Efficient recovery of microplastics from sediments by foam flotation

Sediments play a pivotal role in the ecological cycle of microplastics, serving as both a hub for their aggregation and accumulation, and potentially as a source and distributor of these particles. This dual function underscores the importance of sediment analysis in understanding the environmental distribution and origins of microplastics. To comprehensively evaluate microplastic presence and contamination levels in sediments, the development of an efficient and standardized separation method is imperative. Hence, this study introduces an integrated froth flotation approach that has been successfully applied to separate microplastics from various substrates including surface water, wastewater treatment plant sludge, and soil. Compared to conventional froth flotation-based methods, this novel approach yields significantly higher recovery rates of microplastics. Notably, the use of a fully biodegradable surfactant ensures pollution-free separation and achieves recovery rates nearing 100%. Moreover, the study delves into the interaction mechanism between surfactants and plastic particles, particularly focusing on the adsorption process between anionic and cationic surfactants and microplastics. These experimental findings are pivotal in advancing microplastic separation and extraction technologies, guiding future research in this critical area.