Penney - Groundwater Aeration For Removing Volatile Organic Compounds
Groundwater aeration, air sparging, or in-place air stripping is a proven remedial technology for removing volatile organic compounds from groundwater. Ambient air is usually forced into the upper portion of a shallow groundwater aquifer through an injection well or sparger. A regenerative blower, a positive displacement blower or an oil-less compressor are usually used to overcome the hydraulic pressure and force the air into a saturated soil formation. Sparger depths are usually limited to less than 100 feet based upon the 50 psi maximum pressure of compressors. Air can also be forced into bedrock fractures. A pilot test is usually conducted on a sparger to determine the best pressure and flow rate.
After the air enters the saturated soil it moves upward through channels in the soil be the force of buoyancy. As the clean, warm air moves upward, a portion of the dissolved volatile organic contaminants migrate or transfer from eh water into the air. The now contaminated air is usually drawn from the vadose zone above the groundwater table by a soil vapor extractor (SVE) system of perforated pipe placed horizontally in permeable media. The contaminated air is usually treated through vapor phase carbon. The concentrations of the volatile organic compounds in the air are usually too low to use incinerators. The air to be treated is usually passed through a moisture separator to remove water droplets and dust. In-line heaters are sometimes used to raise the temperature of the air in order to lower the relative humidity. Warmer air can hold more water. Vapor phase carbon likes air at a relative humidity of 50% or less in order to reduce the potential for water to compress for absorption sites.
We offer design assistance; small rental systems to conduct pilot tests; moisture separators; and complete systems. We manufacture two trailer mounted systems. Custom designed systems are also available.