Acrylamide monomer leaching from polyacrylamide-treated irrigation furrows

Water-soluble anionic polyacrylamide (WSPAM), which is used to reduce erosion in furrow irrigated fields and other agriculture applications, contains less than 0.05% acrylamide monomer (AMD). Acrylamide monomer, a potent neurotoxicant and suspected carcinogen, is readily dissolved and transported in flowing water. The study quantified AMD leaching losses from a WSPAM-treated corn (Zea mays L.) field using continuous extraction-walled percolation samplers buried at 1.2 m depth. The samplers were placed 30 and 150 m from the inflow source along a 180-m-long corn field. The field was furrow irrigated using WSPAM at the rate of 10 mg L?1 during furrow advance. Percolation water and furrow inflows were monitored for AMD during and after three furrow irrigations. The samples were analyzed for AMD using a gas chromatograph equipped with an electron-capture detector. Furrow inflows contained an average AMD concentration of 5.5 ?g L?1. The AMD in percolation water samples never exceeded the minimum detection limit and the de facto potable water standard of 0.5 ?g L?1. The risk that ground water beneath these WSPAM-treated furrow irrigated soils will be contaminated with AMD appears minimal

Fate of acrylamide monomer following application of polyacrylamide to cropland

Acrylamide (AMD) is the basic monomeric unit used in the production of a major class of water soluble polymers, generically termed polyacrylamides (PAMs). The structural formula of AMD is shown in Fig. 1. Under the proper conditions and with suitable catalysts, AMD can polymerize with other molecules of AMD, or with other vinyl monomers to yield products with extremely high molecular weights. PAMs with molecular weights in excess of 10 million, i.e. with chain lengths of more than 105,000 monomeric units, are produced commercially. By utilizing the appropriate comonomers or by postreaction with other reagents, these polymers may be cationic, nonionic. or in the case of those used to control soil erosion, anionic. The anionic reaction product of AMD and a salt of acrylic acid is shown in Fig. 2. The same chemical structure can also be produced by hydrolysis of the nonionic homopolymer of AMD or by hydrolysis of polyacrylonitrile

Irrigating with polyacrylamide (PAM) - Nine years and a million acres of experience

Polyacrylamide (PAM) has been available commercially since 1995 for reducing irrigation-induced erosion and enhancing infiltration. The first series of practical field tests was conducted in 1991. PAM used for erosion control is a large water soluble (non-crosslinked) anionic molecule (12-15 megagrams per mole) containing < 0.05% acrylamide monomer. In controlled field studies PAM eliminated, on average, 94% (80-99% range) of sediment loss in field runoff from furrow irrigation, with a typical 15-50% relative infiltration increase on medium to fine textured soils compared to untreated controls. Similar but less dramatic results have been seen with sprinkler irrigation. Under some conditions infiltration is unchanged or can even be slightly reduced, e.g. in sandy soils or where PAM application rates are very high. Results are achieved with per irrigation field application rates of about 1 kg per hectare, for furrow irrigation, and 2 to 4 kg per hectare for sprinkler irrigation. Cost of PAM is $7 to$13 per kg. Seasonal application totals vary from 3 to 7 kg per hectare. Farmer field sediment control has been around 80% of test plot results. Substantial runoff reductions have been documented for nutrients, pesticides, microorganisms, BOD, and weed seed. No adverse effects have been seen for soil microbial populations. Crop yields have not been widely documented, though evidence exists for yield increases related to infiltration improvement. High effectiveness, low cost, and ease of application, compared to traditional conservation measures, has resulted in rapid technology acceptance in the US and internationally. PAM-use for runoff water quality protection is one of the most potent new irrigation environmental technologies in the market place. New uses in construction and dryland erosion control are being developed rapidly. This paper discusses new insights and understanding of PAM-use and potential for future development

Fate of acrylamide monomer following application of polyacrylamide to cropland

Acrylamide (AMD) is the basic monomeric unit used in the production of a major class of water soluble polymers, generically termed polyacrylamides (PAMs). The structural formula of AMD is shown in Fig. 1. Under the proper conditions and with suitable catalysts, AMD can polymerize with other molecules of AMD, or with other vinyl monomers to yield products with extremely high molecular weights. PAMs with molecular weights in excess of 10 million, i.e. with chain lengths of more than 105,000 monomeric units, are produced commercially. By utilizing the appropriate comonomers or by postreaction with other reagents, these polymers may be cationic, nonionic. or in the case of those used to control soil erosion, anionic. The anionic reaction product of AMD and a salt of acrylic acid is shown in Fig. 2. The same chemical structure can also be produced by hydrolysis of the nonionic homopolymer of AMD or by hydrolysis of polyacrylonitrile