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Highlights • Reviewed the transport characteristics influence the contaminant transport. • Reviewed the empirical and mechanical contaminant transport model. • Coupling the hydrology and contaminant transport models can design VFS precisely. Abstract This work provides a comprehensive review on the specific transport characteristics and the associated transport models of sediments, chemicals, and colloids in vegetative filter strips (VFSs). The main goal of the review is to improve current understanding of the main processes, mechanisms, and models of VFSs as the best management practice to mitigate the non-point source pollution. The overall removal efficiency of a VFS varies among different contaminants. For sediments, particle size and distribution are the critical factors that influence their fate and transport in VFSs. For adsorptive chemicals such as pesticides and phosphorus (P), one critical factor for their fate and transport in a VFS is the distribution coefficient between soluble and particle phases. For non-reactive chemicals such as nitrogen (N), soluble phase plays an important role in controlling their fate and transport in a VFS, while bio-chemical reaction may also be important. For colloids, particle and flow characteristics are the main factors affecting their transport and removal in a VFS. Previous studies have built transport models based on the specific characteristic of contaminants. Some of the models are empirical with regression equations based on experimental data. There are also some mechanistic VFS models that are process-based and rely on contaminant transport mechanisms. When coupled with the hydrology models, these models can be used to simulate the fate and transport of various contaminants in VFSs. [ABSTRACT FROM AUTHOR]

The effectiveness of submerged synthetic aquatic vegetation on removal of colloids from flowing water was investigated to explore retention of particulate nonpoint source pollutants in aquatic systems. In colloid transport experiments, the deposition rate coefficient of colloids in dense vegetation is often taken as spatially constant. This assumption was tested by experiments and modeling aimed at quantifying changes in colloid retention with travel distance in submerged synthetic aquatic vegetation. Experiments were performed in a 10-m long, 0.6-m wide flume with a 5-cm water depth under different fluid velocities, initial colloid concentrations, and solution pH values. A model accounting for advection, dispersion and first-order kinetic deposition described the experimental data. The colloid deposition rate coefficient showed a power-law decrease with travel distance, and reached a steady state value before the end of the flume. Measured changes in colloid properties with transport distance (ζ potential and size) could not explain the observed decrease. While gravity was shown to contribute to the decrease, its impact was too weak to explain the decreasing power law trend, suggesting that processes operating in granular media to produce similar outcomes may also apply to submerged vegetation. [Display omitted] • Colloid deposition rate decreased with travel distance following an approximate power law under various flow conditions. • Gravity contributed to the decrease, but could not explain its magnitude. • Mechanisms driving decreased deposition rate coefficient in granular media may also apply to submerged vegetation. [ABSTRACT FROM AUTHOR]