Macro Porous Polymer Extraction |
The GCW-MPPE process is an in situ system for the remediation of groundwater contaminated with dissolved or dispersed aromatic, aliphatic, poly aromatic and halogenated hydrocarbons using a combination of a hydraulic controlled flushing/extraction system with a high efficient physical purification system based on macro porous polymer extraction. Groundwater circulation well (GCW) systems are designed to create in situvertical groundwater cells without removing groundwater from the aquifer. Induced differences in potentiometric head establish a 3-dimensional circulation cell in an ellipsoidal area around the central well. The vertical and horizontal circulation flow patterns force water to move through the entire aquifer portion within the circulation cell thus improving contaminant mobilisation by forcing flow through less permeable formation lenses. The vertical circulation flow system offers the opportunity of a intensive flushing of an aquifer, even if the aquifer is highly stratified.
In the GCW-MPPE process the contaminated groundwater is pumped from the lower and upper screen section of a specially designed well with a total of three screen sections. Inflatable packers separate the screen sections from each other. Through the re-injection of clean water into the intermediate screen section and the position of the packers, two separate circulation cells will be established. The upper one in a reverse mode, the lower one in a standard mode. The hydraulic pressure forces the water into the aquifer through the intermediate screen section and intensive vertical and horizontal flows are created in the sphere of influence of the circulation cell. The GCW technology provides a robust and hydraulically controllable flow field with large vertical flow components. This allows to control a direct injection of alcohols and surfactants into the groundwater circulation. This allows to recover DNAPL and LNAPL in a short remediation time flushing only about 2 pore volumes. In the MPPE process, hydrocarbon-contaminated water is passed through a column packed with MPPE particles. The particles are porous polymer beads, which contain a specific extraction liquid. The immobilized extraction liquid removes the hydrocarbon from the groundwater. Only the hydrocarbon are removed.. Alcohol or the surfactants are not affected and can be re-infiltrated into the GCW for the next flushing cycle. Periodical regeneration of the MPP column is accomplished by low-pressure steam injection. The stripped hydrocarbons are condensed and separated from the water by gravity. Almost 100% pure hydrocarbon phase is recovered. The application of two columns allow continuous operation with simultaneous extraction and regeneration.
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