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ARS Home » Plains Area » Lubbock, Texas » Cropping Systems Research Laboratory » Wind Erosion and Water Conservation Research » Research » Publications at this Location » Publication #322444

Title: Phosphate Sorption in Water by Several cationic Polyer flocculants

item Goebel, Tim
item Lascano, Robert
item DAVIS, TODD - United States Air Force

Submitted to: Journal of Agricultural Chemistry and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2016
Publication Date: 2/29/2016
Citation: Goebel, T.S., Lascano, R.J., Davis, T. 2016. Phosphate Sorption in Water by Several cationic Polyer flocculants. Journal of Agricultural Chemistry and Environment. 5:45-51.

Interpretive Summary: Inorganic phosphate is commonly applied as a fertilizer and is frequently found in surface waters such as playa lakes. Phosphate contamination of surface waters can lead to algal blooms and in extreme cases damage the habitat for wildlife. Previous research by our group showed some affinity for phosphate by a commercially available polymer flocculant, with the implication that the polymer could be used as an agent to neutralize the phosphate and minimize environmental damage. The study presented here is a through investigation into the ability of several commercially available polymer flocculants to remove phosphate from solution. The results from our experiments showed that as the positive charge density increases on the polymer more negatively charged phosphate is removed from solution. The polymer with the highest positive charge density was able to remove about 40% of the phosphate of a solution that contained 10 ppm of phosphate. This result suggests that the use of commercially available polymers may be used to reduce phosphate concentration in lakes.

Technical Abstract: Although inorganic phosphate is an essential plant nutrient, elevated levels in surface waters may 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 move away from the application sites and 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 was to determine the amount, if any, of phosphate removed by several commercial polymers. The polymers chosen included the polyacrylamides Magnifloc 494C, Magnifloc 985N and Poly (diallyldimethyl ammonium chloride) (Poly (DADMAC)). Using these polymers it was discovered that the positive charge density of the polymers affected 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.