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...
Evaluation of Sludge Screening and Screenings Dewatering Technologies
The concept of digested sludge screening has been utilized at the City of Los Angeles' Hyperion Treatment Plant to remove extraneous objects, hair, and fibrous material in...
Composting, Past, Present and Future
Over the past ten years, the composting process has taken on a different look as a method of processing municipal sludge. Today it is one of the most popular and prevalent methods of sludge...
Autothermal Thermophilic Aerobic Digestion: A Two-Year Appraisal of Canadian Facilities
Full scale, autothermal thermophilic aerobic digestion (ATAD) facilities were constructed or upgraded in 1988 to demonstrate high temperature aerobic digestion of municipal sludges at...
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...
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...
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