Research Topics
Research on Colloidal Particle Transport Through Dense Vegetation and Vegetative Filter Strips (VFS)
Participants: Congrong Yu, Rafael Muñoz-Carpena, Bin Gao
Timeline: September 2007 – September 2010 (Experimental Setup and Study); September 2009 – December 2010 (Data Analysis and Modeling)
Project Summary
Colloids are particles with diameters less than 10 um, which could be divided into non-organic and organic colloidal particles. Example of non-organic colloids is clay particles, industrial particles, such as single-wall carbon nanotube. Viruses, protozoa (e.g. Cryptosporidium parvum) and certain bacteria are bio-colloids of concern which may be introduced into the natural environment from land disposal of treated wastewater effluents or animal fecal deposits. (Tufenkji 2007) Colloids can cause widespread contamination in water supply; what’s more, certain endogenous colloids present in the water have been found to enhance the mobility of radio-nucleotides, metal and other toxic contaminants. A mechanistic understanding of colloidal particle transport processes is of significant interest in various environmental applications and water supplies protection.
Vegetative filter strips (VFS) are a common method for alleviating nutrient, sediment and pesticide loading to nearby surface waters (Popov 2005; Reichenberger, Bach et al. 2007). Are areas of dense vegetation like VFS effective in trapping colloidal particles? The purpose of the research is to study removal of overland flow colloids through vegetation. Comparison of the chemical tracer and colloid transport patterns is providing insights into the factors that control effectiveness of VFS to remove the colloids from the surface runoff. In this project bench scale experiment and modeling methods are combined to investigate the mechanism of the process.