Biogeochemical processes in rivers are controlled by biological, chemical, geomorphic and hydrologic interactions. These interactions produce variable redox environments wherein microorganisms derive energy and synthesize tissue using oxidation-reduction reactions associated with several elements including C, N, P, S, and to a lesser extent Fe and Mn. Biogeochemistry of river water and surface ...

Sludge dewatering and treatment may cost as much as the wastewater treatment. Usually large proportion of the pollutants in wastewater is organic. They are attacked by saprophytic microorganisms, i.e., organisms that feed upon dead organic matter. Activity of organisms causes decomposition of organic matter and destroys them, where the bacteria convert the organic matter or other constituents i...

Tillage has been reported to reduce organic matter concentrations and increase organic matter turnover rates to a variable extent. The change of soil climate and the incorporation of aboveground C inputs within the soil lead to no unique effect on biodegradation rates, because of their strong interaction with the regional climate and the soil physical properties. The periodical perturbation of ...

Cockles Cerastoderma edule were fed two different concentrations ( approximately 0.8 and 2 mm(3) l(-1)) of two diets with different qualities ( approximately 10 and 60% of organic content) which were achieved by mixing different proportions of ashed silt particles with cells of the microalgae Tetraselmis suecica. Clearance, ingestion and absorption rates of organic matter and biochemical compon...

Sewage-sludge-amended soils generally contain elevated levels of organic matter and heavy metals compared to control soils. Because organic matter is known to complex with heavy metals, the solubility behavior of the organic matter in such soils may exert a significant influence on the solubility of the metals. Little is known about such a process. Using batch experiments in which the solubilit...

Sediments and rocks recovered in CRP-2/2A coring operations contain relatively little organic matter (average TOC=0.28%) and very small amounts of solvent-soluble organic matter. Because Early Oligocene sediment included significant amounts of coal detritus, TOC values are higher in Early Oligocene rocks than in younger rocks. TOC values are highest in the fine-grained rocks deposited as part o...

We compared forest floor depth, soil organic matter, soil moisture, anaerobic mineralizable nitrogen (a measure of microbial biomass), denitrification potential, and soil/litter arthropod communities among old growth, unthinned mature stands, and thinned mature stands at nine sites (each with all three stand types) distributed among three regions of Oregon. Mineral soil measurements were restri...