Damage Tolerance Analysis in Structural Rehabilitation
The rehabilitation of existing structures requires an evaluation by the structural engineer of past performance to determine the extent of existing damage. Following evaluation of the...
Design, Construction, and Maintenance of Relief Wells
Technical Engineering and Design Guides, as adapted from the U.S. Army Corps of Engineers, No. 3 This engineering manual provides guidance and information...
Environment-Friendly Deicing/Anti-Icing Fluid
NASA Ames has formulated a unique candidate non-glycol based freezing point depressant (FPD) fluid material that performs essentially the same or superior to currently used glycol based...
Removal Of Chromium From Groundwater Using Permeable Barriers: An Aquifer Simulation Study
Previous efforts to remediate groundwater contaminated by chromium-bearing industrial wastes have involved post-extraction methods, whereby groundwater is pumped to the surface treated...
Impacts of Natural and Manmade Changes on the San Luis Rey River Environment
Almost all rivers continually change their position and shape based on various geomorphic and hydraulic factors, caused by natural as well as manmade activities on the riverine environment....
Building Groundwater Optimizers That Respond to the Needs of Decision-Makers
Optimization methods are being sought and employed to design systems that remediate contaminated groundwater regions (and, in fact, the subsurface in general) with increasing frequency....
A Physically Based Conceptual Model for Simulating Contaminant Levels in Subsurface Water
A conceptual physical model is developed to simulate solute transport and mixing in the vadose (unsaturated) and groundwater zones. The conceptual model couples lumped-parameters models...
Plate and Frame Membrane Air Stripping
This paper examines utilization of a plate and frame membrane air stripping system for the removal of volatile organic chemicals (VOCs) and radon from a water supply. Previous work explored...
Use of Expert Systems in Selecting Equilibrium Isotherms of Organic Compound Adsorption on Activated Carbon
An outline of an Expert System (ES) that aids in selecting adsorption isotherms is presented. Such an ES provides an efficient technique for screening the present literature. The ES helps...
The Role of Shale Pores in Settlement
Waste fills resulting from the mining of coal in Appalachia should ideally consist of large, free-draining sedimentary rock fragments. The successful performance of these embankments is...
Controlling Lead and Copper Corrosion and Sequestering of Iron and Manganese
With the recently enacted Lead and Copper Rule (LCR), many utilities are faced with the conflict of meeting the requirements of the Rule and controlling aesthetic problems caused by source...
Modeling Issues of Copper Solubility in Drinking Water
The paper discusses the application of a model to the solubility of copper in drinking water. This paper is the result of numerous forms of pitting corrosion and pipe failures. Monitoring...
The Effects of NOM and Coagulation on Copper Corrosion
Copper corrosion was examined in solutions containing natural organic matter (NOM) and in situations where NOM was removed by enhanced coagulation with alum or ferric chloride. Electrochemical...
Water Chemistry of Lead Corrosion Control
Requirements of the Lead and Copper Rule (U.S. EPA) makes it necessary for regulators, consultants, and water purveyors to understand the fundamental relationships between water quality...
The Relationship of Speciation to Iron and Manganese Removal Strategies
Case studies are presented describing how Fe and Mn speciation procedures were used to solve process problems at two water utilities. A series of filtration steps are used to separate...
Comparison of Biological and Chemical/Physical Iron Removal
The report compares the efficiency of chemical/physical and biological iron removal processes during the entire filter cycle. The results of the first three pilot studies performed in...
The Performance of Unconfined Hollow Fiber Membranes as Pipe Flow and Mixed Flow Aerators
Unconfined gas permeable membranes situated within mixed reactors are currently being evaluated as a viable technology for gas transfer. The use of sealed hollow fiber membranes that are...
Evaluation of Fe oxide-coated GAC for removal and recovery of Cu(II) from water
A composite solid, prepared by precipitating an Fe oxide onto granular activated carbon (GAC), was evaluated as an adsorbent for the removal and recovery of Cu(II) from water. Relative...
Modeling of Chemical Inhibition of Nitrification
This work contains two quantitative structure-activity relationships (QSARs) modeling chemical inhibition of nitrification, one for heterocyclic compounds and one for acetylenic materials....
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,...
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