MONITORING OF A HYBRID SEQUENCING BATCH REACTOR BY RESPIROMETRY

Abstract

This work studies the performance of a hybrid sequencing batch reactor (HSBR) in the treatment of domestic wastewater. The reactor’s operation consisted of 3 daily cycles of 8 hours, with 3 step-feedings per cycle. The wastewater volume of each feeding was 180 L resulting in a total of 540 L treated wastewater per cycle. Nylon nets were used in the hybrid system as support material. Carbon degradation processes, nitrification-denitrification, and phosphorous biological removal were evaluated as well as the oxygen uptake rate by respirometry. The reactor presented average efficiencies of: 84 ± 8.8% for CODT removal; 78 ± 15% for nitrification; 94 ± 6.4% for denitrification; 45 ± 30% for PT removal; and 44 ± 31% for PO4-P removal. The average oxygen uptake rate (OUR) varied between 18.7 and 32.3 mgO2/L.h. The reactor’s sludge consisted of well structured and compact flocs with good settleability; the biofilm was dense with the presence of many amoebas and rotifers in its surface.

Keywords: hybrid sequencing batch reactor, nutrients removal, respirometry, domestic wastewater treatment.