Common Treatment Train for Halogenated VOCs
In general, no single technology can remediate an entire site. Several treatment technologies are usually combined at a single site to form what is known as a treatment train. A system diagram of a common treatment train for halogenated VOCs is illustrated below. A ground water pumping system is used to pull contaminated water from the subsurface. The VOC contaminated water is pumped to a liquid phase granulated activated carbon (GAC) adsorption system. The GAC system removes VOCs in the water and the effluent is either discharged or re-injected back into the subsurface. Additionally, exhausted GAC is taken off-site for either reactivation, regeneration, or disposal once the effluent (treated water) no longer meets the treatment objective. The exhausted GAC is replaced with new GAC. If GAC is to be discarded, it may have to be handled as a hazardous waste. In most cases, spent GAC can be regenerated, typically using steam to desorb and collect concentrated contaminants for further treatment.