Department of Chemical Engineering, School of Engineering & Information Technologies, Adama Science & Technology University, Adama, Ethiopia, Africa
Online published on 26 June, 2013.
The main objective of this work is to redesign the aerator which is used for a tertiary treatment plant in a nitrogenous fertilizer plant. The existing aerator used in the fertilizer tertiary treatment plant is surface aerator. Totally there are 8 aerators used, each consuming 35HP power per day which was found non economical and least efficient because of higher power consumption. So a fine bubble aerator was proposed. In this fine bubble aerator the factors such as retention time, sludge age, BOD removal, and oxygen required were analyzed. The result shows that oxygen transfer efficiency is 50% and also it exhibits high aeration efficiency. Compared to coarse bubble aeration, fine bubble aeration can reduce power required to transfer oxygen by up to 50%. By this research work it was suggested that the existing 8 numbers of surface aerators which consumes 35HP per day can be replaced by 2 numbers of fine bubble aerators which consume 20HP each per day only.
Aerator, Surface aerator, Fine bubble aerator, Aeration efficiency, Tertiary treatment, Waste water treatment, Oxygen transfer
