In the ocean, sinking of particulate organic matter (POM) drives carbon export from the euphotic zone and supplies nutrition to mesopelagic communities, the feeding and degradation activities of which in turn lead to export flux attenuation. Oxygen (O2) minimum zones (OMZs) with suboxic water layers (< 5 μmol O2 kg−1) show a lower carbon flux attenuation compared to welloxygenated waters (> 100...

The interactions between catalyzed H(2)O(2) propagations (CHP-i.e. modified Fenton's reagent) and soil organic matter (SOM) during the treatment of contaminated soils and groundwater was studied in a well-characterized surface soil. The fate of two fractions of SOM, particulate organic matter (POM) and nonparticulate organic matter (NPOM), during CHP reactions was evaluated using concentrations...

We propose a direct method of partitioning the particulate spectral scattering coefficient of the marine hydrosol based on the concurrent determination of the concentrations of particulate mineral and organic matter (the total mass of optically active scattering material exclusive of water) with the particulate spectral scattering coefficient. For this we derive a Model II multiple linear regre...

The rehabilitation of sandy desertified land in various dryland ecosystems by different management practices has a great potential to increase aggregate stability and improve soil quality. However, plants in general may have a different ability to sustain soil. The objective was to determine the effects of reclamation practices including Haloxylon ammodendron and Atriplex canescens plantation o...

awma.org Copyright 2012 Air & Waste Management Association The organic fraction of fine particulate matter (PM2.5) can comprise a large fraction of total concentrations of PM across the United States.1 Typically, organic aerosol (OA) or organic particulate matter (OPM) has been viewed as primary and secondary in nature, referring to material that is directly emitted to the atmosphere or PM that...

An analyticai procedure involving Sequential chemical extractions has been developed for the partitioning of Particulate trace metals (Cd, Co, Cu, Ni, Pb, Zn, Fe, and Mn) into five fractions: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter, and residual. Experimental results obtained on replicate samples of fluvial bottom sediments demonstrate that the relative...

Although the freely dissolved form of hydrophobic organic chemicals may best predict aquatic toxicity, differentiating between dissolved and particle-bound forms is challenging at environmentally relevant concentrations for compounds with low toxicity thresholds such as pyrethroid insecticides. The authors investigated the distribution of pyrethroids among 3 forms: freely dissolved, complexed w...

Earthworms are known to be important regulators of soil structure and soil organic matter (SOM) dynamics, however, quantifying their influence on carbon (C) and nitrogen (N) stabilization in agroecosystems remains a pertinent task. We manipulated population densities of the earthworm Aporrectodea rosea in three maize-tomato cropping systems [conventional (i.e., mineral fertilizer), organic (i.e...

The heterogeneous OH oxidation of palmitic acid in single component and internally mixed aerosol particles: vaporization, secondary chemistry, and the role of particle phase V. F. McNeill, R. L. N. Yatavelli, J. A. Thornton, C. B. Stipe, and O. Landgrebe Department of Atmospheric Sciences, University of Washington, Seattle, WA, 98195, USA Department of Chemical Engineering, Columbia University,...

In aquatic environments, the term humic substances (HS) encompasses terrestrial and autochthonous refractory organic matter. HS are one of main fractions natural matter important chelators trace elements. environmental studies, determination is often restricted to dissolved fraction, content in suspended particles remains unknown. this work, we present composition dynamics along mixing gradient...