A Comparison of Physical Properties of Synthetic Sludge with Activated Sludge
Abstract:Conducting physical and chemical tests with activated sludge is difficult because of its constantly changing properties. To overcome this difficulty a synthetic sludge that physically and chemically resembles activated sludge was created. In this study, the physical properties of synthetic sludge were examined and compared to those of activated sludge, including particle size, filterability by specific resistance to filtration and capillary suction time, conditioning with two polyelectrolytes, floc strength, rheological properties, and residual turbidity after settling. Results of this study show striking similarities between activated sludge and synthetic sludge. Filterabilities of both sludges are almost identical. A medium-molecular-weight, medium-charge-density, cationic polymer is effective in conditioning both sludges at approximately the same dose. Activated sludge is found to have stronger flocs than synthetic sludge. However, both sludges seem to have flocs stronger than some loose and weak flocs reported in the literature. Rheological behavior in terms of apparent viscosity of the two sludges is similar. The average particle size of activated sludge is found to be slightly larger than that of synthetic sludge. Also, synthetic sludge has a higher residual turbidity than activated sludge. These differences are explained by the fact that the synthetic sludge is lacking filamentous microorganisms that form the backbone of a floc structure in activated sludge. Even though there are some differences in properties, because its overall behavior is close to that of activated sludge, synthetic sludge can be used as a surrogate material for activated sludge when reproducibility in testing is necessary.
Document Type: Research Article
Publication date: 1999-03-01
More about this publication?
- Water Environment Research® (WER®) publishes peer-reviewed research papers, research notes, state-of-the-art and critical reviews on original, fundamental and applied research in all scientific and technical areas related to water quality, pollution control, and management. An annual Literature Review provides a review of published books and articles on water quality topics from the previous year. Published as: Sewage Works Journal, 1928 - 1949; Sewage and Industrial Wastes, 1950 - 1959; Journal Water Pollution Control Federation, 1959 - Oct 1989; Research Journal Water Pollution Control Federation, Nov 1989 - 1991; Water Environment Research, 1992 - present.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- WEF Bookstore
- Ingenta Connect is not responsible for the content or availability of external websites