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Since the early 1900s, high temperature processes have been used for combustion of municipal wastewater solids. The popularity of these processes has fluctuated greatly because of their adaptation from the industrial combustion field. In the past, combustion of wastewater solids was both practical and inexpensive. Solids were easily dewatered, and the fuel required for combustion was cheap and plentiful. In addition, air emission standards were virtually nonexistent. [ABSTRACT FROM AUTHOR]

Water removal from municipal and industrial effluent streams constitutes an important step in wastewater and sludge treatment. The purpose is to concentrate, separate, dispose, or utilize wastes and pollutants and to regenerate and return clean water to the environment. In this context, the discussion here will be limited only to industrial and municipal sludge dewatering, evaporation, and drying (1-5). [ABSTRACT FROM AUTHOR]

There are two kinds of thermal processes for sludge treatment: (a) heat conditioning: a conditioning process which prepares sludge (i.e., mainly biosolids) for dewatering on filter presses or vacuum filters without the use of chemicals and (b) heat-drying: a process which evaporates water from sludge by thermal means (1)-(11). Ambient air-drying processes are dealt with in another two chapters: "Evaporation processes" and "Drying beds." [ABSTRACT FROM AUTHOR]

Alkaline or lime stabilization is a very simple process. Its principal advantages over other stabilization processes include low cost and simplicity of operation. However, lime stabilization accomplished at a pH of 10.0-11.0, may allow odors to return during storage owing to pH decay. To eliminate this problem and reduce pathogen levels, addition of sufficient quantities of lime to raise and maintain the biosolids pH to 12.0 for 2 h is required. The lime-stabilized biosolids readily dewaters with mechanical equipment and is generally suitable for application on an agricultural land or disposal in a sanitary landfill. [ABSTRACT FROM AUTHOR]