Recently recharged water (defined here as <60 years old) is generally the most vulnerable part of a groundwater resource to nonpoint-source nitrate contamination. Understanding at the appropriate scale the interactions of natural and anthropogenic controlling factors that influence nitrate occurrence in recently recharged groundwater is critical to support best management and policy decisions t...

Five sets of microcosm batch experiments were performed to evaluate mechanisms of nitrate removal in constructed wetlands. The study evaluated biological denitrification activity as a function of 1) electron donors carbon and sulfur 2) wetland sediment depth 3) oxygen and abiotic reactions and 4) carbon addition and attached populations from wetland bulrushes. Wetland-water-only controls amende...

Nitrate N fluxes from tile-drained watersheds have been implicated in water quality studies of the Mississippi River basin, but actual NO3-N loads from small watersheds during long periods are poorly documented. We evaluated discharge and NO3-N fluxes passing the outlet of an Iowa watershed (5134 ha) and two of its tile-drained subbasins (493 and 863 ha) from mid-1992 through 2000. The cumulati...

Nitrate ions are one of the causes surface water eutrophication. In present research, effective adsorption nitrate (NO3) on bioadsorbents prepared from yam skins (Dioscorea alata) was evaluated. The skin chemically modified with ammonium chloride (NH4Cl), and biochar thermally biomass. results were compared commercial coal (CC). characterized by SEM-EDS analysis, which showed that synthesized a...

Globally, the presence of nitrate anions in water beyond the threshold limit can be deleterious to both flora and fauna life. Guyana‟s waste and domestic water needs monitoring to assess the concentration of toxic anions and cations. High levels of nitrate anion beyond the threshold limit can induce the “blue baby” syndrome amongst other effects. This paper focuses on the determination of nitra...

A constructed wetland (CW) was strategically placed to treat nitrates in groundwater as part of a watershed-based farmer engagement process. Using stream water quality data collected before and after installation, this CW was found to reduce stream concentrations of nitrogen from nitrate (NO3-N) during the growing season by about 0.14 mg/l at mean streamflow, a 17% reduction. Based upon realist...

Background & objectives: Because of its very high solubility, nitrate penetrates easily into soil and underground waters. Surface waters such as lakes, reservoirs, and rivers are exposed to nitrate pollution. Photocatalytic processes have a high potential for nitrate removal due to complete oxidation, lack of formation of multi-cycle metabolites and the availability of catalysts. The purpose of...

The aim was to assess the ability of microcosms (laboratory-scale shallow ponds) as a post polishing stage for the remediation of artificial textile wastewater comprising two commercial dyes (basic red 46 (BR46) and reactive blue 198 (RB198)) as a mixture. The objectives were to evaluate the impact of Lemna minor L. (common duckweed) on the water quality outflows; the elimination of dye mixture...