Degradation of Polyvinyl Alcohol in Sequencing Batch Reactors

This paper presents the experimental results of degradation of polyvinyl alcohol (PVA) in sequencing batch reactors (SBR) under different operating conditions. The set up of an anaerobic mixing period in an SBR's cycle did not benefit for PVA degradation, while the introduction of nitrate (NO3-N) could slightly increase PVA removal efficiency. But the induced denitrification might lead to the formation of some intermediates which were degraded with a great difficulty during the subsequent aeration period, resulting in relatively a poorer chemical oxygen demand (COD) reduction. An anaerobic SBR seeded with anaerobic sludge could partly hydrolyze and acidify PVA into readily-degradable intermediates, which were subsequently treated through a 14-h aeration in a conventional SBR, a total PVA reduction of 91.8% could be achieved. The fill mode had no significant influence on the performance of SBRs treating PVA-containing wastewater. For making full use of the purification capability of the SBR during the fill...