Bacterial Survival in Snow Made from Wastewater

Abstract : This study examined the effects of a patented wastewater treatment process that makes snow from secondary wastewater, and the subsequent freeze-thaw cycling processes that occur in a snow column, on bacterial survival. Coliform bacteria were observed to be the most adversely affected by snowmaking, with more than a 3-log reduction in the total coliform counts and more than a 2-log reduction in the fecal coliform counts. Other species of bacteria were less affected by snowmaking, especially the gram-positive, fecal streptococci. Many species of bacteria also survived the multiple freeze-thaw cycles in the snow column and replicated during melting.