Self-Sustaining Treatment for Active Remediation (STAR) System

GWTT was selected to assist with the implementation of an innovative technology developed to remediate non-aqueous phase liquids (NAPLs) contamination using the principles of “self-sustaining smoldering,” or Self-Sustaining Treatment for Active Remediation (STAR).

In summary, by increasing the temperature of soils to a range of 200C to 400C using a heating element, ignition of the NAPL contaminate is achieved and propagated directionally with a strategically designed air injection system. The technology is self-sufficient because after contaminate ignition is attained, external heat sources are no longer necessary. Off-gasses generated during the process are captured, extracted, and treated using a method akin to that of a soil vapor extraction (SVE) system.

A target area of source contamination at a former cresol manufacturing facility in New Jersey was chosen for the location of a series of pilot tests. GWTT assisted in the design and construction of the remediation system for Phase I and subsequent Phase II. Phase I was a proof-of-concept study in which 300 kg of coal tar was successfully destroyed by the smoldering combustion process. Phase II was a fully developed pilot test scaled up to target the remediation of 26 tons of coal tar within the target area.

GWTT constructed an air injection system comprised of two 600 CFM air compressors, an injection manifold, process lines, and well head connections. A 12,000 CFM SVE system was constructed to remediate off-gasses generated from the STAR process. The system consists of two 12,500 CFM, 100 HP blowers, two 21,000-gal closed-top frac tanks, two 10,000-lb vapor phase granular activated carbon units, two SVE wells, and a 40’ discharge stack.

During Phase III of the field trial, GWTT provided an air injection system comprised of two 900 CFM air compressors, an injection manifold, process lines, and well head connections. A vapor containment and extraction system were constructed to remediate off-gasses generated from the STAR process, which consisted of two 2,500 CFM blowers, moisture knock out tank, and two 5,000-lb vapor phase granular activated carbon units that were tied to a 40’ discharge stack.