Comparing methods to remove emerging contaminants and disinfection by-product precursors at pilot scale

The removal of selected pharmaceuticals and personal care products, atrazine, and disinfection by-product precursors, was evaluated during a pilot-scale study conducted at the Bollman Water Treatment Plant in Concord, California, USA. Treatment alternatives included ozonation followed by biologically active filtration (BAF), and nanofiltration. Both technologies exhibited excellent broad-spectrum removal of the spiked target contaminants. The ozone/BAF system in particular showed a high degree of effectiveness despite relatively low ozone doses corresponding to a low disinfection target (0.5-log Giardia reduction). The BAF system was observed to remove several contaminants that were relatively unreactive with ozone, demonstrating an important synergy between the ozone and BAF.