Sludge, or residual solids, is the end products of wastewater treatment processes, whether it is biological or physical-chemical treatment. Sludge production in MENA countries is increasing because of the growth in wastewater treatment systems. This chapter presents sludge management practices in some MENA countries, where there are various alternative processes available for sludge treatment and disposal. The processes selected depend primarily on the nature and characteristics of the sludge and on the final disposal method employed, in addition to the economic evaluation, beneficial use requirements, and local conditions. The system selected must be able to receive the sludge produced and to economically convert it to a product that is environmentally acceptable for disposal.
The sources of sludge and solids produced by wastewater treatment plants related to the wastewater types and sources. However, the characteristic of sludge is depending on its origin and on the treatment methods of wastewater treatment operational process. Various sludge treatment and disposal processes will be presented in this study, with emphasis on the most used technologies in MENA region.
There are some technologies are applied to produce sludge treatment process like dewatering, Thickening, and sludge drying to minimizing sludge volume by removing water from sludge. Aerobic or anaerobic digestion and composting are used to treat or stabilize the organic material in the sludge. Final disposal methods like incineration, land application and sanitary landfill will be discussed in terms of environmental constraints, and public health, as well as legislation for the reuse and disposal of sludge. Case studies will be provided to discuss practices and trends in sludge management in selected MENA countries.
Keywords : sludge treatment, sludge disposal, MENA region, biosolids, land application.