Quantitative Recovery of Microplastics from Sediments Using an Integrated Foam Flotation Method with a Biodegradable Surfactant

Abstract

Sediments represent an important sink for microplastics, making efficient separation and recovery essential for their quantitative and qualitative analysis. In this study, an integrated froth-flotation method was developed for recovering microplastics from artificially prepared sediment samples using alkyl polyglucoside (APG) as a biodegradable surfactant. The effects of airflow rate, APG concentration, particle size, polymer type, and surfactant characteristics on flotation behavior were systematically evaluated. Under the selected operating conditions, including an airflow rate of 200 mL/min, the APG assisted flotation system achieved recovery efficiencies approaching 100% for the tested microplastics, including relatively high density polymers, and the separation process could be completed within approximately 2 min. The results further indicated that surfactant concentration and particle size influenced flotation behavior through changes in microplastic wettability and bubble particle interactions. Compared with conventional density and oil assisted separation approaches, the integrated flotation system provides rapid flotation and direct collection without requiring a high density salt solution or an additional oil phase. These findings demonstrate the potential of APG assisted froth flotation as a rapid approach for microplastic recovery from sediment matrices under controlled laboratory conditions.