Search results for "DEGASSING"

Preliminary results of carbon degassing in the tectonically active areas of Balkan Peninsula

2020

The deeply derived CO2 from tectonically active areas is contributing in a significant proportion, still unquantified in detail, to CO2 Earth degassing. Several studies highlighted how in these tectonically active areas most of the CO2 is dissolved in the groundwaters circulating in the large regional aquifers hosted by the permeable formations of the active orogens. Quantifying the amount of deep CO2 dissolved into groundwater can represent a powerful tool for regional investigations, because springs are representative of their catchment area that can extend from tens to hundreds of square kilometers. In the framework of a Deep Carbon Observatory supported project, we investigated for the …

Development and application of active and passive DOAS instrumentation for the remote sensing measurement of volcanic gas emissions and continuous ge…

2011

The CO2 output from the Sperchios Basin area (central Greece): the role of hidden degassing from streams

2018

The Sperchios Basin is an actively spreading rift area with deeply rooted extensional faults and also a site of quaternary volcanic activity. Such geologic conditions favoured the formation of many hydrothermal systems, whose surface expressions are among the biggest thermal springs of the whole Greece. Degassing of deeply derived geogenic CO2 is highlighted by strong bubbling within the main pools of the springs. Flux measurements were made in the Thermopyles spring with the floating chamber method and results showed that bubbling gases in the spring release about 1 ton/day of CO2. The outgoing stream has a flow of more than 250 l/s of water rich in CO2 (about 16 mmol/l). Although no bubbl…

Widening the applicability of AnMBR for urban wastewater treatment through PDMS membranes for dissolved methane capture: Effect of temperature and hy…

2021

[EN] AnMBR technology is a promising alternative to achieve future energy-efficiency and environmental-friendly urban wastewater (UWW) treatment. However, the large amount of dissolved methane lost in the effluent represents a potential high environmental impact that hinder the feasibility of this technology for full-scale applications. The use of degassing membranes (DM) to capture the dissolved methane from AnMBR effluents can be considered as an interesting alternative to solve this problem although further research is required to assess the suitability of this emerging technology. The aim of this study was to assess the effect of operating temperature and hydrodynamics on the capture of…

Impact of geogenic degassing on C-isotopic composition of dissolved carbon in karst systems of Greece

2022

The Earth C-cycle is complex, where endogenic and exogenic sources are interconnected, operating in a multiple spatial and temporal scale (Lee et al., 2019). Non-volcanic CO2 degassing from active tectonic structures is one of the less defined components of this cycle (Frondini et al., 2019). Carbon mass-balance (Chiodini et al., 2000) is a useful tool to quantify the geogenic carbon output from regional karst hydrosystems. This approach has been demonstrated for central Italy and may be valid also for Greece, due to the similar geodynamic settings. Deep degassing in Greece has been ascertained mainly at hydrothermal and volcanic areas, but the impact of geogenic CO2 released by active tect…

Fluid geochemistry and CO2 output in the southern Apennine (Italy): Preliminary results from the study of cold and thermal waters

2019

Characterization of the Etna volcanic emissions through an active biomonitoring technique (moss-bags): Part 2 – Morphological and mineralogical featu…

2013

Volcanic emissions were studied at Mount Etna (Italy) by using moss-bags technique. Mosses were exposed around the volcano at different distances from the active vents to evaluate the impact of volcanic emissions in the atmosphere. Morphology and mineralogy of volcanic particulate intercepted by mosses were investigated using scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS). Particles emitted during passive degassing activity from the two active vents, Bocca Nuova and North East Crater (BNC and NEC), were identified as silicates, sulfates and halide compounds. In addition to volcanic particles, we found evidences also of geogenic, anthropogenic and marin…

Forecasting Etnean eruptions by real-time observations of volcanic gas composition.

2007

It is generally accepted but not experimentally proven that a quantitative prediction of volcanic eruptions is possible from the evaluation of volcanic gas data. By discussing the results of two years of real-time observation of H2O, CO2 and SO2 in volcanic gases from Mt. Etna volcano, we unambiguously demonstrate that increasing CO2/SO2 ratios can allow detecting the pre-eruptive degassing of uprising magmas. Quantitative modeling by the use of a saturation model allows us to relate the pre-eruptive increases of the CO2/SO2 ratio to the refilling of Etna’s shallow conduits with CO2-rich deep-reservoir magmas, leading to pressurization and eruption triggering. The advent of real-time observ…

Halogen (Cl, F) release during explosive, effusive, and intrusive phases of the 2011 rhyolitic eruption at Cordón Caulle volcano (Chile)

2019

We investigate sulphur, chlorine and fluorine release during explosive, effusive and intrusive phases of the 2011 Cordon Caulle eruption, with a focus on halogen devolatilization. Petrological analysis shows halogen release to have been promoted by isobaric crystallization in slowly-cooled magma that was emplaced in a lava flow and sub-vent intrusion. Fluorine in particular mobilized only after extensive groundmass crystallization and incipient devitrification. By 2017, the gas emitted from vent-proximal fumaroles had hydrothermal compositions, with HCl/HF ratios decreasing with decreasing temperature. We estimate that the eruption could eventually emit up to 0.84 Mt of SO2, 6.3 Mt of HCl, …

Diffuse soil gas emissions of gaseous elemental mercury (GEM) from hydrothermal-volcanic systems: An innovative approach by using the static closed-c…

2016

This study was aimed to test a new methodological approach to carry out measurements of gaseous elemental mercury (GEM) diffusively emitted from soils in hydrothermal-volcanic environments. This method was based on the use of a static closed-chamber (SCC) in combination with a Lumex® RA-915M analyzer that provides GEM measurements in a wide range of concentrations (from 2 to 50,000 ng m-3). Gas samples were collected at fixed time intervals from the SCC positioned on the ground (time-series samples). The Lumex® inlet port was equipped with a three-way Teflon valve allowing the free entrance of air through a carbon trap, in order to: (i) prevent disturbance to the Lumex® operative flow rate …