Use of amphiphilic polymer particles for in situ extraction of sorbed phenanthrene from a contaminated aquifer material

Amphiphilic polyurethane (APU) nano-network polymer particles were tested for their efficiency to remove a model hydrophobic pollutant (phenanthrene)from a contaminated sandy aquifer material. Results from batch experiments indicated that the APU particles were weakly adsorbed onto the aquifer sand (K-d(P) = 0.0063 mL/g). In column experiments, 97 to 98% of applied APU particles were recovered after passage of 2 to 3 pore-volumes of rinse water. The chemically cross-linked nature of the APU particles and ionic functional groups on particle surfaces decrease their affinity to adsorb onto the soil. APU nano-network suspensions extracted up to 98% of the phenanthrene sorbed on the aquifer material with extremely low loss of particles. Passage of fewer pore-volumes of an APU emulsion was needed to achieve a given level of remediation relative to results reported for surfactant solutions. Although the concentration of APU particles in the washing solution was greater than the reported concentrations used for surfactant solutions, the enhanced phenanthrene extraction and the recovery of the APU particles suggest further research is warranted.