Pollution Research Paper

A COMPREHENSIVE REVIEW OF SURFACE JET AERATORS

BISHNU KANT SHUKLA, V. RAJESH KUMAR AND ARUN GOEL

Abstract

Aeration is one of the major steps in treatment of waste water in which mechanical aerators are frequently used. Oxygenation by using plunging water jet is a better way to achieve oxygen transfer than most of the conventional oxygenation systems. Surface jet aerators are simple closed systems which are easy in design, construction and working. Various research works have been undertaken in past to achieve better oxygen-transfer for the treatment of waste water. However, it seems that very little comprehensive study has been done to suggest the selection of a suitable aerator under a situation. Attempts have been made in this paper to study hollow jet aerators, single jet aerators, multiple jet aerators with different plunge angles and aerators of different shapes and subsequently their salient features have been highlighted. Further, aerators are compared based on oxygen transfer rates and efficiencies. It has been concluded that jets from elliptical shaped nozzles were found to be more suitable for deep tanks. On the other hand, jets from rectangular nozzles with rounded ends have overall highest oxygen transfer efficiency. It has also been observed that the minimum oxygen transfer efficiency comes out in case of single vertical jets while Inclined multiple plunging jets of 60o plunge angle with sixteen aerating units have shown highest oxygen transfer efficiency. It is also concluded that aerators having single jets are more suitable for low discharges while multiple jet aerators are suitable for higher discharges for waste water treatment. Finally, a comprehensive paper has been prepared for the available surface jet aerators on the basis of their performance for the purpose of waste water treatment.