Performance of Closed Loop Venturi Aspirated Aeration System: Experimental Study and Numerical Analysis with Discrete Bubble Model

Abstract

In wastewater treatment plants, aeration plays a significant role as it encourages aerobic respiration of microbes, which are necessary to break down carbonaceous matter in the waste stream. This process can account for the majority of energy use in wastewater treatment plants. The aeration process is also necessary in odor control in lagoons and in the aquaculture industry. Generally, the aeration process is accomplished with compressors or blowers which can be of low efficiency due to ideal gas laws. This study introduces the idea of increasing aeration efficiency by looping water from a reservoir through a piping network which includes a venturi aspirator at its inlet. For this purpose, an experimental study has been conducted in a laboratory setup with a pump which pulls water from a tank, passes it through a Venturi aspirator and a helical piping network intended to increase bubble residence time, before depositing it back into the bulk fluid tank. This same process is modeled computationally, using a discrete bubble method (DBM), with good agreement with experiments. The overall purpose here is to determine the optimal configurations for standard aeration efficiency (SAE) and the standard oxygen transfer rate (SOTR). A parametric study has been implemented using the DBM based on different hydraulic and flow parameters. The model is also used to predict the SAE of a hypothetical aeration system. Results indicate that it is possible to achieve SAE values in the range of surface aerators or submersed jet aerators using the proposed aeration system with less complex components, thereby decreasing overall costs.

Application of jetventurimixer for developing low-energy-demand and highly efficient aeration process of wastewater treatment

“…There have been studies applying venturi for aeration process and the studies has focused developing devices related to pipe and nozzle to increase aeration efficiency [ 25 ]. [ 26 ] studied the use of an aerator and venturi tube to increase the aeration efficiency by hydraulic pressure according to pipe diameter and pipe length. To the best of our knowledge, no study has been tried to apply Bernoulli’s principle and JVM into aeration process.…”

Modelling and prediction of aeration efficiency of the venturi aeration system using ANN-PSO and ANN-GA

“…The venturi aeration system can be utilised in various fields or industries such as water treatment plants, agriculture fields, fertiliser application, integrated irrigation systems, hatchery farms, and recirculating aquaculture systems (Omary et al, 2020;Wang et al, 2022). The venturi is highly efficient and provides significant benefits to the farmers as low power is needed to operate, is durable and compatibly cheaper, and requires less maintenance (Mahmud et al, 2020).…”

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“…More and more hydraulic and environmental engineers are discovering the benefits of the relatively new Venturi aeration method, which has seen an increase in interest recently [6]. Venturi aeration is one of the best methods for increasing water body oxygen content and air entrainment.…”