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United States Department of Agriculture

Agricultural Research Service

Title: Synthetic and Bio-Polymer Use for Runoff Water Quality Management in Irrigated Agriculture

Authors
item Sojka, Robert
item Entry, James
item Morishita, D - UNIVERSITY OF IDAHO
item Ross, C - LANDCARE RES, N. ZEALAND
item Horne, D - MASSEY UNIV., N. ZEALAND

Submitted to: Water Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 4, 2004
Publication Date: N/A

Interpretive Summary: Low concentrations of synthetic- or bio-polymers in irrigation water can nearly eliminate sediment, N, ortho- and total-P, DOM, pesticides, micro-organisms, and weed seed from runoff. These environmentally safe polymers are employed in various sensitive uses including food processing, animal feeds, and potable water purification. The most common synthetic polymer is anionic, high purity polyacrylamide (PAM), which typically provides 70-90% contaminant elimination. Excellent results are achieved adding only 10 ppm PAM to irrigation water, applying 1-2 kg/ha per irrigation, costing $4-$12 per kg. Biopolymers are less effective, but show promise; they include starch co-polymers, microfibril suspensions, chitin, polysaccharides and protein derivatives. Using twice or higher concentrations, existing biopolymers are approximately 60% effective as PAM, at 2-3 times the cost per kg. A half million ha of US irrigated land use PAM for erosion control and runoff protection. The practice is spreading rapidly in the US and worldwide. Interest in development of biopolymer surrogates for PAM is high. If the supply of cheap natural gas (raw material for PAM synthesis) diminishes, industries may seek alternative polymers. Also "green" perceptions and preferences favor biopolymers for certain applications. More complete history, user/technical information and bibliography are found at .

Technical Abstract: Low concentrations of synthetic- or bio-polymers in irrigation water can nearly eliminate sediment, N, ortho- and total-P, DOM, pesticides, micro-organisms, and weed seed from runoff. These environmentally safe polymers are employed in various sensitive uses including food processing, animal feeds, and potable water purification. The most common synthetic polymer is anionic, high purity polyacrylamide (PAM), which typically provides 70-90% contaminant elimination. Excellent results are achieved adding only 10 ppm PAM to irrigation water, applying 1-2 kg/ha per irrigation, costing $4-$12 per kg. Biopolymers are less effective, but show promise; they include starch co-polymers, microfibril suspensions, chitin, polysaccharides and protein derivatives. Using twice or higher concentrations, existing biopolymers are approximately 60% effective as PAM, at 2-3 times the cost per kg. A half million ha of US irrigated land use PAM for erosion control and runoff protection. The practice is spreading rapidly in the US and worldwide. Interest in development of biopolymer surrogates for PAM is high. If the supply of cheap natural gas (raw material for PAM synthesis) diminishes, industries may seek alternative polymers. Also "green" perceptions and preferences favor biopolymers for certain applications. More complete history, user/technical information and bibliography are found at <http://kimberly.ars.usda.gov/pampage.shtml>.

Last Modified: 11/27/2014
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