of PCP in the SM reduces the concentration of PCP in the air phase.

Environmental Assessment of Tributyltin in Canada

1992 ◽  
Vol 25 (11) ◽  
pp. 125-132 ◽  
Author(s):  
R. J. Maguire
Keyword(s):  
Fresh Water ◽  
Aquatic Ecosystems ◽  
Degradation Products ◽  
Subsurface Water ◽  
Surface Microlayer ◽  
Biological Degradation ◽  
Sensitive Species ◽  
Water And Sediment ◽  
Antifouling Agent ◽  
Shipping Traffic

The aquatic chemistry, fate and toxicity of tributyltin are reviewed. A summary is given of investigations of the occurrence and persistence of tributyltin and its less toxic degradation products in water and sediment in Canada. Tributyltin was mainly found in areas of heavy boating or shipping traffic, which was consistent with its use as an antifouling agent. In about 8% of the 269 locations across Canada at which samples were collected, tributyltin was found in water at concentrations which could cause chronic toxicity in a sensitive species, rainbow trout. Tributyltin was occasionally found in the surface microlayer of fresh water at much higher concentrations than in subsurface water. It was also found in about 30% of sediment samples collected across Canada. The few fish analyzed that contained tributyltin were from harbours, a finding consistent with findings in water and sediment. Biological degradation in water and sediment appears to be the most important factor limiting the persistence of tributyltin in aquatic ecosystems. Estimates of the half-life of biological degradation of tributyltin in fresh water and sediment in Canada are in the range of a few weeks to 4-5 months, respectively. Recent Canadian regulations of tributyltin are discussed as well as the current Canadian Environmental Protection Act review of non-pesticidal organotins.

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

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