Andosol clay re-aggregation observed at the microscale during physical organic matter fractionation

In this study the influence of water matrix and oxidation treatment by ozone on natural organic matter (NOM) fractionation and corresponding disinfection by-products formation was investigated. Three water types were selected, based on their different NOM contents (5.16–9.85 mg/L dissolved organic carbon (DOC)) and structures (42–79% proportion of hydrophobic NOM fraction). It was determined that increasing the ozone dose (0.2–0.8 mg O3/mg DOC) generally led to reductions in DOC (2–26%) and trihalomethane formation potential values (4–58%). Results of NOM fractionation showed that the reactivity of all the individual NOM fractions towards trihalomethane formation decreased after ozone oxidation (0.8 mg O3/mg DOC) by 47–69%, relative to the raw waters.

Download Full-text

Comparison of Labile Soil Organic Matter Fractionation Techniques

Soil Science Society of America Journal ◽

10.2136/sssaj2004.1616 ◽

2004 ◽

Vol 68 (5) ◽

pp. 1616-1625 ◽

Cited By ~ 174

Author(s):

Kendra K. McLauchlan ◽

Sarah E. Hobbie

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Organic Matter Fractionation ◽

Labile Soil Organic Matter

Download Full-text

Variation in Phenanthrene Sorption Coefficients with Soil Organic Matter Fractionation: The Result of Structure or Conformation?

Environmental Science & Technology ◽

10.1021/es061471+ ◽

2007 ◽

Vol 41 (1) ◽

pp. 153-159 ◽

Cited By ~ 61

Author(s):

Julia L. Bonin ◽

Myrna J. Simpson

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Organic Matter Fractionation

Download Full-text

Is ozonation environmentally benign for reverse osmosis concentrate treatment? Four-level analysis on toxicity reduction based on organic matter fractionation

Chemosphere ◽

10.1016/j.chemosphere.2017.10.054 ◽

2018 ◽

Vol 191 ◽

pp. 971-978 ◽

Cited By ~ 12

Author(s):

Jingxia Weng ◽

Huichao Jia ◽

Bing Wu ◽

Bingcai Pan

Keyword(s):

Organic Matter ◽

Reverse Osmosis ◽

Environmentally Benign ◽

Toxicity Reduction ◽

Organic Matter Fractionation ◽

Concentrate Treatment ◽

Level Analysis

Download Full-text

Variation of 1-naphthol sorption with organic matter fractionation: the role of physical conformation

Organic Geochemistry ◽

10.1016/s0146-6380(01)00007-9 ◽

2001 ◽

Vol 32 (5) ◽

pp. 709-719 ◽

Cited By ~ 57

Author(s):

Myrna J Salloum ◽

Marvin J Dudas ◽

William B McGill

Keyword(s):

Organic Matter ◽

Organic Matter Fractionation ◽

Physical Conformation

Download Full-text

Natural organic matter fractionation along the treatment of water for human consumption

Global NEST Journal ◽

10.30955/gnj.000828 ◽

2013 ◽

Vol 14 (4) ◽

pp. 399-406

Keyword(s):

Organic Matter ◽

Seasonal Variation ◽

Water Treatment ◽

Dissolved Organic Matter ◽

Natural Organic Matter ◽

Treatment Plant ◽

Human Consumption ◽

Raw Water ◽

Organic Matter Fractionation ◽

Hydrophobic Acids

The main objective of this study was to characterize the organic matter present in raw water and along the treatment process, as well as its seasonal variation. A natural organic matter fractionation approach has been applied to Lever water treatment plant located in Douro River, in Oporto (Portugal). The process used was based on the sorption of dissolved organic matter in different types of ion exchange resins, DAX-8, DAX-4 and IRA-958, allowing its separation into four fractions: very hydrophobic acids (VHA), slightly hydrophobic acids (SHA), charged hydrophilic (CHA) and hydrophilic neutral (NEU). The dissolved organic carbon (DOC) determination was used to quantify dissolved organic matter. Samples were collected monthly, during approximately one year, from raw water captured at the surface and under the bed of the river, and after each step of the treatment: pre-filtration in sand/anthracite filters, ozonation, coagulation/flocculation, counter current dissolved air flotation and filtration (CoCoDAFF) and chlorination. The NEU fraction showed a seasonal variation, with maximum values in autumn for the sampling points corresponding to raw water captured at the surface and under the bed of the river. It was usually the predominating fraction and did not show a significant decrease throughout the treatment. Nevertheless their low concentration, the same occurred for the CHA and VHA fractions. There was an overall decrease in the SHA fraction throughout the water treatment (especially after CoCoDAFF and ozonation) as well as in the DOC. The TSUVA254 values obtained for raw water generally varied between 2.0 and 4.0 L mgC-1 m-1 and between 0.75 and 1.78 L mgC-1 m-1 for treated water. It was observed a decrease of TSUVA values along the treatment, especially after ozonation. These results may contribute to a further optimization in the process of treating water for human consumption.

Download Full-text

STXM analysis of fungal soil aggregation

10.5194/egusphere-egu2020-17614 ◽

2020 ◽

Author(s):

Edith C. Hammer ◽

Per Persson ◽

Milda Pucetaite

Keyword(s):

Organic Matter ◽

Mycorrhizal Fungi ◽

Soil Aggregates ◽

Soil Aggregation ◽

Dimensional Structure ◽

Soil Matrix ◽

Physical Organic ◽

Organic Matter Stabilization ◽

Mineral Interfaces

Understanding soil&#8217;s C sink potential is crucial to support soil management that increases its long-term carbon storage. Soil aggregate formation is known to be a main factor for long-term C sequestration, as C becomes physically protected, or &#8220;hidden&#8221;, within an increasingly complex three-dimensional structure.The dynamic process of soil aggregation is however not yet clearly understood. Soil (micro) organisms are thought to play a decisive role in &#8220;gluing together&#8221; and redistributing particles. They also move existing organic material, and include own exudates and dead cells into aggregates. Fungi, and especially mycorrhizal fungi play a key role in physical organic matter stabilization as they transport carbon compounds over long distances and into narrow soil pores, but little is known about the chemical remnants they leave to soil aggregates. We investigated the exudates of single hyphae of two saprotrophic and two mycorrhizal fungi (G. confluens, P. subvisciva, P. involutus, R. irregularis), with and without contact to three types of minerals (quarts, goethite, muscovite). We grew them in sterile cultures on Si3N4 windows and analysed hyphae, their exudate layers and the organo-mineral interfaces. STXM analysis was performed at CLS, Canada, Diamond, UK, at the C(K), K(L), N(K) and Fe(L) absorption edges, and we made complementary measurements with photothermal IR microspectroscopy at Soleil, France. We found differential composition of the exudates depending on fungal species and environmental conditions. In some cases, we could identify spatially resolved oscillating plumes of K exudates emitted from the hyphae, indicating possible exudation channels. Goethite particles in close vicinity to a hypha showed reduced Fe(2+) compounds, suggesting that oxidative processes may take place. We further investigated thin-polished samples of AMF hyphae grown in a sterile soil, and located polysaccharide-, lipid- and protein-compounds in the surrounding soil matrix.&#160;Our results will help to better understand the processes of fungal soil aggregation and physical organic matter stabilization.

Download Full-text