Protecting water resource quality is a global concern, as both solute and colloidal contaminants from various sources can infiltrate into soil and eventually pollute groundwater. Understanding the fate and transport of colloidal contaminants- such as engineered nano- and micro-particles, as well as biological entities like bacteria and viruses- is crucial for mitigating their associated risks. The transport and deposition of the colloidal contaminants are complex and multiscale processes in porous media.
This dissertation explored the application of DNA-based particles as potential tracer agents. Advances in nanotechnology and molecular biology have enabled the development of synthetic DNA-based particles that synthetic DNA act as “barcodes”. These particles are highly detectable and quantifiable at low concentrations using qPCR techniques, making them ideal for mapping contamination pathways, determining aquifer hydraulic connectivity, tracking multiple sources simultaneously, and serving as surrogates for tracking the transport and pathways of colloidal contaminants.
DNA-based particles have recently been used as tracers in hydrological studies. The focus of the dissertation is on DNA-based particles with a core-shell structure made of silica encapsulating double-stranded DNA (referred to as DNAcol). Since DNA-based particles can be classified as colloidal particles, this research aims to better understand the mechanisms governing their transport and fate under varying physicochemical conditions. By examining its responses to different tested conditions, the study seeks to identify the environmental conditions in which this tracer can be most effectively applied.