Prediction of Water Quality in Stratified Reservoirs
A transient mathematical model which couples the conservation of heat and mass equations is developed and solved numerically. Vertical temperature and concentration profiles within the...

Multilevel Control of Multipollutant System
The problem of maintaining water quality is considered. The following assumptions are made in problem formulation: (1) the existence of a Regional Authority; (2) the use of effluent charges...

Gas Transfer Kinetics of Pure Oxygen System
A mathematical model is described which determines the gas and liquid phase of oxygen, nitrogen, and carbon dioxide concentrations along with the variation in gas flow and pH in a completely...

Surface Aerator Interactions
Adequate mixing is essential for oxygen transfer and solids suspension in activated sludge systems. A case history is presented including: (1) selection of mechanical surface aerators...

Nonlinear Parameter Estimation in Water Quality Modeling
The quality of water in streams, lakes and estuaries is generally measured in terms of the dissolved oxygen concentration and biochemical oxygen demand. Mathematical models for describing...

Simulation of Dissolved Oxygen Profile
A stochastic mathematical model is developed to describe the probability distribution of dissolved oxygen in streams which have received an input of both thermal and organic pollution....

Leachate Treatment by Coagulation and Precipitation
When sanitary landfills are constructed with provisions for collection and treatment of leachates, chemical treatment may be one of the treatment processes employed. The research described...

Oxygen Sag Curve with Thermal Overload
A deterministic model is developed for the oxygen sag curve for a variable temperature condition under thermal overload. With the help of this model, optimal locations of thermal and organic...

Laboratory Studies on Feedlot Runoff
Stabilization of feedlot runoff is attainable in activated sludge systems at liquid retention times of 2 days or more. Data on a laboratory aeration system operated at retention times...

Electroprecipitation of Phosphate from Sewage
A study of phosphate removal from secondary sewage effluent was conducted using a two-step method of electroprecipitation followed by lanthanum chloride precipitation. In the first step,...

Multigoal Water Quality Planning Model
A nonlinear programming river basin model is presented which can be solved for the least-cost combination of treatment strategies to meet some predetermined quality goals. The model presented...

Reaeration Experiments with Microorganisms
The presence of microorganisms and biological oxygen demand can change the reaeration rate coefficient from what it would be with the same mixing conditions in plain water. There are several...

Dissolved Oxygen Improvement by Hydroelectric Turbine Aspiration
Atmospheric oxygen introduced into the draft tube of a modern low head hydroelectric turbine by a draft tube aspiration system is shown by experimental data to be absorbed with efficiencies...

Optimal Water Quality Management for Houston Ship Channel
The results of this research indicate that savings can be obtained through the application of systems analysis and optimization methods to water quality management problems of the Houston...

Variable Respiration in Aquatic Plant Communities
Test species for the study, which was run in continuous flow and batch type respirometers, included the aquatic macrophytes Potamogeton crispus...

Oxygen Depletion in Ice Covered River
Oxygen use in the Red Deer River is compared to stream loading. The drop in dissolved oxygen levels below the City of Red Deer is related to the change in biochemical oxygen demand (BOD)...

Clean Water—An Environmental Challenge
In 1969 the Porter-Cologne Act in California broke through institutional constraints to link the environmental goals of society to the objectives of water pollution control technology....

Oxygen Theory in Biological Treatment Plant Design
A design approach for plastic media bio-oxidation towers is presented. This paper considers that the rate of mass transfer of oxygen is the rate controlling factor in the overall rate...

Reducing Ice Formation at Navigation Dams
Increasing the turbulence at the movable gates of the Mississippi River Navigation Dams in the St. Paul District by discharging over bulkheads during the winter rather than under the gates...