Proceedings

On most small sewage treatment plants, the off-site transport of liquid sludge is the normal mechanism for sludge disposal. However, the typically low dry solids content of the sludge at around 2% imposes clear economical limits to this disposal method. Thickening of the sludge reduces the transport costs as well as the required storage volume and also enhances sludge digestion. However, this is often either considered to be not cost effective from a capital point of view, or practicable from an operating point of view. This paper presents first operating results from a newly developed sludge thickening system which is simple, robust, fully automated and very compact. Therefore, it is ideally suited to the requirements of small sewage treatment plants.

KEY WORDS Disposal Costs, Sewage Sludge, Sludge Thickening, Small Plants, Surplus Activated Sludge, Transport Costs