Since the development of the activated sludge process in 1913
many attempts have been made to improve it. One approach has been
to increase the oxygen available to the bio-mass. This study combined the use of elevated pressure and high-shear mixing to increase
the oxygen transfer.
The conventional method of...
Biosolids are a by-product of municipal wastewater treatment. They contain organic matter and nutrients that are beneficial for soil, crop, and livestock productivity. Raw sewage solids must be processed to meet U.S. Environmental Protection Agency (USEPA) standards before they can be called biosolids. This publication focuses on how biosolids can...
Published May 1980. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Predicting agronomic rates is important to derive optimum economic and environmental benefits from biosolids fertilizer applications. We conducted this research to 1) evaluate dryland wheat response to biosolids applications over a range of climate zones in the Pacific Northwest and 2) compare agronomic application rates predicted from yield curves with...
Published June 1992. Reprinted April 1994. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
A study of the effect of elevated pressure on the activated
sludge waste treatment process is presented. The method of study
involved a comparison of two laboratory, batch type, activated sludge
units. One unit was operated at atmospheric pressure as a base control
and the other operated at elevated pressures...
The purification capacity of an activated sludge process is highly
dependent of the rate of oxygen transfer from the air to the microorganisms.
This rate can be increased in an air diffusion system by
subjecting the culture to high shear and high pressure.
A study of the effects of high...
Fluorinated alkyl substances, which can be persistent, toxic, and
bioaccumulative, have been quantitated in many densely populated and
remote regions, including in air, surface waters, groundwater, and biota;
however, little is known about their transport or behavior in the environment.
Wastewater effluent is one of the principal routes for introducing...
A laboratory study of anaerobically digested sewage
sludge was performed to measure equilibrium constants for
ammonia in the sludge. Measured constants describing the
solution and dissociation of ammonia in sludge were compared
to theoretical constants obtained from thermodynamic data.
No significant difference was found between these two sets
of constants....
The purpose of this report is to document changes
resulting from long-term application of biosolids to
grazed dryland pasture. The report contains two chapters:
• Chapter 1: Biosolids Increase Grass Yield and Quality
in Dryland Pasture
• Chapter 2: Biosolids Increase Soil Fertility in Dryland
Pasture
Data summarized here was...
Published March 1990. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Revised September 1995. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Since the introduction of pure oxygen activated sludge systems in
the late 1960's, proponents have claimed several advantages resulting
from the elevated dissolved oxygen (DO) levels maintained. However,
numerous comparative studies have failed to produce a consensus of
professional opinion regarding the validity of these claimed advantages.
The purpose of...
The fertilizer value of anaerobically-digested, dewatered biosolids in dryland cereal cropping systems was evaluated at six locations in central and eastern Washington (25 to 35 cm annual precipitation zone). Biosolids were applied at rates of 3 to 20 Mg/ha (approximately 150 to 900 kg N/ha). We measured increases in soil...
Within the last 15 years, wastewater treatment plants have increasingly begun to find radioactive isotopes incorporated in biosolids. Regulations concerning the disposal of radioactive material via sanitary sewer systems were in place since the early 1960's and recently were further restricted. However, the updated regulations would not have prevented certain...
A year-long, bench-scale treatability study was performed to assess whether an activated sludge sequencing batch reactor could be used to treat an influent stream of 50/50 (v/v) municipal wastewater and landfill leachate to discharge standards established by the Oregon Department of Environmental Quality. One primary obstacle that was exposed during...
Anaerobic ammonium oxidation (anammox) has recently appeared as a promising approach for removing nitrogen from landfill leachates because it requires less oxygen and no organic carbon compared to traditional nitrification-denitrification system, and it produces low sludge volumes, thereby reducing operating and biological sludge disposal costs by over 60%. Anammox bacteria...