The activated sludge unit of a wastewater treatment plant requires an aerator. Two options exist and have the characteristics shown in the table. The city owner of the treatment plant sets an interest rate of 8% p.a. Analysis period is 10 years.
Determine which aerator to purchase by PRESENT WORTH analysis and ANNUAL WORTH analysis.
|Aerator A||Aerator B|
|Annual operating cost||60,000||75,000|