Removal and recovery of priority pollutant phenols from industrial effluents using polyurethane foam medium

The application of flexible polyurethane (PU) foam for the removal and recovery of priority pollutant phenols, such as phenol, anisole, guaiacol, 2,3-dimethyl, 2,4-dimethyl, 2,5-dimethyl, 2,6-dimethyl, 3,4-dimethyl, 3,5-dimethyl phenols, 1,2-dihydroxy benzene (Catechol), 1,3-dihydroxy benzene (Resorcinol), 1,2,3-trihydroxy benzene (Pyrocatechol) and 1,3,5-trihydroxy benzene (Phloroglucinol) and their mixtures, from dilute aqueous solutions was investigated. The effect of various parameters on the absorption of phenols by PUfoam was examined. Maximum absorption can be achieved at a flow rate of I ml/min in the range pH 3–9, which is marginally increased as the temperature of the effluent variesfrom 30 to 60°C. As phenol concentration is increased, though the total quantity of phenol absorbed increases, the percentage absorption decreases. It is also observed that at low concentrations of some phenols, satisfactory extraction can be achieved even with increasing volumes of aqueous phase. Based on the extraction data, an extraction mechanism was proposed. Model schemes for the removal and recovery of phenols from industrial effluents (10–100 kl), both by dynamic and static methods, are proposed.