Benthic hypoxia in anthropogenically-impacted rivers provides positive feedback enhancing the level of bioavailable metals at sediment-water interface

2020 ◽  
Vol 258 ◽  
pp. 113643
Author(s):  
Deepa Jaiswal ◽  
Jitendra Pandey
Author(s):  
Randall W. Smith ◽  
John Dash

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.


2020 ◽  
Author(s):  
Bingqing qian ◽  
Haiqiao Wang ◽  
Dong Wang ◽  
Hao-Bin Zhang ◽  
Jessica Wu ◽  
...  

2019 ◽  
Vol 128 (3) ◽  
pp. 228-233 ◽  
Author(s):  
Brianne L. Glazier ◽  
Lynn E. Alden

2006 ◽  
Author(s):  
Holley S. Hodgins ◽  
Kathryn Adair ◽  
Rachel Gordon ◽  
Yaritza Saavedra ◽  
Sara Shiffman ◽  
...  

2011 ◽  
Author(s):  
Kent Harber ◽  
Jamie L. Gorman ◽  
Frank P. Gengaro ◽  
Samantha Butisingh ◽  
Rebecca Ouellette ◽  
...  

2018 ◽  
Vol 13 (Number 1) ◽  
pp. 55-67
Author(s):  
Shafini M. Shafie ◽  
Zakirah Othman ◽  
N Hami

Malaysia has an abundance of biomass resources that can be utilised for power generation. One of them is paddy residue. Paddy residue creates ahuge potential in the power generation sector. The consumption of paddy residue can help Malaysia become less dependent on conventional sources of energy, mitigate greenhouse gas(GHG) emission, offer positive feedback in the economic sector, and at the same time, provide thebest solution for waste management activities. The forecast datafor 20 years on electricity generation wasused to calculate the GHG emission and its saving when paddy residue is used for electricity generation. The government’scost saving was also identified when paddy residue substituted coal fuel in electricity generation.This paper can provide forecast information so that Malaysia is able to move forward to apply paddy residue as feedstock in energy supply. Hopefully, the data achieved can encourage stakeholder bodies in the implementation of paddy residue inelectricity generation since there is apositive impact towardscost and emission saving.


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