Studies on technical and economical feasibility of digesters anaerobic-aerobic-anox to sewage treatment, water reuse and use of biogas

Abstract

This paper evaluates technically and economically a miniSST (mini station of sewage treatment) by anaerobic-aerobic-anoxious process, associated to the utilization of biogas produced and utilization of treated sewage to fertilization and irrigation of green areas. The miniSST is modular, energy self-sufficient and constituted by the following systems: a) anaerobic, constituted by three sequential cascade UASB(up-flow anaerobic in sludge blanket) digesters, with a helix shape phase separator system; b) aerobic-anoxious, constituted by a vertical cylindrical aerobic-anoxious reactor operating with aeration of the fine bubble type; c) compact cogenerator, powered by biogas, capable of simultaneous production of electrical energy and hot water; d) effluent utilization for fertilization and irrigation, constituted by a distribution network. The process aims the sanitation of sewage, utilization of produced biogas and treated sewage, decreasing this way the environmental impact caused by the discharge without treatment of sewage in natural water courses and biogas into the atmosphere.