Removal of Herbicides from Groundwater

Herbicides are groundwater pollutants found where intensive agricultural practices are performed. This is the case in Northern Italy: atrazine, symazine, bentazone, molinate, and others were found in many aquifers over the last five years. Presents the first results of a series of pilot plant tests using low ozone doses (prior to GAC adsorption) to reduce oxidation by‐products formation. Tests were carried out utilizing a transportable emergency plant used by the Civil Protection Agency, based on ozone oxidation and GAC adsorption. Herbicides influent concentrations were up to 1.8 μg/l and ozone doses between 0.4 and 1.7 mg/l. Tested molecules displayed different behaviour but, with the exception of bentazone, contact time seemed to be the basic parameter for the removal of these compounds, some of which appeared to be quite resistant to ozone oxidation at these concentrations.