`Anionic surfactant-assisted the transport of carbon dots through saturated soil and its variation with aqueous chemistry

There is little understanding of how anionic surfactants affect the transport carbon dots (CDs) nanoparticles in soil. In this study, mobility characteristics CDs soil columns with sodium dodecyl sulfate (SDS, a model surfactant) under various conditions were investigated. The results showed that presence SDS enhanced at pH 7.0 when Na + was main background electrolyte. increased electrostatic repulsion, competitive deposition between and for sites on particle surfaces, decreased straining effect, steric hindrance all attributed to trend. Interestingly, divalent metal cation (i.e., Ca 2+ or Cu ), suppressed CDs. This phenomenon most likely stemmed from precipitation scum SDS–Cu /Ca complexes) adsorbed SDS-metal-CDs complexes. Furthermore, extent effects increasing solution 5.0 9.0, which primarily due decrease effect site competition. A two-site also applied fit observed data media. Overall, findings work provide meaningful insights into fate co-existing carbon-based subsurface systems. • Effect (SDS) studied. enhances through multi-mechanisms. inhibits formation scum. Lower promotes mobility.