Magnetic DNA-based microparticle as a hydrological tracer in river-water tracing experiments

Recently an new microparticle tracer has been developed for investigating in stream-mass transport: a silica coated synthetic-DNA-tagged microparticles with a superparamagnetic core (SiDNAMag). SiDNAMag particles can be easily recovered by magnetic separation, with high DNA signal amplification by Quantitative Polymerase Chain Reaction (qPCR). However, with the presence of natural colloids, particulate matter and river bed sediments, SiDNAMag are likely to undergo complex interaction processes besides dispersion and advection. Moreover, little has been known for the possible sink sources of SiDNAMag tracer mass loss during transport in river waters.

In this research the focus is on investigating the transport behaviour of the SiDNAMag particle as a potential hydrological tracer. The behaviour of the SiDNAMag particles will be compared to those of solute tracers (NaCl) and silica microparticles in terms of breakthrough curves and mass recoveries, by performing open channel injection experiments in laboratory environment. The resulting breakthrough curves will be interpreted with a 1-D advection and dispersion model. Possible interactions and mass loss will be examined by performing batch and injection experiments in different river water types with the presence of river bottom sediments.