Dissolved organic nitrogen (DON) derived from wastewater effluent can participate in reactions that lead to formation of nitrogenous chlorination by-products, membrane fouling, eutrophication, and nitrification issues, so management of DON is important for both wastewater reuse applications and nutrient-sensitive watersheds that receive discharges from treated wastewater. This study documents D...

Factors that affect the removal of organic carbon by heterotrophic bacterioplankton can impact the rate and magnitude of organic carbon loss in the ocean through the conversion of a portion of consumed organic carbon to CO2. Through enhanced rates of consumption, surface bacterioplankton communities can also reduce the amount of dissolved organic carbon (DOC) available for export from the surfa...

To examine the effects of dissolved organic matter on metal bioavailability, uptake of trace metals (Cd, Co, Hg, Cr, Ag, Zn) by American oysters (Crassostrea virginica) was compared between treatments with different dissolved organic carbon (DOC) concentrations and contrasting low molecular weight (LMW, 1 kDa) and high molecular weight (HMW, 1 kDa-0.2 micron) DOC fractions, using radiotracer te...

We examined annual nutrient changes (nitrate, phosphate and ammonium) and the net dissolved organic carbon (DOC), nitrogen (DON) and phosphorus (DOP) release using in situ benthic incubations in a Posidonia oceanica meadow and in unvegetated sediments of Magalluf Bay (Mallorca Island, Spain) at monthly intervals. We also examined the role of the P. oceanica meadow in the C:N:P ratio transformat...

Our recent finding that dilution limits dissolved organic carbon (DOC) utilization in the deep ocean has been criticized based on the common misconception that lability equates to rapid and complete utilization. Even when considering the redefinition of recalcitrant DOC recently proposed by Jiao et al., the dilution hypothesis best explains our experimental observations.

The inventories of carbon residing in organic matter dissolved in the ocean [dissolved organic carbon (DOC)] and in the atmosphere as CO2 are of the same order of magnitude, such that small changes in the DOC pool could have important consequences in atmospheric carbon and thus climate. DOC in the global ocean is largely formed in the sunlit euphotic zone, but identifying predictable controls o...

We investigated the long-term photochemical and microbial decomposition of biologically recalcitrant humiclike dissolved organic matter (DOM) leached from a vascular wetland plant, the common rush (Juncus effusus). Although the leachate would have been characterized as biologically recalcitrant by short-term (,14 d) bioassays, microbes decomposed 51% of its organic carbon in 898 d with a first-...

1. Dissolved organic carbon (DOC) plays a central role in the dynamics of stream and river ecosystems, affecting processes such as metabolism, the balance between autotrophy and heterotrophy, acidity, nutrient uptake and bioavailability of toxic compounds. However, despite its importance to stream processes, restoration and management activities rarely incorporate DOC as a major management crit...

The bacteria and their phages are the most abundant constituents of the aquatic environment, and so represent an ideal model for studying carbon regulation in an aquatic system. The microbe-mediated interconversion of bioavailable organic carbon (OC) into dissolved organic carbon (DOC) by the microbial carbon pump (MCP) has been suggested to have the potential to revolutionize our view of carbo...

Mobility of dissolved organic matter (DOM) strongly affects the export of nitrogen (N) and phosphorus (P) from soils to surface waters. To study the sorption and mobility of dissolved organic C and P (DOC, DOP) in soil, the pH-dependent sorption of DOM to samples from Ap, EB, and Bt horizons from a Danish agricultural Humic Hapludult was investigated and a kinetic model applicable in field-scal...