Origin and Preservation Conditions of Organic Matter in the Mozambique Channel: Evidence for Widespread Oxidation Processes in the Deep-Water Domains

2021 ◽  
pp. 106589
Author(s):  
Martina Torelli ◽  
Anne Battani ◽  
Daniel Pillot ◽  
Eric Kohler ◽  
Joel Lopes De Azevedo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Deep Water ◽  
Oxidation Processes ◽  
Mozambique Channel ◽  
Preservation Conditions

Advanced oxidation processes: flowsheet options for bulk natural organic matter removal

2004 ◽  
Vol 4 (4) ◽  
pp. 113-119 ◽  
Author(s):  
C.A. Murray ◽  
S.A. Parsons
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Natural Organic Matter ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Fenton’S Reagent ◽  
Fenton's Reagent ◽  
Oxidation Processes

Advanced oxidation processes have been reported to have the potential to remove natural organic matter from source waters. Of these Fenton's reagent, photo-Fenton's reagent and titanium dioxide photocatalysis are the three most promising processes. Compared to conventional coagulation/flocculation processes they have higher removal efficiencies in terms of both dissolved organic carbon and UV254 absorbance. Under optimum reaction conditions all three remove over 80% dissolved organic carbon and 0% UV254 absorbance. In addition the enhanced removal of natural organic matter leads to a corresponding reduction in the formation of disinfection by-products following chlorination of the treated water. Advanced oxidation processes give enhanced removal of organic species ranging from low to high molecular weight while coagulation/flocculation is inefficient at removing low molecular weight species. One additional benefit is all three processes produce less residuals compared to conventional coagulation, which is advantageous as the disposal of such residuals normally contributes a large proportion of the costs at water treatment works.

Organo-metallic clay complexes

Clay Minerals ◽  
1966 ◽  
Vol 6 (3) ◽  
pp. 167-177 ◽  
Author(s):  
W. Bodenheimer ◽  
L. Heller ◽  
S. Yariv
Keyword(s):  
Thermal Analysis ◽  
Organic Matter ◽  
Differential Thermal Analysis ◽  
Organic Material ◽  
Inert Atmosphere ◽  
Reaction Cell ◽  
Oxidation Processes

AbstractDifferential thermal analysis curves were obtained for a series of diamine and glycol complexes with natural and copper substituted montmorillonite, in air and in an inert atmosphere. Thermobalance curves of the diamine-clay systems were also determined. The exothermic peaks observed in air are characteristic for any particular system and reflect the nature and binding of the interlamellar material; no direct correlation was, however, observed with pyrolysis and oxidation processes in the clay. Organic matter is frequently liberated from the clay before oxidation, which then occurs within the reaction cell but outside the clay phase. The extent to which oxidation is completed at any particular temperature depends upon the supply of oxygen and the amount of organic material present.

Benthic decomposition of organic matter at a deep-water site in the Panama Basin

Nature ◽  
1987 ◽  
Vol 327 (6124) ◽  
pp. 703-704 ◽  
Author(s):  
Jonathan J. Cole ◽  
Susumu Honjo ◽  
Jonathan Erez
Keyword(s):  
Organic Matter ◽  
Deep Water ◽  
Decomposition Of Organic Matter

Maintenance of Iron Meromixis by Iron Redeposition in a Rapidly Flushed Monimolimnion

1980 ◽  
Vol 37 (8) ◽  
pp. 1303-1313 ◽  
Author(s):  
P. Campbell ◽  
T. Torgersen
Keyword(s):  
Organic Matter ◽  
Residence Time ◽  
Deep Water ◽  
Lake Water ◽  
Redox Reactions ◽  
Water Mass ◽  
Experimental Lakes Area ◽  
Water Renewal ◽  
Renewal Time ◽  
High Concentrations

Water mass ages determined by the 3H–3He method gave a water renewal time of 2.5 ± 1 yr for the monimolimnion of softwater iron meromictic Lake 120. The water renewal time of the monimolimnion is less than, or equal to, the renewal time of the whole lake. The monimolimnion of Lake 120 was, therefore, not found to be a stratum of "perennially stagnant deep water." The rates of supply to, and degradation of, organic matter in the monimolimnion are responsible, in the first place, for the low redox potential necessary to establish the high concentrations of soluble Fe2+ observed (up to 4.2 mmol∙L−1). However, it was found that the major key to maintenance of high monimolimnetic concentrations of Fe, i.e. maintenance of iron meromixis, is recycling of Fe at the chemocline by an [Formula: see text] "Ferrous Wheel." Up to 90% recycling of iron between chemocline and monimolimnion results in an iron residence time of [Formula: see text] for the whole lake (greater than 4 times the whole lake water renewal time).Key words: meromixis, iron recycling, 3H–3He water ages, water renewal times, chemical budgets, sediment funneling, redox reactions, Experimental Lakes Area (ELA).

scholarly journals Monsoonal forcing of cold-water coral growth off southeastern Brazil during the past 160 kyr

2020 ◽  
Vol 17 (23) ◽  
pp. 5883-5908
Author(s):  
André Bahr ◽  
Monika Doubrawa ◽  
Jürgen Titschack ◽  
Gregor Austermann ◽  
Andreas Koutsodendris ◽  
...  
Keyword(s):  
Organic Matter ◽  
Continental Slope ◽  
Deep Water ◽  
Cold Water ◽  
Southeastern Brazil ◽  
Nepheloid Layer ◽  
Saturation State ◽  
The Past ◽  
Water Ecosystems ◽  
The Impact

Abstract. Cold-water corals (CWCs) constitute important deep-water ecosystems that are under increasing environmental pressure due to ocean acidification and global warming. The sensitivity of these deep-water ecosystems to environmental change is demonstrated by abundant paleorecords drilled through CWC mounds that reveal characteristic alterations between rapid formation and dormant or erosive phases. Previous studies have identified several central parameters for driving or inhibiting CWC growth such as food supply, oxygenation, and the carbon saturation state of bottom water, yet there are still large uncertainties about the relative importance of the different environmental parameters. To advance this debate we have performed a multiproxy study on a sediment core retrieved from the 25 m high Bowie Mound, located at 866 m water depth on the continental slope off southeastern Brazil, a structure built up mainly by the CWC Solenosmilia variabilis. Our results indicate a multifactorial control on CWC growth at Bowie Mound during the past ∼ 160 kyr, which reveals distinct formation pulses during northern high-latitude glacial cold events (Heinrich stadials, HSs) largely associated with anomalously strong monsoonal rainfall over the continent. The ensuing enhanced runoff elevated the terrigenous nutrient and organic-matter supply to the continental margin and likely boosted marine productivity. The dispersal of food particles towards the CWC colonies during HSs was facilitated by the highly dynamic hydraulic conditions along the continental slope that prevailed throughout glacial periods. These conditions caused the emplacement of a pronounced nepheloid layer above Bowie Mound, thereby aiding the concentration and along-slope dispersal of organic matter. Our study thus emphasizes the impact of continental climate variability on a highly vulnerable deep-marine ecosystem.

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