Search results for "dissolved organic matter"

showing 6 items of 36 documents

Carbon Budget and Molecular Structure of Natural Organic Matter in Bank Infiltrated Groundwater

2021

Groundwater : : journal of the Association of Ground-Water Scientists and Engineers, a division of the National Ground Water Association (2021). doi:10.1111/gwat.13087

liuennut orgaaninen hiilimassaspektrometria550Water table0208 environmental biotechnologychemistry.chemical_elementAquiferFresh Watertekopohjavesi02 engineering and technologyjärvetVadose zoneddc:550Organic matterComputers in Earth SciencesGroundwaterWater Science and TechnologyTotal organic carbonchemistry.chemical_classificationmanaged aquifer rechargegeographypohjavesivedenpuhdistusgeography.geographical_feature_categoryMolecular StructureGroundwater rechargedissolved organic matterpohjavesialueetCarbon020801 environmental engineeringlake-groundwater interactionmolecular compositionpintavesichemistryEnvironmental chemistryEnvironmental scienceorgaaninen ainesSeasonsCarbonGroundwaterWater Pollutants Chemical
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Coupling of iron and dissolved organic matter in lakes–selective retention of different size fractions

2023

AbstractIncreasing concentration of iron (Fe) is observed in many boreal lakes, such as for the present study in Oslo Østmark, SE-Norway (1983–2018). As Fe-regulating processes are complex and dynamic, the link between mobilizing and retention processes is still not well understood. A seasonal study (2017–2018) from two headwaters, with medium and high dissolved organic matter (DOM) concentrations, showed that the loading of Fe to the lakes was highly dependent on flow conditions. Significantly higher values of Fe were related to autumn and winter periods with high runoff of highly colored and aromatic DOM compared to a severe drought period with minimum Fe values in the lakes. Compared to …

liuennut orgaaninen hiiliretentionEcologyrautasulfatedissolved organic matterAquatic Sciencevedenlaatujärvetcolloidal fractionironboreaalinen vyöhykehydrogeokemiasulfaatitaineiden kiertoorgaaninen ainesmobilizationEcology Evolution Behavior and SystematicsWater Science and TechnologyAquatic Sciences
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Revisiting the disappearance of terrestrial dissolved organic matter in the ocean: A δ13C study

2014

Abstract. Organic carbon (OC) depleted in 13 C is a widely used tracer for terrestrial organic matter (OM) in aquatic sys- tems. Photochemical reactions can, however, change δ 13 C of dissolved organic carbon (DOC) when chromophoric, aromatic-rich terrestrial OC is selectively mineralized. We assessed the robustness of the δ 13 C signature of DOC ( δ 13 C DOC ) as a tracer for terrestrial OM by estimating its change during the photobleaching of chromophoric DOM (CDOM) from 10 large rivers. These rivers cumulatively ac- count for approximately one-third of the world’s freshwater discharge to the global ocean. Photobleaching of CDOM by simulated solar radiation was associated with the photoch…

mineralizationreaction kineticsvalokemiabiogeochemical cycledissolved organic matterauringonsäteily
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KOSMOS 2017 Peru Side Experiment: nutrients, phytoplankton abundances, enzyme rates, photophysiology

2022

This data was collected during an short-term incubation experiment in March 2017 that investigated the response of a surface plankton community to upwelling. This experiment was carried in the framework of the SFB754-funded KOSMOS mesocosm study that took place in La Punta, Callao, Peru between February-April 2017. A total of six different treatments were used to disentangle chemical and biological characteristics of deep water that influence surface plankton blooms: 2 different deep water sources with different nutrient concentrations; 3 treatments to distinguish the effects of inorganic nutrients, organic nutrients and deep water microbial populations. Measured variables include inorganic…

ratioDay of experimentSFB754colored dissolved organic matter at 325 nmNitriteChlorophyll aAbsorption coefficient colored dissolved organic matter at 254 nmClimate - Biogeochemistry Interactions in the Tropical Ocean (SFB754)colorimetric determinationFluorometerFluorometricNitrateNanoplanktonPhytoplankton cells phycocyanin-containing (FL-4)PicoeukaryotesFluorometer fast repetition rateCalculatedFlow cytometryNutrient consumption ratioforward scatterSynechococcusupwelling systemsMesocosm experimentSpectrophotometricClimate Biogeochemistry Interactions in the Tropical Ocean SFB754SilicateBiogeochemistryBiospheric SciencesMaximum photochemical quantum yield of photosystem IIenzyme activitycell sizeDissolved inorganic nitrogen/dissolved inorganic phosphorus ratioKOSMOS_2017chainsAbsorption coefficient colored dissolved organic matter 250 nm/365 nm ratioeastern tropical South Pacific OceanKOSMOSExcess phosphateAbsorption coefficient colored dissolved organic matter at 325 nmNatural SciencesGeosciencescolored dissolved organic matter at 254 nmphycocyanin containing FL 4Absorption coefficientPhosphateTank numberPhytoplankton cells chainsNetwork of Leading European AQUAtic MesoCOSM Facilities Connecting Mountains to Oceans from the ArctReplicatenutrientsfast repetition rateDATE TIMECryptophytesMicrophytoplanktonPhytoplankton cellsLeucine aminopeptidase activityDissolved inorganic nitrogen dissolved inorganic phosphorus ratiofungiEnzymatic assayContinuous flow analyserTreatmentDATE/TIMEcolored dissolved organic matter 250 nm 365 nmPhytoplanktonPhytoplankton cell size forward scatterNetwork of Leading European AQUAtic MesoCOSM Facilities Connecting Mountains to Oceans from the Arctic to the Mediterranean (AQUACOSM)CDOMContinuous flow analyser colorimetric determinationNitrate and Nitrite
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The effect of iron on the biodegradation of natural dissolved organic matter

2016

Iron (Fe) may alter the biodegradation of dissolved organic matter (DOM), by interacting with DOM, phosphorus (P), and microbes. We isolated DOM and a bacterial community from boreal lake water and examined bacterial growth on DOM in laboratory experiments. Fe was introduced either together with DOM (DOM-Fe) or into bacterial suspension, which led to the formation of insoluble Fe precipitates on bacterial surfaces (Fe coating). In the latter case, the density of planktonic bacteria was an order of magnitude lower than that in the corresponding treatment without introduced Fe. The association of Fe with DOM decreased bacterial growth, respiration, and growth efficiency compared with DOM alon…

rautadissolved organic matterfosforicomplexbiohajoaminenbakteerit
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Iron and pH regulating the photochemical mineralization of dissolved organic carbon

2017

Solar radiation mineralizes dissolved organic matter (DOM) to dissolved inorganic carbon through photochemical reactions (DIC photoproduction) that are influenced by iron (Fe) and pH. This study addressed as to what extent Fe contributes to the optical properties of the chromophoric DOM (CDOM) and DIC photoproduction at different pH values. We created the associations of Fe and DOM (Fe-DOM) that cover the range of loadings of Fe on DOM and pH values found in freshwaters. The introduced Fe enhanced the light absorption by CDOM independent of pH. Simulated solar irradiation decreased the light absorption by CDOM (i.e., caused photobleaching). Fe raised the rate of photobleaching and steepened…

ta222mineralisation010504 meteorology & atmospheric sciencesphGeneral Chemical Engineeringsolar radiationhiiliInorganic chemistryta1172education116 Chemical sciencesrauta010501 environmental sciencesPhotochemistry01 natural sciencesMineralization (biology)Articlelaw.inventionlcsh:ChemistryironMagazinelawDissolved organic carbonIrradiationauringonsäteilyta1161172 Environmental sciences0105 earth and related environmental sciencesChemistrypHcarbonGeneral ChemistryPhotobleaching6. Clean watermineralisaatioColored dissolved organic matterlcsh:QD1-999
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