Enhancement of extraction amount and dispersibility of soil nanoparticles by natural organic matter in soils

Abstract

Natural organic matter (NOM) is an essential part of soil and plays an important role in many biochemical processes. Extraction amount and dispersibility of soil nanoparticles released from soils (both with and without the removal of NOM) were investigated in this study to evaluate the influence of NOM on the liberation of natural nanoparticles from soils. Extraction amount of nanoparticles released from the native soils was about 4-6 times more than those released from NOM-removed soils, indicating that the NOM in soils could enhance the release of natural nanoparticles from soils. After removal of soil NOM, the natural nanoparticles released have larger size and less negative zeta potentials. The aggregation results derived from dynamic light-scattering analysis (DLS) for 30 min showed that the natural nanoparticles released from NOM-removed soils had a more rapid aggregation, indicating that the removal of soil organic carbon would reduce the negative surface potentials between nanoparticles and thus induce the aggregation of nanoparticles.