Analysis of Biomass Distribution and Chemical Interactions in Nitrifying Biofilms
Steady-state models of nitrifying biofilms are developed taking into account the mass transfer of neutral and ionic species, electroneutrality, pH-dependent Monod kinetics, chemical equilibrium,...
DBP and Hardness Control by Membrane Filtration
Ultra (UF) and nanofiltration (NF) were evaluated for removal of disinfection by-product (DBP) precursors and hardness from Rio Grande water in New Mexico and Texas. In order to compare...
Denitrification Inhibition by High Nitrate Wastes
The adaptation of activated sludge and inhibition of denitrification at high nitrate concentrations was studied using pH controlled bench-scale sequencing batch reactors (SBRs), operated...
Biological Upflow Fluidized Bed Denitrification Reactor Demonstration Project-Stamford, Ct.
Results of a demonstration project using a biological upflow fluidized bed reactor to remove nitrogen from wastewater treatment plant effluent are described. The reactor was operated at...
Biofilm Sorption of Natural Organic Material
The biosorption of non-ozonated and ozonated natural organic matter (NOM) onto a dense biofilm was investigated at the University of Colorado Environmental Engineering laboratories. Bench-scale...
Emissions, Ambient Concentrations, and Potential Health Hazards of VOCs from Wastewater Treatment
Volatile organic compounds (VOCs) are yielded from wastewater treatment. The potential environmental and health hazards imposed by VOCs has only been recently determined. VOC emissions...
Development of a Model for the ABF/AS Process
A modelling approach has been established for the activated biofiltration/activated sludge (ABF/AS) process. This approach indicates that ABF/AS systems can be considered as a variation...
Biodegradation of 2,4-Dinitrotoluene in a Two Stage System
An anaerobic/anoxic fluidized-bed GAC bioreactor in series with an activated sludge reactor was used to treat 2,4-Dinitrotoluene (2,4-DNT). A simulated high strength wastewater solution...
The Sensitized Photocatalysis of a Mixed Reactant System of 4-Chlorophenol and 4-Nitrophenol
Sensitized photocatalysis has been demonstrated with colored pollutants such as nitrophenols. With visible light excitation of an adsorbed nitrophenolic compound, charge injection into...
Innovative Treatment of Soil Contamination: Radiolytic Destruction of Dioxin and Co-Contaminants by Cobalt-60
Recent work in our laboratory has demonstrated that gamma radiolysis is a feasible method by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can be converted to products of negligible...
Predicting the Impact from Significant Storm Events on a Hazardous Waste Site
The Stringfellow Hazardous Waste Site is a former Class I industrial waste disposal facility located near the community of Glen Avon in southern California. In response to community concerns...
Reliability and Validity of Modeling Sedimentation and Debris Flow Hazards Over Initially Dry Areas
Extreme floods may inundate populated areas of a river valley that are normally dry. Two-dimensional flow analysis is a useful method for predicting the spatial and temporal behavior of...
A model to describe the fate of agricultural pollutants
The distributed parameter hydrological model CEQUEAU is coupled to nitrogen and pesticide sub-models to study agricultural non-point pollution at the watershed level. This developing tool...
Interfacing GIS and Water Quality Models for Agricultural Areas
Agricultural activities significantly impact water quality, including increases in stream sediment, nutrients, pesticides, and salt concentrations from runoff. South Florida is unique...
Groundwater Remediation at a Superfund Site
Soil and groundwater contamination at the Montana Post & Pole site in Butte, Montana, one of the nation's oldest Superfund sites, has developed into one of the most significant...
Development of Transport Model for Groundwater Planning and Management in Taipei Basin
The objective of this paper is to develop a groundwater model for contaminant transport simulation. The transport model, in conjunction with the previously developed flow model, is used...
Erosion and Deposition by Debris Flows in Mountainous Channels on North Fork Mountain, Eastern West Virginia
A study of four debris-flow impacted channels in the North Fork Mountain area of eastern West Virginia shows that the geomorphic effect of debris flows on channel morphology is variable...
Size Characteristics of Debris Flow Deposition
The size distribution of debris flow deposition is extremely wide which may contain nearly all particles from clay and colloid to boulder. Particle size and composition have very important...
An Approach to the Calculation Method of Mean Sediment Size
Mean sediment size is an important parameter expressing the characteristics of sediment. Several calculation methods of mean sediment size which are popular at present almost have some...
The Rest of the Best
Nominations for this year's Outstanding Civil Engineering Achievement Award ranged from a channel built to control flood waters to the construction of a wastewater pollution...
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