Mathematical model of dissolved air flotation (DAF) based on impulse conservation law

Abstract

Commissioning of new dissolved air flotation (DAF) installations and optimization of already existing installations takes at least one year of laboratory and pilot plant experiments. Such studies are labor-intensive. Using mathematical modeling, it is possible to minimize time and costs. For such purposes, mathematical model of the DAF process was developed based on the law of momentum (impulse) behavior and Navier-Stokes equations. The model allows to describe the kinetic relations between the water stream, air bubbles and aggregates arising as a result of coagulation of surface water pollution. The model takes into account the exchange of impulses between different phases as a result of laminar and turbulent flow. The developed model was used to prepare a simulation computer program. In order to check the feasibility of the model, laboratory tests were carried out under static conditions. Comparison of the results of laboratory tests with the results of computer simulation showed its suitability for analyzing the effectiveness of removing solid phase from water by means of dissolved air flotation. Proposed model was also compared with models proposed by different authors.

Dissolved Air Flotation: A Review from the Perspective of System Parameters and Uses in Wastewater Treatment

“…It is a key technique factored into future projects for improving the effectiveness of wastewater and drinking water treatment. Table 9 highlights its advantages [34], [45], [88], [102], [113] and disadvantages [71], [95], [75] in comparison with other wastewater treatment technologies. The flotation tank must be protected from low and high temperatures.…”

“…Studying the hydrodynamic characteristics of the flotation system is fundamental in the design, control, analysis, optimization, operation, and modeling of DAF equipment because these factors significantly affect the efficiency of the process [49], [50], [99]. Consequently, CFD allows researchers to predict the design and construction of DAF systems and identify Página 16 | 23 the parameters needed to establish the optimal conditions for wastewater cleaning processes [102], [110].…”

“…In order to establish optimal DAF operating parameters, it is essential to understand MB flow and interaction with surrounding particles [102], [110]. More studies should be conducted to optimize DAF processes in terms of reducing energy consumption.…”

Understanding the Role of Surface Charge on Nanobubble Capillary Bridging during Particle–Particle Interaction

“…Sometimes the feed is treated with a range of flotation reagents to increase hydrophobicity. This, in turn, induces particle aggregation and increases the apparent size of the particles. , These aggregates are easier for the large bubbles to collect as they have much higher inertia as compared to fine particles, which enables them to drain the hydration film that separates them from the gas phase of the bubbles. , Particle–particle interaction are also encountered in other applications such as enhanced oil recovery, − dissolved air flotation, − etc.…”

Various surface-active agents used in flotation technology for the removal of noxious pollutants from wastewater: a critical review

“…Thereby, the supernatant solution is gathered at the base of the flotation cell. [25][26][27][28][29][30][31][32][33][34][35] There are different types of flotation techniques available which are potent for treating contaminants that are discharged as effluents from industry. It is cost-effective for pollutants with high concentrations that allow high loading rates.…”