▎ 摘　　要

A particle size change occurs ubiquitously during transport of nanoparticles in the subsurface and is likely to influence nanoparticle fate and transport behaviours. The effects of this size change on the subsequent transport of eluted graphene oxide (GO) in saturated media were therefore investigated under various ionic strength (IS) and filtration degree conditions. Aggregation kinetics revealed that size change after filtration only occurred at relatively high IS conditions. As the filtration column length increased from 15 cm to 30 cm, sizes of aggregates in filtrates for large-sized and small-sized GO populations decreased and increased, respectively, and both approached to their steady aggregate sizes. Aggregation, straining, sedimentation, bridging, DLVO interactions, or a combination of these mechanisms were involved in the size change process during filtration. After passing through the 30 cm filtration column, filtered GO, in comparison with original GO, exhibited stronger mobility than expected, suggesting neglecting size change will result in underestimation of the nanoparticle mobility in porous media. (C) 2020 Elsevier B.V. All rights reserved.