Wastewater Treatment Technologies

Abstract

Waste-water treatment is becoming ever more critical due to diminishing water resources, increasing waste-water disposal costs and stricter discharge regulations that have lowered permissible contaminant levels in waste streams. The treatment of waste-water for reuse and disposal is particularly important for countries, since they occupy one of the most arid regions in the world. Physical, chemical and biological methods are used to remove contaminants from waste-water. In order to achieve different levels of contaminant removal, individual waste-water treatment procedures are combined into a variety of systems, classified as primary, secondary and tertiary waste-water treatment. More rigorous treatment of waste-water includes the removal of specific contaminants as well as the removal and control of nutrients. Natural systems are also used for the treatment of waste-water in land-based applications. Sludge resulting from waste-water treatment operations is treated by various methods in order to reduce its water and organic content and make it suitable for final disposal and reuse. This chapter describes the various conventional and advanced technologies in current use and explains how they are applied for the effective treatment of municipal waste-water.