The most effective means is source control. Drugstores in Canada now accept pills and other medications for disposal by incineration. Once drugs have entered the wastewater they are difficult to treat biologically due to their complex nature and dilution. Ozone and advanced oxidation (hydroxyl radical generation) have shown to be effective in break up the complex molecules into more readily biodegradable components. A certain portion of these chemicals become adsorbed to suspended solids and bacteria clusters in the treatment process and, consequently, there is more time for degradation to occur than for the chemicals that remain in solution and are subject to only hours of biological degradation. Treatment processes that have a high suspended solids or retain solids for long periods of time are logically believed to treat pharmaceuticals in solution due to the large adsorption capacity and long sludge ages. Membrane Bioreactor (MBR) processes have suspended solids more than double conventional activated sludge secondary treatment sludge and sludge ages in the order of greater than 90 days. Fixed film processes with recirculation such as recirculating biofilters, TFAS, or constructed wetlands (polishing) systems are also processes with similar characteristics.
Published by Troy Vassos, Senior Environmental Engineer
The most effective means is source control. Drugstores in Canada now accept pills and other medications for disposal by incineration. Once drugs have entered the wastewater they are difficult to treat biologically due to their complex nature and dilution. Ozone and advanced oxidation (hydroxyl radical generation) have shown to be effective in break up the complex molecules into more readily biodegradable components. A certain portion of these chemicals become adsorbed to suspended solids and bacteria clusters in the treatment process and, consequently, there is more time for degradation to occur than for the chemicals that remain in solution and are subject to only hours of biological degradation. Treatment processes that have a high suspended solids or retain solids for long periods of time are logically believed to treat pharmaceuticals in solution due to the large adsorption capacity and long sludge ages. Membrane Bioreactor (MBR) processes have suspended solids more than double conventional activated sludge secondary treatment sludge and sludge ages in the order of greater than 90 days. Fixed film processes with recirculation such as recirculating biofilters, TFAS, or constructed wetlands (polishing) systems are also processes with similar characteristics.