Lakes are significant sources of methane (CH4) to the atmosphere. Within these systems, methanotrophs consume CH4 and act as a potential biofilter mitigating the emission of this potent greenhouse gas. However, it is still not well understood how spatial and temporal variation in environmental parameters influence the abundance, diversity, and community structure of methanotrophs in lakes. To a...

The last decade has seen a dramatic increase in domestic energy production from unconventional reservoirs. This energy boom has generated marked economic benefits, but simultaneously evoked significant concerns regarding the potential for drinking-water contamination in shallow aquifers. Presently, efforts to evaluate the environmental impacts of shale gas development in the northern Appalachia...

Carbon dioxide (CO2) enrichment of anaerobic digesters (AD) was previously identified as a potential on-site carbon revalorisation strategy. This study addresses the lack of studies investigating this concept in up-scaled units and the need to understand the mechanisms of exogenous CO2 utilisation. Two pilot-scale ADs treating food waste were monitored for 225 days, with the test unit being per...

Hydrogen (H2) consumption and methane (CH4) production in pure cultures of three different methanogens were investigated during cultivation with 0, 0.2 and 4.21 μM added nickel (Ni). The results showed that the level of dissolved Ni in the anaerobic growth medium did not notably affect CH4 production in the cytochrome-free methanogenic species Methanobacterium bryantii and Methanoculleus bourge...

1.1 This test method covers three procedures for extraction and measurement of gases dissolved in electrical insulating oil having a viscosity of 20 cSt (100 SUS) or less at 40°C (104°F), and the identification and determination of the individual component gases extracted. Other methods have been used to perform this analysis. 1.2 The individual component gases that may be identified and determ...

A series of liquid-state computer simulations has been performed on the system [(CH&laq at 25 "C as a function of the separation R between the dissolved CH, molecules. The potential functions for HzO-H20, CH4-HzO and CH4-CH4 are based on quantum-mechanical calculations of the corresponding intermolecular interactions. The simulation was carried out by the Monte Carlo method augmented with conve...

The Oubangui is a major tributary of the Congo River. We describe the biogeochemistry of contrasting tributaries within its central catchment, with watershed vegetation ranging from wooded savannahs to humid rainforest. Compared to a 2-year monitoring record on the mainstem Oubangui, these tributaries show a wide range of biogeochemical signatures, from highly diluted blackwaters (low turbidity...

Methane (CH4) is a climate-relevant trace gas that emitted from the open and coastal oceans in considerable amounts. However, its distribution remote oceanic areas largely unknown. To fill this knowledge gap, dissolved CH4 was measured at nine stations 75°S Ross Sea during austral summer January 2020. undersaturation (mean: 82 ± 20%) found throughout water column. In subsurface waters, of mainl...

This study aimed to evaluate a gas-liquid membrane contactor for recovering the dissolved gases of methane (CH4) and carbon dioxide (CO2) from model aqueous anaerobic effluents. For this purpose, synthetic effluents were prepared by using gas mixtures SE-1: 100/0, SE-2: 0/100 SE-3: 50/50 CH4/CO2 vol.% as well DI water. The units in which effluent was coupled with dense hollow fiber module emplo...

Dissolved gas analysis (DGA) is a reliable technique for detecting the presence of incipient fault conditions in oil immersed transformers. In this method the presence of certain key gases is monitored. The various analysis methods are : Rogers ratio, IEC ratio, Doernenburg, Duval triangle, key gas, artificial neural network (ANN) method. In this paper the various DGA methods are evaluated and ...