Inside the Manhole: New Design on a Leaky Link
Wastewater collection systems represent a major investment for every community, not only in capital dollars, but also in the well-being of community members. Though sanitary sewer manholes...
Combined Nitrogen and Phosphorus Removal in a Cyclic Activated Sludge System Without Anoxic Mixing Sequences
A simplified methodology for combined phosphorus and nitrogen removal through reactor configuration, cyclic sequencing and the control of aeration intensity in variable volume activated...
Toxicity Bioassay Using Nitrifying Bacteria
Monitoring water quality by the use of toxicity bioassay was studied with respect to the interrelationship between nitrifying activities, ammonium and inorganic compounds. Differential...
Toxicity Bio-Assays, 5-Day BOD and
This article revisits some of the basic definitions of toxicity bioassays and 5-day BOD and questions the the precision of these measuements and the long duration of these tests....
Screening Level Modeling in Support of an Estuarine Toxics Management Program
Mathematical models will be used in the future to determine maximum allowable pollutant loading rates for several toxics to the South San Francisco Bay Estuary. This project consisted...
An Engineered Reactor Approach to Integrating Physicochemical and Biological Processes for In-Situ Bioremediation of Contaminated Subsurface Systems
The concept of integrating biologically active granular carbon reactors into groundwater recycle schemes to provide continuous acclimation and enrichment of microorganisms and inoculation...
Adsorption of Lindane onto Whole Soil and Soil Organic Fractions
The work presented here investigated interactions of the subject pesticide with whole soil and select soil organic fractions and evaluated the commonly applied assumptions that adsorption...
Development of a Sorbent for Removal of Nonionic Pollutants from Water
Sorption of anionic surfactants onto mineral oxides and, and the subsequent partitioning of non-ionic organic substance into the organic phase of these synthetic sorbents was studied....
Behavior of Three Organic Chemicals Passing Through Columns Packed with Sand and Silt in the Presence of Landfill Leachate
This study examines the effect of leachate on the migration of three common industrial chemicals in unsaturated flow under two sets of soil conditions: sand and sand with a layer of silt....
Impact of Proposed Radon Drinking Water Regulations on Groundwater Systems in California
This summer, the Environmental Protection Agency is expected to propose a maximum contaminant level (MCL) of 300 pCi/l for radon in drinking water. This anticipated MCL, if adopted, will...
Fate of PCBs in Municipal-Sludge Amended Soil
This paper presents the preliminary results of a five-year field study of the fate of PCBs in soil that has been amended with municipal sewage sludge. A first-order model describes the...
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...
Destruction of VOC's By Thermal Oxidation
The Clean Air Act Amendments of 1990 call for the regulation of 189 air toxics and requires control standard benchmarks of Maximum Achievable Control Technology (MACT). These emissions...
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...
Biological Methods for Air Decontamination: Modeling Hydrocarbon Removal
Bench-scale tests indicate biofilter treatment of gasoline and diesel with activated carbon support media is first order, while removal of ethanol on compost is zero order. Treatment of...
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...
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...
Modeling Emissions from Aerobic Treatment Systems
A mathematical model has been developed specifically for accurately quantifying the dispersion of emissions in the near vicinity of a groundlevel area source. This model accounts for variations...
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