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RECORD NUMBER: 274 OF 309

OLS Field Name OLS Field Data
Main Title Settling and Coagulation Characteristics of Fluorescent Particles Determined by Flow Cytometry and Fluorometry.
Author Newman, K. A. ; Morel, F. M. M. ; Stolzenbach, K. D. ;
CORP Author Environmental Research Lab., Narragansett, RI. ;Massachusetts Inst. of Tech., Cambridge. Ralph M. Parsons Lab.
Publisher c1990
Year Published 1990
Report Number EPA/600/J-90/268 ;ERLN-NX05;
Stock Number PB91-144790
Additional Subjects Particle size distribution ; Water ; Cell flow systems ; Fluorescence ; Sewage treatment ; Coagulation ; Settling ; Laboratory tests ; Reprints ;
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
NTIS  PB91-144790 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/13/1991
Collation 10p
Abstract
A new technique for detecting particles in natural waters relies upon analysis of fluorescent emission by flow cytometry. Fluorescent pigment particles ranging in radius from around 0.1 to 5 micrometers are available in sufficient quantity to be useful as model particles. Laboratory coagulation and settling experiments analyzed by fluorometry demonstrate that the efficiency with which the pigment particles coagulate with sewage particles is very low (less than 0.0005). Hence, in field applications these particles provide the limiting case of low-interaction behavior relative to natural particles. Removal from laboratory columns occurs primarily by noninteractive settling while thermal convection currents maintain nearly uniform particle concentration within the columns. Observed decreases in particle number are exponential (first order) for each size class as predicted for settling from well-mixed suspensions. The decrease in total suspended particle mass is higher order as a result of the difference in settling rates among particles. Thus, a system in which noninteractive settling dominates mimics systems in which coagulation processes are important. Flow cytometric analysis of particles removed by noninteractive settling shows the fluorescent emission from individual particles to be proportional to the particle surface area. These results enable flow cytometry to be used to detect, count, and size large numbers of particles rapidly. (Copyright (c) by the American Chemical Society, 1990.)