Abstract: A process system for removal of toxic volatile organic compounds (VOCs) from contaminated groundwater is described. This process system involves groundwater pumping, groundwater treatment by air stripping in an enclosed sparging aeration chamber, air purification by granular activated carbon contactor, and recycling of GAC-purified air for further groundwater treatment by air stripping. The process system is cost-effective and eliminates the problem of secondary air contamination caused by conventional air stripping process.

Abstract: An improved gas dissolving and releasing system involving the use of multistages of porous gas dissolving media at the center and near the wall of a pressure vessel is described. The gas dissolving system includes a liquid pressure pump, a pressure vessel with tangential inlet and outlet, a gas injector, an inlet nozzle assembly, a center gas dissolving tube, one or more wall-mounted gas dissolving plate assembly, a gas compressor, gas regulators, gas flow meter(s), pressure gauge(s), safety valve(s), sight tube(s), a bleed-off point, a pressurized water release unit, and a liquid flow meter. The liquid flow pattern inside of the pressure vessel is controlled to be of either swirling upflow, swirling downflow or swirling horizontal flow at a rotation speed of over 2,500 rpm. A set of special nozzles with different orifices is designated for precise liquid flow control and liquid rotation speed control.