Forecasting regeneration parameters of free-floating biocarriers in an aeration tank

Abstract

A mathematical model was developed to describe the efficiency of air regeneration used for immobilised biofilm on free-floating biocarriers “FB Bio-850”. For this purpose, a physical model of an aeration tank bioreactor was developed, forming the basis for this study. The use of biocarriers contributes to decreasing the concentration of water pollutants that pose a threat to humans and the environment when released into the surface or groundwater without adequate treatment. This increases the efficiency of the aeration tanks, accelerates the oxidation of pollutants and ensures high-quality water purification. In addition, biocarriers increase the performance of the biological treatment plant, promote the resilience of biological structures to abrupt discharges of pollutants and facilitate the nitrification process. Carrying out such studies on an industrial aerated facility poses significant technical challenges. The model aerated tank and the experimental setup provided the flexibility to vary the intensity of the air medium-bubble regeneration for free-floating biocarriers, regeneration time, and the specific gravity of the biocarriers across a broad range, along with controlling the concentration of free-floating sludge. The correlation between the efficiency of regeneration of the plastic carriers “FB Bio-850” and the following technical parameters was established, including the regeneration time of the biocarriers, the loading mass and the intensity of the fine bubble aeration of the water-sludge mixture. A mathematical model of the efficiency of air regeneration was developed, reflecting the influence of all the above parameters. The obtained predictive matrix for efficiency values was used to develop a geometric model of the efficiency surface. This model provides an optimal selection of technological parameters for air regeneration of immobilised biofilm in a biological wastewater treatment aeration tank bioreactor, ensuring a sufficiently high regeneration efficiency.