sulfur utilizing autotrophic denitrification synthetic wastewater in up flow packed --bed reactor was evaluated under different concentrations of alkalinity and organic matter. the reactor was filled with granular elemental sulfur particles with diameters of 2.8-5.6 mm and porosity of 40%. the initial culture was prepared from sludge of shahrak ghods wastewater treatment plant. first, the stoic...

Nitrate in water from tile drained corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] fields in the U.S. Midwest contributes to nitrate contamination of surface waters. Denitrification-based biofilters are a promising strategy for reducing nitrate concentrations, but these systems require an external carbon supply to sustain denitrification. The ability of four organic materials to serve a...

background: surface water and groundwater pollution with various forms of nitrogen such as ammonium and nitrate ions is one of the main environmental risks. the major objectives of this study were to evaluate the capacity of natural zeolite (clinoptilolite) to remove no3- and nh4+ from polluted water under both batch and column conditions. methods: the laboratory batch and column experiments we...

Nutrient addition has been proved to be an effective strategy to enhance oil biodegradation in marine shorelines. To determine the optimal range of nutrient concentrations in the bioremediation of oil-polluted beaches, nitrate was added to the simulated shoreline models in the initial concentration of 1, 5 and 10 mg/L. Whenever the NO3-N concentration declined to 70% of its original value, addi...

Background: Surface water and groundwater pollution with various forms of nitrogen such as ammonium and nitrate ions is one of the main environmental risks. The major objectives of this study were to evaluate the capacity of natural zeolite (clinoptilolite) to remove NO3- and NH4+ from polluted water under both batch and column conditions. Methods: The laboratory batch and column experiments we...

During the last decade, more stringent effluent requirements concerning the nutrients effluent values have been imposed by legislation and social concern. In this study, efficiency of total nitrogen removal in activated sludge and trickling filter processes (AS/TF) was investigated in Tehran North wastewater treatment plant. Biological system in this site was included, anoxic selector tank, aer...

denitrification is a reduction of nitrate by heterotrophic and autotrophic bacteria that may ultimately produce molecular nitrogen (n2) through a series of intermediate nitrogen compounds.vermiculite is a hydrous phyllosilicate mineral (mg, fe+2,fe+3)3[(al,si)4o10](oh)2·4h2o with several layers for bacterial immobilization. the goal of this study was removal of nitrate from water with vermiculi...

Denitrifying polyphosphate accumulating organisms (DNPAOs) are very promising for simultaneous nitrogen and phosphorus removal. While during denitrification, emission of a greenhouse gas, nitrous oxide (N2O), may occur. In this study, DNPAOs were enriched in a lab-scale reactor, and N2O emission was examined under different electron acceptor conditions. During the anoxic phase, with the uptake ...

Denitrification is a reduction of nitrate by heterotrophic and autotrophic bacteria that may ultimately produce molecular nitrogen (N2) through a series of intermediate nitrogen compounds.Vermiculite is a hydrous phyllosilicate mineral (Mg, Fe+2,Fe+3)3[(Al,Si)4O10](OH)2·4H2O with several layers for bacterial immobilization. The goal of this study was removal of nitrate from water with vermiculi...

The Catskill Mountains of southeastern New York State have among the highest rates of atmospheric nitrogen deposition in the United States. Some streams draining Catskill catchments have shown dramatic increases in nitrate concentrations while others have maintained low nitrate concentrations. Streams in which exchange occurs between surface and subsurface (i.e. hyporheic) waters are thought to...