Treatment of dairy wastewater by fixed-film system in continuous flow

abstract

The objective of this work was to assess the feasibility of biological phosphorus removal for dairy processing wastewater. In this study, two fixed-film systems carried out continuously were tested in the laboratory. The effect of aerobic and “anoxic/anaerobic/aerobic” conditions on phosphates removal has been investigated on both the fixed-film systems and reported, that alternating phase’s system (bioreactor 1) resulted in higher phosphorus removals relating to aerobic system (bioreactor 2). The main results showed that the effectiveness of COD and phosphates for bioreactor 1 reached, respectively, to 66 and 91% at stable biofilm functioning. Similarly, the effectiveness of COD and phosphates removal for bioreactor 2 reached to 70 and 84.61%, respectively. No clogging of media occurred and no backwashing was applied on both the systems during the study. Also, kinetic analysis of the reactor with regard to phosphorus removal has been studied with the modified Stover-Kincannon kinetic model which was chosen for modeling studies and experimental data analysis of the fixed-film system used in this study. The experimental data showed that the Stover-Kincannon kinetic model was the most suitable for predicting the removal of phosphate in the bioreactor 1, but not in the bioreactor 2.

Keywords:

• Biological phosphorus removal
• Phases alternation
• Aerobic
• Continuous feeding process
• Stover-Kincannon model