Battling Concrete Corrosion
For decades engineers have fought concrete corrosion, but few methods have offered a long-term solution�until now. Electrochemical techniques such as electrochemical chloride extraction...
Wetlands Treat Mine Runoff
Engineers were asked to design a treatment system for the severely acidic drainage from the Mike Horse and Anaconda metals mines in Montana. Challenges included the mountainous terrain,...
Impacts of CSO Swirl Concentrator on Dissolved Oxygen Concentrations in the Anacostia River
Purpose: To assess impacts of the CSO control, two continuous monitoring stations were located upstream and downstream from the CSO outfall. The monitors recorded dissolved oxygen (DO),...
Leachate Chemistry: Its Implications for Clogging
The clogging of leachate collection systems is controlled by interrelated mi and chemical phenomena. Mesocosms containing landfill materials and simulating leachate collection were infiltrated...
Study of Biological Reactors for Control of Odor, VOC and Toxic Emissions from Wastewater Treatment Plants
An experiment was performed to assess the use of biological reactors to treat off-gases from publicly owned treatment works (POTWs) containing low concentrations of hydrogen sulfide (H2S)...
Enhanced Trichloroethene Desorption from Long-Term Contaminated Soil Using Triton X-100 and pH Increases
Laboratory experiments were conducted to study the effect of Triton X-100 and pH changes on trichloroethene (TCE) desorption from field-contaminated soil to water. In laboratory batch...
Specification of Cu, Pb and Cr in Contaminated Sediment Effected by pH
Sediment was sampled from a contaminated river. Sequential extraction was applied to determine the speciations of Cu, Pb, and Cr in the sediment with varied pH (5?9), and the redox potential...
Use of NaOH to Control pH for Solubilization of Waste Activated Sludge
Waste activated sludge was collected from the final clarifier of a local municipal wastewater treatment plant. NaOH was used in comparison made of the controlled pH batch experiments with...
Advanced Oxidation Processes for Removal of Natural Organics and Pesticides from Drinking Water
Among the technologies available to deal with the problem of pesticides in drinking water, advanced oxidation processes (AOPs) represent a treatment that has the potential of completely...
A Study of Alkalinity Leaching and Residual Strength of Alkaline Stabilized Sludge
The addition of sufficient amounts of quicklime or other alkaline earth oxides to dewatered sludge raises both the pH and temperature of the sludge, resulting in microbial inactivation....
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,...
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...
Investigations of Potential Radical Interaction in the Formation of Brominated Organic Compounds in Water
A system has been designed that permits the examination of the formation of organic bromine compounds via a radical pathway. Hydroxyl radicals (HO?)...
Effects of Molecular Oxygen and pH on the Adsorption of Aniline to Activated Carbon
This paper examines the influence of molecular oxygen and pH on the adsorption of aniline to F-300 Calgon Carbon. Molecular oxygen increased the adsorptive capacity of GAC for anilines...
Arsenic Removal Via Softening
The removal of arsenic during softening was investigated using synthetic solutions. Arsenic removal is facilitated by formation of a variety of solids including Mg(OH)2,...
Removal of Bromate After Ozonation by Electron Beam Irradiation
Drinking water regulations related to disinfection, disinfectant by-product (DBP) control, DBP precursor removal and contaminated source water pre-treatment will become increasingly stringent...
Are Colloids Important for Transport Rate Assessment of Radionuclides? A Microscopic Modeling Approach
Understanding the transport phenomena of radionuclides migrating through weakly-permeable rocks forms an essential part of far-field safety assessment studies. Colloidal matter can be...
Neptunium Retardation with Tuffs and Groundwaters from Yucca Mountain
The retardation of neptunium was studied using batch sorption and column techniques. Pure mineral separates, tuffs and groundwaters from Yucca Mountain were used for these experiments....
Assessing the Quality of Citizen Volunteer Monitoring
Total-error profiles and quality control charts are presented as quantitative techniques to determine acceptability of methodology and analyses for volunteer water quality monitoring programs....
Acidity and Chemistry of Arizona's Snowpacks
Acid snow, the frozen version of the acid rain phenomena, has been sampled in several western states, e.g., California, Nevada, Montana, and Oregon. Measurements of snowpack acidity in...
Return to search