Effects of thermal treatment of sludge on municipal wastewater treatment costs /

Mode of access: Internet.

Study of activated sludge separation by dynamic straining /

Mode of access: Internet.

A study of nitrate respiration in the activated sludge process /

Mode of access: Internet.

Control strategies for the activated sludge process /

Mode of access: Internet.

Applicability of two mathematical models to the batch settling of activated sludge.

"Supported by Federal Water Pollution Control Administration, U.S. Department of the Interior. Research project WP-01011."

Uptake of soluble phosphate by activated sludge /

"Supported by Federal Water Pollution Control Administration ... research fellowship F1-WP-21, 616, and Ford Foundation."

Biological removal of colloidal waste in activated sludge process /

Vita.

Applicability of prevailing gravity thickening theories to activated sludge /

Vita.

Aeration with a high-oxygen atmosphere in the activated sludge process /

"These Studies deal with current activities in the department of Civil Engineering. They serve as progress reports of major investigations, and in general as a means for disseminating information not readily adaptable for presentation in formal technical papers or bulletins."

Flocculation and clarification in activated sludge systems /

Vita.

The influence of ultrasonic vibrations upon the physical features of activated sludge.

Thesis (M.S.)--University of Illinois.

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.

Impacts of morphological, physical and chemical properties of sludge flocs on dewaterability of activated sludge

This study examined how the floc characteristics affect dewaterability of activated sludge. The floc properties were characterized by morphological parameters (floc size distribution, fractal dimension and filament index), physical properties (flocculating ability, surface charge, relative hydrophobicity and viscosity), and chemical constituents in sludge and extracted extracellular polymeric substances (EPS), including the polymeric compounds protein, humic substances, carbohydrates and the ions Ca2+, Mg2+, Fe3+ and Al3+. The dewaterability was defined in terms of the bound water content and capillary suction time (CST). The bound water and CST corresponded to a similar indication with respect to dewaterability of activated sludge. The floc physical parameters were the most important factors which effect significantly on the water binding ability of the sludge flocs. The morphological characteristics had relatively weak impact on the dewaterability. The polymeric components protein and carbohydrate had a significant contribution to enhance the water binding ability of the sludge flocs. The effect of humic substances in the sludge on the dewaterability was, however, insignificant. The CST had good statistical correlations with the polymeric constituents measured in both sludge and the extracted EPS, and the bound water was only correlated well with the individual polymers measured in the sludge. High concentration of Ca2+, Mg2+, Fe3+ and Al3+ had significant improvement for dewaterability. (C) 2003 Elsevier B.V. All rights reserved.

Piggery pond sludge as a nitrogen source for crops. 1. Mineral N supply estimated from laboratory incubations and field application of stockpiled and wet sludge

Piggery pond sludge (PPS) was applied, as-collected (Wet PPS) and following stockpiling for 12 months ( Stockpiled PPS), to a sandy Sodosol and clay Vertosol at sites on the Darling Downs of Queensland. Laboratory measures of N availability were carried out on unamended and PPS-amended soils to investigate their value in estimating supplementary N needs of crops in Australia's northern grains region. Cumulative net N mineralised from the long-term ( 30 weeks) leached aerobic incubation was described by a first-order single exponential model. The mineralisation rate constant (0.057/week) was not significantly different between Control and PPS treatments or across soil types, when the amounts of initial mineral N applied in PPS treatments were excluded. Potentially mineralisable N (N-o) was significantly increased by the application of Wet PPS, and increased with increasing rate of application. Application of Wet PPS significantly increased the total amount of inorganic N leached compared with the Control treatments. Mineral N applied in Wet PPS contributed as much to the total mineral N status of the soil as did that which mineralised over time from organic N. Rates of CO2 evolution during 30 weeks of aerobic leached incubation indicated that the Stockpiled PPS was more stabilised (19-28% of applied organic C mineralised) than the Wet PPS (35-58% of applied organic C mineralised), due to higher lignin content in the former. Net nitrate-N produced following 12 weeks of aerobic non-leached incubation was highly correlated with net nitrate-N leached during 12 weeks of aerobic incubation (R-2 = 0.96), although it was