TITLE:
Phosphate Sorption in Water by Several Cationic Polymer Flocculants
AUTHORS:
Timothy S. Goebel, Robert J. Lascano, Todd A. Davis
KEYWORDS:
Polymer Flocculants, Phosphate, Sorption, Polyacrylamides, Poly (DADMAC), Smectite
JOURNAL NAME:
Journal of Agricultural Chemistry and Environment,
Vol.5 No.1,
February
29,
2016
ABSTRACT: Although inorganic phosphate is an essential plant nutrient, elevated levels in surface waters
lead to adverse effects in the environment. These effects are attributed to runoff from rain or irrigation
events that may cause the sorbed phosphate to be transported from the application sites
and to move into neighboring watersheds. Increased phosphate concentration in watersheds may
lead to a variety of environmental problems including increased algal blooms, bacterial contamination,
and in some cases eutrophication. To overcome these effects, polymer flocculants have
been shown to reduce the phosphate concentration in water by removing suspended solids and
thereby removing the phosphate sorbed to the solids. The purpose of this study is to determine
the amount, if any, of phosphate removed by several commercial polymers. The polymers chosen
include the polyacrylamides Magnifloc 494C, Magnifloc 985N and Poly (diallyldimethyl ammonium
chloride) (Poly (DADMAC)). Using these polymers, it is discovered that the positive charge density
of the polymers affects the amount of phosphate removed from solution with Poly (DADMAC)
(having 100% positive charge density) removing 40% of the phosphate from a solution containing
10 ppm phosphate.