|
|
|
| Publication: |
|
Operation of Municipal Wastewater Treatment Plants
Manual of Practice-MOP 11 Fifth Edition
|
| Medium: |
| Download Chapter |
| Pages |
| 26 |
| Publisher: |
|
Water Environment Federation (WEF) |
| Year: |
| 1996 |
| Order No: |
| MOP1131 |
Table of Contents
|
Cover Art
|
| |
Abstract:
|
|
Aerobic digestion is a biological treatment process that uses long-term aeration to stabilize and reduce the total mass of organic waste by biologically destroying volatile solids. This process extends decomposition of solids and regrowth of organisms to a point where available energy in active cells and storage of waste materials are sufficiently low to permit the waste sludge to be considered stable enough for discharge to some disposal operation (California State University, 1990). The waste sludge consists of suspended solids that have been removed during clarification and solids that are a result of the growth of the biological mass during the treatment process. The aerobic digestion process renders the digested sludge less likely to generate odors on disposal and reduces bacteriological hazards.
Stabilization of waste sludge to the degree necessary for disposal can be accomplished by either aerobic or anaerobic digestion. One of the major differences between aerobic and anaerobic digestion is in the metabolic characteristics of the respective microorganism populations. In aerobic digestion, aerobic and facultative microorganisms use oxygen and obtain energy from the available biodegradable organic matter. The end products of aerobic digestion typically are carbon dioxide, water and ÒnondegradableÓ materials (such as polysaccharides, hemicellulose, and cellulose). During anaerobic digestion, facultative and strict anaerobes simultaneously hydrolyze complex organics and assimilate intermediate volatile organic acids. The end products of anaerobic digestion primarily are carbon dioxide, methane, and water (WPCF, 1982).
Both aerobic and anaerobic digestion produce stabilized sludge that is suitable for disposal. Disposal may be in the form of incineration with ash disposal in a landfill, burial in a landfill, or some form of beneficial reuse such as composting or farm land application as a soil conditioner or fertilizer.
|
|
| |
| Member Price: $15.00 |
| List Price: $19.00 |
|
|
|
|
|