ABSTRACT
To beneficially reuse sludge, a market must be created for a sludge product. In most cases, a public aversion to municipal sludge requires that some level of sludge processing is carried out to produce a marketable product. A wide variety of sludge products can be produced by a municipal wastewater treatment plant. Sludge can be land applied as a liquid, spread as sludge cake, or pelletized; it can be composted, incinerated, or stabilized with additives to be reused as structural fill. Economic factors include the operational costs of sludge processing, the lifetime costs of the processing facility, the revenue potential of the sludge product, the avoided costs of alternate disposal, and the cost of delay. Political realities may limit available processing sites to parcels within the collection area of the POTW or within communities sympathetic toward the sludge producers.
