Eni trademark, registered in the EU in January 2018, defines the technology for the selective recovery of hydrocarbons from groundwater and the associated automatic device.
The e-hyrec® technology is applicable in the case of groundwater contamination by organic compounds slightly soluble in water, generally hydrocarbons, with low density, present as supernatant product (Light Non Aqueous Phase Liquids, LNAPLs).
The e-hyrec® device works on the principle of selective permeation, thanks to the use of a hydrophobic and oleophilic filter capable of recovering only the organic phase. Due to the chemical-physical characteristics of the material, when it is immersed at the interface between the supernatant hydrocarbon layer and the groundwater, the LNAPL permeates through the pores of the filter and the water is rejected from the surface.
E-hyrec® is a highly selective and efficient system: by separating the aqueous phase from the oily one and recovering only the latter, it allows a drastic reduction in the quantities of extracted water to be sent for disposal, thus allowing a very positive impact on the environmental and economic sustainability of remediation.
Even from an energy point of view, e-hyrec® is very sustainable, guaranteeing lower consumption compared to traditional recovery systems, thanks also to the possibility of being completely self-powered by renewable sources (photovoltaic).
Since the end of 2018, e-hyrec® has been installed and is currently in operation in various Italian sites managed by Eni Rewind: field applications have demonstrated the system effectiveness in terms of LNAPL selectivity and recovery time compared to traditional technologies.
The system ensures a constant check on the supernatant thickness, provides information on the piezometer refilling and is particularly useful to delineate with great precision the areas on which it is necessary to intensify the recovery and where this is marginal, without disturbing the hydrodynamics in the area of installation.
Many methods are used for groundwater remediation in case of supernatant oil contamination (LNAPLs - Light Non Aqueous Phase Liquids), based on different technologies: in situ flushing, soil vapour extraction, bioremediation, pumping systems [1, 2, 3].
