The retention of nutrients in narrow, vegetated riparian buffer strips (VBS) is uncertain and underlying processes are poorly understood. Evidence suggests that buffer soils are poor at retaining dissolved nutrients, especially phosphorus (P), necessitating management actions if P retention is not to be compromised. We sampled 19 buffer strips and adjacent arable field soils. Differences in nut...

Nitrification, the chemoautotrophic process by which NH4-N is converted to NO,-N, is an integral biogeochemical transformation in stream ecosystems. Previous research has shown that experimental addition of dissolved organic C inhibits rates of nitrification, and that NH4-N addition stimulates rates of nitrification. In many streams, large amounts of C and N may be present in particulate and so...

The mobility of selected heavy metals in trace concentrations was investigated in a standard OECD soil irrigated with the effluent of a real municipal wastewater treatment plant. While Cd, Cu and Ni accumulation-migration patterns were mainly influenced by the mobility of colloids generated from soil organic and inorganic matter, Zn mobility was more influenced by the wastewater content of diss...

In order to investigate sources and turnover rates of dissolved organic matter from Chesapeake Bay and Galveston Bay, colloidal organic matter (COM) was isolated using cross-flow ultrafiltration and subsequently characterized for its elemental (C, N, and S) and isotopic (13C and 14C) composition. Distributions of dissolved organic carbon (DOC) in Chesapeake Bay showed a non-systematic variation...

The sea-surface microlayer (SML) has different physical, chemical and biological properties compared to the subsurface water, with an enrichment of organic matter i.e., dissolved organic matter including UV absorbing humic substances, fatty acids and many others. Here we present experimental evidence that dissolved organic matter, such as humic acids, when exposed to sunlight, can photosensitiz...

large amounts of degradable wastes including sewage water and agricultural waste or nutrients that stimulate growth of organic matter are discharged into the caspian sea. as a result, average dissolved oxygen concentration in deeper layers is decreasing. this paper presents distribution and seasonal variations of the concentration of dissolved oxygen over the southern shelf of the caspian sea a...