Design and development of decentralized water and wastewater technologies: a combination of safe wastewater disposal and fertilizer production

摘要

Modern wastewater treatment plants are often inappropriate for communities in developingncountries. Such communities lack the funding, resources and skilled labour required tonimplement, operate, and maintain these plants. This research was conducted to investigatenand establish an appropriate wastewater treatment system for the district of Gunung Kidul,nIndonesia. Due to its lack of water during the dry season, this district is considered one ofnthe poorest areas in the nation. First, wastewater was stored in septic tank units for a retentionntime of 26 days. Anaerobic conditions occurred, resulting in an 80% reduction of initial COD.nThe retained sludge was well stabilized with great potential, if dewatered, for reuse as fertilizer.nConsequently, supernatant was separated for experiments consisting of lab scale aerobic sandnfiltering unit. Through filtration, further removals of COD (about 30%) and pathogens werenachieved. Rich in nitrogen, the resulting effluent could be used for irrigation and soil conditioning.nWith faecal sludge and also a mixture of septic sludge and food waste, the hydrolysis stagenof anaerobic digestion was examined. This paper discusses the laboratory findings in Karlsruhenand the design and implementation of a treatment system in Glompong, Indonesia.