China
Africa
Explore chapters and articles related to this topic
Effect of Alternative Co-substrates on the Rate of Anaerobic Oxidation of Methane and Sulphate Reduction
Published in Joana Cassidy, Optimization of Biological Sulphate Reduction to Treat Inorganic Wastewaters:, 2020
In marine environments, dissimilatory sulphate reduction (SR) plays a key role in the oxidation of organic matter due to its high concentrations in sea water (Jørgensen and Kasten, 2006). When the oxidants (O2, NO3−,Fe(III), Mn(IV) and SO42-) are depleted in the sediment, CO2 becomes the oxidant of choice, and decomposition of organic matter is linked to CH4 production (Valentine, 2002). The sediment depth where sulphate reduction gives way to methanogenesis is known as the sulphate to methane transition (SMTZ). Anaerobic oxidation of methane (AOM), which is thought to be responsible for the oxidation of 90% of methane produced in marine sediments (Reeburgh, 2007), occurs in the SMTZ and is believed to be coupled to (SR) according to the following net equation: ()CH4+SO42-→HCO3-+HS-+H2O
Selenate bioreduction using methane as the electron donor in a biotrickling filter
Published in Tejaswini Eregowda, Anaerobic treatment and resource recovery from methanol rich waste gases and wastewaters, 2019
The sediment biomass used in this study was collected from the marine lake Grevelingen (Scharendijke basin, the Netherlands), from a sulfate-methane transition zone (SMTZ), a region in the sea sediment where the methane rising from below and the sulfate sinking from above form a region suitable for anaerobic methanotrophy (Mcglynn et al., 2015). Recently Bhattarai et al. (2017) studied and confirmed deep sea sediments from SMTZ for possibilities of the reduction of thiosulfate (S2O32−), sulfate (SO42−) and sulfur (S0) using ethanol, lactate, acetate and methane as electron donor. Se has a chemical behaviour similar to that of sulfur. Therefore, a selenate reduction similar to sulfate reduction coupled with methane oxidation using the Grevelingen biomass (Bhattarai et al., 2018a; Cassarini et al., 2017) was expected in this study.
Selenate bioreduction using methane as electron donor inoculated with marine sediment in a biotrickling filter
Published in Shrutika Laxmikant Wadgaonkar, Novel bioremediation processes for treatment of seleniferous soils and sediment, 2018
The sediment biomass used in this study was collected from the marine lake Grevelingen (Scharendijke basin, the Netherlands), from a sulfate-methane transition zone (SMTZ), a region in the sea sediment where the methane rising from below and the sulfate sinking from above form a region suitable for anaerobic methanotrophy (Mcglynn et al., 2015). Recently Bhattarai et al. (2017) studied and confirmed deep sea sediments from SMTZ for possibilities of the reduction of thiosulfate (S2O32−), sulfate (SO42−) and sulfur (S0) using ethanol, lactate, acetate and methane as electron donor. Se has a chemical behaviour similar to that of sulfur. Therefore, a selenate reduction similar to sulfate reduction coupled with methane oxidation using the Grevelingen biomass (Bhattarai et al., 2017; Cassarini et al., 2017) was expected in this study.
Depositional rate, grain size and magnetic mineral sulfidization in turbidite sequences, Hikurangi Margin, New Zealand
Published in New Zealand Journal of Geology and Geophysics, 2022
Atsushi Noda, Annika Greve, Adam Woodhouse, Martin Crundwell
The original purpose of this study was to reveal the sediment provenance of turbidites in the Hikurangi Trough based on their environmental magnetic properties. However, as we proceeded with our analysis, we realised that the original information was significantly modified by authigenesis, in particular the reduction of the original remanence carriers to the greigite (Fe3S4). Greigite is a strongly ferrimagnetic iron sulfide mineral and is an intermediate mineral phase in a progressive reduction chain from magnetite (Fe3O4) to pyrite (FeS2) (Roberts 2015; Greve et al. 2021). This kind of alteration is common in marine sediments exposed to organo-clastic sulfate reduction (degradation of organic materials or anaerobic oxidation of methane, AOM) in the sulfate–methane transition zone (SMTZ) where hydrogen sulfide (H2S or HS−1) forms iron sulfides (e.g. Roberts 2015). This paper documents the diagenetic characteristics of the detrital magnetic minerals preserved in these turbidites (trench-wedge deposits) and explores relationships between sedimentary features of turbidites (grain size, bed thickness, frequency, and so on) and diagenetic processes that occur during and following turbidite deposition.