Complex Principal Component Analysis of Wave-Like Sand Motions
Complex Principal Component Analysis is applied to bathymetric data from the SUPERDUCK experiment at Duck, NC. This approach is shown to describe more of the variation with fewer functions...

Integrated Photogrammetric and Geophysical Monitoring of Shoreline Instability in Littoral Cells in the Pacific Northwest, USA
Several factors have recently focused on the attention of government agencies, academic researchers, and the general public on coastal erosion and beach resource management in the Pacific...

Sediment Budget at Oceanside, California, Calculated Using a Calibrated Shoreline Change Model
A quantitative sediment budget analysis was made for the shoreline segment extending from 4 miles north to 4 miles south of Oceanside Harbor using a calibrated shoreline change model....

Transport of Volatile Organic Compounds (VOCs) Through a Clay Liner
A series of tests have been performed using laboratory-scale flexible wall permeameters. A synthetic organic leachate mixture of methylene chloride, toluene, and trichloroethylene (TCE)...

PITTLEACH: A Numerical Model of Landfill Stabilization
This paper addresses the theoretical development, use and application of PITTLEACH, a computer program conceived to simulate the processes of landfill stabilization. Since the physical,...

An Evaluation of Area Source Dispersion Algorithms
The correct simulation of air pollutant dispersion from area sources of pollutants has presented some unique challenges to dispersion modelers. This study employs geometric tests and sensitivity...

Hydraulic Analysis of the Impacts of I/I on System Capacity
The USEPA Stormwater Management Model was used to evaluate the impact of infiltration and inflow on the separate sewer facilities of one of the largest sewage treatment districts in the...

Propositions for Packed Bed Adsorption Reactor Design
This paper states ten propositions which describe the behavior of 'wave fronts', i.e., adsorbate concentration versus distance profiles at given elapsed times,...

Screening Level Modeling in Support of an Estuarine Toxics Management Program
Mathematical models will be used in the future to determine maximum allowable pollutant loading rates for several toxics to the South San Francisco Bay Estuary. This project consisted...

Preliminary Investigation into Using Oxidation-Reduction Potential (ORP) for Real-Time Control of Aerobic-Anoxic Sludge Digesters
This research explores the use of Oxidation-Reduction Potential (ORP) to control an Aerobic-Anoxic Sludge Digestion Process. It compares a Fixed-Time Control reactor (3 hours of air on/3...

Pilot-scale Trickling Filter Nitrification at the Longmont WWTP
Nitrification rates in trickling filters can be affected by influent organic matter, filter length, and hydraulic loading rate. The effects of these parameters on nitrification rate were...

Biological Methods for Air Decontamination: Modeling Hydrocarbon Removal
Bench-scale tests indicate biofilter treatment of gasoline and diesel with activated carbon support media is first order, while removal of ethanol on compost is zero order. Treatment of...

Constructed Wetlands at Mesquite, Nevada
Subsurface flow (SF) wetlands are used to provide effluent polishing following treatment in an aerated lagoon at Mesquite, Nevada. General SF wetland design methodology is discussed in...

Reliability-Based Estimates of Wetland Detention Times for Wastewater Treatment
Determination of the hydraulic residence or detention time is often the first step in design of wetlands constructed for wastewater treatment. Current methods for estimating wetland detention...

Inventory of Constructed Wetlands for Municipal Wastewater Treatment in the U.S.
The U.S. EPA's Risk Reduction Engineering Laboratory is conducting an inventory of constructed wetlands (CW) for municipal wastewater treatment in the U.S. The inventory is...

Modeling Emissions from Aerobic Treatment Systems
A mathematical model has been developed specifically for accurately quantifying the dispersion of emissions in the near vicinity of a groundlevel area source. This model accounts for variations...

Permeability of Cement Grout Plugs in Basaltic Rocks
Flow tests have been conducted on expansive cement grout plugs with diameters of 160 mm and 200 mm, and length-to-diameter ratios of one, in boreholes in basalt blocks, and in steel pipes....

Assessment of Effects of a Water Supply Withdrawal on Downstream Flows for Anadromous Fish Reproduction
A BASIC computer model was developed to simulate reservoir operations in conjunction with a proposed water supply withdrawal. The model was used to assess the potential impacts of the...

Using Multiple Water Quality Models for Determining Variable Emission Levels for Wasteload Allocation
We present a methodology for determining the least-cost wasteload allocations from multiple point sources discharging into a single water body. The system of point sources is modeled as...

An Analysis of Modeling Techniques in Pollution Management of Natural Water Systems
This paper will focus on various models to demonstrate the difficulties with modeling techniques. The difficulty with developing a valid model for a system is explored through the study...

 

 

 

 

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