STUDY OF AERATION EFFICIENCY OVER THE PIANO KEY WEIRS

Abstract

Aeration is the process of increasing the dissolved oxygen content of water, which is an important water quality parameter for the survival of flora and fauna on this planet. The dissolved oxygen level can be increased using hydraulic structures or by installing mechanical aerators. Hydraulic structures proved to be an economical and efficient way of enhancing the aeration process, thereby increasing the dissolved oxygen in the water stream. It develops large amounts of air bubbles; as a result, contact surface area increases, and hence the water-air -mass transfer accelerates. Weirs are having the highest aeration efficiency among all hydraulic structures. Various researchers study the aeration process involved in weirs and various experiments have been done to study the parameters involved. As literature said that the aeration efficiency of the different hydraulic structures depends on their geometry. According to past studies, the researchers have stated that the hydraulic structures help enhance the dissolved oxygen of the water body. Rivers clean themselves naturally after movement over a certain distance by the process of aeration. It is also known as the self-cleaning nature of rivers. Weirs also follow the same process for cleaning as well as maintaining the various water quality parameters. They function in the same manner as rivers naturally perform the self-cleansing process for its purification. In the self-cleansing process, the river clears itself and maintains various water quality parameters. In order to enhance the DO content of the water body (river, dams, and reservoirs), an experimental study was conducted in Fluid Mechanics and Hydraulic Laboratory at the Delhi Technological University. The primary goal of this research was to increase the DO content of the water body through aeration. The author conducted an experimental study over three different types (Type-A, Type-B, and Type-C) of Piano Key Wier models and compared them to achieve this goal. The present study's findings conclude that the aeration of the free-flowing water can be enhanced by constructing hydraulic structures across the stream or river.