Effect of pH on Aerobic Granulation and Treatment Performance in Sequencing Batch Reactors

Abstract

Two sequencing batch reactors were operated to investigate the effect of influent alkalinity and reactor pH on aerobic granulation. In the first reactor R1 with high influent alkalinity the pH was adjusted in the neutral range, and in the second reactor R2 with low alkalinity the pH was held within the acidic range. The R1‐dominating species were bacteria and the appearance time of granules was three weeks after reactor start‐up. On the other hand, the acidic environment of R2 provided favorable conditions for fungal growth, and rapid granule formation occurred within the first week of operation. The varying microbial structure of granules resulted in different reactor performance in terms of evolution time and morphology of granules, suspended solids in the reactors, settling ability of granules, effluent quality of treated wastewater, and physical strength of the granules.

Biological Treatment of Wastewater from Pyrolysis Plant: Effect of Organics Concentration, pH and Temperature

“…Comparing these values to the corresponding values obtained in the tests performed at uncontrolled pH (49.47% TOC removal and 51.54% COD removal), it was possible to confirm that neutral pH compromised the microbial metabolism reducing process effectiveness ( Figure 5). This effect also suggests that the acclimation of microorganism under acidic pH conditions could result in a process enhancement and prevent process inhibition under acidic conditions [26,27].…”

Trace Dissolved Oxygen Removal Using a Hydrocyclone to Enhance Denitrification

“…Operational control is difficult to implement in this biological treatment process because of large disturbances in flow and load as well as its complex and nonlinear behavior. The denitrification stage in the PDBNR process is influenced by the temperature, dissolved oxygen (DO), pH, carbon source, C/N ratio, toxic substances, etc., making it particularly difficult to operate effectively, and it has thus attracted more attention than nitrification . DO control in particular, which is closely related to nitrate/nitrite reduction due to the electron donor competition and excessive carbon source consumption, has attracted much more attention.…”