Removal of Natural Hormones by Nanofiltration Membranes:  Measurement, Modeling, and Mechanisms

The removal mechanisms of four natural steroid hormonesestradiol, estrone, testosterone, and progesteroneby nanofiltration (NF) membranes were investigated. Two nanofiltration membranes with quite different permeabilities and salt retention characteristics were utilized. To better understand hormo...

Full description

Saved in:
Bibliographic Details
Published in:Environmental science & technology 2004-03, Vol.38 (6), p.1888-1896
Main Authors: Nghiem, Long D, Schäfer, Andrea I, Elimelech, Menachem
Format: Article
Language:English
Subjects:
Applied sciences
Diffusion
Exact sciences and technology
Filtration
Gonadal Hormones - isolation & purification
Hormones
Hydrogen Bonding
Measurement
Membranes
Membranes, Artificial
Models, Theoretical
Nanoparticles
Other wastewaters
Pollution
Retention
Wastewaters
Water Pollutants - isolation & purification
Water treatment and pollution
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The removal mechanisms of four natural steroid hormonesestradiol, estrone, testosterone, and progesteroneby nanofiltration (NF) membranes were investigated. Two nanofiltration membranes with quite different permeabilities and salt retention characteristics were utilized. To better understand hormone removal mechanisms, the membrane average pore size was determined from retention data of inert organic solutes of various molecular weights and a pore transport model that incorporates steric (size) exclusion and hindered convection and diffusion. Results indicate that, at the early stages of filtration, adsorption (or partitioning) of hormones to the membrane polymer is the dominant removal mechanism. Because the adsorptive capacity of the membrane is limited, the final retention stabilizes when the adsorption of hormones into the membrane polymer has reached equilibrium. At this later filtration stage, the overall hormone retention is lower than that expected based solely on the size exclusion mechanism. This behavior is attributed to partitioning and subsequent diffusion of hormone molecules in the membrane polymeric phase, which ultimately results in a lower retention. Hormone diffusion in the membrane polymeric matrix most likely depends on the size of the hormone molecule, hydrogen bonding of hormones to membrane functional groups, and hydrophobic interactions of the hormone with the membrane polymeric matrix.
ISSN:0013-936X
1520-5851
DOI:10.1021/es034952r