MODELING VIRUS TRANSPORT THROUGH CLAY SLUDGE RESIDUALS USING NANOPARTICLES AND ESCHERICHIA COLI AS PATHOGEN SURROGATES

Clay ‘sludge’ is a water treatment residue that is produced during the drinking water treatment process. The present study aims to characterize and assess the ability of drinking water treatment sludge to filter/adsorb virus surrogates in the form of nanoparticles and Escherichia coli. It is hypothesized that the sludge will have increased filtration capacity since it is mostly made up of clay-sized particles that typically have numerous sorption sites. Furthermore, the transport of the nanoparticles will be retarded and experience more sorption when run through sludge than in clean sand. Sludge composition was analyzed using X-ray fluorescence (XRF) and soil-column and batch experiments were conducted to compare transport through sludge and clean sand. Sodium chloride (NaCl) was used as a conservative tracer to compare the breakthrough curves in the clay and clean sand. Results of the soil-column and lab experiments were analyzed and used in CXTFIT to obtain transport properties for the different media. Preliminary results indicate that nanoparticles and E. coli moved slower through the clay sludge than a conservative tracer of NaCl. Understanding the transport parameters is crucial in finding alternative uses for the sludge, since one proposed use is filtration of runoff.