Removal of Hydrophobic Micro-Organic Pollutants from Municipal Wastewater Treatment Plant Effluents by Sorption onto Synthetic Polymeric Adsorbents: Batch Sorption Experiments

Abstract

The use of a synthetic form polymer, polypropylene, as a sorbent for hydrophobic organic compounds present in municipal wastewater treatment plant effluent was investigated. To enhance the sorption capacity of polypropylene for hydrophobic organic compounds, polypropylene was coated with a thin layer of n-hexane. Sorption of target compounds onto polypropylene and polypropylene coated with n-hexane was evaluated by carrying out equilibrium and kinetic batch experiments. Three polycyclic aromatic hydrocarbons, namely, phenanthrene, fluorene and naphthalene, were selected as representative hydrophobic organic compounds for experimental purposes. The effect of pH, ionic strength and dissolved organic matter on sorption was investigated. The results showed that polypropylene coated with n-hexane performed better than polypropylene as a sorbent for polycyclic aromatic hydrocarbons, in terms of sorption capacity and sorption kinetics. Ionic strength and pH did not have a significant effect on the sorption of polycyclic aromatic hydrocarbons. Dissolved organic matter in the form of humic acid did not sorb onto polypropylene or polypropylene coated with n-hexane, and the presence of dissolved organic matter in the aqueous phase did not significantly affect sorption of polycyclic aromatic hydrocarbons.