Latest Research News on Water and Sediment: Jan – 2020

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Latest Research News on Water and Sediment: Jan – 2020

January 11, 2020 Environment & Ecology 0

Geochemical processes. Water and sediment environments.

The book begins with a chapter introducing the broad picture of the worldwide geochemical cycles, and proceeds to treat in additional detail the individual processes liable for the main fluxes of materials ashore , in waters, and, to a lesser degree, within the atmosphere. the next chapters affect the subsequent subjects: transport of dissolved and suspended materials; controls of the chemical composition and acidity of rain; the physical and chemical weathering of the land surface; interactions between solids and waters in rivers, lakes, and oceans; regeneration of biologically formed materials; transport across the sediment water interface; and chemical reactions and diagenesis in sediments. Appendix C (pp 420-434) provides a mathematical treatment of the settling velocities of particles classified as solid spheres, hollow spheres, polyhedral particles, prolate and oblate ellipsoids, needles, discs, circular cylinders, hemispherical caps and circular rings. [1]

Continuous-Time Water and Sediment-Routing Model for Large Basins

Simulation models are needed to guage the impact of changes in land use and agricultural management on streamflow and sediment yields from watersheds and river basins. Current agricultural-management models are limited by spatial scale, and river-basin models don’t simulate land use and management adequately to guage management strategies. A model called ROTO (routing outputs to the outlet) was developed to estimate water and sediment yield on large basins (several thousand square miles). ROTO may be a continuous model operating on a daily time step that accepts inputs from continuous-time soil-water balance models. Components for water and sediment movement in channels and reservoirs are developed within a comprehensive basin-scale agricultural management model. [2]

Polycyclic aromatic hydrocarbons in water and sediment of the Baltic Sea

Between 1992 and 1994, the distribution of 15 polycyclic aromatic hydrocarbons (PAHs) was investigated in seawater and surface sediments of the Baltic . The analysis of PAHs in seawater is extremely difficult thanks to the low concentration. High separation capability is required. a way for analysing very low concentrations of PAHs is presented. the tactic is predicated on the high-performance liquid chromatography (HPLC) with fluorescence detection. The concentrations of PAHs in seawater are discussed in reference to water depth. A seasonal variation of PAHs in seawater was observed, with lowest concentrations occurring in summer and usually higher concentrations occurring in November. consistent with the regional distribution, elevated concentrations of PAHs were found in coastal regions of the Baltic . The regional distribution of PAHs in surface sediments of the Belt Sea and therefore the Arkona Basin were also investigated. the connection between the content of PAHs and therefore the percentage of total organic carbon in sediments is discussed. [3]

Microbial uptake kinetics of dissolved organic carbon (DOC) compound groups from river water and sediments

Dissolved organic matter (DOM) represents a key component of carbon (C) cycling in freshwater ecosystems. While the behaviour of bulk dissolved organic carbon (DOC) in aquatic ecosystems is well studied, comparatively little is understood about the turnover of specific DOC compounds. The aim of this study was to research the persistence of 14C-labelled low relative molecular mass (LMW) DOC at a good range of concentrations (0.1 µM to 10 mM), in sediments and waters from oligotrophic and mesotrophic rivers within an equivalent catchment. Overall, rates of DOC loss varied between compound groups (amino acids > sugars = organic acids > phenolics). Sediment-based microbial communities contributed to higher DOC loss from river waters, which was attributed, in part, to its greater microbial biomass. [4]

Determination of Polynuclear Aromatic Hydrocarbons in Water and Sediment of River Benue in Makurdi Metropolis, Nigeria

Polynuclear Aromatic Hydrocarbons (PAHs) were investigated in water and sediment samples from River Benue in Makurdi metropolis. Samples of water and sediment were collected from 6 sites in River Benue during the season . The samples were extracted using liquid-liquid extraction and soxhlet extraction methods respectively and analyzed for acenaphthene, fluoranthene, 2-methynaphthalene and naphthalene using gas chromatography coupled to mass spectrometry (GC-MS). The results showed that the samples contained very low concentrations of those PAHs (concentrations varied from 0.06 to 8.02 ppb). So, there was little or no threat to fish, wildlife or humans, supported low concentrations determined within the samples but accumulation over time may pose a health risk. [5]

Reference

[1] Lerman, A., 1979. Geochemical processes. Water and sediment environments. John Wiley and Sons, Inc. (Web Link)

[2] Arnold, J.G., Williams, J.R. and Maidment, D.R., 1995. Continuous-time water and sediment-routing model for large basins. Journal of Hydraulic engineering, 121(2), (Web Link)

[3] Witt, G., 1995. Polycyclic aromatic hydrocarbons in water and sediment of the Baltic Sea. Marine Pollution Bulletin, 31(4-12), (Web Link)

[4] Microbial uptake kinetics of dissolved organic carbon (DOC) compound groups from river water and sediments
Francesca L. Brailsford, Helen C. Glanville, Peter N. Golyshin, Penny J. Johnes, Christopher A. Yates & Davey L. Jones
Scientific Reports volume 9, (Web Link)

[5] I. Arowojolu, M., M. Tongu, S., U. Itodo, A., T. Yinusa, S., A. Basheeru, K. and Mejida, S. (2018) “Determination of Polynuclear Aromatic Hydrocarbons in Water and Sediment of River Benue in Makurdi Metropolis, Nigeria”, Chemical Science International Journal, 22(2), (Web Link)

 

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