Municipal wastewater treatment sludge processing

Corrective Action Application In Massachusetts, a municipal wastewater treatment plant receives a number of wastestreams containing heavy metals from local industries. When tested, the dewatered sludge failed the EP toxicity test. In order to permit landfill disposal of the sludge, solidification processes were examined. A soluble, silicate-based system, developed by Chemfix, was ultimately selected which produced a product whose leachate passed the EP toxicity test (Sullivan, 1984). 

Precipitation is nonselective in that compounds other than those targeted may be removed. Both precipitation and flocculation are nondestructive and generate a large volume of sludge which must be disposed of. Coagulation, flocculation, sedimentation, and filtration, are typically followed by chlorination in municipal wastewater treatment processes. 

Engelhard , N., W. Firk, and W. Wamken (1998). Integration of membrane filtration into the activated sludge process in municipal wastewater treatment. Water Science Technol, Wastewater Industrial Wastewater Treatment, Proc. 1998 19th Biennial Conf. Int. Assoc, on Water Quality, Part 4, June 21-26, 38, 4—5, 429 36, Elsevier Science Ltd., Exeter, England. 

An important consideration in industrial wastewater treatment is the fate and disposal of residues from the treatment processes, which may contain contaminants not normally encountered in municipal wastewater. The sludges produced in biological treatment may contain hazardous constituents such as toxic heavy metal ions contained in the sludge. Spent activated carbon from industrial wastewater treatment may contain toxic organic materials and heavy metals. Another potential hazard is that from sludges formed by chemical treatment of wastewater. 

Giinder, B. (2001). The Membrane-Coupled Activated Sludge Process in Municipal Wastewater Treatment. Technomic Publishing Lancaster, PA. 

Cote, P., Buisson, H. and Praderie, M. (1998) Immersed membranes activated sludge process applied to the treatment of municipal wastewater. Water Science and Technology, 38 (4-5), 437-442. 

Bomhardt, C., J. E. Drewes, and M. Jekel (1997). Removal of organic halogens (AOX) from municipal wastewater by powdered activated arbon (PAC)/activated sludge (AS) treatment, Water Science TechnoL, Proc. 1996 lAWQ Int. Conf. Advanced Wastewater Treatment Nutrient Removal and Anaerobic Processes, Sept. 23-25,1996, Amsterdam, Netherlands, 35, 10, 147-153. Elsevier Science Ltd., Oxford England. 

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