Bacterial production and their role in the removal of dissolved organic matter from tributaries of drinking water reservoirs

Conventional pyrolysis—GC—MS,thermochemolysis and alkaline CuO oxidation were applied to determine differences between dissolved organic matter (DOM)from terrestrial plants,soil horizons and drinking water reservoirs in two catchments in South Australia.These two reservoir-catchment systems were selected on the basis of contrasting vegetation and land use.Pyrolysis of DOM yielded furans,aliphatic products and N-containing compounds,which are indicative of polysaccharides,lipids and proteins,respectively.Thermo-chemolysis enabled detection of methoxy-benzyl compounds derived from various sources of DOM,indicating that these compounds can be used as bio-markers of vascular plant sources.Vanillic acid was detected from DOM isolates from the vegetation,soils and reservoir waters of the two catchments,using CuO oxidation,and hence this compound also appears to be a suitable bio-marker for tracing allochthonous DOM input into the reservoirs. Each of the three techniques resulted in the formation of different compounds from the DOM isolates,which indicated the type of precursor bio-polymer and/or some of the methoxyphenol structures of lignin.

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Rising trends of dissolved organic matter in drinking-water reservoirs as a result of recovery from acidification in the Ore Mts., Czech Republic

Environmental Pollution ◽

10.1016/j.envpol.2009.06.020 ◽

2009 ◽

Vol 157 (12) ◽

pp. 3433-3439 ◽

Cited By ~ 34

Author(s):

Filip Oulehle ◽

Jakub Hruška

Keyword(s):

Drinking Water ◽

Organic Matter ◽

Czech Republic ◽

Dissolved Organic Matter ◽

Water Reservoirs ◽

Recovery From Acidification

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Photodegraded dissolved organic matter from peak freshet river discharge as a substrate for bacterial production in a lake-rich great Arctic delta

Arctic Science ◽

10.1139/as-2017-0055 ◽

2018 ◽

Vol 4 (4) ◽

pp. 557-583 ◽

Cited By ~ 6

Author(s):

Jolie A.L. Gareis ◽

Lance F.W. Lesack

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Bacterial Production ◽

River Discharge ◽

Bacterial Community Composition ◽

Open Water ◽

Growth Efficiency ◽

Mackenzie Delta ◽

River Deltas ◽

Solar Exposure

Lake-rich Arctic river deltas are recharged with terrigenous dissolved organic matter (DOM) during the yearly peak water period corresponding with the solstice (24 h day−1 solar irradiance). Bacteria-free DOM collected during peak Mackenzie River discharge was exposed to sunlight for up to 14 days in June 2010. As solar exposure increased, carbon and lignin concentrations declined (10% and 42%, respectively, after 14 days), as did DOM absorptivity (62% after 14 days), aromaticity, and molecular weight. Photochemical changes were on par with those normally observed in Mackenzie Delta lakes over the entire open-water season. When irradiated freshet DOM was provided as a substrate, no significant differences were observed in community-level metabolism among five bacterial communities from representative delta habitats. However, bacterial abundance was significantly greater when nonirradiated (0 day) rather than irradiated DOM (7 or 14 days) was provided, while cell-specific metabolic measures revealed that per-cell bacterial production and growth efficiency were significantly greater when communities were provided irradiated substrate. This complex response to rapid DOM photodegradation may result from the production of inhibitory reactive oxygen species (ROS), along with shifts in bacterial community composition to species that are better able to tolerate ROS, or metabolize the labile photodegraded DOM.

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Synthesis of an amphoteric chitosan-based flocculant and its flocculation performance in the treatment of dissolved organic matter from drinking water

10.5004/dwt.2020.24852 ◽

2020 ◽

Vol 174 ◽

pp. 171-177 ◽

Cited By ~ 1

Author(s):

Xiaomin Tang ◽

Ting Huang ◽

Shixin Zhang ◽

Jie Zheng ◽

Huaili Zheng

Keyword(s):

Drinking Water ◽

Organic Matter ◽

Dissolved Organic Matter

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Resolution of photo chemically induced changes of dissolved organic matter as function of cumulated radiation in a sample of a humic-rich and forested stream

10.5194/egusphere-egu2020-5145 ◽

2020 ◽

Author(s):

Peter Herzsprung ◽

Christin Wilske ◽

Wolf von Tümpling ◽

Norbert Kamjunke ◽

Oliver J. Lechtenfeld

Keyword(s):

Drinking Water ◽

Organic Matter ◽

Dissolved Organic Matter ◽

Fluorescence Intensity ◽

Solar Irradiation ◽

Large Reservoir ◽

Photo Degradation ◽

Peak Intensity ◽

Ft Icr Ms ◽

Ft Icr

Photochemical processing is a major transformation pathway for allochthonous and autochthonous dissolved organic matter (DOM). DOM consists of thousands or even millions of different molecules and the isomer-resolved identification molecular structures is still far from any analytical realization. The highest analytical resolution of DOM can be achieved on a molecular mass basis via Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). With this technique, the molecular elemental compositions of thousands of DOM components can be assessed, given that they are extractable from water (via e.g. solid phase extraction, SPE-DOM) and ionizable (e.g. via electrospray ionization).Increasing levels of DOC in drinking water reservoirs pose serious challenges for drinking water processing. Photochemical processes potentially influence the DOM quality in the reservoir water. The photo degradation and / or the photo production of DOM components in surface freshwater as function of cumulated radiation was rarely investigated. In order to fill this gap we performed an irradiation experiment with water from a shaded forest stream flowing into a large reservoir (Muldenberg, Germany). DOC concentration, UV absorption, excitation-emission-matrices (EEMs) including calculated PARAFAC components and fluorescence indices, and FT-ICR MS derived molecular formulas of SPE-DOM were recorded at 13 different time points. The cumulated radiation was recorded during six days of solar irradiation (sunny days in August at 50.401847 deg. latitude and 12.380528 deg. longitude). Changes in relative peak intensity of DOM components as function of cumulated radiation were evaluated both by Spearman`s rank correlation and linear regression.We found components with different types of photo reaction behavior. Relative aliphatic components like C9H12O5 were identified as photo products showing a monotonous mass peak intensity increase with irradiation time. Highly unsaturated and oxygen-rich components like C15H6O8 showed a more or less monotonous intensity decrease indicating photo degradation. Many similar components were positively correlated to the humic-like fluorescence intensity and the humification index (HIX). The strong degradation of these components can explain the high loss of fluorescence intensity and the drop of the HIX in our experiment. As a result of the high temporal resolution in our experiment (i.e. intensity change as function of cumulated irradiation) we found another type of photo reaction. Components like C15H16O8 showed first increasing and then decreasing intensity indicating the formation of intermediate products.In general, the river DOM from the forested catchment area showed high potential for photochemical transformations which probably occur in the sunlight exposed predam of the drinking water reservoir.

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