Laserfiche WebLink
Ms. Vicki McCartney Project No. 880040 1 A.0201 <br /> t October 26, 2004 <br /> Page 9 <br /> Ozone Microsparging <br /> Ozone microsparging uses air stripping and oxidative decomposition to treat water <br /> contaminated with volatile organic compounds (VOCs). The reaction rapidly detoxifies <br /> groundwater containing VOCs to groundwater standards without producing harmful <br /> byproducts. The reaction is produced with very low ozone concentrations compared to <br /> VOC concentrations in groundwater. In the process, air and ozone are injected directly <br /> into groundwater through specially designed spargers to create microbubbles that have a <br /> very high surface area-to-volume ratio. As the microbubbles rise within a column of <br /> groundwater, they extract or strip the VOCs from groundwater by partitioning from the <br /> aqueous to the gas phase. Upon entering the microbubbles, the VOCs react with ozone <br /> in the gaseous state or in the aqueous thin layer. surrounding the bubble to decompose. <br /> t VOCs are rapidly degraded with time. In field tests, ozone microbubbles appeared <br /> effective in reducing MtBE concentrations to beyond 90%,of original levels. Because of <br /> the high solubility of ozone, over 10 times that of oxygen, the decomposed ozone leaves <br /> behind elevated dissolved oxygen, which has the added benefit of stimulating <br /> bioremediation. <br /> :j Cost: $164,500.00 <br /> Time Frame: 3 years <br /> 1 Advantages: ➢ Rapidly decomposes VOCs and ME, and provides secondary benefit <br /> of supplying dissolved oxygen for stimulating bioremediation. <br /> ➢ Reduction of volume and toxicity provide migration control from reduced <br /> source material. <br /> ➢ Potential to meet remedial objectives and clean-up goals in a short <br /> period of time. <br /> ➢ Does not pose a risk to the environment. Ozone not consumed in <br /> j remedial action decomposes to oxygen, which poses no threat in the <br /> atmosphere, and provides a secondary effect in the subsurface of <br /> enhancing biodegradation. <br /> Disadvantages: ➢ Some disruption of station activities in order to install groundwater <br /> IJ <br /> extraction system. <br /> 1 <br /> �1 <br /> j <br /> �j <br /> ` N.-sacDP120041Pg188018800401A.4ad.doc Shaw Environmental,Inc. <br />