Reports of endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs) have raised substantial concern among important potable drinking water and reclaimed wastewater quality issues. Our study investigates the removal of EDC/PPCPs of 52 compounds having different physico-chemical properties (e.g., size, hydrophobicity, and polarity) by nanofiltration (NF) and ultrafiltration (UF) membranes using a dead-end stirred-cell filtration system. EDC/PPCPs were applied to the membrane in one model water and three natural waters. Experiments were performed at environmentally relevant initial EDC/PPCP concentrations ranging typically from 2 to <250 ng/L. EDC/PPCP retention was quantified by liquid and gas chromatography with mass spectroscopy-mass spectroscopy. A general separation trend due to hydrophobic adsorption as a function of octanol-water partition coefficient was observed between the hydrophobic compounds and porous hydrophobic membrane during the membrane filtration in unequilibrium conditions. The results showed that the NF membrane retained many EDC/PPCPs due to both hydrophobic adsorption and size exclusion, while the UF membrane retained typically hydrophobic EDC/PPCPs due mainly to hydrophobic adsorption. However, the transport phenomenon associated with adsorption may depend on water chemistry conditions and membrane material.
Bibliographical noteFunding Information:
This work was funded by the American Water Works Association Research Foundation (Mrs. Kim Linton, senior project manager, Project #2758). The authors would also like to thank Rebecca Trenholm and Brett Vanderford for the GC/MS/MS and LC/MS/MS analyses at Southern Nevada Water Authority (David Rexing, Water Quality Research and Development Manager).
- Endocrine disrupting compounds
- Water treatment