TRANSPORT AND RECOVERY OF BACTERIOPHAGE PRD1 IN A SAND AND GRAVEL AQUIFER - EFFECT OF SEWAGE-DERIVED ORGANIC-MATTER

To test the effects of sewage-derived organic matter on virus attachme nt, P-32-labeled bacteriophage PRD1, linear alkylbenzene sulfonates (L AS), and tracers were injected into sewage-contaminated (suboxic, elev ated organic matter) and uncontaminated (oxic, low organic matter) zon es of an iron oxide-coated quartz sand and gravel aquifer on Cape God, MA. In the uncontaminated zone, 83% of the PRD1 were attenuated over the first meter of transport by attachment to aquifer grains. In the c ontaminated zone, 42% of the PRD1 were attenuated over the first meter of transport. Sewage-derived organic matter contributed to the differ ence in PRD1 attenuation by blocking attachment sites in the contamina ted zone. At greater distances downgradient (to a total transport dist ance of 3.6 m), a near-constant amount of PRD1 continued to break thro ugh, suggesting that aquifer grain heterogeneities allowed a small amo unt of reversible attachment. Injection of an LAS mixture (25 mg L(-1) ), a common sewage constituent, remobilized 87% of the attached PRD1 i n the contaminated zone, but only 2.2% in the uncontaminated zone. LAS adsorption promoted virus recovery in the contaminated zone by alteri ng the PRD1-surface interactions; however, the amount of LAS adsorbed was not sufficient to promote release of the attached PRD1 in the unco ntaminated zone.