Effective removal of nanoplastic and microplastic particles by using microalgae cells with dielectrophoresis-assisted method

This work presents the removal of nanoplastic and microplastic particles using microalgae cells in a dielectrophoresis-assisted system. Microalgae cell was tested against two types of particles: 500 nm polystyrene nanoplastic particles, and 1 μm polystyrene microplastic particles and silicon dioxide microspheres. The growth ratio of the microalgae was determined by quantifying the suspension against the particles. Then the microalgae chains adsorbed with particles were trapped by the dielectrophoretic effects in the vicinity of the electrode cross-corner, which was induced by applying DC electric field through the embedded electrode meshes. Accurate quantification of capture efficiency was achieved by quantifying the microalgae adsorbed with plastic particles before and after the treatment in the DEP assisted device. This study examined the effects of the concentration of microalgae cells and microplastic particles, the particles size and type on its removal, and the applied electrical potential and electrode mesh on the capture of microalgae cells adsorbed with MPs and NPs. The results suggest that the particles were successfully removed by microalgae cells which was further trapped by the DEP-assisted device with capture ratio as high as 95 %, demonstrating a promising strategy for the removal of nanoplastic and microplastic particles using microalgae cells.