Search results for "Sediment"

Chemical composition of modern and fossil Hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation – Part 1: M…

2012

Bioapatite in mammalian teeth is readily preserved in continental sediments and represents a very important archive for reconstructions of environment and climate evolution. This project provides a comprehensive data base of major, minor and trace element and isotope tracers for tooth apatite using a variety of microanalytical techniques. The aim is to identify specific sedimentary environments and to improve our understanding on the interaction between internal metabolic processes during tooth formation and external nutritional control and secondary alteration effects. Here, we use the electron microprobe to determine the major and minor element contents of fossil and modern molar enamel, …

BIOMASSA AND ACCUMULATION CARBON ON SEAGRASS Enhalus acroides IN GUNUNG BOTAK BAY COASTAL, WEST PAPUA

2018

Seagrass is a high level and a flowering plant that is fully adapted to life in the coastal and has ability to store carbon by 10% of the carbon content in the oceans. The research doing at Gunung Botak Bay Coastal South Manokwari Regency with objective of research to estimate seagrass density and to estimate rate accumulation of carbon from Enhalus acroides. Some the stages of the research done is density sample as long to period 2015 (April and Mei) into (September and Ocktober). Other sampling to collecting seagrass to estimate carbon storage in part like daun, rhizome root and substrat. Result to showing average carbon accumulation of seagrass in above below ground is rhizome part and h…

Messa a punto di un protocollo sperimentale per la ricerca di Enterovirus in sedimenti marini

2009

In riferimento al Decreto Ministeriale del 24/01/1996, il controllo dei fondali marini utilizzati per il ripascimento dei litorali, costituisce un passo importante per la valutazione della salubrità dell’ambiente marino e dei prodotti ittici da allevamento, con particolare riferimento alla coltivazione di molluschi eduli lamellibranchi. Diversi studi, infatti, hanno dimostrato come i sedimenti, per le loro caratteristiche chimico-fisiche, rappresentano dei “serbatoi” di agenti microbici di varia natura che, da qui possono essere risospesi nelle acque, compromettendo la salubrità dell’ambiente. Poiché i molluschi eduli lamellibranchi sono organismi filtratori e trattengono agenti patogeni ca…

Chironomus riparius exposure to fullerene-contaminated sediment results in oxidative stress and may impact life cycle parameters

2015

A key component of understanding the potential environmental risks of fullerenes (C60) is their potential effects on benthic invertebrates. Using the sediment dwelling invertebrate Chironomus riparius we explored the effects of acute (12 h and 24 h) and chronic (10 d, 15 d, and 28 d) exposures of sediment associated fullerenes. The aims of this study were to assess the impact of exposure to C60 in the sediment top layer ((0.025, 0.18 and 0.48) C60 mg/cm2) on larval growth, oxidative stress and emergence rates and to quantify larval body burdens in similarly exposed organisms. Oxidative stress localization was observed in the tissues next to the microvilli and exoskeleton through a method fo…

The impact of soil erosion on soil fertility and vine vigor. A multidisciplinary approach based on field, laboratory and remote sensing approaches

2018

Soil erosion processes in vineyards, beyond surface runoff and sediment transport, have a strong effect on soil organic carbon (SOC) loss and redistribution along the slope. Variation in SOC across the landscape can determine differences in soil fertility and vine vigor. The goal of this research was to analyze the interactions among vines vigor, sediment delivery and SOC in a sloping vineyard located in Sicily. Six pedons were studied along the slope by digging 6 pits up to 60 cm depth. Soil was sampled every 10 cm and SOC, water extractable organic carbon (WEOC) and specific ultraviolet absorbance (SUVA) were analyzed. Erosion rates, detachment and deposition areas were measured by the po…

Strontium isotopes as tracers of water-rocks interactions, mixing processes and residence time indicator of groundwater within the granite-carbonate …

2016

This study aims at identifying the water-rock interactions and mixing rates within a complex granite-carbonate coastal aquifer under high touristic pressure. Investigations have been carried out within the coastal aquifer of Bonifacio (southern Corsica, France) mainly composed of continental granitic weathering products and marine calcarenite sediments filling a granitic depression. A multi-tracer approach combining physico-chemical parameters, major ions, selected trace elements, stable isotopes of the water molecule and 87Sr/86Sr ratios measurements is undertaken for 20 groundwater samples during the low water period in November 2014. 5 rock samples of the sedimentary deposits and surroun…

Ecotest device for estimation of environmental fate of chemicals in the laboratory

1995

Abstract A glass vessel device with water volume of 20 L was constructed for fast testing of the fate of a chemical in freshwater watercourse environment. The dynamic system consisted of natural water with throughflow, of 4.5 mL min−1 and bottom sediment from a clean oligohumic lake in Central Finland. Duckweed (Lemna sp.) as plant material, lake mussel (Anodonta piscinalis) and crucian carp (Carassius carassius) as test animals were included in the test device. Tetrachloroguaiacol (TeCG) was dissolved at start to water to make 2 μg L−1 concentration. The same concentration of TeCG was maintained in inflow water. After static and dynamic pre-tests, a dynamic four weeks test at 15°C was run …

Simulation and control of dissolved air flotation and column froth flotation with simultaneous sedimentation.

2020

Abstract Flotation is a separation process where particles or droplets are removed from a suspension with the aid of floating gas bubbles. Applications include dissolved air flotation (DAF) in industrial wastewater treatment and column froth flotation (CFF) in wastewater treatment and mineral processing. One-dimensional models of flotation have been limited to steady-state situations for half a century by means of the drift-flux theory. A newly developed dynamic one-dimensional model formulated in terms of partial differential equations can be used to predict the process of simultaneous flotation of bubbles and sedimentation of particles that are not attached to bubbles. The governing model…

2018

Abstract Sediment microbes have a great potential to transform reactive N to harmless N2, thus decreasing wastewater nitrogen load into aquatic ecosystems. Here, we examined if spatial allocation of the wastewater discharge by a specially constructed sediment diffuser pipe system enhanced the microbial nitrate reduction processes. Full-scale experiments were set on two Finnish lake sites, Keuruu and Petajavesi, and effects on the nitrate removal processes were studied using the stable isotope pairing technique. All nitrate reduction rates followed nitrate concentrations, being highest at the wastewater-influenced sampling points. Complete denitrification with N2 as an end-product was the ma…

Runoff initiation, soil detachment and connectivity are enhanced as a consequence of vineyards plantations.

2017

[EN] Rainfall-induced soil erosion is a major threat, especially in agricultural soils. In the Mediterranean belt, vineyards are affected by high soil loss rates, leading to land degradation. Plantation of new vines is carried out after deep ploughing, use of heavy machinery, wheel traffic, and trampling. Those works result in soil physical properties changes and contribute to enhanced runoff rates and increased soil erosion rates. The objective of this paper is to assess the impact of the plantation of vineyards on soil hydrological and erosional response under low frequency - high magnitude rainfall events, the ones that under the Mediterranean climatic conditions trigger extreme soil ero…