Removal of Microplastic From Liquid Medium By Dissolved Air Flotation

Abstract

Objective: The objective of this study is to verify the removal of MPs from the liquid medium through the application of the dissolved air flotation (FAD) technique. Theoretical Framework: FAD is a technology used to remove low-density solid particles from a liquid medium, with the introduction of air bubbles to the system, which aims to reduce the density of plastic particles and increase their rise speed. Method: In the flotest, coagulant dosage tests and FAD operational conditions were carried out. The suspension analyzed consisted of 2 L of water supply, 400 mg/L of PVC MPs, 5 mL/L of Tween-20 surfactant, aluminum sulfate coagulant in dosages of 2.5 to 6.0 mg/L and Turbidity was the parameter used to verify the removal of MPs. Results and Discussion: The optimal results obtained for coagulant dosage were 3.01 mg/L and the operational conditions of FAD, recirculation rate of 10% and flotation time of 15 min. Research Implications: The FAD technique used in the research is capable of efficiently removing MPs from liquid media above 90%. Originality/Value: This study contributes by using a technique that has a high PM removal rate, produces easy-to-treat sludge and is one of the most used in WWTP.