Long-Term Effects of Tillage and Crop Rotation on the Leaching of Nitrate and Pesticides to Shallow Groundwater
Contamination of groundwater by nitrate-nitrogen (NO3-N) and pesticides is a serious problem and concern in Iowa. The extent of contamination can...

Effects of Solute Transport Processes on In-Situ Denitrification for Nitrate Control in Ground Water
This paper discusses the effects of solute transport mechanisms on the effectiveness of biodenitrification in the subsurface environment. The only solute transport processes apparently...

Transport Models to Simulate Nitrate Contamination
Computer models can be used to simulate groundwater flow and contaminant transport in the vadose zone, the results of which can be used as input to simulate flow and transport in the saturated...

Nitrate in Rural Water Supplies in North Carolina
Over 9000 rural water supplies in North Carolina were analyzed for nitrate, chloride, electrical conductivity and pH. Data were collected on well characteristics and potential sources...

Influence of Soil and Sediment pH and Redox Conditions on Degradation of Toxic Organics
The presence of toxic organics in soil and sediments has raised concern over persistence and bioaccumulation. In the absence of oxygen, microbial degradation of toxic organics proceeds...

Modeling Nitrogen Movement Through Loess Soils
This study evaluates the ability of the Root Zone Water Quality Model (RZWQM) to track the movement and fate of nitrate (NO3--N)...

Risk Management for Groundwater Contamination: Fuzzy Set Approach
A methodology is developed for health risk management under uncertainty, using fuzzy sets. Groundwater nitrate contamination illustrates the methodology. A risk management framework is...

Nitrogen Discharge in Secondary Effluent and Its Effect on Nitrate in Groundwater

The Role of Nitrate in Biological Phosphorus Removal

Nitrate and Bromide Transport Through a Vadose Zone in New Jersey
Ongoing field experiments on monitoring transport of Sodium Nitrate and Potassium Bromide in the vadose zone over a shallow groundwater table in the coastal plains of New Jersey are discussed....

Impact of Agriculture on Ground-Water Quality on the Delmarva Peninsula
Both pesticides and nitrates have been detected in the ground water on the Delmarva Peninsula. Highest nitrate concentrations have been found on well-drained soils. Poultry manure is one...

Managing Nitrates, Salinas Valley, California

Modeling of Nitrate Transport Coupled Dentrification in the Saturated Zone
A numerical model for simulating nitrate transport coupled to microbial activity in the saturated zone is presented. A coupled system of equations describes the transport and microbial...

Identifying Temporal Change in the Spatial Correlation of Regional Groundwater Contamination
An approach for estimating the semivariogram based on the jackknife method can be used in connection with standard confidence procedures to set closely approximate confidence limits on...

The Economic Feasibility of Using Ethanol to Accelerate Groundwater Denitrification
A substantial buildup of nitrate in the groundwater of the eastern Sandhills region of Nebraska is projected by some planners. A groundwater carbon source such as ethanol promotes denitrification,...

Leaching of Nitrate from Freely Drained–Irrigated Fields Treated with Municipal Sludges
A municipal sludge land application experiment was initiated in 1975 near Riverside, California. From 1975 to 1983 sludges from the Los Angeles Metropolitan Area were applied on experimental...

Irrigation and Nitrogen Management Impacts on Ground-Water Quality
The effect of irrigation management and nitrogen management on ground-water quality has been evaluated for four years on a sandy loam Coastal Plain soil. Nitrogen sidedressing and fertigation...

Modeling Irrigation and Nitrogen Management
Irrigation increases the potential for nitrate accumulation in the groundwater in two ways. It increases the water content in the root zone creating a greater potential for leaching. Two...

Economic Evaluation of Treatment Alternatives for Nitrate-Contaminated Water Supplies
This paper discusses the economic feasibility of removing nitrates from water supplies. Potential nitrate treatment methods include ion exchange, reverse osmosis, bio-denitrification,...

Pesticide and Nitrate Movement Under Conservation and Conventional Tilled Plots
Carbofuran, alachlor, atrazine, nitrate and bromide (a tracer) were applied to plots with conventional and conservation tillage. During the early part of the growing season the conservation...

 

 

 

 

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