Anoxic-Aerobic Activated Sludge Treatment
An activated sludge system was operated at a relatively low SRT of 1-2 days at the City of Phoenix to meet secondary treatment requirements. Operating MLSS concentrations were 400-600...
Aerobic Denitrification in Activated Sludge
Definitive proof of the phenomenon of concurrent biological nitrification-denitrification in activated sludge is presented. The mechanism appears to be an inhibition of oxygen respiration...
Effects of Temperature and Mean Cell Residence Time on Enhanced Biological Phosphorus Removal
The effects of temperature and mean cell residence time (MCRT) on biological phosphorus and nitrogen removal were investigated by operating pilot-scale continuous-flow activated sludge...
The Effect of Operational Parameters on the Acid-phase Anaerobic Fermentation in the Biological Phosphorus Removal Process
A series of laboratory-scale, continuous flow experiments has been employed to study the effects of selected HRTs and SRTs on the acid-phase fermentation of primary sludge. The VFA production...
Crossflow vs. Counterflow Air Stripping Costs
Crossflow towers offer a potential economic advantage over counterflow towers due to savings in fan power costs as well as material costs. These savings increase as contaminant volatility...
Air Stripping of Refinery Effluent for TC Compliance
In order to manage the risk that the water effluent may at times exceed the limits of the USEPA final Toxicity Characteristics (TC) rule which came into effect on September 25, 1990, a...
Minimization of Hazardous Waste Generation: Preliminary Investigation of Waste Management Properties of a Solvent Substitute for TCE
The objective of this study was to conduct a preliminary evaluation of waste management properties of a terpene-based solvent substitute. Waste management properties which were evaluated...
Hazardous Waste Reduction?An International Perspective
Waste reduction has long been recognized as the preferred option for the management of hazardous wastes. As early as 1976, the United States Environmental Protection Agency (EPA) adopted...
Complete Recyling in the Organics Chemicals Industry
Regulations for both direct and indirect discharges have become so stringent in order to protect the environment that wastewater treatment and effluent levels in the organics chemicals...
Waste Minimization/Reduction Initiatives and Consequences
This paper summarizes the various waste minimization and waste reduction initiatives being implemented nationwide. Areas of evaluation include: Material Substitution, Production Modification,...
Practical Use of Plants for Water Purification
Problems with contaminated wastewater in USA, Eastern Europe, and developing countries are outlined. Botanical sewage purification for purifying human, animal, and industrial sewage is...
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...
Design Considerations for Control of Volatile Organic Compounds at Wastewater Treatment Facilities
New federal and state regulations require publicly owned treatment works (POTW's) to consider emissions of volatile organic compounds (VOC's) as potentially significant...
Continuing Effort to Eliminate Odors at Orange County's Wastewater Treatment Plants
The County Sanitation Districts of Orange County (CSDOC), California own and operate two wastewater treatment plants. Reclamation Plant No. 1, in Fountain Valley, treats approximately...
Influence of Moisture Influx on the Hygro-thermal Performance of a Clay Buffer Developed for Nuclear Disposal Vault
This paper focusses on an experimental study that investigates the heat transfer and moisture movement within a bentonite clay buffer compacted in a borehole located in a granite block....
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....
Results of the Engineering Special Studies for the UMTRA Project?FY90
The proposed U.S. Environmental Protection Agency (EPA) groundwater standards (40 CFR 192) require that Uranium Mill Tailings Remedial Action (UMTRA) Project remedial action designs meet...
Composite Liner, Leak Detection System, and Floating Cover for Nuclear Reactor Emergency Retention Basins
Existing reactor effluent basins are being retrofitted with composite liners, leak detection system and floating covers. Such basins have a 15-year life and remain empty until an accident...
Return to search