Application of UASB Technology for Sewage Treatment with a Novel Post-treatment Process

The upflow anaerobic sludge blanket (UASB) process has been shown to be effective for removal of organic substances from sewage, especially under warm climate conditions. However, treatment of sewage by UASB alone is not sufficient to meet the effluent discharge standards set by many developing countries, meaning that UASB effluent needs post-treatment process. In combination with properly selected processes, a sustainable and appropriate wastewater treatment system can be established. In this chapter, the down-flow hanging sponge (DHS) process is introduced as an appropriate post-treatment process for UASB-treated sewage, with emphasis on its basic concept, mechanism of treatment, history of development, and recent successful results of a demonstration study at a full-scale DHS plant in India.