Laserfiche WebLink
<br />7 CONCLUSIONS <br />The data generated from operating a TrojanUVPhox™ A02 pilot-scale UV reactor together with H 2 O2 <br />injection at the Saint Anthony Water Treatment Plant has demonstrated that the UV/H2 O 2 AOP is <br />effective at treating 1,4-dioxane in the filtered Saint Anthony groundwater. Specifically, <br />• A water sample demonstrated high UV transmittance (>96.3%) making it a very good candidate <br />for UV/H2 O 2 AOP treatment despite a moderately high hydroxyl radical scavenging demand. <br />• Greater than 3.4-log (>99.96%) destruction of 1,4-dioxane was demonstrated by the pilot <br />system. <br />• 1,4-dioxane log reductions were shown to be proportional to both the H2 O 2 levels dosed and <br />UV energy delivered (i.e., EED). Therefore, the same log reduction target could be achieved by <br />increasing H 2 O 2 and reducing power or vice versa. This supports the conclusion that the <br />process is operationally flexible and able to be optimized to minimize the overall cost of <br />treatment. <br />• The EEO values for 1,4-dioxane were shown to vary inversely with the H 2 O2 level dosed. That <br />is, the E EO decreases with increasing H2 O 2 and vice versa. <br />• Destruction of 1,4-dioxane was achieved using UV/H2 O2 with relatively low EEO values (~1.2 - <br />3.4 kWh/kgal/order) depending primarily upon the H 2O 2 dose selected. Full-scale EEOs are <br />expected to be lower since larger reactors are more efficient than pilot-scale equipment. <br />• Trojan’s model of the UV/H2 O 2 process was demonstrated to match the pilot data very well. <br />This same model was adjusted for the full-scale system parameters and provided the basis for <br />the full-scale system recommendation. <br />• The proposed full-scale UV/H 2 O2 system comprises three parallel trains of 2-D72AL75 <br />TrojanUVPhox reactors (2 duty trains, 1 redundant train) each with 18 ppm H2 O2 . This system <br />will treat 3000 gpm of 96%T water by 2-log (i.e., 99%) reduction of 1,4-dioxane. <br />• The process was demonstrated to be relatively simple to operate. Full-scale system controls <br />simplify those operations further. <br /> 20