Abstract
Current integrity tests are not sufficiently sensitive to detect nanometric scale breaches in the active layer of ultrafiltration membranes. The current paper describes a new approach for the detection of such breaches. We introduce two representative types of nanoprobes emulating virus transport over the membrane. Gold nanoparticles and fluorescent-dye-labeled MS2 bacteriophages were introduced for seeding tests. The affordability of the former probe has become more realistic with the development of electrochemical detection of gold nanoparticles by anodic stripping voltammetry (ASV). Our ASV system showed high sensitivity, of the order of single parts per billion, indicating the feasibility of developing the experimental protocol for on-site analysis. However, the physical characteristics of gold nanoparticles and particularly their specific density differ from those of viruses. The fluorescent bacteriophage probe emulates viral transport much better, though this technique is less sensitive, and further lowering of the limit of detection is required. Application of the probes for testing membrane integrity will provide a basis for developing on-line testing for removal of virus-sized particles and in addition to being a valuable research tool may provide a means to confirm compliance of membrane systems with the stringent regulatory requirements of the drinking water industry.
Original language | English |
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Pages (from-to) | 199-207 |
Number of pages | 9 |
Journal | Journal of Membrane Science |
Volume | 276 |
Issue number | 1-2 |
DOIs | |
State | Published - 1 May 2006 |
Bibliographical note
Funding Information:This study was supported by the U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Water Supply and Water Resources Division. The authors thank Mr. Boris Anisimov, of The National Physical Laboratory, Israel, for his help in comparative gold detection analysis. The authors are also grateful to Dr. Nasser, from the Israel Ministry of Health for providing a purified solution of MS2 bacteriophages. The views expressed in this paper are those of the authors and do not necessarily reflect the views of the U.S. EPA.
Keywords
- Citrate-stabilized gold nanoparticles
- Integrity breaches
- MS2 bacteriophages
- Nanoprobes