Synthetic- and bio-polymer use for runoff water quality management in irrigated agriculture

Autor: Don W. Morishita, C.W. Ross, James A. Entry, William J. Orts, David Horne, Robert E. Sojka
Rok vydání: 2005
Předmět:
Zdroj: Water Science and Technology. 51:107-115
ISSN: 1996-9732
0273-1223
DOI: 10.2166/wst.2005.0581
Popis: 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−1 per irrigation, costing $4–$12 kg−1. Biopolymers are less effective. Using twice or higher concentrations, existing biopolymers are ≈60% effective as PAM, at 2–3 times the cost. 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.
Databáze: OpenAIRE