Application of Feedback Control Based on Dissolved Oxygen to a Fixed‐Film Sequencing Batch Reactor for Treatment of Brewery Wastewater

Abstract

Treatment of brewery wastewater was performed using an aerobic fixed‐film sequencing batch reactor using a feedback control system based on dissolved oxygen concentration in the mixed liquor. This control system was modeled after the self‐cycling fermentation technique. The system was operated at 25 and 35 °C and under growthrate limiting conditions. Total biochemical oxygen demand (TBOD) removal efficiency was 83% after 3 hours at 25 °C and 92% after 1.5 to 2 hours at 35 °C. The treated effluent produced had a TBOD between 120 and 438 mg/L, with suspended solids contributing between 63 and 71% of the TBOD. Effectiveness of the treatment process might be improved if an efficient secondary clarifier was installed or if the suspended solids were removed from the brewery wastewater before treatment.

Comparison of PCR-DGGE and Selective Plating Methods for Monitoring the Dynamics of a Mixed Culture Population in Synthetic Brewery Wastewater

“…These include the deep shaft bioreactor (1,2), the jet loop aerator (6), and a fixed film sequencing batch reactor (7). All three involve the use of an activated sludge inoculum derived from wastewater treatment systems that have been acclimated to the brewery wastewater.…”

“…Adequate treatment and sufficient reduction of TSS and BOD was achieved, but control problems occurred as a result of wastewater variability even after installation of an equalization basin in the first two systems. The fixed film sequencing batch reactor used by Nguyen et al (7) provided repeatable and consistent treatment of actual brewery wastewater regardless of the concentration introduced. This was the impetus for investigating the population dynamics of the sequencing batch reactor system similar to the one used in Part 2 of this series of papers.…”

A Kinetic Model for Suspended and Attached Growth of a Defined Mixed Culture

“…Hughes et al (4) investigated SCF as a control strategy for the degradation of phenol by Pseudomonas putida ATCC 12633. In a comparison between SCF, batch, and chemostat fermentations, it was shown that SCF was a better fermentation process in terms of inoculum effects and startup times than both the batch and the chemostat fermentations for emulsan production using Acinetobacter calcoaceticus RAG-1 (5 Expanding SCF to treatment of multiple substrates and mixed cultures, Nguyen et al (10) used the SCF control strategy for treating brewery wastewater in a fixed-film bioreactor. The success of SCF in wastewater treatment is due to the feedback control system that adjusts the residence time of the mixed liquor in the treatment process according to the treatment requirements.…”

“…Even with changes in the nutrient environment or influent composition, SCF results in repeatable treatment, facilitating the development of an optimal treatment strategy. This feedback control strategy was shown to provide consistent biochemical oxygen demand (BOD) removal on a brewery wastewater with variable composition (10).…”

Performance of an optimally filled discontinuous bioreactor degrading 4-chlorophenol

“…Different authors propose control strategies based in oxygen concentration or carbon dioxide evolution rate (Buitró n et al 1993;Nguyen et al 2000;Cohen et al 2003;Betancur et al 2006 Moreno and Buitró n (1998) develop a methodology and mathematical simulations for the time optimal control of a discontinuous reactor for toxic wastewater degradation.…”