Effect of manure colloid on stability and transport of titanium dioxide

This study was to investigate the effect of different manure colloids on the stability and transport of TiO₂ NPs. Manure was used in fields as a common organic fertilizer. Different manure colloids were selected to study their effects on the aggregation and transport of nTiO₂ at neutral pH conditions. The absorbance and particle size of the nTiO₂ suspension at a certain ionic strength and manure colloid concentration were measured to determine the stability and aggregation of the nTiO₂ particles at pH 7. Column experiments were performed to examine colloidal transport in quartz sand under water condition similar to those used in stability tests. The interaction energy among the nTiO₂ particles and between nTiO₂ particle and quartz sand were calculated using the classical DLVO theory to elucidate the underlying mechanisms involved at pH 7. The results showed that manure colloids can promote the dispersion and transport of TiO₂ NPs under different conditions.