A Systems Approach for Wasteload Allocations
A methodology for determining an optimal periodic permit for a single discharger situation was developed which accounts for effluent variability, as well as the variability of the receiving...
Fate and Transport of Metals in a River System
A steady-state model was developed that describes the fate of metals in a shallow river system. Settling and resuspension of solids were defined through empirical equations relating a...
Simplified Methods to Predict the Fate of Metals in Rives
Heavy metal contamination of rivers is of increasing concern to society. To help predict the fate of metals in rivers, researchers have developed computer models to simulate speciation...
NCASI Enhancements of the QUAL-II Model
The mathematical water quality model QUAL-II has been modified to reflect advances in the understanding of algal, nutrient, and light interactions. Code changes were also made to incorporate...
Predicting Lake-Chain Quality with Augmentation
Steady-state mass-balance models of lake phosphorus are analyzed with regard to predicting augmentation (or dilution) effects. One form of these models employs a retention coefficient...
The Use of Activated Carbon as a Polishing Step for Treatment of Industrial Plating Wastewaters
An activated carbon adsorption process was utilized as a polishing step following the precipitation (hydroxide or sulfide) process. Zinc and cadmium were the metals studied. Since plating...
Industrial NPDES Toxicity Goals
Biological monitoring of NPDES (National Pollution Discharge Elimination System) effluents is becoming a reality in several EPA regions. While the advantages are genuine the loopholes...
Factors Influencing Zinc Cementation of Cadmium
The research reported here examines an innovative procedure for removal of cadmium from wastewaters. This process is the cementation of cadmium by zinc metal. Cementation is highly attractive...
The Adsorption Characteristics of NI (II) Onto Bubble Surface
The removal of Ni(II) by foam fractionation is brought about by the electrostatic mechanism. From removal and zeta potential measurements, it clearly demonstrates that Ni**2** plus and...
Direct Filtration of High Turbidity Water Using Contact Flocculation
It is shown that the system of bed contact flocculation followed by standard dual media filters provides a viable alternative to both conventional as well as direct filtration, particularly...
Treatment Plant Comparisons in Removing Molecular Weight Fractions of THM Precursors
This paper describes the performance of several types of water treatment plants in removing various molecular weight fractions of natural occurring aquatic organic matter, some of which...
Direct Filtration of Colored Water Supplies
The effects of raw water quality, chemical treatment, and filtration variables on the performance of direct filtration are examined. Cationic polyelectrolytes as sole coagulants are effective...
Optimization of Design and Operating Parameters for Single-Media, Unstratified-Bed Filters
The potentially successful use of filters containing large grain-size single media for water filtration has prompted investigation of the parameters controlling the performance of these...
Computer Simulation of Lime-Soda Softening of Cooling Waters
A computer model is developed to simulate the process of lime-soda softening of cooling waters. Results from the model are compared with those from a laboratory experimental study using...
Wetland Protection Regulations: A Technical Perspective
This paper summarizes the technical basis for the application of wetland protection regulatory schemes upon a number of typical environmental engineering and related projects. A number...
Age-Specific Cancer Risk Analysis for a Population Exposed to Contaminated Drinking Water
Recent developments in the methodology for estimating cancer risk for environmental contaminants exhibit promise for improved predictability of risk analyses based on EPA risk guidelines....
Impacts of Stormwater Runoff on Receiving Waters
A planning methodology to assess the impact of stormwater runoff on streams in Vermont is demonstrated. The methodology, which is based on a statistical representation of runoff and stream...
A Study of River Foaming and its Possible Causes
Foaming has been observed on uncontaminated upland streams draining watersheds having no human related development. Because water alone will not foam when agitated, the presence of these...
Significance of In-Stream Denitrification
In-stream denitrification rates were calculated using a simultaneous nitrogen and dissolved oxygen mass balancing technique. Anaerobic, laboratory, incubation of stream bottom samples...
Development of a Simplified Nitrogen Mass Balance Model in a Macroalgae Dominated System
A seasonably variable nitrogen uptake rate has been established for Ulva in Mumford Cove, Conn. This rate has been verified using three separate water quality analyses each of which assume...
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