Assessment of the Potential Health Risks Associated with the Injection of Residual Domestic Wastewater Sludges into Soils. Final Report II. Laboratory Studies

摘要

Movement of poliovirus 1, reovirus 3, and bacteriophage 0X174 was studied in nine different soils and two soils amended with sludge. Soils were sampled to a depth of 100 cm in three 33 cm profiles. These profiles were packed into acrylic cylinders, 10 cm in diameter and 33, 66, and 100 cm in length, according to the vertical distribution and bulk density of the soil as found in the field. Viruses were added to the columns in 100 ml of autoclaved secondarily treated wastewater. Columns then were flooded with 800 ml of autoclaved wastewater followed by 800 ml of distilled water for five cycles of wastewater/distilled water application. Column percolates were monitored for viral infectivity, specific conductance, pH, turbidity, and total organic carbon. Cation exchange capacity, percent organic carbon, pH, percent silt/clay, and specific surface area were determined for each soil studied. Recovery of all three virus types in soil column percolates followed a cyclical pattern with a peak of viral release corresponding to a reduction in specific conductance of the percolates after distilled water application. In successively longer columns, the peaks of viral release were lower, and hence the total number of virions recovered from these percolates was less than from the shorter columns. The total number of viruses detected in the column percolates differed among the soils tested. Linear and multiple regression analysis determined that this was due to the differences among soil properties.