scholarly journals Two Approaches to Measure Trace Metals Fluxes at Sediment-Water Interface: Sediment Porewater Profile and Benthic Incubation

Author(s):  
Harmesa ◽  
A’an Johan Wahyudi

The biogeochemical cycle of trace metals is very likely affected by the global change in the ocean, especially due to the increasing of sea surface temperature and acidity. Thus, assessing biogeochemical cycle of trace metals will beneficial in elucidating the potential impact of climate change as well as ocean acidification. The assessment of the biogeochemical cycle of trace metals can be performed by measuring trace metals fluxes crossing the sediment-water interface. The main challenge in this measurement is the difficulty of measuring metal concentrations at trace levels due to either physical factors or biological factors that can affect the total flux. Sediment porewater profile and in situ benthic incubation are the two most commonly used methods for measuring trace metals fluxes from sediment to the overlying water or vice versa. The coefficient of diffusion and gradient of concentration are the two most important values in the sediment porewater profile method, while the constant volume involved in the container during the experiment is an important part of the in situ benthic incubation method. The purpose of this review is to provide an overview of both measurement methods deeply and predict the challenges faced in its implementation in Indonesia. Keywords: Benthic fluxes; Overlying water; Porewater; Sediment; Trace metals


2012 ◽  
Vol 9 (1) ◽  
pp. 41 ◽  
Author(s):  
Yue Gao ◽  
Martine Leermakers ◽  
Annelies Pede ◽  
Aurelie Magnier ◽  
Koen Sabbe ◽  
...  

Environmental contextContaminated sediments can have a large and lasting effect on marine ecosystems. It was discovered that significant amounts of pollutants, especially arsenic, were released from contaminated sediments during a phytoplankton bloom in the Belgian Continental Zone. Once released to the water column, these pollutants can accumulate up marine food chains and be a source of contaminants to humans. AbstractField data from the Belgian Continental Zone showed elevated trace metal concentrations at the sediment–water interface after the occurrence of a phytoplankton bloom. In the present study, laboratory incubation experiments were used to investigate the effect of the phytodetritus remineralisation process on the release of trace metals from contaminated muddy sediments. This remineralisation process was followed by the measurement of chlorophyll-a and dissolved organic carbon levels in the top sediment layers. Two gel techniques, diffusive equilibrium in thin films (DET) and diffusive gradients in thin films (DGT), were used to assess vertical metal profiles in the sediment pore waters and to calculate the metal effluxes. These metal effluxes compared very well with the trace metal concentration variations in the overlying water of the sediment. Much higher effluxes of Mn, Co and As were observed after 2 days of incubation in the microcosms which received additions of phytodetritus. This trend gradually decreased after 7 days of incubation, suggesting that the elevated efflux of trace metals was proportional to the quantity of phytodetritus mineralised at the sediment–water interface. The release of large amounts of toxic elements from the sediments after phytoplankton blooms can therefore potentially affect the marine ecosystem in the Belgian Continental Zone.



1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.



2020 ◽  
Vol 8 (5) ◽  
pp. 1901404 ◽  
Author(s):  
Tianli Han ◽  
Yong Wu ◽  
Yingyi Ding ◽  
Yan Zhong ◽  
Ping Zhou ◽  
...  


Chemosphere ◽  
2021 ◽  
pp. 131014
Author(s):  
Mary-Lou Tercier-Waeber ◽  
Fabio Confalonieri ◽  
Melina Abdou ◽  
Lionel Dutruch ◽  
Cécile Bossy ◽  
...  


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3147
Author(s):  
Ilaria Frau ◽  
Stephen Wylie ◽  
Patrick Byrne ◽  
Patrizia Onnis ◽  
Jeff Cullen ◽  
...  

Thousands of pollutants are threatening our water supply, putting at risk human and environmental health. Between them, trace metals are of significant concern, due to their high toxicity at low concentrations. Abandoned mining areas are globally one of the major sources of toxic metals. Nowadays, no method can guarantee an immediate response for quantifying these pollutants. In this work, a novel technique based on microwave spectroscopy and planar sensors for in situ real-time monitoring of water quality is described. The sensors were developed to directly probe water samples, and in situ trial measurements were performed in freshwater in four polluted mining areas in the UK. Planar microwave sensors were able detect the water pollution level with an immediate response specifically depicted at three resonant peaks in the GHz range. To the authors’ best knowledge, this is the first time that planar microwave sensors were tested in situ, demonstrating the ability to use this method for classifying more and less polluted water using a multiple-peak approach.



Author(s):  
José Lucas Martins Viana ◽  
Adriana Felix de Souza ◽  
Amauris Hechavarría Hernández ◽  
Lucas Pellegrini Elias ◽  
Carlos Eduardo Eismann ◽  
...  


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4155
Author(s):  
Alexander V. Shokurov ◽  
Daria S. Kutsybala ◽  
Andrey P. Kroitor ◽  
Alexander A. Dmitrienko ◽  
Alexander G. Martynov ◽  
...  

Coordination-induced spin crossover (CISCO) in nickel(II) porphyrinates is an intriguing phenomenon that is interesting from both fundamental and practical standpoints. However, in most cases, realization of this effect requires extensive synthetic protocols or extreme concentrations of extra-ligands. Herein we show that CISCO effect can be prompted for the commonly available nickel(II) tetraphenylporphyrinate, NiTPP, upon deposition of this complex at the air/water interface together with a ruthenium(II) phthalocyaninate, CRPcRu(pyz)2, bearing two axial pyrazine ligands. The latter was used as a molecular guiderail to align Ni···Ru···Ni metal centers for pyrazine coordination upon lateral compression of the system, which helps bring the two macrocycles closer together and forces the formation of Ni–pyz bonds. The fact of Ni(II) porphyrinate switching from low- to high-spin state upon acquiring additional ligands can be conveniently observed in situ via reflection-absorption UV-vis spectroscopy. The reversible nature of this interaction allows for dissociation of Ni–pyz bonds, and thus, change of nickel cation spin state, upon expansion of the monolayer.



1986 ◽  
Vol 2 (3) ◽  
pp. 181-186 ◽  
Author(s):  
A. Seritti ◽  
R. Ferrara ◽  
E. Morelli ◽  
C. Barghigiani ◽  
A. Petrosino


2003 ◽  
Vol 83 (5) ◽  
pp. 581-587 ◽  
Author(s):  
J. D. MacDonald ◽  
W. H. Hendershot

The concentrations of metals in soils are spatially heterogeneous and soil sampling carried out when studying metals in forest ecosystems is often inadequate. We examined the spatial variability of Cd, Cu, Mn, Ni, Pb and Zn in northern forest ecosystems on a transect with distance from two point source emitters with the goal of providing basic information about the distribution and variability of metals in these soils. Samples were taken under six sampling points at four depths from three experimental sites on each of the two transects. Soils were analysed for acid digestible metals, pH and organic carbon content. Standard deviation, coefficients of variation, mean and medians were analysed for each horizon of each site. It was observed that Cu and Mn variability is higher in closer proximity to the point source while the variability of Zn increased with decreasing soil pH. In Sudbury, emitted metals Ni and Cu accumulate together in soils, whereas in Rouyn-Noranda, with the exception of Cd and Zn, metal concentrations were not related in forest floors. Observations suggest that physical factors influencing where metals are deposited as well as the inherent variability in soil chemical characteristics, and the distance from the point source can all act together to result in high variability in soil metal concentrations in a single forest site. Sampling in the interest of relating vegetation metal concentrations or response to soil metals should be carried out on an individual plant basis with multiple samples taken for each individual. Soil samples taken at intervals of 1 to 1.7 m will provide relative error in estimating soil concentrations of 10% or 20%, respectively. Key words: Spatial variability, trace metals, podzolic soils, smelter emissions



Sign in / Sign up

Export Citation Format

Share Document