Remediation Applications

Air sparging systems are typically deployed for the injection of air into the contamination groundwater to both oxygenate the groundwater to enhance natural biodegradation and, especially in the case of more volatile organics, to strip the organics from groundwater into the air stream.

Invariably an air sparging system is used in conjunction with a soil vapour extraction system to recover the injected air and associated contaminants stripped from the groundwater.

Generally most suitable for permeable formations with non heterogeneous formations whereby recovery of the injected gases can be reasonably assured.  Where the formation is less permeable or where the ability to control the vapour recovery is limited, the gPRO Oxygen Diffusion system will be a better solution.

Key Benefits

• A relatively low cost and low energy remedial technology;
• A convenient solution where groundwater abstraction is not convenient or, in very permeable formations, would be very costly;
• Suitable for combination with a range of other technologies.
• Extremely robust and reliable design
• Frequently available “off the shelf”

Operation

A typical sparging system would be connected to a number of injection wells via 3, 4, 5 or any number of pipework arrays.  The general idea being to facilitate injection by timed control to different areas at in a programmed manner.

An air sparging system may comprise a compressor or a high pressure blower depending on the depth below groundwater that the injected air is required to be delivered.  Generally a blower will only achieve up to 2 metres below ground level – being 200mbar.

Typically the sparging system will be combined with a Soil Vapour Extraction system for vapour recovery.

Specifications

Cornelsen can build a system to match virtually any required design.  A typical off-the shelf system available for rapid mobilisation and hire is summarised below:

• 10’ Steel Shipping Container with insulation, electric light and ventilation
• Max. Air Flow:  550m3/hr
• Max. Vacuum: -250mbar gauge (750mbar abs.)
• ATEX Cat. 3 with in-line infra-red LEL detection system.
• 200 litre moisture and particulate separator
• 440 litre/min compressor for Air Sparging, or Total Fluids pumping or LNAPL Skimming
• Control Panel with PLC and telemetry with SMS alarm text messages and remote dial in access.

Tech Tips: Timed operation of the injection process is generally preferred.  Continuous injection can lead quite quickly to channelisation of the injected air flow.