Feasibility of a stirred anaerobic sequencing batch reactor containing immobilized biomass for wastewater treatment

This paper proposes a new configuration of a stirred anaerobic bioreactor t o improve the biomass retention in sequencing batch processes for treating low strength wastewater. In the proposed configuration, the biomass was imm obilized on a polyurethane foam matrix, thus resulting in the elimination o f or reduction in settling time. The reactor was operated ata temperature o f 30 degrees C and an agitation rate of 500 rpm supplied by means of a stir ring bar at the bottom of the reactor. An 8-h cycle was used to treat 0.51 of a synthetic substrate containing a chemical oxygen demand (COD) of 485 m g/l. The overall COD removal efficiency attained 86% in the first 3 h of th e cycle, as shown by the concentration profile. (C) 2000 Elsevier Science L td. All rights reserved.