Renovation of Pesticide Contaminated Rinse Water

Many instances of severe contamination of groundwater by pesticides have been traced to spills at pesticide mixing/loading sites.  Under Wisconsin law, farmers and commercial applicators handling more than 1500 lbs of pesticides per year must install containment pads at mixing/loading sites.  Rinsates generated during use of the pads must be collected in sumps and transferred to holding tanks.  Disposal of the rinsates is frequently achieved by utilization in new tank mixes of pesticides, but where crop damage is possible due to pesticides incompatibility, this may not be an option.  New technologies to treat pesticide contaminated waters of this kind are needed, since few other disposal options are available.  Photocatalytic oxidation using titanium dioxide and ultraviolet (UV) light is a promising approach that has been demonstrated to mineralize a wide array of recalcitrant organic compounds such as PCBs.  The purpose of this study was to examine the feasibility of using this technology to treat pesticide waste and to explore ways to optimize treatment conditions.  Studies of this nature are continuing under a different grant.