RETROFITTING OF DISSOLVED AIR FLOTATION TANK VIA AUTO SCRAPPER SYSTEM WITH LEVEL SENSOR

A dissolved air flotation tank requires retrofitting to address technical problems such as inefficient manual scrapper option. This study presents an analysis of retrofitting the auto scrapper system for the dissolved air flotation tank via ultrasonic level sensor installation. It promotes operation time and operation cost saving, prevents human mistakes, and simultaneously moves towards full automation technology. Wastewater quality is improved by producing an optimal solid-liquid separation at the dissolved air floatation tank. The research methodology covers the comparative analysis of the findings before and after the dissolved air floatation retrofitting along with the observation on site. Cost analysis has been developed to identify the level of sensor installation potential and the impact of the sensor on the dissolved air floatation auto scrapper system. The amount of chemical oxygen demand and total suspended solids are significantly lower after the retrofitting. Cost-saving from this project is induced by labour cost to maintain the monthly dissolved air floatation system and water cost-saving using clean final discharge water. Total annualised cost-saving is at RM 22,380/year. Meanwhile, the investment return was calculated for 2.4 months, indicating a shorter period to recover investment and attain a profit.