The three sludge system for nitrogen and phosphorus removal /

"Presented at the 44th Annual Conference of the Water Pollution Control Federation, San Francisco, California (October, 1971)"--P. 1.

Ultraviolet disinfection of activated sludge effluent discharging to shellfish waters /

Mode of access: Internet.

Hydrologic effects of storing liquified sewage sludge on strip-mined land, Fulton County, Illinois /

Mode of access: Internet.

Environmental effects of sewage sludge disposal [microform] : hearing before the Subcommittee on Natural Resources, Agriculture Research, and Environment of the Committee on Science and Technology, U.S. House of Representatives, Ninety-seventh Congress, first session, May 27, 1981.

"No. 24."

Economic impact of proposed regulation R77-12 (Rule 950) on wastewater sludge disposal in the State of Illinois /

Includes bibliographical references.

Illinois EPA sludge regulation guidance document.

"Authors: James J. Janssen and S. Alan Keller." -- Bibliographic data sheet.

Municipal sludge management : planning and policy options /

"Printed: November 1987."

Two-phase anaerobic digestion for enhanced stabilization and methanation of sewage sludge /

"ILENR/AE-92/02."

Use and disposal of wastewater sludge in Illinois : final report /

"Contract: EA99"

Wastes from water treatment plants : literature review, results of an Illinois survey, and effects of alum sludge application to cropland /

"SWS Contract report 429." -- Cover.

The fertilizer value of activated sludge

Mode of access: Internet.

Modelling the effect of shear history on activated sludge flocculation

The aim of this paper is to investigate the effect of shear history on activated sludge flocculation dynamics and to model the observed relationships using population balances. Activated sludge flocs are exposed to dramatic changes in the shear rate within the treatment process, as they pass through localised high and low mixing intensities within the aeration basin and are cycled through the different unit operations of the treatment process. We will show that shear history is a key factor in determining floc size, and that the floc size varies irreversibly with changes in shear rate. A population balance model of the flocculation process is also introduced and evaluated.

Microbial quantification in activated sludge: the hits and misses

Since the implementation of the activated sludge process for treating wastewater, there has been a reliance on chemical and physical parameters to monitor the system. However, in biological nutrient removal (BNR) processes, the microorganisms responsible for some of the transformations should be used to monitor the processes with the overall goal to achieve better treatment performance. The development of in situ identification and rapid quantification techniques for key microorganisms involved in BNR are required to achieve this goal. This study explored the quantification of Nitrospira, a key organism in the oxidation of nitrite to nitrate in BNR. Two molecular genetic microbial quantification techniques were evaluated: real-time polymerase chain reaction (PCR) and fluorescence in situ hybridisation (FISH) followed by digital image analysis. A correlation between the Nitrospira quantitative data and the nitrate production rate, determined in batch tests, was attempted. The disadvantages and advantages of both methods will be discussed.

Phylogenetic and physiological characterization of a heterotrophic, chemolithoautotrophic Thiothrix strain isolated from activated sludge

The sheathed filamentous bacterium known as strain CT3, isolated by micromanipulation from an activated sludge treatment plant in Italy, is a member of the genus Thiothrix in the gamma-Proteobacteria according to 16S rDNA sequence analysis. The closest phylogenetic neighbours of strain CT3 are strains I and Q(T), which were also isolated from activated sludge and belong to the species Thiothrix fructosivorans. These strains have respectively 99.2 and 99.4 % similarity to CT3 by 16S rDNA sequence comparison. CT3 shows 63-67 % DNA-DNA hybridization with strain I, which is the only currently viable strain of T. fructosivorans. CT3 is the second strain in the genus Thiothrix that has been shown to be capable of growing autotrophically with reduced sulfur compounds as the sole energy source; autotrophy was also confirmed in strain I. The first reported chemolithoautotrophic isolate of this genus was a strain of 'Thiothrix ramosa' that was isolated from a hydrogen sulfide spring and is morphologically distinguishable from all other described strains of Thiothrix, including CT3. CT3 is an aerobic organism that is non-fermentative, not capable of denitrification and able to grow heterotrophically. Autotrophy in the genus Thiothrix should be investigated more fully to better define the taxonomy of this genus.