Experimental investigation on performance of stepped cascade aeration

Abstract

Air entrainment at the hydraulic structure is considered as one of the economical means of air-water transmission of atmospheric gases such as nitrogen and oxygen. The content of Dissolved Oxygen (DO) in the water helps to assess the quality of water. Enhancing the DO level in water course helps in the survival of terrestrial animals, fish and other aquatic organisms. More over, oxygen is needed for all algae, macrophytes and also for numerous chemical reactions that are vital for stream and lake functioning. Air-water transfer process can be administrated in the natural flowing channel by provihng appropriate stepped cascade according to the site condition and availability of driving head for flow. The change in form of energy at the cascade and subsequent formation of turbulence in the flow at the immediate vicinity of downstream side of structure creates entrainment of air to water. This study describes the experimental investigation on the water aeration process at stepped cascade aerator with constant slope for different water quality flow. Large size stepped cascade aerator model is constructed in the laboratory to test its performance for three distinct qualities of water. The data is obtained for different step sizes by keeping slope as constant. © 2014 Knowledpa Review, Malaysia.